[linux-2.6-microblaze.git] / arch / x86 / kvm / vmx / nested.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/frame.h>
#include <linux/percpu.h>

#include <asm/debugreg.h>
#include <asm/mmu_context.h>

#include "cpuid.h"
#include "hyperv.h"
#include "mmu.h"
#include "nested.h"
#include "trace.h"
#include "x86.h"

static bool __read_mostly enable_shadow_vmcs = 1;
module_param_named(enable_shadow_vmcs, enable_shadow_vmcs, bool, S_IRUGO);

static bool __read_mostly nested_early_check = 0;
module_param(nested_early_check, bool, S_IRUGO);

#define CC(consistency_check)                                           \
({                                                                      \
        bool failed = (consistency_check);                              \
        if (failed)                                                     \
                trace_kvm_nested_vmenter_failed(#consistency_check);    \
        failed;                                                         \
})

/*
 * Hyper-V requires all of these, so mark them as supported even though
 * they are just treated the same as all-context.
 */
#define VMX_VPID_EXTENT_SUPPORTED_MASK          \
        (VMX_VPID_EXTENT_INDIVIDUAL_ADDR_BIT |  \
        VMX_VPID_EXTENT_SINGLE_CONTEXT_BIT |    \
        VMX_VPID_EXTENT_GLOBAL_CONTEXT_BIT |    \
        VMX_VPID_EXTENT_SINGLE_NON_GLOBAL_BIT)

#define VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE 5

enum {
        VMX_VMREAD_BITMAP,
        VMX_VMWRITE_BITMAP,
        VMX_BITMAP_NR
};
static unsigned long *vmx_bitmap[VMX_BITMAP_NR];

#define vmx_vmread_bitmap                    (vmx_bitmap[VMX_VMREAD_BITMAP])
#define vmx_vmwrite_bitmap                   (vmx_bitmap[VMX_VMWRITE_BITMAP])

struct shadow_vmcs_field {
        u16     encoding;
        u16     offset;
};
static struct shadow_vmcs_field shadow_read_only_fields[] = {
#define SHADOW_FIELD_RO(x, y) { x, offsetof(struct vmcs12, y) },
#include "vmcs_shadow_fields.h"
};
static int max_shadow_read_only_fields =
        ARRAY_SIZE(shadow_read_only_fields);

static struct shadow_vmcs_field shadow_read_write_fields[] = {
#define SHADOW_FIELD_RW(x, y) { x, offsetof(struct vmcs12, y) },
#include "vmcs_shadow_fields.h"
};
static int max_shadow_read_write_fields =
        ARRAY_SIZE(shadow_read_write_fields);

static void init_vmcs_shadow_fields(void)
{
        int i, j;

        memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE);
        memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE);

        for (i = j = 0; i < max_shadow_read_only_fields; i++) {
                struct shadow_vmcs_field entry = shadow_read_only_fields[i];
                u16 field = entry.encoding;

                if (vmcs_field_width(field) == VMCS_FIELD_WIDTH_U64 &&
                    (i + 1 == max_shadow_read_only_fields ||
                     shadow_read_only_fields[i + 1].encoding != field + 1))
                        pr_err("Missing field from shadow_read_only_field %x\n",
                               field + 1);

                clear_bit(field, vmx_vmread_bitmap);
                if (field & 1)
#ifdef CONFIG_X86_64
                        continue;
#else
                        entry.offset += sizeof(u32);
#endif
                shadow_read_only_fields[j++] = entry;
        }
        max_shadow_read_only_fields = j;

        for (i = j = 0; i < max_shadow_read_write_fields; i++) {
                struct shadow_vmcs_field entry = shadow_read_write_fields[i];
                u16 field = entry.encoding;

                if (vmcs_field_width(field) == VMCS_FIELD_WIDTH_U64 &&
                    (i + 1 == max_shadow_read_write_fields ||
                     shadow_read_write_fields[i + 1].encoding != field + 1))
                        pr_err("Missing field from shadow_read_write_field %x\n",
                               field + 1);

                WARN_ONCE(field >= GUEST_ES_AR_BYTES &&
                          field <= GUEST_TR_AR_BYTES,
                          "Update vmcs12_write_any() to drop reserved bits from AR_BYTES");

                /*
                 * PML and the preemption timer can be emulated, but the
                 * processor cannot vmwrite to fields that don't exist
                 * on bare metal.
                 */
                switch (field) {
                case GUEST_PML_INDEX:
                        if (!cpu_has_vmx_pml())
                                continue;
                        break;
                case VMX_PREEMPTION_TIMER_VALUE:
                        if (!cpu_has_vmx_preemption_timer())
                                continue;
                        break;
                case GUEST_INTR_STATUS:
                        if (!cpu_has_vmx_apicv())
                                continue;
                        break;
                default:
                        break;
                }

                clear_bit(field, vmx_vmwrite_bitmap);
                clear_bit(field, vmx_vmread_bitmap);
                if (field & 1)
#ifdef CONFIG_X86_64
                        continue;
#else
                        entry.offset += sizeof(u32);
#endif
                shadow_read_write_fields[j++] = entry;
        }
        max_shadow_read_write_fields = j;
}

/*
 * The following 3 functions, nested_vmx_succeed()/failValid()/failInvalid(),
 * set the success or error code of an emulated VMX instruction (as specified
 * by Vol 2B, VMX Instruction Reference, "Conventions"), and skip the emulated
 * instruction.
 */
static int nested_vmx_succeed(struct kvm_vcpu *vcpu)
{
        vmx_set_rflags(vcpu, vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
                            X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF));
        return kvm_skip_emulated_instruction(vcpu);
}

static int nested_vmx_failInvalid(struct kvm_vcpu *vcpu)
{
        vmx_set_rflags(vcpu, (vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF |
                            X86_EFLAGS_SF | X86_EFLAGS_OF))
                        | X86_EFLAGS_CF);
        return kvm_skip_emulated_instruction(vcpu);
}

static int nested_vmx_failValid(struct kvm_vcpu *vcpu,
                                u32 vm_instruction_error)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * failValid writes the error number to the current VMCS, which
         * can't be done if there isn't a current VMCS.
         */
        if (vmx->nested.current_vmptr == -1ull && !vmx->nested.hv_evmcs)
                return nested_vmx_failInvalid(vcpu);

        vmx_set_rflags(vcpu, (vmx_get_rflags(vcpu)
                        & ~(X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
                            X86_EFLAGS_SF | X86_EFLAGS_OF))
                        | X86_EFLAGS_ZF);
        get_vmcs12(vcpu)->vm_instruction_error = vm_instruction_error;
        /*
         * We don't need to force a shadow sync because
         * VM_INSTRUCTION_ERROR is not shadowed
         */
        return kvm_skip_emulated_instruction(vcpu);
}

static void nested_vmx_abort(struct kvm_vcpu *vcpu, u32 indicator)
{
        /* TODO: not to reset guest simply here. */
        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
        pr_debug_ratelimited("kvm: nested vmx abort, indicator %d\n", indicator);
}

static void vmx_disable_shadow_vmcs(struct vcpu_vmx *vmx)
{
        secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_SHADOW_VMCS);
        vmcs_write64(VMCS_LINK_POINTER, -1ull);
        vmx->nested.need_vmcs12_to_shadow_sync = false;
}

static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!vmx->nested.hv_evmcs)
                return;

        kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
        vmx->nested.hv_evmcs_vmptr = -1ull;
        vmx->nested.hv_evmcs = NULL;
}

/*
 * Free whatever needs to be freed from vmx->nested when L1 goes down, or
 * just stops using VMX.
 */
static void free_nested(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!vmx->nested.vmxon && !vmx->nested.smm.vmxon)
                return;

        kvm_clear_request(KVM_REQ_GET_VMCS12_PAGES, vcpu);

        vmx->nested.vmxon = false;
        vmx->nested.smm.vmxon = false;
        free_vpid(vmx->nested.vpid02);
        vmx->nested.posted_intr_nv = -1;
        vmx->nested.current_vmptr = -1ull;
        if (enable_shadow_vmcs) {
                vmx_disable_shadow_vmcs(vmx);
                vmcs_clear(vmx->vmcs01.shadow_vmcs);
                free_vmcs(vmx->vmcs01.shadow_vmcs);
                vmx->vmcs01.shadow_vmcs = NULL;
        }
        kfree(vmx->nested.cached_vmcs12);
        vmx->nested.cached_vmcs12 = NULL;
        kfree(vmx->nested.cached_shadow_vmcs12);
        vmx->nested.cached_shadow_vmcs12 = NULL;
        /* Unpin physical memory we referred to in the vmcs02 */
        if (vmx->nested.apic_access_page) {
                kvm_release_page_dirty(vmx->nested.apic_access_page);
                vmx->nested.apic_access_page = NULL;
        }
        kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);
        kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true);
        vmx->nested.pi_desc = NULL;

        kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);

        nested_release_evmcs(vcpu);

        free_loaded_vmcs(&vmx->nested.vmcs02);
}

static void vmx_sync_vmcs_host_state(struct vcpu_vmx *vmx,
                                     struct loaded_vmcs *prev)
{
        struct vmcs_host_state *dest, *src;

        if (unlikely(!vmx->guest_state_loaded))
                return;

        src = &prev->host_state;
        dest = &vmx->loaded_vmcs->host_state;

        vmx_set_host_fs_gs(dest, src->fs_sel, src->gs_sel, src->fs_base, src->gs_base);
        dest->ldt_sel = src->ldt_sel;
#ifdef CONFIG_X86_64
        dest->ds_sel = src->ds_sel;
        dest->es_sel = src->es_sel;
#endif
}

static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct loaded_vmcs *prev;
        int cpu;

        if (vmx->loaded_vmcs == vmcs)
                return;

        cpu = get_cpu();
        prev = vmx->loaded_vmcs;
        vmx->loaded_vmcs = vmcs;
        vmx_vcpu_load_vmcs(vcpu, cpu);
        vmx_sync_vmcs_host_state(vmx, prev);
        put_cpu();

        vmx_segment_cache_clear(vmx);
}

/*
 * Ensure that the current vmcs of the logical processor is the
 * vmcs01 of the vcpu before calling free_nested().
 */
void nested_vmx_free_vcpu(struct kvm_vcpu *vcpu)
{
        vcpu_load(vcpu);
        vmx_leave_nested(vcpu);
        vmx_switch_vmcs(vcpu, &to_vmx(vcpu)->vmcs01);
        free_nested(vcpu);
        vcpu_put(vcpu);
}

static void nested_ept_inject_page_fault(struct kvm_vcpu *vcpu,
                struct x86_exception *fault)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 exit_reason;
        unsigned long exit_qualification = vcpu->arch.exit_qualification;

        if (vmx->nested.pml_full) {
                exit_reason = EXIT_REASON_PML_FULL;
                vmx->nested.pml_full = false;
                exit_qualification &= INTR_INFO_UNBLOCK_NMI;
        } else if (fault->error_code & PFERR_RSVD_MASK)
                exit_reason = EXIT_REASON_EPT_MISCONFIG;
        else
                exit_reason = EXIT_REASON_EPT_VIOLATION;

        nested_vmx_vmexit(vcpu, exit_reason, 0, exit_qualification);
        vmcs12->guest_physical_address = fault->address;
}

static void nested_ept_init_mmu_context(struct kvm_vcpu *vcpu)
{
        WARN_ON(mmu_is_nested(vcpu));

        vcpu->arch.mmu = &vcpu->arch.guest_mmu;
        kvm_init_shadow_ept_mmu(vcpu,
                        to_vmx(vcpu)->nested.msrs.ept_caps &
                        VMX_EPT_EXECUTE_ONLY_BIT,
                        nested_ept_ad_enabled(vcpu),
                        nested_ept_get_cr3(vcpu));
        vcpu->arch.mmu->set_cr3           = vmx_set_cr3;
        vcpu->arch.mmu->get_cr3           = nested_ept_get_cr3;
        vcpu->arch.mmu->inject_page_fault = nested_ept_inject_page_fault;
        vcpu->arch.mmu->get_pdptr         = kvm_pdptr_read;

        vcpu->arch.walk_mmu              = &vcpu->arch.nested_mmu;
}

static void nested_ept_uninit_mmu_context(struct kvm_vcpu *vcpu)
{
        vcpu->arch.mmu = &vcpu->arch.root_mmu;
        vcpu->arch.walk_mmu = &vcpu->arch.root_mmu;
}

static bool nested_vmx_is_page_fault_vmexit(struct vmcs12 *vmcs12,
                                            u16 error_code)
{
        bool inequality, bit;

        bit = (vmcs12->exception_bitmap & (1u << PF_VECTOR)) != 0;
        inequality =
                (error_code & vmcs12->page_fault_error_code_mask) !=
                 vmcs12->page_fault_error_code_match;
        return inequality ^ bit;
}


/*
 * KVM wants to inject page-faults which it got to the guest. This function
 * checks whether in a nested guest, we need to inject them to L1 or L2.
 */
static int nested_vmx_check_exception(struct kvm_vcpu *vcpu, unsigned long *exit_qual)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        unsigned int nr = vcpu->arch.exception.nr;
        bool has_payload = vcpu->arch.exception.has_payload;
        unsigned long payload = vcpu->arch.exception.payload;

        if (nr == PF_VECTOR) {
                if (vcpu->arch.exception.nested_apf) {
                        *exit_qual = vcpu->arch.apf.nested_apf_token;
                        return 1;
                }
                if (nested_vmx_is_page_fault_vmexit(vmcs12,
                                                    vcpu->arch.exception.error_code)) {
                        *exit_qual = has_payload ? payload : vcpu->arch.cr2;
                        return 1;
                }
        } else if (vmcs12->exception_bitmap & (1u << nr)) {
                if (nr == DB_VECTOR) {
                        if (!has_payload) {
                                payload = vcpu->arch.dr6;
                                payload &= ~(DR6_FIXED_1 | DR6_BT);
                                payload ^= DR6_RTM;
                        }
                        *exit_qual = payload;
                } else
                        *exit_qual = 0;
                return 1;
        }

        return 0;
}


static void vmx_inject_page_fault_nested(struct kvm_vcpu *vcpu,
                struct x86_exception *fault)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        WARN_ON(!is_guest_mode(vcpu));

        if (nested_vmx_is_page_fault_vmexit(vmcs12, fault->error_code) &&
                !to_vmx(vcpu)->nested.nested_run_pending) {
                vmcs12->vm_exit_intr_error_code = fault->error_code;
                nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
                                  PF_VECTOR | INTR_TYPE_HARD_EXCEPTION |
                                  INTR_INFO_DELIVER_CODE_MASK | INTR_INFO_VALID_MASK,
                                  fault->address);
        } else {
                kvm_inject_page_fault(vcpu, fault);
        }
}

static bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
{
        return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
}

static int nested_vmx_check_io_bitmap_controls(struct kvm_vcpu *vcpu,
                                               struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
                return 0;

        if (CC(!page_address_valid(vcpu, vmcs12->io_bitmap_a)) ||
            CC(!page_address_valid(vcpu, vmcs12->io_bitmap_b)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_msr_bitmap_controls(struct kvm_vcpu *vcpu,
                                                struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS))
                return 0;

        if (CC(!page_address_valid(vcpu, vmcs12->msr_bitmap)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_tpr_shadow_controls(struct kvm_vcpu *vcpu,
                                                struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW))
                return 0;

        if (CC(!page_address_valid(vcpu, vmcs12->virtual_apic_page_addr)))
                return -EINVAL;

        return 0;
}

/*
 * Check if MSR is intercepted for L01 MSR bitmap.
 */
static bool msr_write_intercepted_l01(struct kvm_vcpu *vcpu, u32 msr)
{
        unsigned long *msr_bitmap;
        int f = sizeof(unsigned long);

        if (!cpu_has_vmx_msr_bitmap())
                return true;

        msr_bitmap = to_vmx(vcpu)->vmcs01.msr_bitmap;

        if (msr <= 0x1fff) {
                return !!test_bit(msr, msr_bitmap + 0x800 / f);
        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                return !!test_bit(msr, msr_bitmap + 0xc00 / f);
        }

        return true;
}

/*
 * If a msr is allowed by L0, we should check whether it is allowed by L1.
 * The corresponding bit will be cleared unless both of L0 and L1 allow it.
 */
static void nested_vmx_disable_intercept_for_msr(unsigned long *msr_bitmap_l1,
                                               unsigned long *msr_bitmap_nested,
                                               u32 msr, int type)
{
        int f = sizeof(unsigned long);

        /*
         * See Intel PRM Vol. 3, 20.6.9 (MSR-Bitmap Address). Early manuals
         * have the write-low and read-high bitmap offsets the wrong way round.
         * We can control MSRs 0x00000000-0x00001fff and 0xc0000000-0xc0001fff.
         */
        if (msr <= 0x1fff) {
                if (type & MSR_TYPE_R &&
                   !test_bit(msr, msr_bitmap_l1 + 0x000 / f))
                        /* read-low */
                        __clear_bit(msr, msr_bitmap_nested + 0x000 / f);

                if (type & MSR_TYPE_W &&
                   !test_bit(msr, msr_bitmap_l1 + 0x800 / f))
                        /* write-low */
                        __clear_bit(msr, msr_bitmap_nested + 0x800 / f);

        } else if ((msr >= 0xc0000000) && (msr <= 0xc0001fff)) {
                msr &= 0x1fff;
                if (type & MSR_TYPE_R &&
                   !test_bit(msr, msr_bitmap_l1 + 0x400 / f))
                        /* read-high */
                        __clear_bit(msr, msr_bitmap_nested + 0x400 / f);

                if (type & MSR_TYPE_W &&
                   !test_bit(msr, msr_bitmap_l1 + 0xc00 / f))
                        /* write-high */
                        __clear_bit(msr, msr_bitmap_nested + 0xc00 / f);

        }
}

static inline void enable_x2apic_msr_intercepts(unsigned long *msr_bitmap) {
        int msr;

        for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
                unsigned word = msr / BITS_PER_LONG;

                msr_bitmap[word] = ~0;
                msr_bitmap[word + (0x800 / sizeof(long))] = ~0;
        }
}

/*
 * Merge L0's and L1's MSR bitmap, return false to indicate that
 * we do not use the hardware.
 */
static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
                                                 struct vmcs12 *vmcs12)
{
        int msr;
        unsigned long *msr_bitmap_l1;
        unsigned long *msr_bitmap_l0 = to_vmx(vcpu)->nested.vmcs02.msr_bitmap;
        struct kvm_host_map *map = &to_vmx(vcpu)->nested.msr_bitmap_map;

        /* Nothing to do if the MSR bitmap is not in use.  */
        if (!cpu_has_vmx_msr_bitmap() ||
            !nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS))
                return false;

        if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->msr_bitmap), map))
                return false;

        msr_bitmap_l1 = (unsigned long *)map->hva;

        /*
         * To keep the control flow simple, pay eight 8-byte writes (sixteen
         * 4-byte writes on 32-bit systems) up front to enable intercepts for
         * the x2APIC MSR range and selectively disable them below.
         */
        enable_x2apic_msr_intercepts(msr_bitmap_l0);

        if (nested_cpu_has_virt_x2apic_mode(vmcs12)) {
                if (nested_cpu_has_apic_reg_virt(vmcs12)) {
                        /*
                         * L0 need not intercept reads for MSRs between 0x800
                         * and 0x8ff, it just lets the processor take the value
                         * from the virtual-APIC page; take those 256 bits
                         * directly from the L1 bitmap.
                         */
                        for (msr = 0x800; msr <= 0x8ff; msr += BITS_PER_LONG) {
                                unsigned word = msr / BITS_PER_LONG;

                                msr_bitmap_l0[word] = msr_bitmap_l1[word];
                        }
                }

                nested_vmx_disable_intercept_for_msr(
                        msr_bitmap_l1, msr_bitmap_l0,
                        X2APIC_MSR(APIC_TASKPRI),
                        MSR_TYPE_R | MSR_TYPE_W);

                if (nested_cpu_has_vid(vmcs12)) {
                        nested_vmx_disable_intercept_for_msr(
                                msr_bitmap_l1, msr_bitmap_l0,
                                X2APIC_MSR(APIC_EOI),
                                MSR_TYPE_W);
                        nested_vmx_disable_intercept_for_msr(
                                msr_bitmap_l1, msr_bitmap_l0,
                                X2APIC_MSR(APIC_SELF_IPI),
                                MSR_TYPE_W);
                }
        }

        /* KVM unconditionally exposes the FS/GS base MSRs to L1. */
        nested_vmx_disable_intercept_for_msr(msr_bitmap_l1, msr_bitmap_l0,
                                             MSR_FS_BASE, MSR_TYPE_RW);

        nested_vmx_disable_intercept_for_msr(msr_bitmap_l1, msr_bitmap_l0,
                                             MSR_GS_BASE, MSR_TYPE_RW);

        nested_vmx_disable_intercept_for_msr(msr_bitmap_l1, msr_bitmap_l0,
                                             MSR_KERNEL_GS_BASE, MSR_TYPE_RW);

        /*
         * Checking the L0->L1 bitmap is trying to verify two things:
         *
         * 1. L0 gave a permission to L1 to actually passthrough the MSR. This
         *    ensures that we do not accidentally generate an L02 MSR bitmap
         *    from the L12 MSR bitmap that is too permissive.
         * 2. That L1 or L2s have actually used the MSR. This avoids
         *    unnecessarily merging of the bitmap if the MSR is unused. This
         *    works properly because we only update the L01 MSR bitmap lazily.
         *    So even if L0 should pass L1 these MSRs, the L01 bitmap is only
         *    updated to reflect this when L1 (or its L2s) actually write to
         *    the MSR.
         */
        if (!msr_write_intercepted_l01(vcpu, MSR_IA32_SPEC_CTRL))
                nested_vmx_disable_intercept_for_msr(
                                        msr_bitmap_l1, msr_bitmap_l0,
                                        MSR_IA32_SPEC_CTRL,
                                        MSR_TYPE_R | MSR_TYPE_W);

        if (!msr_write_intercepted_l01(vcpu, MSR_IA32_PRED_CMD))
                nested_vmx_disable_intercept_for_msr(
                                        msr_bitmap_l1, msr_bitmap_l0,
                                        MSR_IA32_PRED_CMD,
                                        MSR_TYPE_W);

        kvm_vcpu_unmap(vcpu, &to_vmx(vcpu)->nested.msr_bitmap_map, false);

        return true;
}

static void nested_cache_shadow_vmcs12(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        struct kvm_host_map map;
        struct vmcs12 *shadow;

        if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
            vmcs12->vmcs_link_pointer == -1ull)
                return;

        shadow = get_shadow_vmcs12(vcpu);

        if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->vmcs_link_pointer), &map))
                return;

        memcpy(shadow, map.hva, VMCS12_SIZE);
        kvm_vcpu_unmap(vcpu, &map, false);
}

static void nested_flush_cached_shadow_vmcs12(struct kvm_vcpu *vcpu,
                                              struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (!nested_cpu_has_shadow_vmcs(vmcs12) ||
            vmcs12->vmcs_link_pointer == -1ull)
                return;

        kvm_write_guest(vmx->vcpu.kvm, vmcs12->vmcs_link_pointer,
                        get_shadow_vmcs12(vcpu), VMCS12_SIZE);
}

/*
 * In nested virtualization, check if L1 has set
 * VM_EXIT_ACK_INTR_ON_EXIT
 */
static bool nested_exit_intr_ack_set(struct kvm_vcpu *vcpu)
{
        return get_vmcs12(vcpu)->vm_exit_controls &
                VM_EXIT_ACK_INTR_ON_EXIT;
}

static bool nested_exit_on_nmi(struct kvm_vcpu *vcpu)
{
        return nested_cpu_has_nmi_exiting(get_vmcs12(vcpu));
}

static int nested_vmx_check_apic_access_controls(struct kvm_vcpu *vcpu,
                                          struct vmcs12 *vmcs12)
{
        if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES) &&
            CC(!page_address_valid(vcpu, vmcs12->apic_access_addr)))
                return -EINVAL;
        else
                return 0;
}

static int nested_vmx_check_apicv_controls(struct kvm_vcpu *vcpu,
                                           struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has_virt_x2apic_mode(vmcs12) &&
            !nested_cpu_has_apic_reg_virt(vmcs12) &&
            !nested_cpu_has_vid(vmcs12) &&
            !nested_cpu_has_posted_intr(vmcs12))
                return 0;

        /*
         * If virtualize x2apic mode is enabled,
         * virtualize apic access must be disabled.
         */
        if (CC(nested_cpu_has_virt_x2apic_mode(vmcs12) &&
               nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)))
                return -EINVAL;

        /*
         * If virtual interrupt delivery is enabled,
         * we must exit on external interrupts.
         */
        if (CC(nested_cpu_has_vid(vmcs12) && !nested_exit_on_intr(vcpu)))
                return -EINVAL;

        /*
         * bits 15:8 should be zero in posted_intr_nv,
         * the descriptor address has been already checked
         * in nested_get_vmcs12_pages.
         *
         * bits 5:0 of posted_intr_desc_addr should be zero.
         */
        if (nested_cpu_has_posted_intr(vmcs12) &&
           (CC(!nested_cpu_has_vid(vmcs12)) ||
            CC(!nested_exit_intr_ack_set(vcpu)) ||
            CC((vmcs12->posted_intr_nv & 0xff00)) ||
            CC((vmcs12->posted_intr_desc_addr & 0x3f)) ||
            CC((vmcs12->posted_intr_desc_addr >> cpuid_maxphyaddr(vcpu)))))
                return -EINVAL;

        /* tpr shadow is needed by all apicv features. */
        if (CC(!nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_msr_switch(struct kvm_vcpu *vcpu,
                                       u32 count, u64 addr)
{
        int maxphyaddr;

        if (count == 0)
                return 0;
        maxphyaddr = cpuid_maxphyaddr(vcpu);
        if (!IS_ALIGNED(addr, 16) || addr >> maxphyaddr ||
            (addr + count * sizeof(struct vmx_msr_entry) - 1) >> maxphyaddr)
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_exit_msr_switch_controls(struct kvm_vcpu *vcpu,
                                                     struct vmcs12 *vmcs12)
{
        if (CC(nested_vmx_check_msr_switch(vcpu,
                                           vmcs12->vm_exit_msr_load_count,
                                           vmcs12->vm_exit_msr_load_addr)) ||
            CC(nested_vmx_check_msr_switch(vcpu,
                                           vmcs12->vm_exit_msr_store_count,
                                           vmcs12->vm_exit_msr_store_addr)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_entry_msr_switch_controls(struct kvm_vcpu *vcpu,
                                                      struct vmcs12 *vmcs12)
{
        if (CC(nested_vmx_check_msr_switch(vcpu,
                                           vmcs12->vm_entry_msr_load_count,
                                           vmcs12->vm_entry_msr_load_addr)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_pml_controls(struct kvm_vcpu *vcpu,
                                         struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has_pml(vmcs12))
                return 0;

        if (CC(!nested_cpu_has_ept(vmcs12)) ||
            CC(!page_address_valid(vcpu, vmcs12->pml_address)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_unrestricted_guest_controls(struct kvm_vcpu *vcpu,
                                                        struct vmcs12 *vmcs12)
{
        if (CC(nested_cpu_has2(vmcs12, SECONDARY_EXEC_UNRESTRICTED_GUEST) &&
               !nested_cpu_has_ept(vmcs12)))
                return -EINVAL;
        return 0;
}

static int nested_vmx_check_mode_based_ept_exec_controls(struct kvm_vcpu *vcpu,
                                                         struct vmcs12 *vmcs12)
{
        if (CC(nested_cpu_has2(vmcs12, SECONDARY_EXEC_MODE_BASED_EPT_EXEC) &&
               !nested_cpu_has_ept(vmcs12)))
                return -EINVAL;
        return 0;
}

static int nested_vmx_check_shadow_vmcs_controls(struct kvm_vcpu *vcpu,
                                                 struct vmcs12 *vmcs12)
{
        if (!nested_cpu_has_shadow_vmcs(vmcs12))
                return 0;

        if (CC(!page_address_valid(vcpu, vmcs12->vmread_bitmap)) ||
            CC(!page_address_valid(vcpu, vmcs12->vmwrite_bitmap)))
                return -EINVAL;

        return 0;
}

static int nested_vmx_msr_check_common(struct kvm_vcpu *vcpu,
                                       struct vmx_msr_entry *e)
{
        /* x2APIC MSR accesses are not allowed */
        if (CC(vcpu->arch.apic_base & X2APIC_ENABLE && e->index >> 8 == 0x8))
                return -EINVAL;
        if (CC(e->index == MSR_IA32_UCODE_WRITE) || /* SDM Table 35-2 */
            CC(e->index == MSR_IA32_UCODE_REV))
                return -EINVAL;
        if (CC(e->reserved != 0))
                return -EINVAL;
        return 0;
}

static int nested_vmx_load_msr_check(struct kvm_vcpu *vcpu,
                                     struct vmx_msr_entry *e)
{
        if (CC(e->index == MSR_FS_BASE) ||
            CC(e->index == MSR_GS_BASE) ||
            CC(e->index == MSR_IA32_SMM_MONITOR_CTL) || /* SMM is not supported */
            nested_vmx_msr_check_common(vcpu, e))
                return -EINVAL;
        return 0;
}

static int nested_vmx_store_msr_check(struct kvm_vcpu *vcpu,
                                      struct vmx_msr_entry *e)
{
        if (CC(e->index == MSR_IA32_SMBASE) || /* SMM is not supported */
            nested_vmx_msr_check_common(vcpu, e))
                return -EINVAL;
        return 0;
}

/*
 * Load guest's/host's msr at nested entry/exit.
 * return 0 for success, entry index for failure.
 */
static u32 nested_vmx_load_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count)
{
        u32 i;
        struct vmx_msr_entry e;

        for (i = 0; i < count; i++) {
                if (kvm_vcpu_read_guest(vcpu, gpa + i * sizeof(e),
                                        &e, sizeof(e))) {
                        pr_debug_ratelimited(
                                "%s cannot read MSR entry (%u, 0x%08llx)\n",
                                __func__, i, gpa + i * sizeof(e));
                        goto fail;
                }
                if (nested_vmx_load_msr_check(vcpu, &e)) {
                        pr_debug_ratelimited(
                                "%s check failed (%u, 0x%x, 0x%x)\n",
                                __func__, i, e.index, e.reserved);
                        goto fail;
                }
                if (kvm_set_msr(vcpu, e.index, e.value)) {
                        pr_debug_ratelimited(
                                "%s cannot write MSR (%u, 0x%x, 0x%llx)\n",
                                __func__, i, e.index, e.value);
                        goto fail;
                }
        }
        return 0;
fail:
        return i + 1;
}

static int nested_vmx_store_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count)
{
        u64 data;
        u32 i;
        struct vmx_msr_entry e;

        for (i = 0; i < count; i++) {
                if (kvm_vcpu_read_guest(vcpu,
                                        gpa + i * sizeof(e),
                                        &e, 2 * sizeof(u32))) {
                        pr_debug_ratelimited(
                                "%s cannot read MSR entry (%u, 0x%08llx)\n",
                                __func__, i, gpa + i * sizeof(e));
                        return -EINVAL;
                }
                if (nested_vmx_store_msr_check(vcpu, &e)) {
                        pr_debug_ratelimited(
                                "%s check failed (%u, 0x%x, 0x%x)\n",
                                __func__, i, e.index, e.reserved);
                        return -EINVAL;
                }
                if (kvm_get_msr(vcpu, e.index, &data)) {
                        pr_debug_ratelimited(
                                "%s cannot read MSR (%u, 0x%x)\n",
                                __func__, i, e.index);
                        return -EINVAL;
                }
                if (kvm_vcpu_write_guest(vcpu,
                                         gpa + i * sizeof(e) +
                                             offsetof(struct vmx_msr_entry, value),
                                         &data, sizeof(data))) {
                        pr_debug_ratelimited(
                                "%s cannot write MSR (%u, 0x%x, 0x%llx)\n",
                                __func__, i, e.index, data);
                        return -EINVAL;
                }
        }
        return 0;
}

static bool nested_cr3_valid(struct kvm_vcpu *vcpu, unsigned long val)
{
        unsigned long invalid_mask;

        invalid_mask = (~0ULL) << cpuid_maxphyaddr(vcpu);
        return (val & invalid_mask) == 0;
}

/*
 * Load guest's/host's cr3 at nested entry/exit. nested_ept is true if we are
 * emulating VM entry into a guest with EPT enabled.
 * Returns 0 on success, 1 on failure. Invalid state exit qualification code
 * is assigned to entry_failure_code on failure.
 */
static int nested_vmx_load_cr3(struct kvm_vcpu *vcpu, unsigned long cr3, bool nested_ept,
                               u32 *entry_failure_code)
{
        if (cr3 != kvm_read_cr3(vcpu) || (!nested_ept && pdptrs_changed(vcpu))) {
                if (CC(!nested_cr3_valid(vcpu, cr3))) {
                        *entry_failure_code = ENTRY_FAIL_DEFAULT;
                        return -EINVAL;
                }

                /*
                 * If PAE paging and EPT are both on, CR3 is not used by the CPU and
                 * must not be dereferenced.
                 */
                if (is_pae_paging(vcpu) && !nested_ept) {
                        if (CC(!load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))) {
                                *entry_failure_code = ENTRY_FAIL_PDPTE;
                                return -EINVAL;
                        }
                }
        }

        if (!nested_ept)
                kvm_mmu_new_cr3(vcpu, cr3, false);

        vcpu->arch.cr3 = cr3;
        __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);

        kvm_init_mmu(vcpu, false);

        return 0;
}

/*
 * Returns if KVM is able to config CPU to tag TLB entries
 * populated by L2 differently than TLB entries populated
 * by L1.
 *
 * If L1 uses EPT, then TLB entries are tagged with different EPTP.
 *
 * If L1 uses VPID and we allocated a vpid02, TLB entries are tagged
 * with different VPID (L1 entries are tagged with vmx->vpid
 * while L2 entries are tagged with vmx->nested.vpid02).
 */
static bool nested_has_guest_tlb_tag(struct kvm_vcpu *vcpu)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        return nested_cpu_has_ept(vmcs12) ||
               (nested_cpu_has_vpid(vmcs12) && to_vmx(vcpu)->nested.vpid02);
}

static u16 nested_get_vpid02(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        return vmx->nested.vpid02 ? vmx->nested.vpid02 : vmx->vpid;
}


static inline bool vmx_control_verify(u32 control, u32 low, u32 high)
{
        return fixed_bits_valid(control, low, high);
}

static inline u64 vmx_control_msr(u32 low, u32 high)
{
        return low | ((u64)high << 32);
}

static bool is_bitwise_subset(u64 superset, u64 subset, u64 mask)
{
        superset &= mask;
        subset &= mask;

        return (superset | subset) == superset;
}

static int vmx_restore_vmx_basic(struct vcpu_vmx *vmx, u64 data)
{
        const u64 feature_and_reserved =
                /* feature (except bit 48; see below) */
                BIT_ULL(49) | BIT_ULL(54) | BIT_ULL(55) |
                /* reserved */
                BIT_ULL(31) | GENMASK_ULL(47, 45) | GENMASK_ULL(63, 56);
        u64 vmx_basic = vmx->nested.msrs.basic;

        if (!is_bitwise_subset(vmx_basic, data, feature_and_reserved))
                return -EINVAL;

        /*
         * KVM does not emulate a version of VMX that constrains physical
         * addresses of VMX structures (e.g. VMCS) to 32-bits.
         */
        if (data & BIT_ULL(48))
                return -EINVAL;

        if (vmx_basic_vmcs_revision_id(vmx_basic) !=
            vmx_basic_vmcs_revision_id(data))
                return -EINVAL;

        if (vmx_basic_vmcs_size(vmx_basic) > vmx_basic_vmcs_size(data))
                return -EINVAL;

        vmx->nested.msrs.basic = data;
        return 0;
}

static int
vmx_restore_control_msr(struct vcpu_vmx *vmx, u32 msr_index, u64 data)
{
        u64 supported;
        u32 *lowp, *highp;

        switch (msr_index) {
        case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
                lowp = &vmx->nested.msrs.pinbased_ctls_low;
                highp = &vmx->nested.msrs.pinbased_ctls_high;
                break;
        case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
                lowp = &vmx->nested.msrs.procbased_ctls_low;
                highp = &vmx->nested.msrs.procbased_ctls_high;
                break;
        case MSR_IA32_VMX_TRUE_EXIT_CTLS:
                lowp = &vmx->nested.msrs.exit_ctls_low;
                highp = &vmx->nested.msrs.exit_ctls_high;
                break;
        case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
                lowp = &vmx->nested.msrs.entry_ctls_low;
                highp = &vmx->nested.msrs.entry_ctls_high;
                break;
        case MSR_IA32_VMX_PROCBASED_CTLS2:
                lowp = &vmx->nested.msrs.secondary_ctls_low;
                highp = &vmx->nested.msrs.secondary_ctls_high;
                break;
        default:
                BUG();
        }

        supported = vmx_control_msr(*lowp, *highp);

        /* Check must-be-1 bits are still 1. */
        if (!is_bitwise_subset(data, supported, GENMASK_ULL(31, 0)))
                return -EINVAL;

        /* Check must-be-0 bits are still 0. */
        if (!is_bitwise_subset(supported, data, GENMASK_ULL(63, 32)))
                return -EINVAL;

        *lowp = data;
        *highp = data >> 32;
        return 0;
}

static int vmx_restore_vmx_misc(struct vcpu_vmx *vmx, u64 data)
{
        const u64 feature_and_reserved_bits =
                /* feature */
                BIT_ULL(5) | GENMASK_ULL(8, 6) | BIT_ULL(14) | BIT_ULL(15) |
                BIT_ULL(28) | BIT_ULL(29) | BIT_ULL(30) |
                /* reserved */
                GENMASK_ULL(13, 9) | BIT_ULL(31);
        u64 vmx_misc;

        vmx_misc = vmx_control_msr(vmx->nested.msrs.misc_low,
                                   vmx->nested.msrs.misc_high);

        if (!is_bitwise_subset(vmx_misc, data, feature_and_reserved_bits))
                return -EINVAL;

        if ((vmx->nested.msrs.pinbased_ctls_high &
             PIN_BASED_VMX_PREEMPTION_TIMER) &&
            vmx_misc_preemption_timer_rate(data) !=
            vmx_misc_preemption_timer_rate(vmx_misc))
                return -EINVAL;

        if (vmx_misc_cr3_count(data) > vmx_misc_cr3_count(vmx_misc))
                return -EINVAL;

        if (vmx_misc_max_msr(data) > vmx_misc_max_msr(vmx_misc))
                return -EINVAL;

        if (vmx_misc_mseg_revid(data) != vmx_misc_mseg_revid(vmx_misc))
                return -EINVAL;

        vmx->nested.msrs.misc_low = data;
        vmx->nested.msrs.misc_high = data >> 32;

        return 0;
}

static int vmx_restore_vmx_ept_vpid_cap(struct vcpu_vmx *vmx, u64 data)
{
        u64 vmx_ept_vpid_cap;

        vmx_ept_vpid_cap = vmx_control_msr(vmx->nested.msrs.ept_caps,
                                           vmx->nested.msrs.vpid_caps);

        /* Every bit is either reserved or a feature bit. */
        if (!is_bitwise_subset(vmx_ept_vpid_cap, data, -1ULL))
                return -EINVAL;

        vmx->nested.msrs.ept_caps = data;
        vmx->nested.msrs.vpid_caps = data >> 32;
        return 0;
}

static int vmx_restore_fixed0_msr(struct vcpu_vmx *vmx, u32 msr_index, u64 data)
{
        u64 *msr;

        switch (msr_index) {
        case MSR_IA32_VMX_CR0_FIXED0:
                msr = &vmx->nested.msrs.cr0_fixed0;
                break;
        case MSR_IA32_VMX_CR4_FIXED0:
                msr = &vmx->nested.msrs.cr4_fixed0;
                break;
        default:
                BUG();
        }

        /*
         * 1 bits (which indicates bits which "must-be-1" during VMX operation)
         * must be 1 in the restored value.
         */
        if (!is_bitwise_subset(data, *msr, -1ULL))
                return -EINVAL;

        *msr = data;
        return 0;
}

/*
 * Called when userspace is restoring VMX MSRs.
 *
 * Returns 0 on success, non-0 otherwise.
 */
int vmx_set_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * Don't allow changes to the VMX capability MSRs while the vCPU
         * is in VMX operation.
         */
        if (vmx->nested.vmxon)
                return -EBUSY;

        switch (msr_index) {
        case MSR_IA32_VMX_BASIC:
                return vmx_restore_vmx_basic(vmx, data);
        case MSR_IA32_VMX_PINBASED_CTLS:
        case MSR_IA32_VMX_PROCBASED_CTLS:
        case MSR_IA32_VMX_EXIT_CTLS:
        case MSR_IA32_VMX_ENTRY_CTLS:
                /*
                 * The "non-true" VMX capability MSRs are generated from the
                 * "true" MSRs, so we do not support restoring them directly.
                 *
                 * If userspace wants to emulate VMX_BASIC[55]=0, userspace
                 * should restore the "true" MSRs with the must-be-1 bits
                 * set according to the SDM Vol 3. A.2 "RESERVED CONTROLS AND
                 * DEFAULT SETTINGS".
                 */
                return -EINVAL;
        case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
        case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
        case MSR_IA32_VMX_TRUE_EXIT_CTLS:
        case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
        case MSR_IA32_VMX_PROCBASED_CTLS2:
                return vmx_restore_control_msr(vmx, msr_index, data);
        case MSR_IA32_VMX_MISC:
                return vmx_restore_vmx_misc(vmx, data);
        case MSR_IA32_VMX_CR0_FIXED0:
        case MSR_IA32_VMX_CR4_FIXED0:
                return vmx_restore_fixed0_msr(vmx, msr_index, data);
        case MSR_IA32_VMX_CR0_FIXED1:
        case MSR_IA32_VMX_CR4_FIXED1:
                /*
                 * These MSRs are generated based on the vCPU's CPUID, so we
                 * do not support restoring them directly.
                 */
                return -EINVAL;
        case MSR_IA32_VMX_EPT_VPID_CAP:
                return vmx_restore_vmx_ept_vpid_cap(vmx, data);
        case MSR_IA32_VMX_VMCS_ENUM:
                vmx->nested.msrs.vmcs_enum = data;
                return 0;
        case MSR_IA32_VMX_VMFUNC:
                if (data & ~vmx->nested.msrs.vmfunc_controls)
                        return -EINVAL;
                vmx->nested.msrs.vmfunc_controls = data;
                return 0;
        default:
                /*
                 * The rest of the VMX capability MSRs do not support restore.
                 */
                return -EINVAL;
        }
}

/* Returns 0 on success, non-0 otherwise. */
int vmx_get_vmx_msr(struct nested_vmx_msrs *msrs, u32 msr_index, u64 *pdata)
{
        switch (msr_index) {
        case MSR_IA32_VMX_BASIC:
                *pdata = msrs->basic;
                break;
        case MSR_IA32_VMX_TRUE_PINBASED_CTLS:
        case MSR_IA32_VMX_PINBASED_CTLS:
                *pdata = vmx_control_msr(
                        msrs->pinbased_ctls_low,
                        msrs->pinbased_ctls_high);
                if (msr_index == MSR_IA32_VMX_PINBASED_CTLS)
                        *pdata |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
                break;
        case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
        case MSR_IA32_VMX_PROCBASED_CTLS:
                *pdata = vmx_control_msr(
                        msrs->procbased_ctls_low,
                        msrs->procbased_ctls_high);
                if (msr_index == MSR_IA32_VMX_PROCBASED_CTLS)
                        *pdata |= CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
                break;
        case MSR_IA32_VMX_TRUE_EXIT_CTLS:
        case MSR_IA32_VMX_EXIT_CTLS:
                *pdata = vmx_control_msr(
                        msrs->exit_ctls_low,
                        msrs->exit_ctls_high);
                if (msr_index == MSR_IA32_VMX_EXIT_CTLS)
                        *pdata |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR;
                break;
        case MSR_IA32_VMX_TRUE_ENTRY_CTLS:
        case MSR_IA32_VMX_ENTRY_CTLS:
                *pdata = vmx_control_msr(
                        msrs->entry_ctls_low,
                        msrs->entry_ctls_high);
                if (msr_index == MSR_IA32_VMX_ENTRY_CTLS)
                        *pdata |= VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR;
                break;
        case MSR_IA32_VMX_MISC:
                *pdata = vmx_control_msr(
                        msrs->misc_low,
                        msrs->misc_high);
                break;
        case MSR_IA32_VMX_CR0_FIXED0:
                *pdata = msrs->cr0_fixed0;
                break;
        case MSR_IA32_VMX_CR0_FIXED1:
                *pdata = msrs->cr0_fixed1;
                break;
        case MSR_IA32_VMX_CR4_FIXED0:
                *pdata = msrs->cr4_fixed0;
                break;
        case MSR_IA32_VMX_CR4_FIXED1:
                *pdata = msrs->cr4_fixed1;
                break;
        case MSR_IA32_VMX_VMCS_ENUM:
                *pdata = msrs->vmcs_enum;
                break;
        case MSR_IA32_VMX_PROCBASED_CTLS2:
                *pdata = vmx_control_msr(
                        msrs->secondary_ctls_low,
                        msrs->secondary_ctls_high);
                break;
        case MSR_IA32_VMX_EPT_VPID_CAP:
                *pdata = msrs->ept_caps |
                        ((u64)msrs->vpid_caps << 32);
                break;
        case MSR_IA32_VMX_VMFUNC:
                *pdata = msrs->vmfunc_controls;
                break;
        default:
                return 1;
        }

        return 0;
}

/*
 * Copy the writable VMCS shadow fields back to the VMCS12, in case they have
 * been modified by the L1 guest.  Note, "writable" in this context means
 * "writable by the guest", i.e. tagged SHADOW_FIELD_RW; the set of
 * fields tagged SHADOW_FIELD_RO may or may not align with the "read-only"
 * VM-exit information fields (which are actually writable if the vCPU is
 * configured to support "VMWRITE to any supported field in the VMCS").
 */
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx)
{
        struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
        struct vmcs12 *vmcs12 = get_vmcs12(&vmx->vcpu);
        struct shadow_vmcs_field field;
        unsigned long val;
        int i;

        if (WARN_ON(!shadow_vmcs))
                return;

        preempt_disable();

        vmcs_load(shadow_vmcs);

        for (i = 0; i < max_shadow_read_write_fields; i++) {
                field = shadow_read_write_fields[i];
                val = __vmcs_readl(field.encoding);
                vmcs12_write_any(vmcs12, field.encoding, field.offset, val);
        }

        vmcs_clear(shadow_vmcs);
        vmcs_load(vmx->loaded_vmcs->vmcs);

        preempt_enable();
}

static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx)
{
        const struct shadow_vmcs_field *fields[] = {
                shadow_read_write_fields,
                shadow_read_only_fields
        };
        const int max_fields[] = {
                max_shadow_read_write_fields,
                max_shadow_read_only_fields
        };
        struct vmcs *shadow_vmcs = vmx->vmcs01.shadow_vmcs;
        struct vmcs12 *vmcs12 = get_vmcs12(&vmx->vcpu);
        struct shadow_vmcs_field field;
        unsigned long val;
        int i, q;

        if (WARN_ON(!shadow_vmcs))
                return;

        vmcs_load(shadow_vmcs);

        for (q = 0; q < ARRAY_SIZE(fields); q++) {
                for (i = 0; i < max_fields[q]; i++) {
                        field = fields[q][i];
                        val = vmcs12_read_any(vmcs12, field.encoding,
                                              field.offset);
                        __vmcs_writel(field.encoding, val);
                }
        }

        vmcs_clear(shadow_vmcs);
        vmcs_load(vmx->loaded_vmcs->vmcs);
}

static int copy_enlightened_to_vmcs12(struct vcpu_vmx *vmx)
{
        struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
        struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;

        /* HV_VMX_ENLIGHTENED_CLEAN_FIELD_NONE */
        vmcs12->tpr_threshold = evmcs->tpr_threshold;
        vmcs12->guest_rip = evmcs->guest_rip;

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_BASIC))) {
                vmcs12->guest_rsp = evmcs->guest_rsp;
                vmcs12->guest_rflags = evmcs->guest_rflags;
                vmcs12->guest_interruptibility_info =
                        evmcs->guest_interruptibility_info;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_PROC))) {
                vmcs12->cpu_based_vm_exec_control =
                        evmcs->cpu_based_vm_exec_control;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EXCPN))) {
                vmcs12->exception_bitmap = evmcs->exception_bitmap;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_ENTRY))) {
                vmcs12->vm_entry_controls = evmcs->vm_entry_controls;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_EVENT))) {
                vmcs12->vm_entry_intr_info_field =
                        evmcs->vm_entry_intr_info_field;
                vmcs12->vm_entry_exception_error_code =
                        evmcs->vm_entry_exception_error_code;
                vmcs12->vm_entry_instruction_len =
                        evmcs->vm_entry_instruction_len;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_GRP1))) {
                vmcs12->host_ia32_pat = evmcs->host_ia32_pat;
                vmcs12->host_ia32_efer = evmcs->host_ia32_efer;
                vmcs12->host_cr0 = evmcs->host_cr0;
                vmcs12->host_cr3 = evmcs->host_cr3;
                vmcs12->host_cr4 = evmcs->host_cr4;
                vmcs12->host_ia32_sysenter_esp = evmcs->host_ia32_sysenter_esp;
                vmcs12->host_ia32_sysenter_eip = evmcs->host_ia32_sysenter_eip;
                vmcs12->host_rip = evmcs->host_rip;
                vmcs12->host_ia32_sysenter_cs = evmcs->host_ia32_sysenter_cs;
                vmcs12->host_es_selector = evmcs->host_es_selector;
                vmcs12->host_cs_selector = evmcs->host_cs_selector;
                vmcs12->host_ss_selector = evmcs->host_ss_selector;
                vmcs12->host_ds_selector = evmcs->host_ds_selector;
                vmcs12->host_fs_selector = evmcs->host_fs_selector;
                vmcs12->host_gs_selector = evmcs->host_gs_selector;
                vmcs12->host_tr_selector = evmcs->host_tr_selector;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP1))) {
                vmcs12->pin_based_vm_exec_control =
                        evmcs->pin_based_vm_exec_control;
                vmcs12->vm_exit_controls = evmcs->vm_exit_controls;
                vmcs12->secondary_vm_exec_control =
                        evmcs->secondary_vm_exec_control;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_IO_BITMAP))) {
                vmcs12->io_bitmap_a = evmcs->io_bitmap_a;
                vmcs12->io_bitmap_b = evmcs->io_bitmap_b;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP))) {
                vmcs12->msr_bitmap = evmcs->msr_bitmap;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2))) {
                vmcs12->guest_es_base = evmcs->guest_es_base;
                vmcs12->guest_cs_base = evmcs->guest_cs_base;
                vmcs12->guest_ss_base = evmcs->guest_ss_base;
                vmcs12->guest_ds_base = evmcs->guest_ds_base;
                vmcs12->guest_fs_base = evmcs->guest_fs_base;
                vmcs12->guest_gs_base = evmcs->guest_gs_base;
                vmcs12->guest_ldtr_base = evmcs->guest_ldtr_base;
                vmcs12->guest_tr_base = evmcs->guest_tr_base;
                vmcs12->guest_gdtr_base = evmcs->guest_gdtr_base;
                vmcs12->guest_idtr_base = evmcs->guest_idtr_base;
                vmcs12->guest_es_limit = evmcs->guest_es_limit;
                vmcs12->guest_cs_limit = evmcs->guest_cs_limit;
                vmcs12->guest_ss_limit = evmcs->guest_ss_limit;
                vmcs12->guest_ds_limit = evmcs->guest_ds_limit;
                vmcs12->guest_fs_limit = evmcs->guest_fs_limit;
                vmcs12->guest_gs_limit = evmcs->guest_gs_limit;
                vmcs12->guest_ldtr_limit = evmcs->guest_ldtr_limit;
                vmcs12->guest_tr_limit = evmcs->guest_tr_limit;
                vmcs12->guest_gdtr_limit = evmcs->guest_gdtr_limit;
                vmcs12->guest_idtr_limit = evmcs->guest_idtr_limit;
                vmcs12->guest_es_ar_bytes = evmcs->guest_es_ar_bytes;
                vmcs12->guest_cs_ar_bytes = evmcs->guest_cs_ar_bytes;
                vmcs12->guest_ss_ar_bytes = evmcs->guest_ss_ar_bytes;
                vmcs12->guest_ds_ar_bytes = evmcs->guest_ds_ar_bytes;
                vmcs12->guest_fs_ar_bytes = evmcs->guest_fs_ar_bytes;
                vmcs12->guest_gs_ar_bytes = evmcs->guest_gs_ar_bytes;
                vmcs12->guest_ldtr_ar_bytes = evmcs->guest_ldtr_ar_bytes;
                vmcs12->guest_tr_ar_bytes = evmcs->guest_tr_ar_bytes;
                vmcs12->guest_es_selector = evmcs->guest_es_selector;
                vmcs12->guest_cs_selector = evmcs->guest_cs_selector;
                vmcs12->guest_ss_selector = evmcs->guest_ss_selector;
                vmcs12->guest_ds_selector = evmcs->guest_ds_selector;
                vmcs12->guest_fs_selector = evmcs->guest_fs_selector;
                vmcs12->guest_gs_selector = evmcs->guest_gs_selector;
                vmcs12->guest_ldtr_selector = evmcs->guest_ldtr_selector;
                vmcs12->guest_tr_selector = evmcs->guest_tr_selector;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_GRP2))) {
                vmcs12->tsc_offset = evmcs->tsc_offset;
                vmcs12->virtual_apic_page_addr = evmcs->virtual_apic_page_addr;
                vmcs12->xss_exit_bitmap = evmcs->xss_exit_bitmap;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CRDR))) {
                vmcs12->cr0_guest_host_mask = evmcs->cr0_guest_host_mask;
                vmcs12->cr4_guest_host_mask = evmcs->cr4_guest_host_mask;
                vmcs12->cr0_read_shadow = evmcs->cr0_read_shadow;
                vmcs12->cr4_read_shadow = evmcs->cr4_read_shadow;
                vmcs12->guest_cr0 = evmcs->guest_cr0;
                vmcs12->guest_cr3 = evmcs->guest_cr3;
                vmcs12->guest_cr4 = evmcs->guest_cr4;
                vmcs12->guest_dr7 = evmcs->guest_dr7;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_POINTER))) {
                vmcs12->host_fs_base = evmcs->host_fs_base;
                vmcs12->host_gs_base = evmcs->host_gs_base;
                vmcs12->host_tr_base = evmcs->host_tr_base;
                vmcs12->host_gdtr_base = evmcs->host_gdtr_base;
                vmcs12->host_idtr_base = evmcs->host_idtr_base;
                vmcs12->host_rsp = evmcs->host_rsp;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_CONTROL_XLAT))) {
                vmcs12->ept_pointer = evmcs->ept_pointer;
                vmcs12->virtual_processor_id = evmcs->virtual_processor_id;
        }

        if (unlikely(!(evmcs->hv_clean_fields &
                       HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1))) {
                vmcs12->vmcs_link_pointer = evmcs->vmcs_link_pointer;
                vmcs12->guest_ia32_debugctl = evmcs->guest_ia32_debugctl;
                vmcs12->guest_ia32_pat = evmcs->guest_ia32_pat;
                vmcs12->guest_ia32_efer = evmcs->guest_ia32_efer;
                vmcs12->guest_pdptr0 = evmcs->guest_pdptr0;
                vmcs12->guest_pdptr1 = evmcs->guest_pdptr1;
                vmcs12->guest_pdptr2 = evmcs->guest_pdptr2;
                vmcs12->guest_pdptr3 = evmcs->guest_pdptr3;
                vmcs12->guest_pending_dbg_exceptions =
                        evmcs->guest_pending_dbg_exceptions;
                vmcs12->guest_sysenter_esp = evmcs->guest_sysenter_esp;
                vmcs12->guest_sysenter_eip = evmcs->guest_sysenter_eip;
                vmcs12->guest_bndcfgs = evmcs->guest_bndcfgs;
                vmcs12->guest_activity_state = evmcs->guest_activity_state;
                vmcs12->guest_sysenter_cs = evmcs->guest_sysenter_cs;
        }

        /*
         * Not used?
         * vmcs12->vm_exit_msr_store_addr = evmcs->vm_exit_msr_store_addr;
         * vmcs12->vm_exit_msr_load_addr = evmcs->vm_exit_msr_load_addr;
         * vmcs12->vm_entry_msr_load_addr = evmcs->vm_entry_msr_load_addr;
         * vmcs12->cr3_target_value0 = evmcs->cr3_target_value0;
         * vmcs12->cr3_target_value1 = evmcs->cr3_target_value1;
         * vmcs12->cr3_target_value2 = evmcs->cr3_target_value2;
         * vmcs12->cr3_target_value3 = evmcs->cr3_target_value3;
         * vmcs12->page_fault_error_code_mask =
         *              evmcs->page_fault_error_code_mask;
         * vmcs12->page_fault_error_code_match =
         *              evmcs->page_fault_error_code_match;
         * vmcs12->cr3_target_count = evmcs->cr3_target_count;
         * vmcs12->vm_exit_msr_store_count = evmcs->vm_exit_msr_store_count;
         * vmcs12->vm_exit_msr_load_count = evmcs->vm_exit_msr_load_count;
         * vmcs12->vm_entry_msr_load_count = evmcs->vm_entry_msr_load_count;
         */

        /*
         * Read only fields:
         * vmcs12->guest_physical_address = evmcs->guest_physical_address;
         * vmcs12->vm_instruction_error = evmcs->vm_instruction_error;
         * vmcs12->vm_exit_reason = evmcs->vm_exit_reason;
         * vmcs12->vm_exit_intr_info = evmcs->vm_exit_intr_info;
         * vmcs12->vm_exit_intr_error_code = evmcs->vm_exit_intr_error_code;
         * vmcs12->idt_vectoring_info_field = evmcs->idt_vectoring_info_field;
         * vmcs12->idt_vectoring_error_code = evmcs->idt_vectoring_error_code;
         * vmcs12->vm_exit_instruction_len = evmcs->vm_exit_instruction_len;
         * vmcs12->vmx_instruction_info = evmcs->vmx_instruction_info;
         * vmcs12->exit_qualification = evmcs->exit_qualification;
         * vmcs12->guest_linear_address = evmcs->guest_linear_address;
         *
         * Not present in struct vmcs12:
         * vmcs12->exit_io_instruction_ecx = evmcs->exit_io_instruction_ecx;
         * vmcs12->exit_io_instruction_esi = evmcs->exit_io_instruction_esi;
         * vmcs12->exit_io_instruction_edi = evmcs->exit_io_instruction_edi;
         * vmcs12->exit_io_instruction_eip = evmcs->exit_io_instruction_eip;
         */

        return 0;
}

static int copy_vmcs12_to_enlightened(struct vcpu_vmx *vmx)
{
        struct vmcs12 *vmcs12 = vmx->nested.cached_vmcs12;
        struct hv_enlightened_vmcs *evmcs = vmx->nested.hv_evmcs;

        /*
         * Should not be changed by KVM:
         *
         * evmcs->host_es_selector = vmcs12->host_es_selector;
         * evmcs->host_cs_selector = vmcs12->host_cs_selector;
         * evmcs->host_ss_selector = vmcs12->host_ss_selector;
         * evmcs->host_ds_selector = vmcs12->host_ds_selector;
         * evmcs->host_fs_selector = vmcs12->host_fs_selector;
         * evmcs->host_gs_selector = vmcs12->host_gs_selector;
         * evmcs->host_tr_selector = vmcs12->host_tr_selector;
         * evmcs->host_ia32_pat = vmcs12->host_ia32_pat;
         * evmcs->host_ia32_efer = vmcs12->host_ia32_efer;
         * evmcs->host_cr0 = vmcs12->host_cr0;
         * evmcs->host_cr3 = vmcs12->host_cr3;
         * evmcs->host_cr4 = vmcs12->host_cr4;
         * evmcs->host_ia32_sysenter_esp = vmcs12->host_ia32_sysenter_esp;
         * evmcs->host_ia32_sysenter_eip = vmcs12->host_ia32_sysenter_eip;
         * evmcs->host_rip = vmcs12->host_rip;
         * evmcs->host_ia32_sysenter_cs = vmcs12->host_ia32_sysenter_cs;
         * evmcs->host_fs_base = vmcs12->host_fs_base;
         * evmcs->host_gs_base = vmcs12->host_gs_base;
         * evmcs->host_tr_base = vmcs12->host_tr_base;
         * evmcs->host_gdtr_base = vmcs12->host_gdtr_base;
         * evmcs->host_idtr_base = vmcs12->host_idtr_base;
         * evmcs->host_rsp = vmcs12->host_rsp;
         * sync_vmcs02_to_vmcs12() doesn't read these:
         * evmcs->io_bitmap_a = vmcs12->io_bitmap_a;
         * evmcs->io_bitmap_b = vmcs12->io_bitmap_b;
         * evmcs->msr_bitmap = vmcs12->msr_bitmap;
         * evmcs->ept_pointer = vmcs12->ept_pointer;
         * evmcs->xss_exit_bitmap = vmcs12->xss_exit_bitmap;
         * evmcs->vm_exit_msr_store_addr = vmcs12->vm_exit_msr_store_addr;
         * evmcs->vm_exit_msr_load_addr = vmcs12->vm_exit_msr_load_addr;
         * evmcs->vm_entry_msr_load_addr = vmcs12->vm_entry_msr_load_addr;
         * evmcs->cr3_target_value0 = vmcs12->cr3_target_value0;
         * evmcs->cr3_target_value1 = vmcs12->cr3_target_value1;
         * evmcs->cr3_target_value2 = vmcs12->cr3_target_value2;
         * evmcs->cr3_target_value3 = vmcs12->cr3_target_value3;
         * evmcs->tpr_threshold = vmcs12->tpr_threshold;
         * evmcs->virtual_processor_id = vmcs12->virtual_processor_id;
         * evmcs->exception_bitmap = vmcs12->exception_bitmap;
         * evmcs->vmcs_link_pointer = vmcs12->vmcs_link_pointer;
         * evmcs->pin_based_vm_exec_control = vmcs12->pin_based_vm_exec_control;
         * evmcs->vm_exit_controls = vmcs12->vm_exit_controls;
         * evmcs->secondary_vm_exec_control = vmcs12->secondary_vm_exec_control;
         * evmcs->page_fault_error_code_mask =
         *              vmcs12->page_fault_error_code_mask;
         * evmcs->page_fault_error_code_match =
         *              vmcs12->page_fault_error_code_match;
         * evmcs->cr3_target_count = vmcs12->cr3_target_count;
         * evmcs->virtual_apic_page_addr = vmcs12->virtual_apic_page_addr;
         * evmcs->tsc_offset = vmcs12->tsc_offset;
         * evmcs->guest_ia32_debugctl = vmcs12->guest_ia32_debugctl;
         * evmcs->cr0_guest_host_mask = vmcs12->cr0_guest_host_mask;
         * evmcs->cr4_guest_host_mask = vmcs12->cr4_guest_host_mask;
         * evmcs->cr0_read_shadow = vmcs12->cr0_read_shadow;
         * evmcs->cr4_read_shadow = vmcs12->cr4_read_shadow;
         * evmcs->vm_exit_msr_store_count = vmcs12->vm_exit_msr_store_count;
         * evmcs->vm_exit_msr_load_count = vmcs12->vm_exit_msr_load_count;
         * evmcs->vm_entry_msr_load_count = vmcs12->vm_entry_msr_load_count;
         *
         * Not present in struct vmcs12:
         * evmcs->exit_io_instruction_ecx = vmcs12->exit_io_instruction_ecx;
         * evmcs->exit_io_instruction_esi = vmcs12->exit_io_instruction_esi;
         * evmcs->exit_io_instruction_edi = vmcs12->exit_io_instruction_edi;
         * evmcs->exit_io_instruction_eip = vmcs12->exit_io_instruction_eip;
         */

        evmcs->guest_es_selector = vmcs12->guest_es_selector;
        evmcs->guest_cs_selector = vmcs12->guest_cs_selector;
        evmcs->guest_ss_selector = vmcs12->guest_ss_selector;
        evmcs->guest_ds_selector = vmcs12->guest_ds_selector;
        evmcs->guest_fs_selector = vmcs12->guest_fs_selector;
        evmcs->guest_gs_selector = vmcs12->guest_gs_selector;
        evmcs->guest_ldtr_selector = vmcs12->guest_ldtr_selector;
        evmcs->guest_tr_selector = vmcs12->guest_tr_selector;

        evmcs->guest_es_limit = vmcs12->guest_es_limit;
        evmcs->guest_cs_limit = vmcs12->guest_cs_limit;
        evmcs->guest_ss_limit = vmcs12->guest_ss_limit;
        evmcs->guest_ds_limit = vmcs12->guest_ds_limit;
        evmcs->guest_fs_limit = vmcs12->guest_fs_limit;
        evmcs->guest_gs_limit = vmcs12->guest_gs_limit;
        evmcs->guest_ldtr_limit = vmcs12->guest_ldtr_limit;
        evmcs->guest_tr_limit = vmcs12->guest_tr_limit;
        evmcs->guest_gdtr_limit = vmcs12->guest_gdtr_limit;
        evmcs->guest_idtr_limit = vmcs12->guest_idtr_limit;

        evmcs->guest_es_ar_bytes = vmcs12->guest_es_ar_bytes;
        evmcs->guest_cs_ar_bytes = vmcs12->guest_cs_ar_bytes;
        evmcs->guest_ss_ar_bytes = vmcs12->guest_ss_ar_bytes;
        evmcs->guest_ds_ar_bytes = vmcs12->guest_ds_ar_bytes;
        evmcs->guest_fs_ar_bytes = vmcs12->guest_fs_ar_bytes;
        evmcs->guest_gs_ar_bytes = vmcs12->guest_gs_ar_bytes;
        evmcs->guest_ldtr_ar_bytes = vmcs12->guest_ldtr_ar_bytes;
        evmcs->guest_tr_ar_bytes = vmcs12->guest_tr_ar_bytes;

        evmcs->guest_es_base = vmcs12->guest_es_base;
        evmcs->guest_cs_base = vmcs12->guest_cs_base;
        evmcs->guest_ss_base = vmcs12->guest_ss_base;
        evmcs->guest_ds_base = vmcs12->guest_ds_base;
        evmcs->guest_fs_base = vmcs12->guest_fs_base;
        evmcs->guest_gs_base = vmcs12->guest_gs_base;
        evmcs->guest_ldtr_base = vmcs12->guest_ldtr_base;
        evmcs->guest_tr_base = vmcs12->guest_tr_base;
        evmcs->guest_gdtr_base = vmcs12->guest_gdtr_base;
        evmcs->guest_idtr_base = vmcs12->guest_idtr_base;

        evmcs->guest_ia32_pat = vmcs12->guest_ia32_pat;
        evmcs->guest_ia32_efer = vmcs12->guest_ia32_efer;

        evmcs->guest_pdptr0 = vmcs12->guest_pdptr0;
        evmcs->guest_pdptr1 = vmcs12->guest_pdptr1;
        evmcs->guest_pdptr2 = vmcs12->guest_pdptr2;
        evmcs->guest_pdptr3 = vmcs12->guest_pdptr3;

        evmcs->guest_pending_dbg_exceptions =
                vmcs12->guest_pending_dbg_exceptions;
        evmcs->guest_sysenter_esp = vmcs12->guest_sysenter_esp;
        evmcs->guest_sysenter_eip = vmcs12->guest_sysenter_eip;

        evmcs->guest_activity_state = vmcs12->guest_activity_state;
        evmcs->guest_sysenter_cs = vmcs12->guest_sysenter_cs;

        evmcs->guest_cr0 = vmcs12->guest_cr0;
        evmcs->guest_cr3 = vmcs12->guest_cr3;
        evmcs->guest_cr4 = vmcs12->guest_cr4;
        evmcs->guest_dr7 = vmcs12->guest_dr7;

        evmcs->guest_physical_address = vmcs12->guest_physical_address;

        evmcs->vm_instruction_error = vmcs12->vm_instruction_error;
        evmcs->vm_exit_reason = vmcs12->vm_exit_reason;
        evmcs->vm_exit_intr_info = vmcs12->vm_exit_intr_info;
        evmcs->vm_exit_intr_error_code = vmcs12->vm_exit_intr_error_code;
        evmcs->idt_vectoring_info_field = vmcs12->idt_vectoring_info_field;
        evmcs->idt_vectoring_error_code = vmcs12->idt_vectoring_error_code;
        evmcs->vm_exit_instruction_len = vmcs12->vm_exit_instruction_len;
        evmcs->vmx_instruction_info = vmcs12->vmx_instruction_info;

        evmcs->exit_qualification = vmcs12->exit_qualification;

        evmcs->guest_linear_address = vmcs12->guest_linear_address;
        evmcs->guest_rsp = vmcs12->guest_rsp;
        evmcs->guest_rflags = vmcs12->guest_rflags;

        evmcs->guest_interruptibility_info =
                vmcs12->guest_interruptibility_info;
        evmcs->cpu_based_vm_exec_control = vmcs12->cpu_based_vm_exec_control;
        evmcs->vm_entry_controls = vmcs12->vm_entry_controls;
        evmcs->vm_entry_intr_info_field = vmcs12->vm_entry_intr_info_field;
        evmcs->vm_entry_exception_error_code =
                vmcs12->vm_entry_exception_error_code;
        evmcs->vm_entry_instruction_len = vmcs12->vm_entry_instruction_len;

        evmcs->guest_rip = vmcs12->guest_rip;

        evmcs->guest_bndcfgs = vmcs12->guest_bndcfgs;

        return 0;
}

/*
 * This is an equivalent of the nested hypervisor executing the vmptrld
 * instruction.
 */
static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu,
                                                 bool from_launch)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        bool evmcs_gpa_changed = false;
        u64 evmcs_gpa;

        if (likely(!vmx->nested.enlightened_vmcs_enabled))
                return 1;

        if (!nested_enlightened_vmentry(vcpu, &evmcs_gpa))
                return 1;

        if (unlikely(evmcs_gpa != vmx->nested.hv_evmcs_vmptr)) {
                if (!vmx->nested.hv_evmcs)
                        vmx->nested.current_vmptr = -1ull;

                nested_release_evmcs(vcpu);

                if (kvm_vcpu_map(vcpu, gpa_to_gfn(evmcs_gpa),
                                 &vmx->nested.hv_evmcs_map))
                        return 0;

                vmx->nested.hv_evmcs = vmx->nested.hv_evmcs_map.hva;

                /*
                 * Currently, KVM only supports eVMCS version 1
                 * (== KVM_EVMCS_VERSION) and thus we expect guest to set this
                 * value to first u32 field of eVMCS which should specify eVMCS
                 * VersionNumber.
                 *
                 * Guest should be aware of supported eVMCS versions by host by
                 * examining CPUID.0x4000000A.EAX[0:15]. Host userspace VMM is
                 * expected to set this CPUID leaf according to the value
                 * returned in vmcs_version from nested_enable_evmcs().
                 *
                 * However, it turns out that Microsoft Hyper-V fails to comply
                 * to their own invented interface: When Hyper-V use eVMCS, it
                 * just sets first u32 field of eVMCS to revision_id specified
                 * in MSR_IA32_VMX_BASIC. Instead of used eVMCS version number
                 * which is one of the supported versions specified in
                 * CPUID.0x4000000A.EAX[0:15].
                 *
                 * To overcome Hyper-V bug, we accept here either a supported
                 * eVMCS version or VMCS12 revision_id as valid values for first
                 * u32 field of eVMCS.
                 */
                if ((vmx->nested.hv_evmcs->revision_id != KVM_EVMCS_VERSION) &&
                    (vmx->nested.hv_evmcs->revision_id != VMCS12_REVISION)) {
                        nested_release_evmcs(vcpu);
                        return 0;
                }

                vmx->nested.dirty_vmcs12 = true;
                vmx->nested.hv_evmcs_vmptr = evmcs_gpa;

                evmcs_gpa_changed = true;
                /*
                 * Unlike normal vmcs12, enlightened vmcs12 is not fully
                 * reloaded from guest's memory (read only fields, fields not
                 * present in struct hv_enlightened_vmcs, ...). Make sure there
                 * are no leftovers.
                 */
                if (from_launch) {
                        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
                        memset(vmcs12, 0, sizeof(*vmcs12));
                        vmcs12->hdr.revision_id = VMCS12_REVISION;
                }

        }

        /*
         * Clean fields data can't de used on VMLAUNCH and when we switch
         * between different L2 guests as KVM keeps a single VMCS12 per L1.
         */
        if (from_launch || evmcs_gpa_changed)
                vmx->nested.hv_evmcs->hv_clean_fields &=
                        ~HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;

        return 1;
}

void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * hv_evmcs may end up being not mapped after migration (when
         * L2 was running), map it here to make sure vmcs12 changes are
         * properly reflected.
         */
        if (vmx->nested.enlightened_vmcs_enabled && !vmx->nested.hv_evmcs)
                nested_vmx_handle_enlightened_vmptrld(vcpu, false);

        if (vmx->nested.hv_evmcs) {
                copy_vmcs12_to_enlightened(vmx);
                /* All fields are clean */
                vmx->nested.hv_evmcs->hv_clean_fields |=
                        HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;
        } else {
                copy_vmcs12_to_shadow(vmx);
        }

        vmx->nested.need_vmcs12_to_shadow_sync = false;
}

static enum hrtimer_restart vmx_preemption_timer_fn(struct hrtimer *timer)
{
        struct vcpu_vmx *vmx =
                container_of(timer, struct vcpu_vmx, nested.preemption_timer);

        vmx->nested.preemption_timer_expired = true;
        kvm_make_request(KVM_REQ_EVENT, &vmx->vcpu);
        kvm_vcpu_kick(&vmx->vcpu);

        return HRTIMER_NORESTART;
}

static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
{
        u64 preemption_timeout = get_vmcs12(vcpu)->vmx_preemption_timer_value;
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        /*
         * A timer value of zero is architecturally guaranteed to cause
         * a VMExit prior to executing any instructions in the guest.
         */
        if (preemption_timeout == 0) {
                vmx_preemption_timer_fn(&vmx->nested.preemption_timer);
                return;
        }

        if (vcpu->arch.virtual_tsc_khz == 0)
                return;

        preemption_timeout <<= VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
        preemption_timeout *= 1000000;
        do_div(preemption_timeout, vcpu->arch.virtual_tsc_khz);
        hrtimer_start(&vmx->nested.preemption_timer,
                      ns_to_ktime(preemption_timeout), HRTIMER_MODE_REL);
}

static u64 nested_vmx_calc_efer(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
{
        if (vmx->nested.nested_run_pending &&
            (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER))
                return vmcs12->guest_ia32_efer;
        else if (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE)
                return vmx->vcpu.arch.efer | (EFER_LMA | EFER_LME);
        else
                return vmx->vcpu.arch.efer & ~(EFER_LMA | EFER_LME);
}

static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx)
{
        /*
         * If vmcs02 hasn't been initialized, set the constant vmcs02 state
         * according to L0's settings (vmcs12 is irrelevant here).  Host
         * fields that come from L0 and are not constant, e.g. HOST_CR3,
         * will be set as needed prior to VMLAUNCH/VMRESUME.
         */
        if (vmx->nested.vmcs02_initialized)
                return;
        vmx->nested.vmcs02_initialized = true;

        /*
         * We don't care what the EPTP value is we just need to guarantee
         * it's valid so we don't get a false positive when doing early
         * consistency checks.
         */
        if (enable_ept && nested_early_check)
                vmcs_write64(EPT_POINTER, construct_eptp(&vmx->vcpu, 0));

        /* All VMFUNCs are currently emulated through L0 vmexits.  */
        if (cpu_has_vmx_vmfunc())
                vmcs_write64(VM_FUNCTION_CONTROL, 0);

        if (cpu_has_vmx_posted_intr())
                vmcs_write16(POSTED_INTR_NV, POSTED_INTR_NESTED_VECTOR);

        if (cpu_has_vmx_msr_bitmap())
                vmcs_write64(MSR_BITMAP, __pa(vmx->nested.vmcs02.msr_bitmap));

        /*
         * The PML address never changes, so it is constant in vmcs02.
         * Conceptually we want to copy the PML index from vmcs01 here,
         * and then back to vmcs01 on nested vmexit.  But since we flush
         * the log and reset GUEST_PML_INDEX on each vmexit, the PML
         * index is also effectively constant in vmcs02.
         */
        if (enable_pml) {
                vmcs_write64(PML_ADDRESS, page_to_phys(vmx->pml_pg));
                vmcs_write16(GUEST_PML_INDEX, PML_ENTITY_NUM - 1);
        }

        if (cpu_has_vmx_encls_vmexit())
                vmcs_write64(ENCLS_EXITING_BITMAP, -1ull);

        /*
         * Set the MSR load/store lists to match L0's settings.  Only the
         * addresses are constant (for vmcs02), the counts can change based
         * on L2's behavior, e.g. switching to/from long mode.
         */
        vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0);
        vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val));
        vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest.val));

        vmx_set_constant_host_state(vmx);
}

static void prepare_vmcs02_early_rare(struct vcpu_vmx *vmx,
                                      struct vmcs12 *vmcs12)
{
        prepare_vmcs02_constant_state(vmx);

        vmcs_write64(VMCS_LINK_POINTER, -1ull);

        if (enable_vpid) {
                if (nested_cpu_has_vpid(vmcs12) && vmx->nested.vpid02)
                        vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->nested.vpid02);
                else
                        vmcs_write16(VIRTUAL_PROCESSOR_ID, vmx->vpid);
        }
}

static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
{
        u32 exec_control, vmcs12_exec_ctrl;
        u64 guest_efer = nested_vmx_calc_efer(vmx, vmcs12);

        if (vmx->nested.dirty_vmcs12 || vmx->nested.hv_evmcs)
                prepare_vmcs02_early_rare(vmx, vmcs12);

        /*
         * PIN CONTROLS
         */
        exec_control = vmx_pin_based_exec_ctrl(vmx);
        exec_control |= (vmcs12->pin_based_vm_exec_control &
                         ~PIN_BASED_VMX_PREEMPTION_TIMER);

        /* Posted interrupts setting is only taken from vmcs12.  */
        if (nested_cpu_has_posted_intr(vmcs12)) {
                vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv;
                vmx->nested.pi_pending = false;
        } else {
                exec_control &= ~PIN_BASED_POSTED_INTR;
        }
        pin_controls_set(vmx, exec_control);

        /*
         * EXEC CONTROLS
         */
        exec_control = vmx_exec_control(vmx); /* L0's desires */
        exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
        exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
        exec_control &= ~CPU_BASED_TPR_SHADOW;
        exec_control |= vmcs12->cpu_based_vm_exec_control;

        if (exec_control & CPU_BASED_TPR_SHADOW)
                vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold);
#ifdef CONFIG_X86_64
        else
                exec_control |= CPU_BASED_CR8_LOAD_EXITING |
                                CPU_BASED_CR8_STORE_EXITING;
#endif

        /*
         * A vmexit (to either L1 hypervisor or L0 userspace) is always needed
         * for I/O port accesses.
         */
        exec_control |= CPU_BASED_UNCOND_IO_EXITING;
        exec_control &= ~CPU_BASED_USE_IO_BITMAPS;

        /*
         * This bit will be computed in nested_get_vmcs12_pages, because
         * we do not have access to L1's MSR bitmap yet.  For now, keep
         * the same bit as before, hoping to avoid multiple VMWRITEs that
         * only set/clear this bit.
         */
        exec_control &= ~CPU_BASED_USE_MSR_BITMAPS;
        exec_control |= exec_controls_get(vmx) & CPU_BASED_USE_MSR_BITMAPS;

        exec_controls_set(vmx, exec_control);

        /*
         * SECONDARY EXEC CONTROLS
         */
        if (cpu_has_secondary_exec_ctrls()) {
                exec_control = vmx->secondary_exec_control;

                /* Take the following fields only from vmcs12 */
                exec_control &= ~(SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES |
                                  SECONDARY_EXEC_ENABLE_INVPCID |
                                  SECONDARY_EXEC_RDTSCP |
                                  SECONDARY_EXEC_XSAVES |
                                  SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                                  SECONDARY_EXEC_APIC_REGISTER_VIRT |
                                  SECONDARY_EXEC_ENABLE_VMFUNC);
                if (nested_cpu_has(vmcs12,
                                   CPU_BASED_ACTIVATE_SECONDARY_CONTROLS)) {
                        vmcs12_exec_ctrl = vmcs12->secondary_vm_exec_control &
                                ~SECONDARY_EXEC_ENABLE_PML;
                        exec_control |= vmcs12_exec_ctrl;
                }

                /* VMCS shadowing for L2 is emulated for now */
                exec_control &= ~SECONDARY_EXEC_SHADOW_VMCS;

                /*
                 * Preset *DT exiting when emulating UMIP, so that vmx_set_cr4()
                 * will not have to rewrite the controls just for this bit.
                 */
                if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated() &&
                    (vmcs12->guest_cr4 & X86_CR4_UMIP))
                        exec_control |= SECONDARY_EXEC_DESC;

                if (exec_control & SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY)
                        vmcs_write16(GUEST_INTR_STATUS,
                                vmcs12->guest_intr_status);

                secondary_exec_controls_set(vmx, exec_control);
        }

        /*
         * ENTRY CONTROLS
         *
         * vmcs12's VM_{ENTRY,EXIT}_LOAD_IA32_EFER and VM_ENTRY_IA32E_MODE
         * are emulated by vmx_set_efer() in prepare_vmcs02(), but speculate
         * on the related bits (if supported by the CPU) in the hope that
         * we can avoid VMWrites during vmx_set_efer().
         */
        exec_control = (vmcs12->vm_entry_controls | vmx_vmentry_ctrl()) &
                        ~VM_ENTRY_IA32E_MODE & ~VM_ENTRY_LOAD_IA32_EFER;
        if (cpu_has_load_ia32_efer()) {
                if (guest_efer & EFER_LMA)
                        exec_control |= VM_ENTRY_IA32E_MODE;
                if (guest_efer != host_efer)
                        exec_control |= VM_ENTRY_LOAD_IA32_EFER;
        }
        vm_entry_controls_set(vmx, exec_control);

        /*
         * EXIT CONTROLS
         *
         * L2->L1 exit controls are emulated - the hardware exit is to L0 so
         * we should use its exit controls. Note that VM_EXIT_LOAD_IA32_EFER
         * bits may be modified by vmx_set_efer() in prepare_vmcs02().
         */
        exec_control = vmx_vmexit_ctrl();
        if (cpu_has_load_ia32_efer() && guest_efer != host_efer)
                exec_control |= VM_EXIT_LOAD_IA32_EFER;
        vm_exit_controls_set(vmx, exec_control);

        /*
         * Interrupt/Exception Fields
         */
        if (vmx->nested.nested_run_pending) {
                vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
                             vmcs12->vm_entry_intr_info_field);
                vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE,
                             vmcs12->vm_entry_exception_error_code);
                vmcs_write32(VM_ENTRY_INSTRUCTION_LEN,
                             vmcs12->vm_entry_instruction_len);
                vmcs_write32(GUEST_INTERRUPTIBILITY_INFO,
                             vmcs12->guest_interruptibility_info);
                vmx->loaded_vmcs->nmi_known_unmasked =
                        !(vmcs12->guest_interruptibility_info & GUEST_INTR_STATE_NMI);
        } else {
                vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);
        }
}

static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
{
        struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;

        if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
                           HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP2)) {
                vmcs_write16(GUEST_ES_SELECTOR, vmcs12->guest_es_selector);
                vmcs_write16(GUEST_CS_SELECTOR, vmcs12->guest_cs_selector);
                vmcs_write16(GUEST_SS_SELECTOR, vmcs12->guest_ss_selector);
                vmcs_write16(GUEST_DS_SELECTOR, vmcs12->guest_ds_selector);
                vmcs_write16(GUEST_FS_SELECTOR, vmcs12->guest_fs_selector);
                vmcs_write16(GUEST_GS_SELECTOR, vmcs12->guest_gs_selector);
                vmcs_write16(GUEST_LDTR_SELECTOR, vmcs12->guest_ldtr_selector);
                vmcs_write16(GUEST_TR_SELECTOR, vmcs12->guest_tr_selector);
                vmcs_write32(GUEST_ES_LIMIT, vmcs12->guest_es_limit);
                vmcs_write32(GUEST_CS_LIMIT, vmcs12->guest_cs_limit);
                vmcs_write32(GUEST_SS_LIMIT, vmcs12->guest_ss_limit);
                vmcs_write32(GUEST_DS_LIMIT, vmcs12->guest_ds_limit);
                vmcs_write32(GUEST_FS_LIMIT, vmcs12->guest_fs_limit);
                vmcs_write32(GUEST_GS_LIMIT, vmcs12->guest_gs_limit);
                vmcs_write32(GUEST_LDTR_LIMIT, vmcs12->guest_ldtr_limit);
                vmcs_write32(GUEST_TR_LIMIT, vmcs12->guest_tr_limit);
                vmcs_write32(GUEST_GDTR_LIMIT, vmcs12->guest_gdtr_limit);
                vmcs_write32(GUEST_IDTR_LIMIT, vmcs12->guest_idtr_limit);
                vmcs_write32(GUEST_CS_AR_BYTES, vmcs12->guest_cs_ar_bytes);
                vmcs_write32(GUEST_SS_AR_BYTES, vmcs12->guest_ss_ar_bytes);
                vmcs_write32(GUEST_ES_AR_BYTES, vmcs12->guest_es_ar_bytes);
                vmcs_write32(GUEST_DS_AR_BYTES, vmcs12->guest_ds_ar_bytes);
                vmcs_write32(GUEST_FS_AR_BYTES, vmcs12->guest_fs_ar_bytes);
                vmcs_write32(GUEST_GS_AR_BYTES, vmcs12->guest_gs_ar_bytes);
                vmcs_write32(GUEST_LDTR_AR_BYTES, vmcs12->guest_ldtr_ar_bytes);
                vmcs_write32(GUEST_TR_AR_BYTES, vmcs12->guest_tr_ar_bytes);
                vmcs_writel(GUEST_ES_BASE, vmcs12->guest_es_base);
                vmcs_writel(GUEST_CS_BASE, vmcs12->guest_cs_base);
                vmcs_writel(GUEST_SS_BASE, vmcs12->guest_ss_base);
                vmcs_writel(GUEST_DS_BASE, vmcs12->guest_ds_base);
                vmcs_writel(GUEST_FS_BASE, vmcs12->guest_fs_base);
                vmcs_writel(GUEST_GS_BASE, vmcs12->guest_gs_base);
                vmcs_writel(GUEST_LDTR_BASE, vmcs12->guest_ldtr_base);
                vmcs_writel(GUEST_TR_BASE, vmcs12->guest_tr_base);
                vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base);
                vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base);
        }

        if (!hv_evmcs || !(hv_evmcs->hv_clean_fields &
                           HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1)) {
                vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs);
                vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS,
                            vmcs12->guest_pending_dbg_exceptions);
                vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->guest_sysenter_esp);
                vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->guest_sysenter_eip);

                /*
                 * L1 may access the L2's PDPTR, so save them to construct
                 * vmcs12
                 */
                if (enable_ept) {
                        vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0);
                        vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1);
                        vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
                        vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
                }

                if (kvm_mpx_supported() && vmx->nested.nested_run_pending &&
                    (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
                        vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
        }

        if (nested_cpu_has_xsaves(vmcs12))
                vmcs_write64(XSS_EXIT_BITMAP, vmcs12->xss_exit_bitmap);

        /*
         * Whether page-faults are trapped is determined by a combination of
         * 3 settings: PFEC_MASK, PFEC_MATCH and EXCEPTION_BITMAP.PF.
         * If enable_ept, L0 doesn't care about page faults and we should
         * set all of these to L1's desires. However, if !enable_ept, L0 does
         * care about (at least some) page faults, and because it is not easy
         * (if at all possible?) to merge L0 and L1's desires, we simply ask
         * to exit on each and every L2 page fault. This is done by setting
         * MASK=MATCH=0 and (see below) EB.PF=1.
         * Note that below we don't need special code to set EB.PF beyond the
         * "or"ing of the EB of vmcs01 and vmcs12, because when enable_ept,
         * vmcs01's EB.PF is 0 so the "or" will take vmcs12's value, and when
         * !enable_ept, EB.PF is 1, so the "or" will always be 1.
         */
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MASK,
                enable_ept ? vmcs12->page_fault_error_code_mask : 0);
        vmcs_write32(PAGE_FAULT_ERROR_CODE_MATCH,
                enable_ept ? vmcs12->page_fault_error_code_match : 0);

        if (cpu_has_vmx_apicv()) {
                vmcs_write64(EOI_EXIT_BITMAP0, vmcs12->eoi_exit_bitmap0);
                vmcs_write64(EOI_EXIT_BITMAP1, vmcs12->eoi_exit_bitmap1);
                vmcs_write64(EOI_EXIT_BITMAP2, vmcs12->eoi_exit_bitmap2);
                vmcs_write64(EOI_EXIT_BITMAP3, vmcs12->eoi_exit_bitmap3);
        }

        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);

        set_cr4_guest_host_mask(vmx);
}

/*
 * prepare_vmcs02 is called when the L1 guest hypervisor runs its nested
 * L2 guest. L1 has a vmcs for L2 (vmcs12), and this function "merges" it
 * with L0's requirements for its guest (a.k.a. vmcs01), so we can run the L2
 * guest in a way that will both be appropriate to L1's requests, and our
 * needs. In addition to modifying the active vmcs (which is vmcs02), this
 * function also has additional necessary side-effects, like setting various
 * vcpu->arch fields.
 * Returns 0 on success, 1 on failure. Invalid state exit qualification code
 * is assigned to entry_failure_code on failure.
 */
static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
                          u32 *entry_failure_code)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct hv_enlightened_vmcs *hv_evmcs = vmx->nested.hv_evmcs;
        bool load_guest_pdptrs_vmcs12 = false;

        if (vmx->nested.dirty_vmcs12 || hv_evmcs) {
                prepare_vmcs02_rare(vmx, vmcs12);
                vmx->nested.dirty_vmcs12 = false;

                load_guest_pdptrs_vmcs12 = !hv_evmcs ||
                        !(hv_evmcs->hv_clean_fields &
                          HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
        }

        if (vmx->nested.nested_run_pending &&
            (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) {
                kvm_set_dr(vcpu, 7, vmcs12->guest_dr7);
                vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl);
        } else {
                kvm_set_dr(vcpu, 7, vcpu->arch.dr7);
                vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.vmcs01_debugctl);
        }
        if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending ||
            !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
                vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
        vmx_set_rflags(vcpu, vmcs12->guest_rflags);

        /* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
         * bitwise-or of what L1 wants to trap for L2, and what we want to
         * trap. Note that CR0.TS also needs updating - we do this later.
         */
        update_exception_bitmap(vcpu);
        vcpu->arch.cr0_guest_owned_bits &= ~vmcs12->cr0_guest_host_mask;
        vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);

        if (vmx->nested.nested_run_pending &&
            (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT)) {
                vmcs_write64(GUEST_IA32_PAT, vmcs12->guest_ia32_pat);
                vcpu->arch.pat = vmcs12->guest_ia32_pat;
        } else if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
                vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
        }

        vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset);

        if (kvm_has_tsc_control)
                decache_tsc_multiplier(vmx);

        if (enable_vpid) {
                /*
                 * There is no direct mapping between vpid02 and vpid12, the
                 * vpid02 is per-vCPU for L0 and reused while the value of
                 * vpid12 is changed w/ one invvpid during nested vmentry.
                 * The vpid12 is allocated by L1 for L2, so it will not
                 * influence global bitmap(for vpid01 and vpid02 allocation)
                 * even if spawn a lot of nested vCPUs.
                 */
                if (nested_cpu_has_vpid(vmcs12) && nested_has_guest_tlb_tag(vcpu)) {
                        if (vmcs12->virtual_processor_id != vmx->nested.last_vpid) {
                                vmx->nested.last_vpid = vmcs12->virtual_processor_id;
                                __vmx_flush_tlb(vcpu, nested_get_vpid02(vcpu), false);
                        }
                } else {
                        /*
                         * If L1 use EPT, then L0 needs to execute INVEPT on
                         * EPTP02 instead of EPTP01. Therefore, delay TLB
                         * flush until vmcs02->eptp is fully updated by
                         * KVM_REQ_LOAD_CR3. Note that this assumes
                         * KVM_REQ_TLB_FLUSH is evaluated after
                         * KVM_REQ_LOAD_CR3 in vcpu_enter_guest().
                         */
                        kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
                }
        }

        if (nested_cpu_has_ept(vmcs12))
                nested_ept_init_mmu_context(vcpu);
        else if (nested_cpu_has2(vmcs12,
                                 SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES))
                vmx_flush_tlb(vcpu, true);

        /*
         * This sets GUEST_CR0 to vmcs12->guest_cr0, possibly modifying those
         * bits which we consider mandatory enabled.
         * The CR0_READ_SHADOW is what L2 should have expected to read given
         * the specifications by L1; It's not enough to take
         * vmcs12->cr0_read_shadow because on our cr0_guest_host_mask we we
         * have more bits than L1 expected.
         */
        vmx_set_cr0(vcpu, vmcs12->guest_cr0);
        vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12));

        vmx_set_cr4(vcpu, vmcs12->guest_cr4);
        vmcs_writel(CR4_READ_SHADOW, nested_read_cr4(vmcs12));

        vcpu->arch.efer = nested_vmx_calc_efer(vmx, vmcs12);
        /* Note: may modify VM_ENTRY/EXIT_CONTROLS and GUEST/HOST_IA32_EFER */
        vmx_set_efer(vcpu, vcpu->arch.efer);

        /*
         * Guest state is invalid and unrestricted guest is disabled,
         * which means L1 attempted VMEntry to L2 with invalid state.
         * Fail the VMEntry.
         */
        if (vmx->emulation_required) {
                *entry_failure_code = ENTRY_FAIL_DEFAULT;
                return -EINVAL;
        }

        /* Shadow page tables on either EPT or shadow page tables. */
        if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12),
                                entry_failure_code))
                return -EINVAL;

        /* Late preparation of GUEST_PDPTRs now that EFER and CRs are set. */
        if (load_guest_pdptrs_vmcs12 && nested_cpu_has_ept(vmcs12) &&
            is_pae_paging(vcpu)) {
                vmcs_write64(GUEST_PDPTR0, vmcs12->guest_pdptr0);
                vmcs_write64(GUEST_PDPTR1, vmcs12->guest_pdptr1);
                vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
                vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
        }

        if (!enable_ept)
                vcpu->arch.walk_mmu->inject_page_fault = vmx_inject_page_fault_nested;

        kvm_rsp_write(vcpu, vmcs12->guest_rsp);
        kvm_rip_write(vcpu, vmcs12->guest_rip);
        return 0;
}

static int nested_vmx_check_nmi_controls(struct vmcs12 *vmcs12)
{
        if (CC(!nested_cpu_has_nmi_exiting(vmcs12) &&
               nested_cpu_has_virtual_nmis(vmcs12)))
                return -EINVAL;

        if (CC(!nested_cpu_has_virtual_nmis(vmcs12) &&
               nested_cpu_has(vmcs12, CPU_BASED_VIRTUAL_NMI_PENDING)))
                return -EINVAL;

        return 0;
}

static bool valid_ept_address(struct kvm_vcpu *vcpu, u64 address)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int maxphyaddr = cpuid_maxphyaddr(vcpu);

        /* Check for memory type validity */
        switch (address & VMX_EPTP_MT_MASK) {
        case VMX_EPTP_MT_UC:
                if (CC(!(vmx->nested.msrs.ept_caps & VMX_EPTP_UC_BIT)))
                        return false;
                break;
        case VMX_EPTP_MT_WB:
                if (CC(!(vmx->nested.msrs.ept_caps & VMX_EPTP_WB_BIT)))
                        return false;
                break;
        default:
                return false;
        }

        /* only 4 levels page-walk length are valid */
        if (CC((address & VMX_EPTP_PWL_MASK) != VMX_EPTP_PWL_4))
                return false;

        /* Reserved bits should not be set */
        if (CC(address >> maxphyaddr || ((address >> 7) & 0x1f)))
                return false;

        /* AD, if set, should be supported */
        if (address & VMX_EPTP_AD_ENABLE_BIT) {
                if (CC(!(vmx->nested.msrs.ept_caps & VMX_EPT_AD_BIT)))
                        return false;
        }

        return true;
}

/*
 * Checks related to VM-Execution Control Fields
 */
static int nested_check_vm_execution_controls(struct kvm_vcpu *vcpu,
                                              struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (CC(!vmx_control_verify(vmcs12->pin_based_vm_exec_control,
                                   vmx->nested.msrs.pinbased_ctls_low,
                                   vmx->nested.msrs.pinbased_ctls_high)) ||
            CC(!vmx_control_verify(vmcs12->cpu_based_vm_exec_control,
                                   vmx->nested.msrs.procbased_ctls_low,
                                   vmx->nested.msrs.procbased_ctls_high)))
                return -EINVAL;

        if (nested_cpu_has(vmcs12, CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) &&
            CC(!vmx_control_verify(vmcs12->secondary_vm_exec_control,
                                   vmx->nested.msrs.secondary_ctls_low,
                                   vmx->nested.msrs.secondary_ctls_high)))
                return -EINVAL;

        if (CC(vmcs12->cr3_target_count > nested_cpu_vmx_misc_cr3_count(vcpu)) ||
            nested_vmx_check_io_bitmap_controls(vcpu, vmcs12) ||
            nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12) ||
            nested_vmx_check_tpr_shadow_controls(vcpu, vmcs12) ||
            nested_vmx_check_apic_access_controls(vcpu, vmcs12) ||
            nested_vmx_check_apicv_controls(vcpu, vmcs12) ||
            nested_vmx_check_nmi_controls(vmcs12) ||
            nested_vmx_check_pml_controls(vcpu, vmcs12) ||
            nested_vmx_check_unrestricted_guest_controls(vcpu, vmcs12) ||
            nested_vmx_check_mode_based_ept_exec_controls(vcpu, vmcs12) ||
            nested_vmx_check_shadow_vmcs_controls(vcpu, vmcs12) ||
            CC(nested_cpu_has_vpid(vmcs12) && !vmcs12->virtual_processor_id))
                return -EINVAL;

        if (!nested_cpu_has_preemption_timer(vmcs12) &&
            nested_cpu_has_save_preemption_timer(vmcs12))
                return -EINVAL;

        if (nested_cpu_has_ept(vmcs12) &&
            CC(!valid_ept_address(vcpu, vmcs12->ept_pointer)))
                return -EINVAL;

        if (nested_cpu_has_vmfunc(vmcs12)) {
                if (CC(vmcs12->vm_function_control &
                       ~vmx->nested.msrs.vmfunc_controls))
                        return -EINVAL;

                if (nested_cpu_has_eptp_switching(vmcs12)) {
                        if (CC(!nested_cpu_has_ept(vmcs12)) ||
                            CC(!page_address_valid(vcpu, vmcs12->eptp_list_address)))
                                return -EINVAL;
                }
        }

        return 0;
}

/*
 * Checks related to VM-Exit Control Fields
 */
static int nested_check_vm_exit_controls(struct kvm_vcpu *vcpu,
                                         struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (CC(!vmx_control_verify(vmcs12->vm_exit_controls,
                                    vmx->nested.msrs.exit_ctls_low,
                                    vmx->nested.msrs.exit_ctls_high)) ||
            CC(nested_vmx_check_exit_msr_switch_controls(vcpu, vmcs12)))
                return -EINVAL;

        return 0;
}

/*
 * Checks related to VM-Entry Control Fields
 */
static int nested_check_vm_entry_controls(struct kvm_vcpu *vcpu,
                                          struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (CC(!vmx_control_verify(vmcs12->vm_entry_controls,
                                    vmx->nested.msrs.entry_ctls_low,
                                    vmx->nested.msrs.entry_ctls_high)))
                return -EINVAL;

        /*
         * From the Intel SDM, volume 3:
         * Fields relevant to VM-entry event injection must be set properly.
         * These fields are the VM-entry interruption-information field, the
         * VM-entry exception error code, and the VM-entry instruction length.
         */
        if (vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK) {
                u32 intr_info = vmcs12->vm_entry_intr_info_field;
                u8 vector = intr_info & INTR_INFO_VECTOR_MASK;
                u32 intr_type = intr_info & INTR_INFO_INTR_TYPE_MASK;
                bool has_error_code = intr_info & INTR_INFO_DELIVER_CODE_MASK;
                bool should_have_error_code;
                bool urg = nested_cpu_has2(vmcs12,
                                           SECONDARY_EXEC_UNRESTRICTED_GUEST);
                bool prot_mode = !urg || vmcs12->guest_cr0 & X86_CR0_PE;

                /* VM-entry interruption-info field: interruption type */
                if (CC(intr_type == INTR_TYPE_RESERVED) ||
                    CC(intr_type == INTR_TYPE_OTHER_EVENT &&
                       !nested_cpu_supports_monitor_trap_flag(vcpu)))
                        return -EINVAL;

                /* VM-entry interruption-info field: vector */
                if (CC(intr_type == INTR_TYPE_NMI_INTR && vector != NMI_VECTOR) ||
                    CC(intr_type == INTR_TYPE_HARD_EXCEPTION && vector > 31) ||
                    CC(intr_type == INTR_TYPE_OTHER_EVENT && vector != 0))
                        return -EINVAL;

                /* VM-entry interruption-info field: deliver error code */
                should_have_error_code =
                        intr_type == INTR_TYPE_HARD_EXCEPTION && prot_mode &&
                        x86_exception_has_error_code(vector);
                if (CC(has_error_code != should_have_error_code))
                        return -EINVAL;

                /* VM-entry exception error code */
                if (CC(has_error_code &&
                       vmcs12->vm_entry_exception_error_code & GENMASK(31, 15)))
                        return -EINVAL;

                /* VM-entry interruption-info field: reserved bits */
                if (CC(intr_info & INTR_INFO_RESVD_BITS_MASK))
                        return -EINVAL;

                /* VM-entry instruction length */
                switch (intr_type) {
                case INTR_TYPE_SOFT_EXCEPTION:
                case INTR_TYPE_SOFT_INTR:
                case INTR_TYPE_PRIV_SW_EXCEPTION:
                        if (CC(vmcs12->vm_entry_instruction_len > 15) ||
                            CC(vmcs12->vm_entry_instruction_len == 0 &&
                            CC(!nested_cpu_has_zero_length_injection(vcpu))))
                                return -EINVAL;
                }
        }

        if (nested_vmx_check_entry_msr_switch_controls(vcpu, vmcs12))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_controls(struct kvm_vcpu *vcpu,
                                     struct vmcs12 *vmcs12)
{
        if (nested_check_vm_execution_controls(vcpu, vmcs12) ||
            nested_check_vm_exit_controls(vcpu, vmcs12) ||
            nested_check_vm_entry_controls(vcpu, vmcs12))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_host_state(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        bool ia32e;

        if (CC(!nested_host_cr0_valid(vcpu, vmcs12->host_cr0)) ||
            CC(!nested_host_cr4_valid(vcpu, vmcs12->host_cr4)) ||
            CC(!nested_cr3_valid(vcpu, vmcs12->host_cr3)))
                return -EINVAL;

        if (CC(is_noncanonical_address(vmcs12->host_ia32_sysenter_esp, vcpu)) ||
            CC(is_noncanonical_address(vmcs12->host_ia32_sysenter_eip, vcpu)))
                return -EINVAL;

        if ((vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) &&
            CC(!kvm_pat_valid(vmcs12->host_ia32_pat)))
                return -EINVAL;

        ia32e = (vmcs12->vm_exit_controls &
                 VM_EXIT_HOST_ADDR_SPACE_SIZE) != 0;

        if (CC(vmcs12->host_cs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_ss_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_ds_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_es_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_fs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_gs_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_tr_selector & (SEGMENT_RPL_MASK | SEGMENT_TI_MASK)) ||
            CC(vmcs12->host_cs_selector == 0) ||
            CC(vmcs12->host_tr_selector == 0) ||
            CC(vmcs12->host_ss_selector == 0 && !ia32e))
                return -EINVAL;

#ifdef CONFIG_X86_64
        if (CC(is_noncanonical_address(vmcs12->host_fs_base, vcpu)) ||
            CC(is_noncanonical_address(vmcs12->host_gs_base, vcpu)) ||
            CC(is_noncanonical_address(vmcs12->host_gdtr_base, vcpu)) ||
            CC(is_noncanonical_address(vmcs12->host_idtr_base, vcpu)) ||
            CC(is_noncanonical_address(vmcs12->host_tr_base, vcpu)))
                return -EINVAL;
#endif

        /*
         * If the load IA32_EFER VM-exit control is 1, bits reserved in the
         * IA32_EFER MSR must be 0 in the field for that register. In addition,
         * the values of the LMA and LME bits in the field must each be that of
         * the host address-space size VM-exit control.
         */
        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER) {
                if (CC(!kvm_valid_efer(vcpu, vmcs12->host_ia32_efer)) ||
                    CC(ia32e != !!(vmcs12->host_ia32_efer & EFER_LMA)) ||
                    CC(ia32e != !!(vmcs12->host_ia32_efer & EFER_LME)))
                        return -EINVAL;
        }

        return 0;
}

static int nested_vmx_check_vmcs_link_ptr(struct kvm_vcpu *vcpu,
                                          struct vmcs12 *vmcs12)
{
        int r = 0;
        struct vmcs12 *shadow;
        struct kvm_host_map map;

        if (vmcs12->vmcs_link_pointer == -1ull)
                return 0;

        if (CC(!page_address_valid(vcpu, vmcs12->vmcs_link_pointer)))
                return -EINVAL;

        if (CC(kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->vmcs_link_pointer), &map)))
                return -EINVAL;

        shadow = map.hva;

        if (CC(shadow->hdr.revision_id != VMCS12_REVISION) ||
            CC(shadow->hdr.shadow_vmcs != nested_cpu_has_shadow_vmcs(vmcs12)))
                r = -EINVAL;

        kvm_vcpu_unmap(vcpu, &map, false);
        return r;
}

/*
 * Checks related to Guest Non-register State
 */
static int nested_check_guest_non_reg_state(struct vmcs12 *vmcs12)
{
        if (CC(vmcs12->guest_activity_state != GUEST_ACTIVITY_ACTIVE &&
               vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu,
                                        struct vmcs12 *vmcs12,
                                        u32 *exit_qual)
{
        bool ia32e;

        *exit_qual = ENTRY_FAIL_DEFAULT;

        if (CC(!nested_guest_cr0_valid(vcpu, vmcs12->guest_cr0)) ||
            CC(!nested_guest_cr4_valid(vcpu, vmcs12->guest_cr4)))
                return -EINVAL;

        if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_PAT) &&
            CC(!kvm_pat_valid(vmcs12->guest_ia32_pat)))
                return -EINVAL;

        if (nested_vmx_check_vmcs_link_ptr(vcpu, vmcs12)) {
                *exit_qual = ENTRY_FAIL_VMCS_LINK_PTR;
                return -EINVAL;
        }

        /*
         * If the load IA32_EFER VM-entry control is 1, the following checks
         * are performed on the field for the IA32_EFER MSR:
         * - Bits reserved in the IA32_EFER MSR must be 0.
         * - Bit 10 (corresponding to IA32_EFER.LMA) must equal the value of
         *   the IA-32e mode guest VM-exit control. It must also be identical
         *   to bit 8 (LME) if bit 31 in the CR0 field (corresponding to
         *   CR0.PG) is 1.
         */
        if (to_vmx(vcpu)->nested.nested_run_pending &&
            (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) {
                ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0;
                if (CC(!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer)) ||
                    CC(ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA)) ||
                    CC(((vmcs12->guest_cr0 & X86_CR0_PG) &&
                     ia32e != !!(vmcs12->guest_ia32_efer & EFER_LME))))
                        return -EINVAL;
        }

        if ((vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS) &&
            (CC(is_noncanonical_address(vmcs12->guest_bndcfgs & PAGE_MASK, vcpu)) ||
             CC((vmcs12->guest_bndcfgs & MSR_IA32_BNDCFGS_RSVD))))
                return -EINVAL;

        if (nested_check_guest_non_reg_state(vmcs12))
                return -EINVAL;

        return 0;
}

static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long cr3, cr4;
        bool vm_fail;

        if (!nested_early_check)
                return 0;

        if (vmx->msr_autoload.host.nr)
                vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, 0);
        if (vmx->msr_autoload.guest.nr)
                vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, 0);

        preempt_disable();

        vmx_prepare_switch_to_guest(vcpu);

        /*
         * Induce a consistency check VMExit by clearing bit 1 in GUEST_RFLAGS,
         * which is reserved to '1' by hardware.  GUEST_RFLAGS is guaranteed to
         * be written (by preparve_vmcs02()) before the "real" VMEnter, i.e.
         * there is no need to preserve other bits or save/restore the field.
         */
        vmcs_writel(GUEST_RFLAGS, 0);

        cr3 = __get_current_cr3_fast();
        if (unlikely(cr3 != vmx->loaded_vmcs->host_state.cr3)) {
                vmcs_writel(HOST_CR3, cr3);
                vmx->loaded_vmcs->host_state.cr3 = cr3;
        }

        cr4 = cr4_read_shadow();
        if (unlikely(cr4 != vmx->loaded_vmcs->host_state.cr4)) {
                vmcs_writel(HOST_CR4, cr4);
                vmx->loaded_vmcs->host_state.cr4 = cr4;
        }

        asm(
                "sub $%c[wordsize], %%" _ASM_SP "\n\t" /* temporarily adjust RSP for CALL */
                "cmp %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
                "je 1f \n\t"
                __ex("vmwrite %%" _ASM_SP ", %[HOST_RSP]") "\n\t"
                "mov %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
                "1: \n\t"
                "add $%c[wordsize], %%" _ASM_SP "\n\t" /* un-adjust RSP */

                /* Check if vmlaunch or vmresume is needed */
                "cmpb $0, %c[launched](%[loaded_vmcs])\n\t"

                /*
                 * VMLAUNCH and VMRESUME clear RFLAGS.{CF,ZF} on VM-Exit, set
                 * RFLAGS.CF on VM-Fail Invalid and set RFLAGS.ZF on VM-Fail
                 * Valid.  vmx_vmenter() directly "returns" RFLAGS, and so the
                 * results of VM-Enter is captured via CC_{SET,OUT} to vm_fail.
                 */
                "call vmx_vmenter\n\t"

                CC_SET(be)
              : ASM_CALL_CONSTRAINT, CC_OUT(be) (vm_fail)
              : [HOST_RSP]"r"((unsigned long)HOST_RSP),
                [loaded_vmcs]"r"(vmx->loaded_vmcs),
                [launched]"i"(offsetof(struct loaded_vmcs, launched)),
                [host_state_rsp]"i"(offsetof(struct loaded_vmcs, host_state.rsp)),
                [wordsize]"i"(sizeof(ulong))
              : "memory"
        );

        if (vmx->msr_autoload.host.nr)
                vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
        if (vmx->msr_autoload.guest.nr)
                vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);

        if (vm_fail) {
                preempt_enable();
                WARN_ON_ONCE(vmcs_read32(VM_INSTRUCTION_ERROR) !=
                             VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                return 1;
        }

        /*
         * VMExit clears RFLAGS.IF and DR7, even on a consistency check.
         */
        local_irq_enable();
        if (hw_breakpoint_active())
                set_debugreg(__this_cpu_read(cpu_dr7), 7);
        preempt_enable();

        /*
         * A non-failing VMEntry means we somehow entered guest mode with
         * an illegal RIP, and that's just the tip of the iceberg.  There
         * is no telling what memory has been modified or what state has
         * been exposed to unknown code.  Hitting this all but guarantees
         * a (very critical) hardware issue.
         */
        WARN_ON(!(vmcs_read32(VM_EXIT_REASON) &
                VMX_EXIT_REASONS_FAILED_VMENTRY));

        return 0;
}

static inline bool nested_vmx_prepare_msr_bitmap(struct kvm_vcpu *vcpu,
                                                 struct vmcs12 *vmcs12);

static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct kvm_host_map *map;
        struct page *page;
        u64 hpa;

        if (nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
                /*
                 * Translate L1 physical address to host physical
                 * address for vmcs02. Keep the page pinned, so this
                 * physical address remains valid. We keep a reference
                 * to it so we can release it later.
                 */
                if (vmx->nested.apic_access_page) { /* shouldn't happen */
                        kvm_release_page_dirty(vmx->nested.apic_access_page);
                        vmx->nested.apic_access_page = NULL;
                }
                page = kvm_vcpu_gpa_to_page(vcpu, vmcs12->apic_access_addr);
                /*
                 * If translation failed, no matter: This feature asks
                 * to exit when accessing the given address, and if it
                 * can never be accessed, this feature won't do
                 * anything anyway.
                 */
                if (!is_error_page(page)) {
                        vmx->nested.apic_access_page = page;
                        hpa = page_to_phys(vmx->nested.apic_access_page);
                        vmcs_write64(APIC_ACCESS_ADDR, hpa);
                } else {
                        secondary_exec_controls_clearbit(vmx,
                                SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES);
                }
        }

        if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) {
                map = &vmx->nested.virtual_apic_map;

                if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->virtual_apic_page_addr), map)) {
                        vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, pfn_to_hpa(map->pfn));
                } else if (nested_cpu_has(vmcs12, CPU_BASED_CR8_LOAD_EXITING) &&
                           nested_cpu_has(vmcs12, CPU_BASED_CR8_STORE_EXITING) &&
                           !nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
                        /*
                         * The processor will never use the TPR shadow, simply
                         * clear the bit from the execution control.  Such a
                         * configuration is useless, but it happens in tests.
                         * For any other configuration, failing the vm entry is
                         * _not_ what the processor does but it's basically the
                         * only possibility we have.
                         */
                        exec_controls_clearbit(vmx, CPU_BASED_TPR_SHADOW);
                } else {
                        /*
                         * Write an illegal value to VIRTUAL_APIC_PAGE_ADDR to
                         * force VM-Entry to fail.
                         */
                        vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, -1ull);
                }
        }

        if (nested_cpu_has_posted_intr(vmcs12)) {
                map = &vmx->nested.pi_desc_map;

                if (!kvm_vcpu_map(vcpu, gpa_to_gfn(vmcs12->posted_intr_desc_addr), map)) {
                        vmx->nested.pi_desc =
                                (struct pi_desc *)(((void *)map->hva) +
                                offset_in_page(vmcs12->posted_intr_desc_addr));
                        vmcs_write64(POSTED_INTR_DESC_ADDR,
                                     pfn_to_hpa(map->pfn) + offset_in_page(vmcs12->posted_intr_desc_addr));
                }
        }
        if (nested_vmx_prepare_msr_bitmap(vcpu, vmcs12))
                exec_controls_setbit(vmx, CPU_BASED_USE_MSR_BITMAPS);
        else
                exec_controls_clearbit(vmx, CPU_BASED_USE_MSR_BITMAPS);
}

/*
 * Intel's VMX Instruction Reference specifies a common set of prerequisites
 * for running VMX instructions (except VMXON, whose prerequisites are
 * slightly different). It also specifies what exception to inject otherwise.
 * Note that many of these exceptions have priority over VM exits, so they
 * don't have to be checked again here.
 */
static int nested_vmx_check_permission(struct kvm_vcpu *vcpu)
{
        if (!to_vmx(vcpu)->nested.vmxon) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 0;
        }

        if (vmx_get_cpl(vcpu)) {
                kvm_inject_gp(vcpu, 0);
                return 0;
        }

        return 1;
}

static u8 vmx_has_apicv_interrupt(struct kvm_vcpu *vcpu)
{
        u8 rvi = vmx_get_rvi();
        u8 vppr = kvm_lapic_get_reg(vcpu->arch.apic, APIC_PROCPRI);

        return ((rvi & 0xf0) > (vppr & 0xf0));
}

static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
                                   struct vmcs12 *vmcs12);

/*
 * If from_vmentry is false, this is being called from state restore (either RSM
 * or KVM_SET_NESTED_STATE).  Otherwise it's called from vmlaunch/vmresume.
+ *
+ * Returns:
+ *   0 - success, i.e. proceed with actual VMEnter
+ *   1 - consistency check VMExit
+ *  -1 - consistency check VMFail
 */
int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, bool from_vmentry)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        bool evaluate_pending_interrupts;
        u32 exit_reason = EXIT_REASON_INVALID_STATE;
        u32 exit_qual;

        evaluate_pending_interrupts = exec_controls_get(vmx) &
                (CPU_BASED_VIRTUAL_INTR_PENDING | CPU_BASED_VIRTUAL_NMI_PENDING);
        if (likely(!evaluate_pending_interrupts) && kvm_vcpu_apicv_active(vcpu))
                evaluate_pending_interrupts |= vmx_has_apicv_interrupt(vcpu);

        if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS))
                vmx->nested.vmcs01_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);
        if (kvm_mpx_supported() &&
                !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
                vmx->nested.vmcs01_guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);

        /*
         * Overwrite vmcs01.GUEST_CR3 with L1's CR3 if EPT is disabled *and*
         * nested early checks are disabled.  In the event of a "late" VM-Fail,
         * i.e. a VM-Fail detected by hardware but not KVM, KVM must unwind its
         * software model to the pre-VMEntry host state.  When EPT is disabled,
         * GUEST_CR3 holds KVM's shadow CR3, not L1's "real" CR3, which causes
         * nested_vmx_restore_host_state() to corrupt vcpu->arch.cr3.  Stuffing
         * vmcs01.GUEST_CR3 results in the unwind naturally setting arch.cr3 to
         * the correct value.  Smashing vmcs01.GUEST_CR3 is safe because nested
         * VM-Exits, and the unwind, reset KVM's MMU, i.e. vmcs01.GUEST_CR3 is
         * guaranteed to be overwritten with a shadow CR3 prior to re-entering
         * L1.  Don't stuff vmcs01.GUEST_CR3 when using nested early checks as
         * KVM modifies vcpu->arch.cr3 if and only if the early hardware checks
         * pass, and early VM-Fails do not reset KVM's MMU, i.e. the VM-Fail
         * path would need to manually save/restore vmcs01.GUEST_CR3.
         */
        if (!enable_ept && !nested_early_check)
                vmcs_writel(GUEST_CR3, vcpu->arch.cr3);

        vmx_switch_vmcs(vcpu, &vmx->nested.vmcs02);

        prepare_vmcs02_early(vmx, vmcs12);

        if (from_vmentry) {
                nested_get_vmcs12_pages(vcpu);

                if (nested_vmx_check_vmentry_hw(vcpu)) {
                        vmx_switch_vmcs(vcpu, &vmx->vmcs01);
                        return -1;
                }

                if (nested_vmx_check_guest_state(vcpu, vmcs12, &exit_qual))
                        goto vmentry_fail_vmexit;
        }

        enter_guest_mode(vcpu);
        if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
                vcpu->arch.tsc_offset += vmcs12->tsc_offset;

        if (prepare_vmcs02(vcpu, vmcs12, &exit_qual))
                goto vmentry_fail_vmexit_guest_mode;

        if (from_vmentry) {
                exit_reason = EXIT_REASON_MSR_LOAD_FAIL;
                exit_qual = nested_vmx_load_msr(vcpu,
                                                vmcs12->vm_entry_msr_load_addr,
                                                vmcs12->vm_entry_msr_load_count);
                if (exit_qual)
                        goto vmentry_fail_vmexit_guest_mode;
        } else {
                /*
                 * The MMU is not initialized to point at the right entities yet and
                 * "get pages" would need to read data from the guest (i.e. we will
                 * need to perform gpa to hpa translation). Request a call
                 * to nested_get_vmcs12_pages before the next VM-entry.  The MSRs
                 * have already been set at vmentry time and should not be reset.
                 */
                kvm_make_request(KVM_REQ_GET_VMCS12_PAGES, vcpu);
        }

        /*
         * If L1 had a pending IRQ/NMI until it executed
         * VMLAUNCH/VMRESUME which wasn't delivered because it was
         * disallowed (e.g. interrupts disabled), L0 needs to
         * evaluate if this pending event should cause an exit from L2
         * to L1 or delivered directly to L2 (e.g. In case L1 don't
         * intercept EXTERNAL_INTERRUPT).
         *
         * Usually this would be handled by the processor noticing an
         * IRQ/NMI window request, or checking RVI during evaluation of
         * pending virtual interrupts.  However, this setting was done
         * on VMCS01 and now VMCS02 is active instead. Thus, we force L0
         * to perform pending event evaluation by requesting a KVM_REQ_EVENT.
         */
        if (unlikely(evaluate_pending_interrupts))
                kvm_make_request(KVM_REQ_EVENT, vcpu);

        /*
         * Do not start the preemption timer hrtimer until after we know
         * we are successful, so that only nested_vmx_vmexit needs to cancel
         * the timer.
         */
        vmx->nested.preemption_timer_expired = false;
        if (nested_cpu_has_preemption_timer(vmcs12))
                vmx_start_preemption_timer(vcpu);

        /*
         * Note no nested_vmx_succeed or nested_vmx_fail here. At this point
         * we are no longer running L1, and VMLAUNCH/VMRESUME has not yet
         * returned as far as L1 is concerned. It will only return (and set
         * the success flag) when L2 exits (see nested_vmx_vmexit()).
         */
        return 0;

        /*
         * A failed consistency check that leads to a VMExit during L1's
         * VMEnter to L2 is a variation of a normal VMexit, as explained in
         * 26.7 "VM-entry failures during or after loading guest state".
         */
vmentry_fail_vmexit_guest_mode:
        if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
                vcpu->arch.tsc_offset -= vmcs12->tsc_offset;
        leave_guest_mode(vcpu);

vmentry_fail_vmexit:
        vmx_switch_vmcs(vcpu, &vmx->vmcs01);

        if (!from_vmentry)
                return 1;

        load_vmcs12_host_state(vcpu, vmcs12);
        vmcs12->vm_exit_reason = exit_reason | VMX_EXIT_REASONS_FAILED_VMENTRY;
        vmcs12->exit_qualification = exit_qual;
        if (enable_shadow_vmcs || vmx->nested.hv_evmcs)
                vmx->nested.need_vmcs12_to_shadow_sync = true;
        return 1;
}

/*
 * nested_vmx_run() handles a nested entry, i.e., a VMLAUNCH or VMRESUME on L1
 * for running an L2 nested guest.
 */
static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
{
        struct vmcs12 *vmcs12;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 interrupt_shadow = vmx_get_interrupt_shadow(vcpu);
        int ret;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (!nested_vmx_handle_enlightened_vmptrld(vcpu, launch))
                return 1;

        if (!vmx->nested.hv_evmcs && vmx->nested.current_vmptr == -1ull)
                return nested_vmx_failInvalid(vcpu);

        vmcs12 = get_vmcs12(vcpu);

        /*
         * Can't VMLAUNCH or VMRESUME a shadow VMCS. Despite the fact
         * that there *is* a valid VMCS pointer, RFLAGS.CF is set
         * rather than RFLAGS.ZF, and no error number is stored to the
         * VM-instruction error field.
         */
        if (vmcs12->hdr.shadow_vmcs)
                return nested_vmx_failInvalid(vcpu);

        if (vmx->nested.hv_evmcs) {
                copy_enlightened_to_vmcs12(vmx);
                /* Enlightened VMCS doesn't have launch state */
                vmcs12->launch_state = !launch;
        } else if (enable_shadow_vmcs) {
                copy_shadow_to_vmcs12(vmx);
        }

        /*
         * The nested entry process starts with enforcing various prerequisites
         * on vmcs12 as required by the Intel SDM, and act appropriately when
         * they fail: As the SDM explains, some conditions should cause the
         * instruction to fail, while others will cause the instruction to seem
         * to succeed, but return an EXIT_REASON_INVALID_STATE.
         * To speed up the normal (success) code path, we should avoid checking
         * for misconfigurations which will anyway be caught by the processor
         * when using the merged vmcs02.
         */
        if (interrupt_shadow & KVM_X86_SHADOW_INT_MOV_SS)
                return nested_vmx_failValid(vcpu,
                        VMXERR_ENTRY_EVENTS_BLOCKED_BY_MOV_SS);

        if (vmcs12->launch_state == launch)
                return nested_vmx_failValid(vcpu,
                        launch ? VMXERR_VMLAUNCH_NONCLEAR_VMCS
                               : VMXERR_VMRESUME_NONLAUNCHED_VMCS);

        if (nested_vmx_check_controls(vcpu, vmcs12))
                return nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);

        if (nested_vmx_check_host_state(vcpu, vmcs12))
                return nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_HOST_STATE_FIELD);

        /*
         * We're finally done with prerequisite checking, and can start with
         * the nested entry.
         */
        vmx->nested.nested_run_pending = 1;
        ret = nested_vmx_enter_non_root_mode(vcpu, true);
        vmx->nested.nested_run_pending = !ret;
        if (ret > 0)
                return 1;
        else if (ret)
                return nested_vmx_failValid(vcpu,
                        VMXERR_ENTRY_INVALID_CONTROL_FIELD);

        /* Hide L1D cache contents from the nested guest.  */
        vmx->vcpu.arch.l1tf_flush_l1d = true;

        /*
         * Must happen outside of nested_vmx_enter_non_root_mode() as it will
         * also be used as part of restoring nVMX state for
         * snapshot restore (migration).
         *
         * In this flow, it is assumed that vmcs12 cache was
         * trasferred as part of captured nVMX state and should
         * therefore not be read from guest memory (which may not
         * exist on destination host yet).
         */
        nested_cache_shadow_vmcs12(vcpu, vmcs12);

        /*
         * If we're entering a halted L2 vcpu and the L2 vcpu won't be
         * awakened by event injection or by an NMI-window VM-exit or
         * by an interrupt-window VM-exit, halt the vcpu.
         */
        if ((vmcs12->guest_activity_state == GUEST_ACTIVITY_HLT) &&
            !(vmcs12->vm_entry_intr_info_field & INTR_INFO_VALID_MASK) &&
            !(vmcs12->cpu_based_vm_exec_control & CPU_BASED_VIRTUAL_NMI_PENDING) &&
            !((vmcs12->cpu_based_vm_exec_control & CPU_BASED_VIRTUAL_INTR_PENDING) &&
              (vmcs12->guest_rflags & X86_EFLAGS_IF))) {
                vmx->nested.nested_run_pending = 0;
                return kvm_vcpu_halt(vcpu);
        }
        return 1;
}

/*
 * On a nested exit from L2 to L1, vmcs12.guest_cr0 might not be up-to-date
 * because L2 may have changed some cr0 bits directly (CRO_GUEST_HOST_MASK).
 * This function returns the new value we should put in vmcs12.guest_cr0.
 * It's not enough to just return the vmcs02 GUEST_CR0. Rather,
 *  1. Bits that neither L0 nor L1 trapped, were set directly by L2 and are now
 *     available in vmcs02 GUEST_CR0. (Note: It's enough to check that L0
 *     didn't trap the bit, because if L1 did, so would L0).
 *  2. Bits that L1 asked to trap (and therefore L0 also did) could not have
 *     been modified by L2, and L1 knows it. So just leave the old value of
 *     the bit from vmcs12.guest_cr0. Note that the bit from vmcs02 GUEST_CR0
 *     isn't relevant, because if L0 traps this bit it can set it to anything.
 *  3. Bits that L1 didn't trap, but L0 did. L1 believes the guest could have
 *     changed these bits, and therefore they need to be updated, but L0
 *     didn't necessarily allow them to be changed in GUEST_CR0 - and rather
 *     put them in vmcs02 CR0_READ_SHADOW. So take these bits from there.
 */
static inline unsigned long
vmcs12_guest_cr0(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        return
        /*1*/   (vmcs_readl(GUEST_CR0) & vcpu->arch.cr0_guest_owned_bits) |
        /*2*/   (vmcs12->guest_cr0 & vmcs12->cr0_guest_host_mask) |
        /*3*/   (vmcs_readl(CR0_READ_SHADOW) & ~(vmcs12->cr0_guest_host_mask |
                        vcpu->arch.cr0_guest_owned_bits));
}

static inline unsigned long
vmcs12_guest_cr4(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        return
        /*1*/   (vmcs_readl(GUEST_CR4) & vcpu->arch.cr4_guest_owned_bits) |
        /*2*/   (vmcs12->guest_cr4 & vmcs12->cr4_guest_host_mask) |
        /*3*/   (vmcs_readl(CR4_READ_SHADOW) & ~(vmcs12->cr4_guest_host_mask |
                        vcpu->arch.cr4_guest_owned_bits));
}

static void vmcs12_save_pending_event(struct kvm_vcpu *vcpu,
                                      struct vmcs12 *vmcs12)
{
        u32 idt_vectoring;
        unsigned int nr;

        if (vcpu->arch.exception.injected) {
                nr = vcpu->arch.exception.nr;
                idt_vectoring = nr | VECTORING_INFO_VALID_MASK;

                if (kvm_exception_is_soft(nr)) {
                        vmcs12->vm_exit_instruction_len =
                                vcpu->arch.event_exit_inst_len;
                        idt_vectoring |= INTR_TYPE_SOFT_EXCEPTION;
                } else
                        idt_vectoring |= INTR_TYPE_HARD_EXCEPTION;

                if (vcpu->arch.exception.has_error_code) {
                        idt_vectoring |= VECTORING_INFO_DELIVER_CODE_MASK;
                        vmcs12->idt_vectoring_error_code =
                                vcpu->arch.exception.error_code;
                }

                vmcs12->idt_vectoring_info_field = idt_vectoring;
        } else if (vcpu->arch.nmi_injected) {
                vmcs12->idt_vectoring_info_field =
                        INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR;
        } else if (vcpu->arch.interrupt.injected) {
                nr = vcpu->arch.interrupt.nr;
                idt_vectoring = nr | VECTORING_INFO_VALID_MASK;

                if (vcpu->arch.interrupt.soft) {
                        idt_vectoring |= INTR_TYPE_SOFT_INTR;
                        vmcs12->vm_entry_instruction_len =
                                vcpu->arch.event_exit_inst_len;
                } else
                        idt_vectoring |= INTR_TYPE_EXT_INTR;

                vmcs12->idt_vectoring_info_field = idt_vectoring;
        }
}


static void nested_mark_vmcs12_pages_dirty(struct kvm_vcpu *vcpu)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        gfn_t gfn;

        /*
         * Don't need to mark the APIC access page dirty; it is never
         * written to by the CPU during APIC virtualization.
         */

        if (nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW)) {
                gfn = vmcs12->virtual_apic_page_addr >> PAGE_SHIFT;
                kvm_vcpu_mark_page_dirty(vcpu, gfn);
        }

        if (nested_cpu_has_posted_intr(vmcs12)) {
                gfn = vmcs12->posted_intr_desc_addr >> PAGE_SHIFT;
                kvm_vcpu_mark_page_dirty(vcpu, gfn);
        }
}

static void vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int max_irr;
        void *vapic_page;
        u16 status;

        if (!vmx->nested.pi_desc || !vmx->nested.pi_pending)
                return;

        vmx->nested.pi_pending = false;
        if (!pi_test_and_clear_on(vmx->nested.pi_desc))
                return;

        max_irr = find_last_bit((unsigned long *)vmx->nested.pi_desc->pir, 256);
        if (max_irr != 256) {
                vapic_page = vmx->nested.virtual_apic_map.hva;
                if (!vapic_page)
                        return;

                __kvm_apic_update_irr(vmx->nested.pi_desc->pir,
                        vapic_page, &max_irr);
                status = vmcs_read16(GUEST_INTR_STATUS);
                if ((u8)max_irr > ((u8)status & 0xff)) {
                        status &= ~0xff;
                        status |= (u8)max_irr;
                        vmcs_write16(GUEST_INTR_STATUS, status);
                }
        }

        nested_mark_vmcs12_pages_dirty(vcpu);
}

static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu,
                                               unsigned long exit_qual)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        unsigned int nr = vcpu->arch.exception.nr;
        u32 intr_info = nr | INTR_INFO_VALID_MASK;

        if (vcpu->arch.exception.has_error_code) {
                vmcs12->vm_exit_intr_error_code = vcpu->arch.exception.error_code;
                intr_info |= INTR_INFO_DELIVER_CODE_MASK;
        }

        if (kvm_exception_is_soft(nr))
                intr_info |= INTR_TYPE_SOFT_EXCEPTION;
        else
                intr_info |= INTR_TYPE_HARD_EXCEPTION;

        if (!(vmcs12->idt_vectoring_info_field & VECTORING_INFO_VALID_MASK) &&
            vmx_get_nmi_mask(vcpu))
                intr_info |= INTR_INFO_UNBLOCK_NMI;

        nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI, intr_info, exit_qual);
}

static int vmx_check_nested_events(struct kvm_vcpu *vcpu, bool external_intr)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long exit_qual;
        bool block_nested_events =
            vmx->nested.nested_run_pending || kvm_event_needs_reinjection(vcpu);

        if (vcpu->arch.exception.pending &&
                nested_vmx_check_exception(vcpu, &exit_qual)) {
                if (block_nested_events)
                        return -EBUSY;
                nested_vmx_inject_exception_vmexit(vcpu, exit_qual);
                return 0;
        }

        if (nested_cpu_has_preemption_timer(get_vmcs12(vcpu)) &&
            vmx->nested.preemption_timer_expired) {
                if (block_nested_events)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_PREEMPTION_TIMER, 0, 0);
                return 0;
        }

        if (vcpu->arch.nmi_pending && nested_exit_on_nmi(vcpu)) {
                if (block_nested_events)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_EXCEPTION_NMI,
                                  NMI_VECTOR | INTR_TYPE_NMI_INTR |
                                  INTR_INFO_VALID_MASK, 0);
                /*
                 * The NMI-triggered VM exit counts as injection:
                 * clear this one and block further NMIs.
                 */
                vcpu->arch.nmi_pending = 0;
                vmx_set_nmi_mask(vcpu, true);
                return 0;
        }

        if ((kvm_cpu_has_interrupt(vcpu) || external_intr) &&
            nested_exit_on_intr(vcpu)) {
                if (block_nested_events)
                        return -EBUSY;
                nested_vmx_vmexit(vcpu, EXIT_REASON_EXTERNAL_INTERRUPT, 0, 0);
                return 0;
        }

        vmx_complete_nested_posted_interrupt(vcpu);
        return 0;
}

static u32 vmx_get_preemption_timer_value(struct kvm_vcpu *vcpu)
{
        ktime_t remaining =
                hrtimer_get_remaining(&to_vmx(vcpu)->nested.preemption_timer);
        u64 value;

        if (ktime_to_ns(remaining) <= 0)
                return 0;

        value = ktime_to_ns(remaining) * vcpu->arch.virtual_tsc_khz;
        do_div(value, 1000000);
        return value >> VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE;
}

static bool is_vmcs12_ext_field(unsigned long field)
{
        switch (field) {
        case GUEST_ES_SELECTOR:
        case GUEST_CS_SELECTOR:
        case GUEST_SS_SELECTOR:
        case GUEST_DS_SELECTOR:
        case GUEST_FS_SELECTOR:
        case GUEST_GS_SELECTOR:
        case GUEST_LDTR_SELECTOR:
        case GUEST_TR_SELECTOR:
        case GUEST_ES_LIMIT:
        case GUEST_CS_LIMIT:
        case GUEST_SS_LIMIT:
        case GUEST_DS_LIMIT:
        case GUEST_FS_LIMIT:
        case GUEST_GS_LIMIT:
        case GUEST_LDTR_LIMIT:
        case GUEST_TR_LIMIT:
        case GUEST_GDTR_LIMIT:
        case GUEST_IDTR_LIMIT:
        case GUEST_ES_AR_BYTES:
        case GUEST_DS_AR_BYTES:
        case GUEST_FS_AR_BYTES:
        case GUEST_GS_AR_BYTES:
        case GUEST_LDTR_AR_BYTES:
        case GUEST_TR_AR_BYTES:
        case GUEST_ES_BASE:
        case GUEST_CS_BASE:
        case GUEST_SS_BASE:
        case GUEST_DS_BASE:
        case GUEST_FS_BASE:
        case GUEST_GS_BASE:
        case GUEST_LDTR_BASE:
        case GUEST_TR_BASE:
        case GUEST_GDTR_BASE:
        case GUEST_IDTR_BASE:
        case GUEST_PENDING_DBG_EXCEPTIONS:
        case GUEST_BNDCFGS:
                return true;
        default:
                break;
        }

        return false;
}

static void sync_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        vmcs12->guest_es_selector = vmcs_read16(GUEST_ES_SELECTOR);
        vmcs12->guest_cs_selector = vmcs_read16(GUEST_CS_SELECTOR);
        vmcs12->guest_ss_selector = vmcs_read16(GUEST_SS_SELECTOR);
        vmcs12->guest_ds_selector = vmcs_read16(GUEST_DS_SELECTOR);
        vmcs12->guest_fs_selector = vmcs_read16(GUEST_FS_SELECTOR);
        vmcs12->guest_gs_selector = vmcs_read16(GUEST_GS_SELECTOR);
        vmcs12->guest_ldtr_selector = vmcs_read16(GUEST_LDTR_SELECTOR);
        vmcs12->guest_tr_selector = vmcs_read16(GUEST_TR_SELECTOR);
        vmcs12->guest_es_limit = vmcs_read32(GUEST_ES_LIMIT);
        vmcs12->guest_cs_limit = vmcs_read32(GUEST_CS_LIMIT);
        vmcs12->guest_ss_limit = vmcs_read32(GUEST_SS_LIMIT);
        vmcs12->guest_ds_limit = vmcs_read32(GUEST_DS_LIMIT);
        vmcs12->guest_fs_limit = vmcs_read32(GUEST_FS_LIMIT);
        vmcs12->guest_gs_limit = vmcs_read32(GUEST_GS_LIMIT);
        vmcs12->guest_ldtr_limit = vmcs_read32(GUEST_LDTR_LIMIT);
        vmcs12->guest_tr_limit = vmcs_read32(GUEST_TR_LIMIT);
        vmcs12->guest_gdtr_limit = vmcs_read32(GUEST_GDTR_LIMIT);
        vmcs12->guest_idtr_limit = vmcs_read32(GUEST_IDTR_LIMIT);
        vmcs12->guest_es_ar_bytes = vmcs_read32(GUEST_ES_AR_BYTES);
        vmcs12->guest_ds_ar_bytes = vmcs_read32(GUEST_DS_AR_BYTES);
        vmcs12->guest_fs_ar_bytes = vmcs_read32(GUEST_FS_AR_BYTES);
        vmcs12->guest_gs_ar_bytes = vmcs_read32(GUEST_GS_AR_BYTES);
        vmcs12->guest_ldtr_ar_bytes = vmcs_read32(GUEST_LDTR_AR_BYTES);
        vmcs12->guest_tr_ar_bytes = vmcs_read32(GUEST_TR_AR_BYTES);
        vmcs12->guest_es_base = vmcs_readl(GUEST_ES_BASE);
        vmcs12->guest_cs_base = vmcs_readl(GUEST_CS_BASE);
        vmcs12->guest_ss_base = vmcs_readl(GUEST_SS_BASE);
        vmcs12->guest_ds_base = vmcs_readl(GUEST_DS_BASE);
        vmcs12->guest_fs_base = vmcs_readl(GUEST_FS_BASE);
        vmcs12->guest_gs_base = vmcs_readl(GUEST_GS_BASE);
        vmcs12->guest_ldtr_base = vmcs_readl(GUEST_LDTR_BASE);
        vmcs12->guest_tr_base = vmcs_readl(GUEST_TR_BASE);
        vmcs12->guest_gdtr_base = vmcs_readl(GUEST_GDTR_BASE);
        vmcs12->guest_idtr_base = vmcs_readl(GUEST_IDTR_BASE);
        vmcs12->guest_pending_dbg_exceptions =
                vmcs_readl(GUEST_PENDING_DBG_EXCEPTIONS);
        if (kvm_mpx_supported())
                vmcs12->guest_bndcfgs = vmcs_read64(GUEST_BNDCFGS);

        vmx->nested.need_sync_vmcs02_to_vmcs12_rare = false;
}

static void copy_vmcs02_to_vmcs12_rare(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int cpu;

        if (!vmx->nested.need_sync_vmcs02_to_vmcs12_rare)
                return;


        WARN_ON_ONCE(vmx->loaded_vmcs != &vmx->vmcs01);

        cpu = get_cpu();
        vmx->loaded_vmcs = &vmx->nested.vmcs02;
        vmx_vcpu_load(&vmx->vcpu, cpu);

        sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);

        vmx->loaded_vmcs = &vmx->vmcs01;
        vmx_vcpu_load(&vmx->vcpu, cpu);
        put_cpu();
}

/*
 * Update the guest state fields of vmcs12 to reflect changes that
 * occurred while L2 was running. (The "IA-32e mode guest" bit of the
 * VM-entry controls is also updated, since this is really a guest
 * state bit.)
 */
static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (vmx->nested.hv_evmcs)
                sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);

        vmx->nested.need_sync_vmcs02_to_vmcs12_rare = !vmx->nested.hv_evmcs;

        vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12);
        vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12);

        vmcs12->guest_rsp = kvm_rsp_read(vcpu);
        vmcs12->guest_rip = kvm_rip_read(vcpu);
        vmcs12->guest_rflags = vmcs_readl(GUEST_RFLAGS);

        vmcs12->guest_cs_ar_bytes = vmcs_read32(GUEST_CS_AR_BYTES);
        vmcs12->guest_ss_ar_bytes = vmcs_read32(GUEST_SS_AR_BYTES);

        vmcs12->guest_sysenter_cs = vmcs_read32(GUEST_SYSENTER_CS);
        vmcs12->guest_sysenter_esp = vmcs_readl(GUEST_SYSENTER_ESP);
        vmcs12->guest_sysenter_eip = vmcs_readl(GUEST_SYSENTER_EIP);

        vmcs12->guest_interruptibility_info =
                vmcs_read32(GUEST_INTERRUPTIBILITY_INFO);

        if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
                vmcs12->guest_activity_state = GUEST_ACTIVITY_HLT;
        else
                vmcs12->guest_activity_state = GUEST_ACTIVITY_ACTIVE;

        if (nested_cpu_has_preemption_timer(vmcs12) &&
            vmcs12->vm_exit_controls & VM_EXIT_SAVE_VMX_PREEMPTION_TIMER)
                        vmcs12->vmx_preemption_timer_value =
                                vmx_get_preemption_timer_value(vcpu);

        /*
         * In some cases (usually, nested EPT), L2 is allowed to change its
         * own CR3 without exiting. If it has changed it, we must keep it.
         * Of course, if L0 is using shadow page tables, GUEST_CR3 was defined
         * by L0, not L1 or L2, so we mustn't unconditionally copy it to vmcs12.
         *
         * Additionally, restore L2's PDPTR to vmcs12.
         */
        if (enable_ept) {
                vmcs12->guest_cr3 = vmcs_readl(GUEST_CR3);
                if (nested_cpu_has_ept(vmcs12) && is_pae_paging(vcpu)) {
                        vmcs12->guest_pdptr0 = vmcs_read64(GUEST_PDPTR0);
                        vmcs12->guest_pdptr1 = vmcs_read64(GUEST_PDPTR1);
                        vmcs12->guest_pdptr2 = vmcs_read64(GUEST_PDPTR2);
                        vmcs12->guest_pdptr3 = vmcs_read64(GUEST_PDPTR3);
                }
        }

        vmcs12->guest_linear_address = vmcs_readl(GUEST_LINEAR_ADDRESS);

        if (nested_cpu_has_vid(vmcs12))
                vmcs12->guest_intr_status = vmcs_read16(GUEST_INTR_STATUS);

        vmcs12->vm_entry_controls =
                (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) |
                (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);

        if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS)
                kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7);

        if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER)
                vmcs12->guest_ia32_efer = vcpu->arch.efer;
}

/*
 * prepare_vmcs12 is part of what we need to do when the nested L2 guest exits
 * and we want to prepare to run its L1 parent. L1 keeps a vmcs for L2 (vmcs12),
 * and this function updates it to reflect the changes to the guest state while
 * L2 was running (and perhaps made some exits which were handled directly by L0
 * without going back to L1), and to reflect the exit reason.
 * Note that we do not have to copy here all VMCS fields, just those that
 * could have changed by the L2 guest or the exit - i.e., the guest-state and
 * exit-information fields only. Other fields are modified by L1 with VMWRITE,
 * which already writes to vmcs12 directly.
 */
static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
                           u32 exit_reason, u32 exit_intr_info,
                           unsigned long exit_qualification)
{
        /* update exit information fields: */
        vmcs12->vm_exit_reason = exit_reason;
        vmcs12->exit_qualification = exit_qualification;
        vmcs12->vm_exit_intr_info = exit_intr_info;

        vmcs12->idt_vectoring_info_field = 0;
        vmcs12->vm_exit_instruction_len = vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
        vmcs12->vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

        if (!(vmcs12->vm_exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY)) {
                vmcs12->launch_state = 1;

                /* vm_entry_intr_info_field is cleared on exit. Emulate this
                 * instead of reading the real value. */
                vmcs12->vm_entry_intr_info_field &= ~INTR_INFO_VALID_MASK;

                /*
                 * Transfer the event that L0 or L1 may wanted to inject into
                 * L2 to IDT_VECTORING_INFO_FIELD.
                 */
                vmcs12_save_pending_event(vcpu, vmcs12);

                /*
                 * According to spec, there's no need to store the guest's
                 * MSRs if the exit is due to a VM-entry failure that occurs
                 * during or after loading the guest state. Since this exit
                 * does not fall in that category, we need to save the MSRs.
                 */
                if (nested_vmx_store_msr(vcpu,
                                         vmcs12->vm_exit_msr_store_addr,
                                         vmcs12->vm_exit_msr_store_count))
                        nested_vmx_abort(vcpu,
                                         VMX_ABORT_SAVE_GUEST_MSR_FAIL);
        }

        /*
         * Drop what we picked up for L2 via vmx_complete_interrupts. It is
         * preserved above and would only end up incorrectly in L1.
         */
        vcpu->arch.nmi_injected = false;
        kvm_clear_exception_queue(vcpu);
        kvm_clear_interrupt_queue(vcpu);
}

/*
 * A part of what we need to when the nested L2 guest exits and we want to
 * run its L1 parent, is to reset L1's guest state to the host state specified
 * in vmcs12.
 * This function is to be called not only on normal nested exit, but also on
 * a nested entry failure, as explained in Intel's spec, 3B.23.7 ("VM-Entry
 * Failures During or After Loading Guest State").
 * This function should be called when the active VMCS is L1's (vmcs01).
 */
static void load_vmcs12_host_state(struct kvm_vcpu *vcpu,
                                   struct vmcs12 *vmcs12)
{
        struct kvm_segment seg;
        u32 entry_failure_code;

        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_EFER)
                vcpu->arch.efer = vmcs12->host_ia32_efer;
        else if (vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE)
                vcpu->arch.efer |= (EFER_LMA | EFER_LME);
        else
                vcpu->arch.efer &= ~(EFER_LMA | EFER_LME);
        vmx_set_efer(vcpu, vcpu->arch.efer);

        kvm_rsp_write(vcpu, vmcs12->host_rsp);
        kvm_rip_write(vcpu, vmcs12->host_rip);
        vmx_set_rflags(vcpu, X86_EFLAGS_FIXED);
        vmx_set_interrupt_shadow(vcpu, 0);

        /*
         * Note that calling vmx_set_cr0 is important, even if cr0 hasn't
         * actually changed, because vmx_set_cr0 refers to efer set above.
         *
         * CR0_GUEST_HOST_MASK is already set in the original vmcs01
         * (KVM doesn't change it);
         */
        vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS;
        vmx_set_cr0(vcpu, vmcs12->host_cr0);

        /* Same as above - no reason to call set_cr4_guest_host_mask().  */
        vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK);
        vmx_set_cr4(vcpu, vmcs12->host_cr4);

        nested_ept_uninit_mmu_context(vcpu);

        /*
         * Only PDPTE load can fail as the value of cr3 was checked on entry and
         * couldn't have changed.
         */
        if (nested_vmx_load_cr3(vcpu, vmcs12->host_cr3, false, &entry_failure_code))
                nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_PDPTE_FAIL);

        if (!enable_ept)
                vcpu->arch.walk_mmu->inject_page_fault = kvm_inject_page_fault;

        /*
         * If vmcs01 doesn't use VPID, CPU flushes TLB on every
         * VMEntry/VMExit. Thus, no need to flush TLB.
         *
         * If vmcs12 doesn't use VPID, L1 expects TLB to be
         * flushed on every VMEntry/VMExit.
         *
         * Otherwise, we can preserve TLB entries as long as we are
         * able to tag L1 TLB entries differently than L2 TLB entries.
         *
         * If vmcs12 uses EPT, we need to execute this flush on EPTP01
         * and therefore we request the TLB flush to happen only after VMCS EPTP
         * has been set by KVM_REQ_LOAD_CR3.
         */
        if (enable_vpid &&
            (!nested_cpu_has_vpid(vmcs12) || !nested_has_guest_tlb_tag(vcpu))) {
                kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
        }

        vmcs_write32(GUEST_SYSENTER_CS, vmcs12->host_ia32_sysenter_cs);
        vmcs_writel(GUEST_SYSENTER_ESP, vmcs12->host_ia32_sysenter_esp);
        vmcs_writel(GUEST_SYSENTER_EIP, vmcs12->host_ia32_sysenter_eip);
        vmcs_writel(GUEST_IDTR_BASE, vmcs12->host_idtr_base);
        vmcs_writel(GUEST_GDTR_BASE, vmcs12->host_gdtr_base);
        vmcs_write32(GUEST_IDTR_LIMIT, 0xFFFF);
        vmcs_write32(GUEST_GDTR_LIMIT, 0xFFFF);

        /* If not VM_EXIT_CLEAR_BNDCFGS, the L2 value propagates to L1.  */
        if (vmcs12->vm_exit_controls & VM_EXIT_CLEAR_BNDCFGS)
                vmcs_write64(GUEST_BNDCFGS, 0);

        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PAT) {
                vmcs_write64(GUEST_IA32_PAT, vmcs12->host_ia32_pat);
                vcpu->arch.pat = vmcs12->host_ia32_pat;
        }
        if (vmcs12->vm_exit_controls & VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL)
                vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL,
                        vmcs12->host_ia32_perf_global_ctrl);

        /* Set L1 segment info according to Intel SDM
            27.5.2 Loading Host Segment and Descriptor-Table Registers */
        seg = (struct kvm_segment) {
                .base = 0,
                .limit = 0xFFFFFFFF,
                .selector = vmcs12->host_cs_selector,
                .type = 11,
                .present = 1,
                .s = 1,
                .g = 1
        };
        if (vmcs12->vm_exit_controls & VM_EXIT_HOST_ADDR_SPACE_SIZE)
                seg.l = 1;
        else
                seg.db = 1;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_CS);
        seg = (struct kvm_segment) {
                .base = 0,
                .limit = 0xFFFFFFFF,
                .type = 3,
                .present = 1,
                .s = 1,
                .db = 1,
                .g = 1
        };
        seg.selector = vmcs12->host_ds_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_DS);
        seg.selector = vmcs12->host_es_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_ES);
        seg.selector = vmcs12->host_ss_selector;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_SS);
        seg.selector = vmcs12->host_fs_selector;
        seg.base = vmcs12->host_fs_base;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_FS);
        seg.selector = vmcs12->host_gs_selector;
        seg.base = vmcs12->host_gs_base;
        vmx_set_segment(vcpu, &seg, VCPU_SREG_GS);
        seg = (struct kvm_segment) {
                .base = vmcs12->host_tr_base,
                .limit = 0x67,
                .selector = vmcs12->host_tr_selector,
                .type = 11,
                .present = 1
        };
        vmx_set_segment(vcpu, &seg, VCPU_SREG_TR);

        kvm_set_dr(vcpu, 7, 0x400);
        vmcs_write64(GUEST_IA32_DEBUGCTL, 0);

        if (cpu_has_vmx_msr_bitmap())
                vmx_update_msr_bitmap(vcpu);

        if (nested_vmx_load_msr(vcpu, vmcs12->vm_exit_msr_load_addr,
                                vmcs12->vm_exit_msr_load_count))
                nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_MSR_FAIL);
}

static inline u64 nested_vmx_get_vmcs01_guest_efer(struct vcpu_vmx *vmx)
{
        struct shared_msr_entry *efer_msr;
        unsigned int i;

        if (vm_entry_controls_get(vmx) & VM_ENTRY_LOAD_IA32_EFER)
                return vmcs_read64(GUEST_IA32_EFER);

        if (cpu_has_load_ia32_efer())
                return host_efer;

        for (i = 0; i < vmx->msr_autoload.guest.nr; ++i) {
                if (vmx->msr_autoload.guest.val[i].index == MSR_EFER)
                        return vmx->msr_autoload.guest.val[i].value;
        }

        efer_msr = find_msr_entry(vmx, MSR_EFER);
        if (efer_msr)
                return efer_msr->data;

        return host_efer;
}

static void nested_vmx_restore_host_state(struct kvm_vcpu *vcpu)
{
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmx_msr_entry g, h;
        gpa_t gpa;
        u32 i, j;

        vcpu->arch.pat = vmcs_read64(GUEST_IA32_PAT);

        if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) {
                /*
                 * L1's host DR7 is lost if KVM_GUESTDBG_USE_HW_BP is set
                 * as vmcs01.GUEST_DR7 contains a userspace defined value
                 * and vcpu->arch.dr7 is not squirreled away before the
                 * nested VMENTER (not worth adding a variable in nested_vmx).
                 */
                if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
                        kvm_set_dr(vcpu, 7, DR7_FIXED_1);
                else
                        WARN_ON(kvm_set_dr(vcpu, 7, vmcs_readl(GUEST_DR7)));
        }

        /*
         * Note that calling vmx_set_{efer,cr0,cr4} is important as they
         * handle a variety of side effects to KVM's software model.
         */
        vmx_set_efer(vcpu, nested_vmx_get_vmcs01_guest_efer(vmx));

        vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS;
        vmx_set_cr0(vcpu, vmcs_readl(CR0_READ_SHADOW));

        vcpu->arch.cr4_guest_owned_bits = ~vmcs_readl(CR4_GUEST_HOST_MASK);
        vmx_set_cr4(vcpu, vmcs_readl(CR4_READ_SHADOW));

        nested_ept_uninit_mmu_context(vcpu);
        vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
        __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);

        /*
         * Use ept_save_pdptrs(vcpu) to load the MMU's cached PDPTRs
         * from vmcs01 (if necessary).  The PDPTRs are not loaded on
         * VMFail, like everything else we just need to ensure our
         * software model is up-to-date.
         */
        if (enable_ept)
                ept_save_pdptrs(vcpu);

        kvm_mmu_reset_context(vcpu);

        if (cpu_has_vmx_msr_bitmap())
                vmx_update_msr_bitmap(vcpu);

        /*
         * This nasty bit of open coding is a compromise between blindly
         * loading L1's MSRs using the exit load lists (incorrect emulation
         * of VMFail), leaving the nested VM's MSRs in the software model
         * (incorrect behavior) and snapshotting the modified MSRs (too
         * expensive since the lists are unbound by hardware).  For each
         * MSR that was (prematurely) loaded from the nested VMEntry load
         * list, reload it from the exit load list if it exists and differs
         * from the guest value.  The intent is to stuff host state as
         * silently as possible, not to fully process the exit load list.
         */
        for (i = 0; i < vmcs12->vm_entry_msr_load_count; i++) {
                gpa = vmcs12->vm_entry_msr_load_addr + (i * sizeof(g));
                if (kvm_vcpu_read_guest(vcpu, gpa, &g, sizeof(g))) {
                        pr_debug_ratelimited(
                                "%s read MSR index failed (%u, 0x%08llx)\n",
                                __func__, i, gpa);
                        goto vmabort;
                }

                for (j = 0; j < vmcs12->vm_exit_msr_load_count; j++) {
                        gpa = vmcs12->vm_exit_msr_load_addr + (j * sizeof(h));
                        if (kvm_vcpu_read_guest(vcpu, gpa, &h, sizeof(h))) {
                                pr_debug_ratelimited(
                                        "%s read MSR failed (%u, 0x%08llx)\n",
                                        __func__, j, gpa);
                                goto vmabort;
                        }
                        if (h.index != g.index)
                                continue;
                        if (h.value == g.value)
                                break;

                        if (nested_vmx_load_msr_check(vcpu, &h)) {
                                pr_debug_ratelimited(
                                        "%s check failed (%u, 0x%x, 0x%x)\n",
                                        __func__, j, h.index, h.reserved);
                                goto vmabort;
                        }

                        if (kvm_set_msr(vcpu, h.index, h.value)) {
                                pr_debug_ratelimited(
                                        "%s WRMSR failed (%u, 0x%x, 0x%llx)\n",
                                        __func__, j, h.index, h.value);
                                goto vmabort;
                        }
                }
        }

        return;

vmabort:
        nested_vmx_abort(vcpu, VMX_ABORT_LOAD_HOST_MSR_FAIL);
}

/*
 * Emulate an exit from nested guest (L2) to L1, i.e., prepare to run L1
 * and modify vmcs12 to make it see what it would expect to see there if
 * L2 was its real guest. Must only be called when in L2 (is_guest_mode())
 */
void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason,
                       u32 exit_intr_info, unsigned long exit_qualification)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        /* trying to cancel vmlaunch/vmresume is a bug */
        WARN_ON_ONCE(vmx->nested.nested_run_pending);

        leave_guest_mode(vcpu);

        if (nested_cpu_has_preemption_timer(vmcs12))
                hrtimer_cancel(&to_vmx(vcpu)->nested.preemption_timer);

        if (vmcs12->cpu_based_vm_exec_control & CPU_BASED_USE_TSC_OFFSETING)
                vcpu->arch.tsc_offset -= vmcs12->tsc_offset;

        if (likely(!vmx->fail)) {
                sync_vmcs02_to_vmcs12(vcpu, vmcs12);

                if (exit_reason != -1)
                        prepare_vmcs12(vcpu, vmcs12, exit_reason, exit_intr_info,
                                       exit_qualification);

                /*
                 * Must happen outside of sync_vmcs02_to_vmcs12() as it will
                 * also be used to capture vmcs12 cache as part of
                 * capturing nVMX state for snapshot (migration).
                 *
                 * Otherwise, this flush will dirty guest memory at a
                 * point it is already assumed by user-space to be
                 * immutable.
                 */
                nested_flush_cached_shadow_vmcs12(vcpu, vmcs12);
        } else {
                /*
                 * The only expected VM-instruction error is "VM entry with
                 * invalid control field(s)." Anything else indicates a
                 * problem with L0.  And we should never get here with a
                 * VMFail of any type if early consistency checks are enabled.
                 */
                WARN_ON_ONCE(vmcs_read32(VM_INSTRUCTION_ERROR) !=
                             VMXERR_ENTRY_INVALID_CONTROL_FIELD);
                WARN_ON_ONCE(nested_early_check);
        }

        vmx_switch_vmcs(vcpu, &vmx->vmcs01);

        /* Update any VMCS fields that might have changed while L2 ran */
        vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
        vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);
        vmcs_write64(TSC_OFFSET, vcpu->arch.tsc_offset);

        if (kvm_has_tsc_control)
                decache_tsc_multiplier(vmx);

        if (vmx->nested.change_vmcs01_virtual_apic_mode) {
                vmx->nested.change_vmcs01_virtual_apic_mode = false;
                vmx_set_virtual_apic_mode(vcpu);
        } else if (!nested_cpu_has_ept(vmcs12) &&
                   nested_cpu_has2(vmcs12,
                                   SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) {
                vmx_flush_tlb(vcpu, true);
        }

        /* Unpin physical memory we referred to in vmcs02 */
        if (vmx->nested.apic_access_page) {
                kvm_release_page_dirty(vmx->nested.apic_access_page);
                vmx->nested.apic_access_page = NULL;
        }
        kvm_vcpu_unmap(vcpu, &vmx->nested.virtual_apic_map, true);
        kvm_vcpu_unmap(vcpu, &vmx->nested.pi_desc_map, true);
        vmx->nested.pi_desc = NULL;

        /*
         * We are now running in L2, mmu_notifier will force to reload the
         * page's hpa for L2 vmcs. Need to reload it for L1 before entering L1.
         */
        kvm_make_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu);

        if ((exit_reason != -1) && (enable_shadow_vmcs || vmx->nested.hv_evmcs))
                vmx->nested.need_vmcs12_to_shadow_sync = true;

        /* in case we halted in L2 */
        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

        if (likely(!vmx->fail)) {
                /*
                 * TODO: SDM says that with acknowledge interrupt on
                 * exit, bit 31 of the VM-exit interrupt information
                 * (valid interrupt) is always set to 1 on
                 * EXIT_REASON_EXTERNAL_INTERRUPT, so we shouldn't
                 * need kvm_cpu_has_interrupt().  See the commit
                 * message for details.
                 */
                if (nested_exit_intr_ack_set(vcpu) &&
                    exit_reason == EXIT_REASON_EXTERNAL_INTERRUPT &&
                    kvm_cpu_has_interrupt(vcpu)) {
                        int irq = kvm_cpu_get_interrupt(vcpu);
                        WARN_ON(irq < 0);
                        vmcs12->vm_exit_intr_info = irq |
                                INTR_INFO_VALID_MASK | INTR_TYPE_EXT_INTR;
                }

                if (exit_reason != -1)
                        trace_kvm_nested_vmexit_inject(vmcs12->vm_exit_reason,
                                                       vmcs12->exit_qualification,
                                                       vmcs12->idt_vectoring_info_field,
                                                       vmcs12->vm_exit_intr_info,
                                                       vmcs12->vm_exit_intr_error_code,
                                                       KVM_ISA_VMX);

                load_vmcs12_host_state(vcpu, vmcs12);

                return;
        }

        /*
         * After an early L2 VM-entry failure, we're now back
         * in L1 which thinks it just finished a VMLAUNCH or
         * VMRESUME instruction, so we need to set the failure
         * flag and the VM-instruction error field of the VMCS
         * accordingly, and skip the emulated instruction.
         */
        (void)nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);

        /*
         * Restore L1's host state to KVM's software model.  We're here
         * because a consistency check was caught by hardware, which
         * means some amount of guest state has been propagated to KVM's
         * model and needs to be unwound to the host's state.
         */
        nested_vmx_restore_host_state(vcpu);

        vmx->fail = 0;
}

/*
 * Decode the memory-address operand of a vmx instruction, as recorded on an
 * exit caused by such an instruction (run by a guest hypervisor).
 * On success, returns 0. When the operand is invalid, returns 1 and throws
 * #UD or #GP.
 */
int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
                        u32 vmx_instruction_info, bool wr, int len, gva_t *ret)
{
        gva_t off;
        bool exn;
        struct kvm_segment s;

        /*
         * According to Vol. 3B, "Information for VM Exits Due to Instruction
         * Execution", on an exit, vmx_instruction_info holds most of the
         * addressing components of the operand. Only the displacement part
         * is put in exit_qualification (see 3B, "Basic VM-Exit Information").
         * For how an actual address is calculated from all these components,
         * refer to Vol. 1, "Operand Addressing".
         */
        int  scaling = vmx_instruction_info & 3;
        int  addr_size = (vmx_instruction_info >> 7) & 7;
        bool is_reg = vmx_instruction_info & (1u << 10);
        int  seg_reg = (vmx_instruction_info >> 15) & 7;
        int  index_reg = (vmx_instruction_info >> 18) & 0xf;
        bool index_is_valid = !(vmx_instruction_info & (1u << 22));
        int  base_reg       = (vmx_instruction_info >> 23) & 0xf;
        bool base_is_valid  = !(vmx_instruction_info & (1u << 27));

        if (is_reg) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        /* Addr = segment_base + offset */
        /* offset = base + [index * scale] + displacement */
        off = exit_qualification; /* holds the displacement */
        if (addr_size == 1)
                off = (gva_t)sign_extend64(off, 31);
        else if (addr_size == 0)
                off = (gva_t)sign_extend64(off, 15);
        if (base_is_valid)
                off += kvm_register_read(vcpu, base_reg);
        if (index_is_valid)
                off += kvm_register_read(vcpu, index_reg)<<scaling;
        vmx_get_segment(vcpu, &s, seg_reg);

        /*
         * The effective address, i.e. @off, of a memory operand is truncated
         * based on the address size of the instruction.  Note that this is
         * the *effective address*, i.e. the address prior to accounting for
         * the segment's base.
         */
        if (addr_size == 1) /* 32 bit */
                off &= 0xffffffff;
        else if (addr_size == 0) /* 16 bit */
                off &= 0xffff;

        /* Checks for #GP/#SS exceptions. */
        exn = false;
        if (is_long_mode(vcpu)) {
                /*
                 * The virtual/linear address is never truncated in 64-bit
                 * mode, e.g. a 32-bit address size can yield a 64-bit virtual
                 * address when using FS/GS with a non-zero base.
                 */
                if (seg_reg == VCPU_SREG_FS || seg_reg == VCPU_SREG_GS)
                        *ret = s.base + off;
                else
                        *ret = off;

                /* Long mode: #GP(0)/#SS(0) if the memory address is in a
                 * non-canonical form. This is the only check on the memory
                 * destination for long mode!
                 */
                exn = is_noncanonical_address(*ret, vcpu);
        } else {
                /*
                 * When not in long mode, the virtual/linear address is
                 * unconditionally truncated to 32 bits regardless of the
                 * address size.
                 */
                *ret = (s.base + off) & 0xffffffff;

                /* Protected mode: apply checks for segment validity in the
                 * following order:
                 * - segment type check (#GP(0) may be thrown)
                 * - usability check (#GP(0)/#SS(0))
                 * - limit check (#GP(0)/#SS(0))
                 */
                if (wr)
                        /* #GP(0) if the destination operand is located in a
                         * read-only data segment or any code segment.
                         */
                        exn = ((s.type & 0xa) == 0 || (s.type & 8));
                else
                        /* #GP(0) if the source operand is located in an
                         * execute-only code segment
                         */
                        exn = ((s.type & 0xa) == 8);
                if (exn) {
                        kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
                        return 1;
                }
                /* Protected mode: #GP(0)/#SS(0) if the segment is unusable.
                 */
                exn = (s.unusable != 0);

                /*
                 * Protected mode: #GP(0)/#SS(0) if the memory operand is
                 * outside the segment limit.  All CPUs that support VMX ignore
                 * limit checks for flat segments, i.e. segments with base==0,
                 * limit==0xffffffff and of type expand-up data or code.
                 */
                if (!(s.base == 0 && s.limit == 0xffffffff &&
                     ((s.type & 8) || !(s.type & 4))))
                        exn = exn || ((u64)off + len - 1 > s.limit);
        }
        if (exn) {
                kvm_queue_exception_e(vcpu,
                                      seg_reg == VCPU_SREG_SS ?
                                                SS_VECTOR : GP_VECTOR,
                                      0);
                return 1;
        }

        return 0;
}

static int nested_vmx_get_vmptr(struct kvm_vcpu *vcpu, gpa_t *vmpointer)
{
        gva_t gva;
        struct x86_exception e;

        if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
                                vmcs_read32(VMX_INSTRUCTION_INFO), false,
                                sizeof(*vmpointer), &gva))
                return 1;

        if (kvm_read_guest_virt(vcpu, gva, vmpointer, sizeof(*vmpointer), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }

        return 0;
}

/*
 * Allocate a shadow VMCS and associate it with the currently loaded
 * VMCS, unless such a shadow VMCS already exists. The newly allocated
 * VMCS is also VMCLEARed, so that it is ready for use.
 */
static struct vmcs *alloc_shadow_vmcs(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct loaded_vmcs *loaded_vmcs = vmx->loaded_vmcs;

        /*
         * We should allocate a shadow vmcs for vmcs01 only when L1
         * executes VMXON and free it when L1 executes VMXOFF.
         * As it is invalid to execute VMXON twice, we shouldn't reach
         * here when vmcs01 already have an allocated shadow vmcs.
         */
        WARN_ON(loaded_vmcs == &vmx->vmcs01 && loaded_vmcs->shadow_vmcs);

        if (!loaded_vmcs->shadow_vmcs) {
                loaded_vmcs->shadow_vmcs = alloc_vmcs(true);
                if (loaded_vmcs->shadow_vmcs)
                        vmcs_clear(loaded_vmcs->shadow_vmcs);
        }
        return loaded_vmcs->shadow_vmcs;
}

static int enter_vmx_operation(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        int r;

        r = alloc_loaded_vmcs(&vmx->nested.vmcs02);
        if (r < 0)
                goto out_vmcs02;

        vmx->nested.cached_vmcs12 = kzalloc(VMCS12_SIZE, GFP_KERNEL_ACCOUNT);
        if (!vmx->nested.cached_vmcs12)
                goto out_cached_vmcs12;

        vmx->nested.cached_shadow_vmcs12 = kzalloc(VMCS12_SIZE, GFP_KERNEL_ACCOUNT);
        if (!vmx->nested.cached_shadow_vmcs12)
                goto out_cached_shadow_vmcs12;

        if (enable_shadow_vmcs && !alloc_shadow_vmcs(vcpu))
                goto out_shadow_vmcs;

        hrtimer_init(&vmx->nested.preemption_timer, CLOCK_MONOTONIC,
                     HRTIMER_MODE_REL_PINNED);
        vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;

        vmx->nested.vpid02 = allocate_vpid();

        vmx->nested.vmcs02_initialized = false;
        vmx->nested.vmxon = true;

        if (pt_mode == PT_MODE_HOST_GUEST) {
                vmx->pt_desc.guest.ctl = 0;
                pt_update_intercept_for_msr(vmx);
        }

        return 0;

out_shadow_vmcs:
        kfree(vmx->nested.cached_shadow_vmcs12);

out_cached_shadow_vmcs12:
        kfree(vmx->nested.cached_vmcs12);

out_cached_vmcs12:
        free_loaded_vmcs(&vmx->nested.vmcs02);

out_vmcs02:
        return -ENOMEM;
}

/*
 * Emulate the VMXON instruction.
 * Currently, we just remember that VMX is active, and do not save or even
 * inspect the argument to VMXON (the so-called "VMXON pointer") because we
 * do not currently need to store anything in that guest-allocated memory
 * region. Consequently, VMCLEAR and VMPTRLD also do not verify that the their
 * argument is different from the VMXON pointer (which the spec says they do).
 */
static int handle_vmon(struct kvm_vcpu *vcpu)
{
        int ret;
        gpa_t vmptr;
        uint32_t revision;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
                | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;

        /*
         * The Intel VMX Instruction Reference lists a bunch of bits that are
         * prerequisite to running VMXON, most notably cr4.VMXE must be set to
         * 1 (see vmx_set_cr4() for when we allow the guest to set this).
         * Otherwise, we should fail with #UD.  But most faulting conditions
         * have already been checked by hardware, prior to the VM-exit for
         * VMXON.  We do test guest cr4.VMXE because processor CR4 always has
         * that bit set to 1 in non-root mode.
         */
        if (!kvm_read_cr4_bits(vcpu, X86_CR4_VMXE)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        /* CPL=0 must be checked manually. */
        if (vmx_get_cpl(vcpu)) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        if (vmx->nested.vmxon)
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMXON_IN_VMX_ROOT_OPERATION);

        if ((vmx->msr_ia32_feature_control & VMXON_NEEDED_FEATURES)
                        != VMXON_NEEDED_FEATURES) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        if (nested_vmx_get_vmptr(vcpu, &vmptr))
                return 1;

        /*
         * SDM 3: 24.11.5
         * The first 4 bytes of VMXON region contain the supported
         * VMCS revision identifier
         *
         * Note - IA32_VMX_BASIC[48] will never be 1 for the nested case;
         * which replaces physical address width with 32
         */
        if (!page_address_valid(vcpu, vmptr))
                return nested_vmx_failInvalid(vcpu);

        if (kvm_read_guest(vcpu->kvm, vmptr, &revision, sizeof(revision)) ||
            revision != VMCS12_REVISION)
                return nested_vmx_failInvalid(vcpu);

        vmx->nested.vmxon_ptr = vmptr;
        ret = enter_vmx_operation(vcpu);
        if (ret)
                return ret;

        return nested_vmx_succeed(vcpu);
}

static inline void nested_release_vmcs12(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);

        if (vmx->nested.current_vmptr == -1ull)
                return;

        copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu));

        if (enable_shadow_vmcs) {
                /* copy to memory all shadowed fields in case
                   they were modified */
                copy_shadow_to_vmcs12(vmx);
                vmx_disable_shadow_vmcs(vmx);
        }
        vmx->nested.posted_intr_nv = -1;

        /* Flush VMCS12 to guest memory */
        kvm_vcpu_write_guest_page(vcpu,
                                  vmx->nested.current_vmptr >> PAGE_SHIFT,
                                  vmx->nested.cached_vmcs12, 0, VMCS12_SIZE);

        kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);

        vmx->nested.current_vmptr = -1ull;
}

/* Emulate the VMXOFF instruction */
static int handle_vmoff(struct kvm_vcpu *vcpu)
{
        if (!nested_vmx_check_permission(vcpu))
                return 1;
        free_nested(vcpu);
        return nested_vmx_succeed(vcpu);
}

/* Emulate the VMCLEAR instruction */
static int handle_vmclear(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 zero = 0;
        gpa_t vmptr;
        u64 evmcs_gpa;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (nested_vmx_get_vmptr(vcpu, &vmptr))
                return 1;

        if (!page_address_valid(vcpu, vmptr))
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMCLEAR_INVALID_ADDRESS);

        if (vmptr == vmx->nested.vmxon_ptr)
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMCLEAR_VMXON_POINTER);

        /*
         * When Enlightened VMEntry is enabled on the calling CPU we treat
         * memory area pointer by vmptr as Enlightened VMCS (as there's no good
         * way to distinguish it from VMCS12) and we must not corrupt it by
         * writing to the non-existent 'launch_state' field. The area doesn't
         * have to be the currently active EVMCS on the calling CPU and there's
         * nothing KVM has to do to transition it from 'active' to 'non-active'
         * state. It is possible that the area will stay mapped as
         * vmx->nested.hv_evmcs but this shouldn't be a problem.
         */
        if (likely(!vmx->nested.enlightened_vmcs_enabled ||
                   !nested_enlightened_vmentry(vcpu, &evmcs_gpa))) {
                if (vmptr == vmx->nested.current_vmptr)
                        nested_release_vmcs12(vcpu);

                kvm_vcpu_write_guest(vcpu,
                                     vmptr + offsetof(struct vmcs12,
                                                      launch_state),
                                     &zero, sizeof(zero));
        }

        return nested_vmx_succeed(vcpu);
}

static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch);

/* Emulate the VMLAUNCH instruction */
static int handle_vmlaunch(struct kvm_vcpu *vcpu)
{
        return nested_vmx_run(vcpu, true);
}

/* Emulate the VMRESUME instruction */
static int handle_vmresume(struct kvm_vcpu *vcpu)
{

        return nested_vmx_run(vcpu, false);
}

static int handle_vmread(struct kvm_vcpu *vcpu)
{
        unsigned long field;
        u64 field_value;
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        int len;
        gva_t gva = 0;
        struct vmcs12 *vmcs12;
        short offset;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (to_vmx(vcpu)->nested.current_vmptr == -1ull)
                return nested_vmx_failInvalid(vcpu);

        if (!is_guest_mode(vcpu))
                vmcs12 = get_vmcs12(vcpu);
        else {
                /*
                 * When vmcs->vmcs_link_pointer is -1ull, any VMREAD
                 * to shadowed-field sets the ALU flags for VMfailInvalid.
                 */
                if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)
                        return nested_vmx_failInvalid(vcpu);
                vmcs12 = get_shadow_vmcs12(vcpu);
        }

        /* Decode instruction info and find the field to read */
        field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

        offset = vmcs_field_to_offset(field);
        if (offset < 0)
                return nested_vmx_failValid(vcpu,
                        VMXERR_UNSUPPORTED_VMCS_COMPONENT);

        if (!is_guest_mode(vcpu) && is_vmcs12_ext_field(field))
                copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);

        /* Read the field, zero-extended to a u64 field_value */
        field_value = vmcs12_read_any(vmcs12, field, offset);

        /*
         * Now copy part of this value to register or memory, as requested.
         * Note that the number of bits actually copied is 32 or 64 depending
         * on the guest's mode (32 or 64 bit), not on the given field's length.
         */
        if (vmx_instruction_info & (1u << 10)) {
                kvm_register_writel(vcpu, (((vmx_instruction_info) >> 3) & 0xf),
                        field_value);
        } else {
                len = is_64_bit_mode(vcpu) ? 8 : 4;
                if (get_vmx_mem_address(vcpu, exit_qualification,
                                vmx_instruction_info, true, len, &gva))
                        return 1;
                /* _system ok, nested_vmx_check_permission has verified cpl=0 */
                kvm_write_guest_virt_system(vcpu, gva, &field_value, len, NULL);
        }

        return nested_vmx_succeed(vcpu);
}

static bool is_shadow_field_rw(unsigned long field)
{
        switch (field) {
#define SHADOW_FIELD_RW(x, y) case x:
#include "vmcs_shadow_fields.h"
                return true;
        default:
                break;
        }
        return false;
}

static bool is_shadow_field_ro(unsigned long field)
{
        switch (field) {
#define SHADOW_FIELD_RO(x, y) case x:
#include "vmcs_shadow_fields.h"
                return true;
        default:
                break;
        }
        return false;
}

static int handle_vmwrite(struct kvm_vcpu *vcpu)
{
        unsigned long field;
        int len;
        gva_t gva;
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);

        /* The value to write might be 32 or 64 bits, depending on L1's long
         * mode, and eventually we need to write that into a field of several
         * possible lengths. The code below first zero-extends the value to 64
         * bit (field_value), and then copies only the appropriate number of
         * bits into the vmcs12 field.
         */
        u64 field_value = 0;
        struct x86_exception e;
        struct vmcs12 *vmcs12;
        short offset;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (vmx->nested.current_vmptr == -1ull)
                return nested_vmx_failInvalid(vcpu);

        if (vmx_instruction_info & (1u << 10))
                field_value = kvm_register_readl(vcpu,
                        (((vmx_instruction_info) >> 3) & 0xf));
        else {
                len = is_64_bit_mode(vcpu) ? 8 : 4;
                if (get_vmx_mem_address(vcpu, exit_qualification,
                                vmx_instruction_info, false, len, &gva))
                        return 1;
                if (kvm_read_guest_virt(vcpu, gva, &field_value, len, &e)) {
                        kvm_inject_page_fault(vcpu, &e);
                        return 1;
                }
        }


        field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
        /*
         * If the vCPU supports "VMWRITE to any supported field in the
         * VMCS," then the "read-only" fields are actually read/write.
         */
        if (vmcs_field_readonly(field) &&
            !nested_cpu_has_vmwrite_any_field(vcpu))
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);

        if (!is_guest_mode(vcpu)) {
                vmcs12 = get_vmcs12(vcpu);

                /*
                 * Ensure vmcs12 is up-to-date before any VMWRITE that dirties
                 * vmcs12, else we may crush a field or consume a stale value.
                 */
                if (!is_shadow_field_rw(field))
                        copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
        } else {
                /*
                 * When vmcs->vmcs_link_pointer is -1ull, any VMWRITE
                 * to shadowed-field sets the ALU flags for VMfailInvalid.
                 */
                if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)
                        return nested_vmx_failInvalid(vcpu);
                vmcs12 = get_shadow_vmcs12(vcpu);
        }

        offset = vmcs_field_to_offset(field);
        if (offset < 0)
                return nested_vmx_failValid(vcpu,
                        VMXERR_UNSUPPORTED_VMCS_COMPONENT);

        /*
         * Some Intel CPUs intentionally drop the reserved bits of the AR byte
         * fields on VMWRITE.  Emulate this behavior to ensure consistent KVM
         * behavior regardless of the underlying hardware, e.g. if an AR_BYTE
         * field is intercepted for VMWRITE but not VMREAD (in L1), then VMREAD
         * from L1 will return a different value than VMREAD from L2 (L1 sees
         * the stripped down value, L2 sees the full value as stored by KVM).
         */
        if (field >= GUEST_ES_AR_BYTES && field <= GUEST_TR_AR_BYTES)
                field_value &= 0x1f0ff;

        vmcs12_write_any(vmcs12, field, offset, field_value);

        /*
         * Do not track vmcs12 dirty-state if in guest-mode as we actually
         * dirty shadow vmcs12 instead of vmcs12.  Fields that can be updated
         * by L1 without a vmexit are always updated in the vmcs02, i.e. don't
         * "dirty" vmcs12, all others go down the prepare_vmcs02() slow path.
         */
        if (!is_guest_mode(vcpu) && !is_shadow_field_rw(field)) {
                /*
                 * L1 can read these fields without exiting, ensure the
                 * shadow VMCS is up-to-date.
                 */
                if (enable_shadow_vmcs && is_shadow_field_ro(field)) {
                        preempt_disable();
                        vmcs_load(vmx->vmcs01.shadow_vmcs);

                        __vmcs_writel(field, field_value);

                        vmcs_clear(vmx->vmcs01.shadow_vmcs);
                        vmcs_load(vmx->loaded_vmcs->vmcs);
                        preempt_enable();
                }
                vmx->nested.dirty_vmcs12 = true;
        }

        return nested_vmx_succeed(vcpu);
}

static void set_current_vmptr(struct vcpu_vmx *vmx, gpa_t vmptr)
{
        vmx->nested.current_vmptr = vmptr;
        if (enable_shadow_vmcs) {
                secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_SHADOW_VMCS);
                vmcs_write64(VMCS_LINK_POINTER,
                             __pa(vmx->vmcs01.shadow_vmcs));
                vmx->nested.need_vmcs12_to_shadow_sync = true;
        }
        vmx->nested.dirty_vmcs12 = true;
}

/* Emulate the VMPTRLD instruction */
static int handle_vmptrld(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        gpa_t vmptr;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (nested_vmx_get_vmptr(vcpu, &vmptr))
                return 1;

        if (!page_address_valid(vcpu, vmptr))
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMPTRLD_INVALID_ADDRESS);

        if (vmptr == vmx->nested.vmxon_ptr)
                return nested_vmx_failValid(vcpu,
                        VMXERR_VMPTRLD_VMXON_POINTER);

        /* Forbid normal VMPTRLD if Enlightened version was used */
        if (vmx->nested.hv_evmcs)
                return 1;

        if (vmx->nested.current_vmptr != vmptr) {
                struct kvm_host_map map;
                struct vmcs12 *new_vmcs12;

                if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmptr), &map)) {
                        /*
                         * Reads from an unbacked page return all 1s,
                         * which means that the 32 bits located at the
                         * given physical address won't match the required
                         * VMCS12_REVISION identifier.
                         */
                        return nested_vmx_failValid(vcpu,
                                VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);
                }

                new_vmcs12 = map.hva;

                if (new_vmcs12->hdr.revision_id != VMCS12_REVISION ||
                    (new_vmcs12->hdr.shadow_vmcs &&
                     !nested_cpu_has_vmx_shadow_vmcs(vcpu))) {
                        kvm_vcpu_unmap(vcpu, &map, false);
                        return nested_vmx_failValid(vcpu,
                                VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID);
                }

                nested_release_vmcs12(vcpu);

                /*
                 * Load VMCS12 from guest memory since it is not already
                 * cached.
                 */
                memcpy(vmx->nested.cached_vmcs12, new_vmcs12, VMCS12_SIZE);
                kvm_vcpu_unmap(vcpu, &map, false);

                set_current_vmptr(vmx, vmptr);
        }

        return nested_vmx_succeed(vcpu);
}

/* Emulate the VMPTRST instruction */
static int handle_vmptrst(struct kvm_vcpu *vcpu)
{
        unsigned long exit_qual = vmcs_readl(EXIT_QUALIFICATION);
        u32 instr_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        gpa_t current_vmptr = to_vmx(vcpu)->nested.current_vmptr;
        struct x86_exception e;
        gva_t gva;

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        if (unlikely(to_vmx(vcpu)->nested.hv_evmcs))
                return 1;

        if (get_vmx_mem_address(vcpu, exit_qual, instr_info,
                                true, sizeof(gpa_t), &gva))
                return 1;
        /* *_system ok, nested_vmx_check_permission has verified cpl=0 */
        if (kvm_write_guest_virt_system(vcpu, gva, (void *)&current_vmptr,
                                        sizeof(gpa_t), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }
        return nested_vmx_succeed(vcpu);
}

/* Emulate the INVEPT instruction */
static int handle_invept(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 vmx_instruction_info, types;
        unsigned long type;
        gva_t gva;
        struct x86_exception e;
        struct {
                u64 eptp, gpa;
        } operand;

        if (!(vmx->nested.msrs.secondary_ctls_high &
              SECONDARY_EXEC_ENABLE_EPT) ||
            !(vmx->nested.msrs.ept_caps & VMX_EPT_INVEPT_BIT)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        type = kvm_register_readl(vcpu, (vmx_instruction_info >> 28) & 0xf);

        types = (vmx->nested.msrs.ept_caps >> VMX_EPT_EXTENT_SHIFT) & 6;

        if (type >= 32 || !(types & (1 << type)))
                return nested_vmx_failValid(vcpu,
                                VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

        /* According to the Intel VMX instruction reference, the memory
         * operand is read even if it isn't needed (e.g., for type==global)
         */
        if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
                        vmx_instruction_info, false, sizeof(operand), &gva))
                return 1;
        if (kvm_read_guest_virt(vcpu, gva, &operand, sizeof(operand), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }

        switch (type) {
        case VMX_EPT_EXTENT_GLOBAL:
        case VMX_EPT_EXTENT_CONTEXT:
        /*
         * TODO: Sync the necessary shadow EPT roots here, rather than
         * at the next emulated VM-entry.
         */
                break;
        default:
                BUG_ON(1);
                break;
        }

        return nested_vmx_succeed(vcpu);
}

static int handle_invvpid(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        u32 vmx_instruction_info;
        unsigned long type, types;
        gva_t gva;
        struct x86_exception e;
        struct {
                u64 vpid;
                u64 gla;
        } operand;
        u16 vpid02;

        if (!(vmx->nested.msrs.secondary_ctls_high &
              SECONDARY_EXEC_ENABLE_VPID) ||
                        !(vmx->nested.msrs.vpid_caps & VMX_VPID_INVVPID_BIT)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        if (!nested_vmx_check_permission(vcpu))
                return 1;

        vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        type = kvm_register_readl(vcpu, (vmx_instruction_info >> 28) & 0xf);

        types = (vmx->nested.msrs.vpid_caps &
                        VMX_VPID_EXTENT_SUPPORTED_MASK) >> 8;

        if (type >= 32 || !(types & (1 << type)))
                return nested_vmx_failValid(vcpu,
                        VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

        /* according to the intel vmx instruction reference, the memory
         * operand is read even if it isn't needed (e.g., for type==global)
         */
        if (get_vmx_mem_address(vcpu, vmcs_readl(EXIT_QUALIFICATION),
                        vmx_instruction_info, false, sizeof(operand), &gva))
                return 1;
        if (kvm_read_guest_virt(vcpu, gva, &operand, sizeof(operand), &e)) {
                kvm_inject_page_fault(vcpu, &e);
                return 1;
        }
        if (operand.vpid >> 16)
                return nested_vmx_failValid(vcpu,
                        VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);

        vpid02 = nested_get_vpid02(vcpu);
        switch (type) {
        case VMX_VPID_EXTENT_INDIVIDUAL_ADDR:
                if (!operand.vpid ||
                    is_noncanonical_address(operand.gla, vcpu))
                        return nested_vmx_failValid(vcpu,
                                VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);
                if (cpu_has_vmx_invvpid_individual_addr()) {
                        __invvpid(VMX_VPID_EXTENT_INDIVIDUAL_ADDR,
                                vpid02, operand.gla);
                } else
                        __vmx_flush_tlb(vcpu, vpid02, false);
                break;
        case VMX_VPID_EXTENT_SINGLE_CONTEXT:
        case VMX_VPID_EXTENT_SINGLE_NON_GLOBAL:
                if (!operand.vpid)
                        return nested_vmx_failValid(vcpu,
                                VMXERR_INVALID_OPERAND_TO_INVEPT_INVVPID);
                __vmx_flush_tlb(vcpu, vpid02, false);
                break;
        case VMX_VPID_EXTENT_ALL_CONTEXT:
                __vmx_flush_tlb(vcpu, vpid02, false);
                break;
        default:
                WARN_ON_ONCE(1);
                return kvm_skip_emulated_instruction(vcpu);
        }

        return nested_vmx_succeed(vcpu);
}

static int nested_vmx_eptp_switching(struct kvm_vcpu *vcpu,
                                     struct vmcs12 *vmcs12)
{
        u32 index = kvm_rcx_read(vcpu);
        u64 address;
        bool accessed_dirty;
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        if (!nested_cpu_has_eptp_switching(vmcs12) ||
            !nested_cpu_has_ept(vmcs12))
                return 1;

        if (index >= VMFUNC_EPTP_ENTRIES)
                return 1;


        if (kvm_vcpu_read_guest_page(vcpu, vmcs12->eptp_list_address >> PAGE_SHIFT,
                                     &address, index * 8, 8))
                return 1;

        accessed_dirty = !!(address & VMX_EPTP_AD_ENABLE_BIT);

        /*
         * If the (L2) guest does a vmfunc to the currently
         * active ept pointer, we don't have to do anything else
         */
        if (vmcs12->ept_pointer != address) {
                if (!valid_ept_address(vcpu, address))
                        return 1;

                kvm_mmu_unload(vcpu);
                mmu->ept_ad = accessed_dirty;
                mmu->mmu_role.base.ad_disabled = !accessed_dirty;
                vmcs12->ept_pointer = address;
                /*
                 * TODO: Check what's the correct approach in case
                 * mmu reload fails. Currently, we just let the next
                 * reload potentially fail
                 */
                kvm_mmu_reload(vcpu);
        }

        return 0;
}

static int handle_vmfunc(struct kvm_vcpu *vcpu)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12;
        u32 function = kvm_rax_read(vcpu);

        /*
         * VMFUNC is only supported for nested guests, but we always enable the
         * secondary control for simplicity; for non-nested mode, fake that we
         * didn't by injecting #UD.
         */
        if (!is_guest_mode(vcpu)) {
                kvm_queue_exception(vcpu, UD_VECTOR);
                return 1;
        }

        vmcs12 = get_vmcs12(vcpu);
        if ((vmcs12->vm_function_control & (1 << function)) == 0)
                goto fail;

        switch (function) {
        case 0:
                if (nested_vmx_eptp_switching(vcpu, vmcs12))
                        goto fail;
                break;
        default:
                goto fail;
        }
        return kvm_skip_emulated_instruction(vcpu);

fail:
        nested_vmx_vmexit(vcpu, vmx->exit_reason,
                          vmcs_read32(VM_EXIT_INTR_INFO),
                          vmcs_readl(EXIT_QUALIFICATION));
        return 1;
}


static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu,
                                       struct vmcs12 *vmcs12)
{
        unsigned long exit_qualification;
        gpa_t bitmap, last_bitmap;
        unsigned int port;
        int size;
        u8 b;

        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
                return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING);

        exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

        port = exit_qualification >> 16;
        size = (exit_qualification & 7) + 1;

        last_bitmap = (gpa_t)-1;
        b = -1;

        while (size > 0) {
                if (port < 0x8000)
                        bitmap = vmcs12->io_bitmap_a;
                else if (port < 0x10000)
                        bitmap = vmcs12->io_bitmap_b;
                else
                        return true;
                bitmap += (port & 0x7fff) / 8;

                if (last_bitmap != bitmap)
                        if (kvm_vcpu_read_guest(vcpu, bitmap, &b, 1))
                                return true;
                if (b & (1 << (port & 7)))
                        return true;

                port++;
                size--;
                last_bitmap = bitmap;
        }

        return false;
}

/*
 * Return 1 if we should exit from L2 to L1 to handle an MSR access access,
 * rather than handle it ourselves in L0. I.e., check whether L1 expressed
 * disinterest in the current event (read or write a specific MSR) by using an
 * MSR bitmap. This may be the case even when L0 doesn't use MSR bitmaps.
 */
static bool nested_vmx_exit_handled_msr(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12, u32 exit_reason)
{
        u32 msr_index = kvm_rcx_read(vcpu);
        gpa_t bitmap;

        if (!nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS))
                return true;

        /*
         * The MSR_BITMAP page is divided into four 1024-byte bitmaps,
         * for the four combinations of read/write and low/high MSR numbers.
         * First we need to figure out which of the four to use:
         */
        bitmap = vmcs12->msr_bitmap;
        if (exit_reason == EXIT_REASON_MSR_WRITE)
                bitmap += 2048;
        if (msr_index >= 0xc0000000) {
                msr_index -= 0xc0000000;
                bitmap += 1024;
        }

        /* Then read the msr_index'th bit from this bitmap: */
        if (msr_index < 1024*8) {
                unsigned char b;
                if (kvm_vcpu_read_guest(vcpu, bitmap + msr_index/8, &b, 1))
                        return true;
                return 1 & (b >> (msr_index & 7));
        } else
                return true; /* let L1 handle the wrong parameter */
}

/*
 * Return 1 if we should exit from L2 to L1 to handle a CR access exit,
 * rather than handle it ourselves in L0. I.e., check if L1 wanted to
 * intercept (via guest_host_mask etc.) the current event.
 */
static bool nested_vmx_exit_handled_cr(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12)
{
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        int cr = exit_qualification & 15;
        int reg;
        unsigned long val;

        switch ((exit_qualification >> 4) & 3) {
        case 0: /* mov to cr */
                reg = (exit_qualification >> 8) & 15;
                val = kvm_register_readl(vcpu, reg);
                switch (cr) {
                case 0:
                        if (vmcs12->cr0_guest_host_mask &
                            (val ^ vmcs12->cr0_read_shadow))
                                return true;
                        break;
                case 3:
                        if ((vmcs12->cr3_target_count >= 1 &&
                                        vmcs12->cr3_target_value0 == val) ||
                                (vmcs12->cr3_target_count >= 2 &&
                                        vmcs12->cr3_target_value1 == val) ||
                                (vmcs12->cr3_target_count >= 3 &&
                                        vmcs12->cr3_target_value2 == val) ||
                                (vmcs12->cr3_target_count >= 4 &&
                                        vmcs12->cr3_target_value3 == val))
                                return false;
                        if (nested_cpu_has(vmcs12, CPU_BASED_CR3_LOAD_EXITING))
                                return true;
                        break;
                case 4:
                        if (vmcs12->cr4_guest_host_mask &
                            (vmcs12->cr4_read_shadow ^ val))
                                return true;
                        break;
                case 8:
                        if (nested_cpu_has(vmcs12, CPU_BASED_CR8_LOAD_EXITING))
                                return true;
                        break;
                }
                break;
        case 2: /* clts */
                if ((vmcs12->cr0_guest_host_mask & X86_CR0_TS) &&
                    (vmcs12->cr0_read_shadow & X86_CR0_TS))
                        return true;
                break;
        case 1: /* mov from cr */
                switch (cr) {
                case 3:
                        if (vmcs12->cpu_based_vm_exec_control &
                            CPU_BASED_CR3_STORE_EXITING)
                                return true;
                        break;
                case 8:
                        if (vmcs12->cpu_based_vm_exec_control &
                            CPU_BASED_CR8_STORE_EXITING)
                                return true;
                        break;
                }
                break;
        case 3: /* lmsw */
                /*
                 * lmsw can change bits 1..3 of cr0, and only set bit 0 of
                 * cr0. Other attempted changes are ignored, with no exit.
                 */
                val = (exit_qualification >> LMSW_SOURCE_DATA_SHIFT) & 0x0f;
                if (vmcs12->cr0_guest_host_mask & 0xe &
                    (val ^ vmcs12->cr0_read_shadow))
                        return true;
                if ((vmcs12->cr0_guest_host_mask & 0x1) &&
                    !(vmcs12->cr0_read_shadow & 0x1) &&
                    (val & 0x1))
                        return true;
                break;
        }
        return false;
}

static bool nested_vmx_exit_handled_vmcs_access(struct kvm_vcpu *vcpu,
        struct vmcs12 *vmcs12, gpa_t bitmap)
{
        u32 vmx_instruction_info;
        unsigned long field;
        u8 b;

        if (!nested_cpu_has_shadow_vmcs(vmcs12))
                return true;

        /* Decode instruction info and find the field to access */
        vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        field = kvm_register_read(vcpu, (((vmx_instruction_info) >> 28) & 0xf));

        /* Out-of-range fields always cause a VM exit from L2 to L1 */
        if (field >> 15)
                return true;

        if (kvm_vcpu_read_guest(vcpu, bitmap + field/8, &b, 1))
                return true;

        return 1 & (b >> (field & 7));
}

/*
 * Return 1 if we should exit from L2 to L1 to handle an exit, or 0 if we
 * should handle it ourselves in L0 (and then continue L2). Only call this
 * when in is_guest_mode (L2).
 */
bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
{
        u32 intr_info = vmcs_read32(VM_EXIT_INTR_INFO);
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12 = get_vmcs12(vcpu);

        if (vmx->nested.nested_run_pending)
                return false;

        if (unlikely(vmx->fail)) {
                pr_info_ratelimited("%s failed vm entry %x\n", __func__,
                                    vmcs_read32(VM_INSTRUCTION_ERROR));
                return true;
        }

        /*
         * The host physical addresses of some pages of guest memory
         * are loaded into the vmcs02 (e.g. vmcs12's Virtual APIC
         * Page). The CPU may write to these pages via their host
         * physical address while L2 is running, bypassing any
         * address-translation-based dirty tracking (e.g. EPT write
         * protection).
         *
         * Mark them dirty on every exit from L2 to prevent them from
         * getting out of sync with dirty tracking.
         */
        nested_mark_vmcs12_pages_dirty(vcpu);

        trace_kvm_nested_vmexit(kvm_rip_read(vcpu), exit_reason,
                                vmcs_readl(EXIT_QUALIFICATION),
                                vmx->idt_vectoring_info,
                                intr_info,
                                vmcs_read32(VM_EXIT_INTR_ERROR_CODE),
                                KVM_ISA_VMX);

        switch (exit_reason) {
        case EXIT_REASON_EXCEPTION_NMI:
                if (is_nmi(intr_info))
                        return false;
                else if (is_page_fault(intr_info))
                        return !vmx->vcpu.arch.apf.host_apf_reason && enable_ept;
                else if (is_debug(intr_info) &&
                         vcpu->guest_debug &
                         (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))
                        return false;
                else if (is_breakpoint(intr_info) &&
                         vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
                        return false;
                return vmcs12->exception_bitmap &
                                (1u << (intr_info & INTR_INFO_VECTOR_MASK));
        case EXIT_REASON_EXTERNAL_INTERRUPT:
                return false;
        case EXIT_REASON_TRIPLE_FAULT:
                return true;
        case EXIT_REASON_PENDING_INTERRUPT:
                return nested_cpu_has(vmcs12, CPU_BASED_VIRTUAL_INTR_PENDING);
        case EXIT_REASON_NMI_WINDOW:
                return nested_cpu_has(vmcs12, CPU_BASED_VIRTUAL_NMI_PENDING);
        case EXIT_REASON_TASK_SWITCH:
                return true;
        case EXIT_REASON_CPUID:
                return true;
        case EXIT_REASON_HLT:
                return nested_cpu_has(vmcs12, CPU_BASED_HLT_EXITING);
        case EXIT_REASON_INVD:
                return true;
        case EXIT_REASON_INVLPG:
                return nested_cpu_has(vmcs12, CPU_BASED_INVLPG_EXITING);
        case EXIT_REASON_RDPMC:
                return nested_cpu_has(vmcs12, CPU_BASED_RDPMC_EXITING);
        case EXIT_REASON_RDRAND:
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDRAND_EXITING);
        case EXIT_REASON_RDSEED:
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_RDSEED_EXITING);
        case EXIT_REASON_RDTSC: case EXIT_REASON_RDTSCP:
                return nested_cpu_has(vmcs12, CPU_BASED_RDTSC_EXITING);
        case EXIT_REASON_VMREAD:
                return nested_vmx_exit_handled_vmcs_access(vcpu, vmcs12,
                        vmcs12->vmread_bitmap);
        case EXIT_REASON_VMWRITE:
                return nested_vmx_exit_handled_vmcs_access(vcpu, vmcs12,
                        vmcs12->vmwrite_bitmap);
        case EXIT_REASON_VMCALL: case EXIT_REASON_VMCLEAR:
        case EXIT_REASON_VMLAUNCH: case EXIT_REASON_VMPTRLD:
        case EXIT_REASON_VMPTRST: case EXIT_REASON_VMRESUME:
        case EXIT_REASON_VMOFF: case EXIT_REASON_VMON:
        case EXIT_REASON_INVEPT: case EXIT_REASON_INVVPID:
                /*
                 * VMX instructions trap unconditionally. This allows L1 to
                 * emulate them for its L2 guest, i.e., allows 3-level nesting!
                 */
                return true;
        case EXIT_REASON_CR_ACCESS:
                return nested_vmx_exit_handled_cr(vcpu, vmcs12);
        case EXIT_REASON_DR_ACCESS:
                return nested_cpu_has(vmcs12, CPU_BASED_MOV_DR_EXITING);
        case EXIT_REASON_IO_INSTRUCTION:
                return nested_vmx_exit_handled_io(vcpu, vmcs12);
        case EXIT_REASON_GDTR_IDTR: case EXIT_REASON_LDTR_TR:
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_DESC);
        case EXIT_REASON_MSR_READ:
        case EXIT_REASON_MSR_WRITE:
                return nested_vmx_exit_handled_msr(vcpu, vmcs12, exit_reason);
        case EXIT_REASON_INVALID_STATE:
                return true;
        case EXIT_REASON_MWAIT_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING);
        case EXIT_REASON_MONITOR_TRAP_FLAG:
                return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_TRAP_FLAG);
        case EXIT_REASON_MONITOR_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING);
        case EXIT_REASON_PAUSE_INSTRUCTION:
                return nested_cpu_has(vmcs12, CPU_BASED_PAUSE_EXITING) ||
                        nested_cpu_has2(vmcs12,
                                SECONDARY_EXEC_PAUSE_LOOP_EXITING);
        case EXIT_REASON_MCE_DURING_VMENTRY:
                return false;
        case EXIT_REASON_TPR_BELOW_THRESHOLD:
                return nested_cpu_has(vmcs12, CPU_BASED_TPR_SHADOW);
        case EXIT_REASON_APIC_ACCESS:
        case EXIT_REASON_APIC_WRITE:
        case EXIT_REASON_EOI_INDUCED:
                /*
                 * The controls for "virtualize APIC accesses," "APIC-
                 * register virtualization," and "virtual-interrupt
                 * delivery" only come from vmcs12.
                 */
                return true;
        case EXIT_REASON_EPT_VIOLATION:
                /*
                 * L0 always deals with the EPT violation. If nested EPT is
                 * used, and the nested mmu code discovers that the address is
                 * missing in the guest EPT table (EPT12), the EPT violation
                 * will be injected with nested_ept_inject_page_fault()
                 */
                return false;
        case EXIT_REASON_EPT_MISCONFIG:
                /*
                 * L2 never uses directly L1's EPT, but rather L0's own EPT
                 * table (shadow on EPT) or a merged EPT table that L0 built
                 * (EPT on EPT). So any problems with the structure of the
                 * table is L0's fault.
                 */
                return false;
        case EXIT_REASON_INVPCID:
                return
                        nested_cpu_has2(vmcs12, SECONDARY_EXEC_ENABLE_INVPCID) &&
                        nested_cpu_has(vmcs12, CPU_BASED_INVLPG_EXITING);
        case EXIT_REASON_WBINVD:
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_WBINVD_EXITING);
        case EXIT_REASON_XSETBV:
                return true;
        case EXIT_REASON_XSAVES: case EXIT_REASON_XRSTORS:
                /*
                 * This should never happen, since it is not possible to
                 * set XSS to a non-zero value---neither in L1 nor in L2.
                 * If if it were, XSS would have to be checked against
                 * the XSS exit bitmap in vmcs12.
                 */
                return nested_cpu_has2(vmcs12, SECONDARY_EXEC_XSAVES);
        case EXIT_REASON_PREEMPTION_TIMER:
                return false;
        case EXIT_REASON_PML_FULL:
                /* We emulate PML support to L1. */
                return false;
        case EXIT_REASON_VMFUNC:
                /* VM functions are emulated through L2->L0 vmexits. */
                return false;
        case EXIT_REASON_ENCLS:
                /* SGX is never exposed to L1 */
                return false;
        default:
                return true;
        }
}


static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
                                struct kvm_nested_state __user *user_kvm_nested_state,
                                u32 user_data_size)
{
        struct vcpu_vmx *vmx;
        struct vmcs12 *vmcs12;
        struct kvm_nested_state kvm_state = {
                .flags = 0,
                .format = KVM_STATE_NESTED_FORMAT_VMX,
                .size = sizeof(kvm_state),
                .hdr.vmx.vmxon_pa = -1ull,
                .hdr.vmx.vmcs12_pa = -1ull,
        };
        struct kvm_vmx_nested_state_data __user *user_vmx_nested_state =
                &user_kvm_nested_state->data.vmx[0];

        if (!vcpu)
                return kvm_state.size + sizeof(*user_vmx_nested_state);

        vmx = to_vmx(vcpu);
        vmcs12 = get_vmcs12(vcpu);

        if (nested_vmx_allowed(vcpu) &&
            (vmx->nested.vmxon || vmx->nested.smm.vmxon)) {
                kvm_state.hdr.vmx.vmxon_pa = vmx->nested.vmxon_ptr;
                kvm_state.hdr.vmx.vmcs12_pa = vmx->nested.current_vmptr;

                if (vmx_has_valid_vmcs12(vcpu)) {
                        kvm_state.size += sizeof(user_vmx_nested_state->vmcs12);

                        if (vmx->nested.hv_evmcs)
                                kvm_state.flags |= KVM_STATE_NESTED_EVMCS;

                        if (is_guest_mode(vcpu) &&
                            nested_cpu_has_shadow_vmcs(vmcs12) &&
                            vmcs12->vmcs_link_pointer != -1ull)
                                kvm_state.size += sizeof(user_vmx_nested_state->shadow_vmcs12);
                }

                if (vmx->nested.smm.vmxon)
                        kvm_state.hdr.vmx.smm.flags |= KVM_STATE_NESTED_SMM_VMXON;

                if (vmx->nested.smm.guest_mode)
                        kvm_state.hdr.vmx.smm.flags |= KVM_STATE_NESTED_SMM_GUEST_MODE;

                if (is_guest_mode(vcpu)) {
                        kvm_state.flags |= KVM_STATE_NESTED_GUEST_MODE;

                        if (vmx->nested.nested_run_pending)
                                kvm_state.flags |= KVM_STATE_NESTED_RUN_PENDING;
                }
        }

        if (user_data_size < kvm_state.size)
                goto out;

        if (copy_to_user(user_kvm_nested_state, &kvm_state, sizeof(kvm_state)))
                return -EFAULT;

        if (!vmx_has_valid_vmcs12(vcpu))
                goto out;

        /*
         * When running L2, the authoritative vmcs12 state is in the
         * vmcs02. When running L1, the authoritative vmcs12 state is
         * in the shadow or enlightened vmcs linked to vmcs01, unless
         * need_vmcs12_to_shadow_sync is set, in which case, the authoritative
         * vmcs12 state is in the vmcs12 already.
         */
        if (is_guest_mode(vcpu)) {
                sync_vmcs02_to_vmcs12(vcpu, vmcs12);
                sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
        } else if (!vmx->nested.need_vmcs12_to_shadow_sync) {
                if (vmx->nested.hv_evmcs)
                        copy_enlightened_to_vmcs12(vmx);
                else if (enable_shadow_vmcs)
                        copy_shadow_to_vmcs12(vmx);
        }

        BUILD_BUG_ON(sizeof(user_vmx_nested_state->vmcs12) < VMCS12_SIZE);
        BUILD_BUG_ON(sizeof(user_vmx_nested_state->shadow_vmcs12) < VMCS12_SIZE);

        /*
         * Copy over the full allocated size of vmcs12 rather than just the size
         * of the struct.
         */
        if (copy_to_user(user_vmx_nested_state->vmcs12, vmcs12, VMCS12_SIZE))
                return -EFAULT;

        if (nested_cpu_has_shadow_vmcs(vmcs12) &&
            vmcs12->vmcs_link_pointer != -1ull) {
                if (copy_to_user(user_vmx_nested_state->shadow_vmcs12,
                                 get_shadow_vmcs12(vcpu), VMCS12_SIZE))
                        return -EFAULT;
        }

out:
        return kvm_state.size;
}

/*
 * Forcibly leave nested mode in order to be able to reset the VCPU later on.
 */
void vmx_leave_nested(struct kvm_vcpu *vcpu)
{
        if (is_guest_mode(vcpu)) {
                to_vmx(vcpu)->nested.nested_run_pending = 0;
                nested_vmx_vmexit(vcpu, -1, 0, 0);
        }
        free_nested(vcpu);
}

static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
                                struct kvm_nested_state __user *user_kvm_nested_state,
                                struct kvm_nested_state *kvm_state)
{
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        struct vmcs12 *vmcs12;
        u32 exit_qual;
        struct kvm_vmx_nested_state_data __user *user_vmx_nested_state =
                &user_kvm_nested_state->data.vmx[0];
        int ret;

        if (kvm_state->format != KVM_STATE_NESTED_FORMAT_VMX)
                return -EINVAL;

        if (kvm_state->hdr.vmx.vmxon_pa == -1ull) {
                if (kvm_state->hdr.vmx.smm.flags)
                        return -EINVAL;

                if (kvm_state->hdr.vmx.vmcs12_pa != -1ull)
                        return -EINVAL;

                /*
                 * KVM_STATE_NESTED_EVMCS used to signal that KVM should
                 * enable eVMCS capability on vCPU. However, since then
                 * code was changed such that flag signals vmcs12 should
                 * be copied into eVMCS in guest memory.
                 *
                 * To preserve backwards compatability, allow user
                 * to set this flag even when there is no VMXON region.
                 */
                if (kvm_state->flags & ~KVM_STATE_NESTED_EVMCS)
                        return -EINVAL;
        } else {
                if (!nested_vmx_allowed(vcpu))
                        return -EINVAL;

                if (!page_address_valid(vcpu, kvm_state->hdr.vmx.vmxon_pa))
                        return -EINVAL;
        }

        if ((kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&
            (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
                return -EINVAL;

        if (kvm_state->hdr.vmx.smm.flags &
            ~(KVM_STATE_NESTED_SMM_GUEST_MODE | KVM_STATE_NESTED_SMM_VMXON))
                return -EINVAL;

        /*
         * SMM temporarily disables VMX, so we cannot be in guest mode,
         * nor can VMLAUNCH/VMRESUME be pending.  Outside SMM, SMM flags
         * must be zero.
         */
        if (is_smm(vcpu) ?
                (kvm_state->flags &
                 (KVM_STATE_NESTED_GUEST_MODE | KVM_STATE_NESTED_RUN_PENDING))
                : kvm_state->hdr.vmx.smm.flags)
                return -EINVAL;

        if ((kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE) &&
            !(kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON))
                return -EINVAL;

        if ((kvm_state->flags & KVM_STATE_NESTED_EVMCS) &&
                (!nested_vmx_allowed(vcpu) || !vmx->nested.enlightened_vmcs_enabled))
                        return -EINVAL;

        vmx_leave_nested(vcpu);

        if (kvm_state->hdr.vmx.vmxon_pa == -1ull)
                return 0;

        vmx->nested.vmxon_ptr = kvm_state->hdr.vmx.vmxon_pa;
        ret = enter_vmx_operation(vcpu);
        if (ret)
                return ret;

        /* Empty 'VMXON' state is permitted */
        if (kvm_state->size < sizeof(*kvm_state) + sizeof(*vmcs12))
                return 0;

        if (kvm_state->hdr.vmx.vmcs12_pa != -1ull) {
                if (kvm_state->hdr.vmx.vmcs12_pa == kvm_state->hdr.vmx.vmxon_pa ||
                    !page_address_valid(vcpu, kvm_state->hdr.vmx.vmcs12_pa))
                        return -EINVAL;

                set_current_vmptr(vmx, kvm_state->hdr.vmx.vmcs12_pa);
        } else if (kvm_state->flags & KVM_STATE_NESTED_EVMCS) {
                /*
                 * Sync eVMCS upon entry as we may not have
                 * HV_X64_MSR_VP_ASSIST_PAGE set up yet.
                 */
                vmx->nested.need_vmcs12_to_shadow_sync = true;
        } else {
                return -EINVAL;
        }

        if (kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON) {
                vmx->nested.smm.vmxon = true;
                vmx->nested.vmxon = false;

                if (kvm_state->hdr.vmx.smm.flags & KVM_STATE_NESTED_SMM_GUEST_MODE)
                        vmx->nested.smm.guest_mode = true;
        }

        vmcs12 = get_vmcs12(vcpu);
        if (copy_from_user(vmcs12, user_vmx_nested_state->vmcs12, sizeof(*vmcs12)))
                return -EFAULT;

        if (vmcs12->hdr.revision_id != VMCS12_REVISION)
                return -EINVAL;

        if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
                return 0;

        vmx->nested.nested_run_pending =
                !!(kvm_state->flags & KVM_STATE_NESTED_RUN_PENDING);

        ret = -EINVAL;
        if (nested_cpu_has_shadow_vmcs(vmcs12) &&
            vmcs12->vmcs_link_pointer != -1ull) {
                struct vmcs12 *shadow_vmcs12 = get_shadow_vmcs12(vcpu);

                if (kvm_state->size <
                    sizeof(*kvm_state) +
                    sizeof(user_vmx_nested_state->vmcs12) + sizeof(*shadow_vmcs12))
                        goto error_guest_mode;

                if (copy_from_user(shadow_vmcs12,
                                   user_vmx_nested_state->shadow_vmcs12,
                                   sizeof(*shadow_vmcs12))) {
                        ret = -EFAULT;
                        goto error_guest_mode;
                }

                if (shadow_vmcs12->hdr.revision_id != VMCS12_REVISION ||
                    !shadow_vmcs12->hdr.shadow_vmcs)
                        goto error_guest_mode;
        }

        if (nested_vmx_check_controls(vcpu, vmcs12) ||
            nested_vmx_check_host_state(vcpu, vmcs12) ||
            nested_vmx_check_guest_state(vcpu, vmcs12, &exit_qual))
                goto error_guest_mode;

        vmx->nested.dirty_vmcs12 = true;
        ret = nested_vmx_enter_non_root_mode(vcpu, false);
        if (ret)
                goto error_guest_mode;

        return 0;

error_guest_mode:
        vmx->nested.nested_run_pending = 0;
        return ret;
}

void nested_vmx_vcpu_setup(void)
{
        if (enable_shadow_vmcs) {
                vmcs_write64(VMREAD_BITMAP, __pa(vmx_vmread_bitmap));
                vmcs_write64(VMWRITE_BITMAP, __pa(vmx_vmwrite_bitmap));
        }
}

/*
 * nested_vmx_setup_ctls_msrs() sets up variables containing the values to be
 * returned for the various VMX controls MSRs when nested VMX is enabled.
 * The same values should also be used to verify that vmcs12 control fields are
 * valid during nested entry from L1 to L2.
 * Each of these control msrs has a low and high 32-bit half: A low bit is on
 * if the corresponding bit in the (32-bit) control field *must* be on, and a
 * bit in the high half is on if the corresponding bit in the control field
 * may be on. See also vmx_control_verify().
 */
void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps,
                                bool apicv)
{
        /*
         * Note that as a general rule, the high half of the MSRs (bits in
         * the control fields which may be 1) should be initialized by the
         * intersection of the underlying hardware's MSR (i.e., features which
         * can be supported) and the list of features we want to expose -
         * because they are known to be properly supported in our code.
         * Also, usually, the low half of the MSRs (bits which must be 1) can
         * be set to 0, meaning that L1 may turn off any of these bits. The
         * reason is that if one of these bits is necessary, it will appear
         * in vmcs01 and prepare_vmcs02, when it bitwise-or's the control
         * fields of vmcs01 and vmcs02, will turn these bits off - and
         * nested_vmx_exit_reflected() will not pass related exits to L1.
         * These rules have exceptions below.
         */

        /* pin-based controls */
        rdmsr(MSR_IA32_VMX_PINBASED_CTLS,
                msrs->pinbased_ctls_low,
                msrs->pinbased_ctls_high);
        msrs->pinbased_ctls_low |=
                PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
        msrs->pinbased_ctls_high &=
                PIN_BASED_EXT_INTR_MASK |
                PIN_BASED_NMI_EXITING |
                PIN_BASED_VIRTUAL_NMIS |
                (apicv ? PIN_BASED_POSTED_INTR : 0);
        msrs->pinbased_ctls_high |=
                PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
                PIN_BASED_VMX_PREEMPTION_TIMER;

        /* exit controls */
        rdmsr(MSR_IA32_VMX_EXIT_CTLS,
                msrs->exit_ctls_low,
                msrs->exit_ctls_high);
        msrs->exit_ctls_low =
                VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR;

        msrs->exit_ctls_high &=
#ifdef CONFIG_X86_64
                VM_EXIT_HOST_ADDR_SPACE_SIZE |
#endif
                VM_EXIT_LOAD_IA32_PAT | VM_EXIT_SAVE_IA32_PAT;
        msrs->exit_ctls_high |=
                VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR |
                VM_EXIT_LOAD_IA32_EFER | VM_EXIT_SAVE_IA32_EFER |
                VM_EXIT_SAVE_VMX_PREEMPTION_TIMER | VM_EXIT_ACK_INTR_ON_EXIT;

        /* We support free control of debug control saving. */
        msrs->exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS;

        /* entry controls */
        rdmsr(MSR_IA32_VMX_ENTRY_CTLS,
                msrs->entry_ctls_low,
                msrs->entry_ctls_high);
        msrs->entry_ctls_low =
                VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR;
        msrs->entry_ctls_high &=
#ifdef CONFIG_X86_64
                VM_ENTRY_IA32E_MODE |
#endif
                VM_ENTRY_LOAD_IA32_PAT;
        msrs->entry_ctls_high |=
                (VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR | VM_ENTRY_LOAD_IA32_EFER);

        /* We support free control of debug control loading. */
        msrs->entry_ctls_low &= ~VM_ENTRY_LOAD_DEBUG_CONTROLS;

        /* cpu-based controls */
        rdmsr(MSR_IA32_VMX_PROCBASED_CTLS,
                msrs->procbased_ctls_low,
                msrs->procbased_ctls_high);
        msrs->procbased_ctls_low =
                CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR;
        msrs->procbased_ctls_high &=
                CPU_BASED_VIRTUAL_INTR_PENDING |
                CPU_BASED_VIRTUAL_NMI_PENDING | CPU_BASED_USE_TSC_OFFSETING |
                CPU_BASED_HLT_EXITING | CPU_BASED_INVLPG_EXITING |
                CPU_BASED_MWAIT_EXITING | CPU_BASED_CR3_LOAD_EXITING |
                CPU_BASED_CR3_STORE_EXITING |
#ifdef CONFIG_X86_64
                CPU_BASED_CR8_LOAD_EXITING | CPU_BASED_CR8_STORE_EXITING |
#endif
                CPU_BASED_MOV_DR_EXITING | CPU_BASED_UNCOND_IO_EXITING |
                CPU_BASED_USE_IO_BITMAPS | CPU_BASED_MONITOR_TRAP_FLAG |
                CPU_BASED_MONITOR_EXITING | CPU_BASED_RDPMC_EXITING |
                CPU_BASED_RDTSC_EXITING | CPU_BASED_PAUSE_EXITING |
                CPU_BASED_TPR_SHADOW | CPU_BASED_ACTIVATE_SECONDARY_CONTROLS;
        /*
         * We can allow some features even when not supported by the
         * hardware. For example, L1 can specify an MSR bitmap - and we
         * can use it to avoid exits to L1 - even when L0 runs L2
         * without MSR bitmaps.
         */
        msrs->procbased_ctls_high |=
                CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR |
                CPU_BASED_USE_MSR_BITMAPS;

        /* We support free control of CR3 access interception. */
        msrs->procbased_ctls_low &=
                ~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING);

        /*
         * secondary cpu-based controls.  Do not include those that
         * depend on CPUID bits, they are added later by vmx_cpuid_update.
         */
        if (msrs->procbased_ctls_high & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS)
                rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2,
                      msrs->secondary_ctls_low,
                      msrs->secondary_ctls_high);

        msrs->secondary_ctls_low = 0;
        msrs->secondary_ctls_high &=
                SECONDARY_EXEC_DESC |
                SECONDARY_EXEC_RDTSCP |
                SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE |
                SECONDARY_EXEC_WBINVD_EXITING |
                SECONDARY_EXEC_APIC_REGISTER_VIRT |
                SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
                SECONDARY_EXEC_RDRAND_EXITING |
                SECONDARY_EXEC_ENABLE_INVPCID |
                SECONDARY_EXEC_RDSEED_EXITING |
                SECONDARY_EXEC_XSAVES;

        /*
         * We can emulate "VMCS shadowing," even if the hardware
         * doesn't support it.
         */
        msrs->secondary_ctls_high |=
                SECONDARY_EXEC_SHADOW_VMCS;

        if (enable_ept) {
                /* nested EPT: emulate EPT also to L1 */
                msrs->secondary_ctls_high |=
                        SECONDARY_EXEC_ENABLE_EPT;
                msrs->ept_caps = VMX_EPT_PAGE_WALK_4_BIT |
                         VMX_EPTP_WB_BIT | VMX_EPT_INVEPT_BIT;
                if (cpu_has_vmx_ept_execute_only())
                        msrs->ept_caps |=
                                VMX_EPT_EXECUTE_ONLY_BIT;
                msrs->ept_caps &= ept_caps;
                msrs->ept_caps |= VMX_EPT_EXTENT_GLOBAL_BIT |
                        VMX_EPT_EXTENT_CONTEXT_BIT | VMX_EPT_2MB_PAGE_BIT |
                        VMX_EPT_1GB_PAGE_BIT;
                if (enable_ept_ad_bits) {
                        msrs->secondary_ctls_high |=
                                SECONDARY_EXEC_ENABLE_PML;
                        msrs->ept_caps |= VMX_EPT_AD_BIT;
                }
        }

        if (cpu_has_vmx_vmfunc()) {
                msrs->secondary_ctls_high |=
                        SECONDARY_EXEC_ENABLE_VMFUNC;
                /*
                 * Advertise EPTP switching unconditionally
                 * since we emulate it
                 */
                if (enable_ept)
                        msrs->vmfunc_controls =
                                VMX_VMFUNC_EPTP_SWITCHING;
        }

        /*
         * Old versions of KVM use the single-context version without
         * checking for support, so declare that it is supported even
         * though it is treated as global context.  The alternative is
         * not failing the single-context invvpid, and it is worse.
         */
        if (enable_vpid) {
                msrs->secondary_ctls_high |=
                        SECONDARY_EXEC_ENABLE_VPID;
                msrs->vpid_caps = VMX_VPID_INVVPID_BIT |
                        VMX_VPID_EXTENT_SUPPORTED_MASK;
        }

        if (enable_unrestricted_guest)
                msrs->secondary_ctls_high |=
                        SECONDARY_EXEC_UNRESTRICTED_GUEST;

        if (flexpriority_enabled)
                msrs->secondary_ctls_high |=
                        SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES;

        /* miscellaneous data */
        rdmsr(MSR_IA32_VMX_MISC,
                msrs->misc_low,
                msrs->misc_high);
        msrs->misc_low &= VMX_MISC_SAVE_EFER_LMA;
        msrs->misc_low |=
                MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS |
                VMX_MISC_EMULATED_PREEMPTION_TIMER_RATE |
                VMX_MISC_ACTIVITY_HLT;
        msrs->misc_high = 0;

        /*
         * This MSR reports some information about VMX support. We
         * should return information about the VMX we emulate for the
         * guest, and the VMCS structure we give it - not about the
         * VMX support of the underlying hardware.
         */
        msrs->basic =
                VMCS12_REVISION |
                VMX_BASIC_TRUE_CTLS |
                ((u64)VMCS12_SIZE << VMX_BASIC_VMCS_SIZE_SHIFT) |
                (VMX_BASIC_MEM_TYPE_WB << VMX_BASIC_MEM_TYPE_SHIFT);

        if (cpu_has_vmx_basic_inout())
                msrs->basic |= VMX_BASIC_INOUT;

        /*
         * These MSRs specify bits which the guest must keep fixed on
         * while L1 is in VMXON mode (in L1's root mode, or running an L2).
         * We picked the standard core2 setting.
         */
#define VMXON_CR0_ALWAYSON     (X86_CR0_PE | X86_CR0_PG | X86_CR0_NE)
#define VMXON_CR4_ALWAYSON     X86_CR4_VMXE
        msrs->cr0_fixed0 = VMXON_CR0_ALWAYSON;
        msrs->cr4_fixed0 = VMXON_CR4_ALWAYSON;

        /* These MSRs specify bits which the guest must keep fixed off. */
        rdmsrl(MSR_IA32_VMX_CR0_FIXED1, msrs->cr0_fixed1);
        rdmsrl(MSR_IA32_VMX_CR4_FIXED1, msrs->cr4_fixed1);

        /* highest index: VMX_PREEMPTION_TIMER_VALUE */
        msrs->vmcs_enum = VMCS12_MAX_FIELD_INDEX << 1;
}

void nested_vmx_hardware_unsetup(void)
{
        int i;

        if (enable_shadow_vmcs) {
                for (i = 0; i < VMX_BITMAP_NR; i++)
                        free_page((unsigned long)vmx_bitmap[i]);
        }
}

__init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *))
{
        int i;

        if (!cpu_has_vmx_shadow_vmcs())
                enable_shadow_vmcs = 0;
        if (enable_shadow_vmcs) {
                for (i = 0; i < VMX_BITMAP_NR; i++) {
                        /*
                         * The vmx_bitmap is not tied to a VM and so should
                         * not be charged to a memcg.
                         */
                        vmx_bitmap[i] = (unsigned long *)
                                __get_free_page(GFP_KERNEL);
                        if (!vmx_bitmap[i]) {
                                nested_vmx_hardware_unsetup();
                                return -ENOMEM;
                        }
                }

                init_vmcs_shadow_fields();
        }

        exit_handlers[EXIT_REASON_VMCLEAR]      = handle_vmclear,
        exit_handlers[EXIT_REASON_VMLAUNCH]     = handle_vmlaunch,
        exit_handlers[EXIT_REASON_VMPTRLD]      = handle_vmptrld,
        exit_handlers[EXIT_REASON_VMPTRST]      = handle_vmptrst,
        exit_handlers[EXIT_REASON_VMREAD]       = handle_vmread,
        exit_handlers[EXIT_REASON_VMRESUME]     = handle_vmresume,
        exit_handlers[EXIT_REASON_VMWRITE]      = handle_vmwrite,
        exit_handlers[EXIT_REASON_VMOFF]        = handle_vmoff,
        exit_handlers[EXIT_REASON_VMON]         = handle_vmon,
        exit_handlers[EXIT_REASON_INVEPT]       = handle_invept,
        exit_handlers[EXIT_REASON_INVVPID]      = handle_invvpid,
        exit_handlers[EXIT_REASON_VMFUNC]       = handle_vmfunc,

        kvm_x86_ops->check_nested_events = vmx_check_nested_events;
        kvm_x86_ops->get_nested_state = vmx_get_nested_state;
        kvm_x86_ops->set_nested_state = vmx_set_nested_state;
        kvm_x86_ops->get_vmcs12_pages = nested_get_vmcs12_pages,
        kvm_x86_ops->nested_enable_evmcs = nested_enable_evmcs;
        kvm_x86_ops->nested_get_evmcs_version = nested_get_evmcs_version;

        return 0;
}