KVM: set_memory_region: Refactor prepare_memory_region()

[linux-2.6-microblaze.git] / arch / arm / kvm / arm.c

/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/mman.h>
#include <linux/sched.h>
#include <linux/kvm.h>
#include <trace/events/kvm.h>

#define CREATE_TRACE_POINTS
#include "trace.h"

#include <asm/unified.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/mman.h>
#include <asm/cputype.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/virt.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_coproc.h>
#include <asm/kvm_psci.h>
#include <asm/opcodes.h>

#ifdef REQUIRES_VIRT
__asm__(".arch_extension        virt");
#endif

static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
static struct vfp_hard_struct __percpu *kvm_host_vfp_state;
static unsigned long hyp_default_vectors;

/* Per-CPU variable containing the currently running vcpu. */
static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_arm_running_vcpu);

/* The VMID used in the VTTBR */
static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
static u8 kvm_next_vmid;
static DEFINE_SPINLOCK(kvm_vmid_lock);

static bool vgic_present;

static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
{
        BUG_ON(preemptible());
        __get_cpu_var(kvm_arm_running_vcpu) = vcpu;
}

/**
 * kvm_arm_get_running_vcpu - get the vcpu running on the current CPU.
 * Must be called from non-preemptible context
 */
struct kvm_vcpu *kvm_arm_get_running_vcpu(void)
{
        BUG_ON(preemptible());
        return __get_cpu_var(kvm_arm_running_vcpu);
}

/**
 * kvm_arm_get_running_vcpus - get the per-CPU array of currently running vcpus.
 */
struct kvm_vcpu __percpu **kvm_get_running_vcpus(void)
{
        return &kvm_arm_running_vcpu;
}

int kvm_arch_hardware_enable(void *garbage)
{
        return 0;
}

int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}

void kvm_arch_hardware_disable(void *garbage)
{
}

int kvm_arch_hardware_setup(void)
{
        return 0;
}

void kvm_arch_hardware_unsetup(void)
{
}

void kvm_arch_check_processor_compat(void *rtn)
{
        *(int *)rtn = 0;
}

void kvm_arch_sync_events(struct kvm *kvm)
{
}

/**
 * kvm_arch_init_vm - initializes a VM data structure
 * @kvm:        pointer to the KVM struct
 */
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
        int ret = 0;

        if (type)
                return -EINVAL;

        ret = kvm_alloc_stage2_pgd(kvm);
        if (ret)
                goto out_fail_alloc;

        ret = create_hyp_mappings(kvm, kvm + 1);
        if (ret)
                goto out_free_stage2_pgd;

        /* Mark the initial VMID generation invalid */
        kvm->arch.vmid_gen = 0;

        return ret;
out_free_stage2_pgd:
        kvm_free_stage2_pgd(kvm);
out_fail_alloc:
        return ret;
}

int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
        return VM_FAULT_SIGBUS;
}

void kvm_arch_free_memslot(struct kvm_memory_slot *free,
                           struct kvm_memory_slot *dont)
{
}

int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
{
        return 0;
}

/**
 * kvm_arch_destroy_vm - destroy the VM data structure
 * @kvm:        pointer to the KVM struct
 */
void kvm_arch_destroy_vm(struct kvm *kvm)
{
        int i;

        kvm_free_stage2_pgd(kvm);

        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                if (kvm->vcpus[i]) {
                        kvm_arch_vcpu_free(kvm->vcpus[i]);
                        kvm->vcpus[i] = NULL;
                }
        }
}

int kvm_dev_ioctl_check_extension(long ext)
{
        int r;
        switch (ext) {
        case KVM_CAP_IRQCHIP:
                r = vgic_present;
                break;
        case KVM_CAP_USER_MEMORY:
        case KVM_CAP_SYNC_MMU:
        case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
        case KVM_CAP_ONE_REG:
        case KVM_CAP_ARM_PSCI:
                r = 1;
                break;
        case KVM_CAP_COALESCED_MMIO:
                r = KVM_COALESCED_MMIO_PAGE_OFFSET;
                break;
        case KVM_CAP_ARM_SET_DEVICE_ADDR:
                r = 1;
        case KVM_CAP_NR_VCPUS:
                r = num_online_cpus();
                break;
        case KVM_CAP_MAX_VCPUS:
                r = KVM_MAX_VCPUS;
                break;
        default:
                r = 0;
                break;
        }
        return r;
}

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
{
        return -EINVAL;
}

int kvm_arch_set_memory_region(struct kvm *kvm,
                               struct kvm_userspace_memory_region *mem,
                               struct kvm_memory_slot old,
                               int user_alloc)
{
        return 0;
}

int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                   struct kvm_memory_slot *memslot,
                                   struct kvm_userspace_memory_region *mem,
                                   enum kvm_mr_change change)
{
        return 0;
}

void kvm_arch_commit_memory_region(struct kvm *kvm,
                                   struct kvm_userspace_memory_region *mem,
                                   struct kvm_memory_slot old)
{
}

void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
}

void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
                                   struct kvm_memory_slot *slot)
{
}

struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
        int err;
        struct kvm_vcpu *vcpu;

        vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
        if (!vcpu) {
                err = -ENOMEM;
                goto out;
        }

        err = kvm_vcpu_init(vcpu, kvm, id);
        if (err)
                goto free_vcpu;

        err = create_hyp_mappings(vcpu, vcpu + 1);
        if (err)
                goto vcpu_uninit;

        return vcpu;
vcpu_uninit:
        kvm_vcpu_uninit(vcpu);
free_vcpu:
        kmem_cache_free(kvm_vcpu_cache, vcpu);
out:
        return ERR_PTR(err);
}

int kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
        return 0;
}

void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
        kvm_mmu_free_memory_caches(vcpu);
        kvm_timer_vcpu_terminate(vcpu);
        kmem_cache_free(kvm_vcpu_cache, vcpu);
}

void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
        kvm_arch_vcpu_free(vcpu);
}

int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
        return 0;
}

int __attribute_const__ kvm_target_cpu(void)
{
        unsigned long implementor = read_cpuid_implementor();
        unsigned long part_number = read_cpuid_part_number();

        if (implementor != ARM_CPU_IMP_ARM)
                return -EINVAL;

        switch (part_number) {
        case ARM_CPU_PART_CORTEX_A15:
                return KVM_ARM_TARGET_CORTEX_A15;
        default:
                return -EINVAL;
        }
}

int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
        int ret;

        /* Force users to call KVM_ARM_VCPU_INIT */
        vcpu->arch.target = -1;

        /* Set up VGIC */
        ret = kvm_vgic_vcpu_init(vcpu);
        if (ret)
                return ret;

        /* Set up the timer */
        kvm_timer_vcpu_init(vcpu);

        return 0;
}

void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        vcpu->cpu = cpu;
        vcpu->arch.vfp_host = this_cpu_ptr(kvm_host_vfp_state);

        /*
         * Check whether this vcpu requires the cache to be flushed on
         * this physical CPU. This is a consequence of doing dcache
         * operations by set/way on this vcpu. We do it here to be in
         * a non-preemptible section.
         */
        if (cpumask_test_and_clear_cpu(cpu, &vcpu->arch.require_dcache_flush))
                flush_cache_all(); /* We'd really want v7_flush_dcache_all() */

        kvm_arm_set_running_vcpu(vcpu);
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
        kvm_arm_set_running_vcpu(NULL);
}

int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                                        struct kvm_guest_debug *dbg)
{
        return -EINVAL;
}


int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        return -EINVAL;
}

int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        return -EINVAL;
}

/**
 * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
 * @v:          The VCPU pointer
 *
 * If the guest CPU is not waiting for interrupts or an interrupt line is
 * asserted, the CPU is by definition runnable.
 */
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
        return !!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v);
}

/* Just ensure a guest exit from a particular CPU */
static void exit_vm_noop(void *info)
{
}

void force_vm_exit(const cpumask_t *mask)
{
        smp_call_function_many(mask, exit_vm_noop, NULL, true);
}

/**
 * need_new_vmid_gen - check that the VMID is still valid
 * @kvm: The VM's VMID to checkt
 *
 * return true if there is a new generation of VMIDs being used
 *
 * The hardware supports only 256 values with the value zero reserved for the
 * host, so we check if an assigned value belongs to a previous generation,
 * which which requires us to assign a new value. If we're the first to use a
 * VMID for the new generation, we must flush necessary caches and TLBs on all
 * CPUs.
 */
static bool need_new_vmid_gen(struct kvm *kvm)
{
        return unlikely(kvm->arch.vmid_gen != atomic64_read(&kvm_vmid_gen));
}

/**
 * update_vttbr - Update the VTTBR with a valid VMID before the guest runs
 * @kvm The guest that we are about to run
 *
 * Called from kvm_arch_vcpu_ioctl_run before entering the guest to ensure the
 * VM has a valid VMID, otherwise assigns a new one and flushes corresponding
 * caches and TLBs.
 */
static void update_vttbr(struct kvm *kvm)
{
        phys_addr_t pgd_phys;
        u64 vmid;

        if (!need_new_vmid_gen(kvm))
                return;

        spin_lock(&kvm_vmid_lock);

        /*
         * We need to re-check the vmid_gen here to ensure that if another vcpu
         * already allocated a valid vmid for this vm, then this vcpu should
         * use the same vmid.
         */
        if (!need_new_vmid_gen(kvm)) {
                spin_unlock(&kvm_vmid_lock);
                return;
        }

        /* First user of a new VMID generation? */
        if (unlikely(kvm_next_vmid == 0)) {
                atomic64_inc(&kvm_vmid_gen);
                kvm_next_vmid = 1;

                /*
                 * On SMP we know no other CPUs can use this CPU's or each
                 * other's VMID after force_vm_exit returns since the
                 * kvm_vmid_lock blocks them from reentry to the guest.
                 */
                force_vm_exit(cpu_all_mask);
                /*
                 * Now broadcast TLB + ICACHE invalidation over the inner
                 * shareable domain to make sure all data structures are
                 * clean.
                 */
                kvm_call_hyp(__kvm_flush_vm_context);
        }

        kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);
        kvm->arch.vmid = kvm_next_vmid;
        kvm_next_vmid++;

        /* update vttbr to be used with the new vmid */
        pgd_phys = virt_to_phys(kvm->arch.pgd);
        vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK;
        kvm->arch.vttbr = pgd_phys & VTTBR_BADDR_MASK;
        kvm->arch.vttbr |= vmid;

        spin_unlock(&kvm_vmid_lock);
}

static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        /* SVC called from Hyp mode should never get here */
        kvm_debug("SVC called from Hyp mode shouldn't go here\n");
        BUG();
        return -EINVAL; /* Squash warning */
}

static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
                      vcpu->arch.hsr & HSR_HVC_IMM_MASK);

        if (kvm_psci_call(vcpu))
                return 1;

        kvm_inject_undefined(vcpu);
        return 1;
}

static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        if (kvm_psci_call(vcpu))
                return 1;

        kvm_inject_undefined(vcpu);
        return 1;
}

static int handle_pabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        /* The hypervisor should never cause aborts */
        kvm_err("Prefetch Abort taken from Hyp mode at %#08x (HSR: %#08x)\n",
                vcpu->arch.hxfar, vcpu->arch.hsr);
        return -EFAULT;
}

static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        /* This is either an error in the ws. code or an external abort */
        kvm_err("Data Abort taken from Hyp mode at %#08x (HSR: %#08x)\n",
                vcpu->arch.hxfar, vcpu->arch.hsr);
        return -EFAULT;
}

typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
static exit_handle_fn arm_exit_handlers[] = {
        [HSR_EC_WFI]            = kvm_handle_wfi,
        [HSR_EC_CP15_32]        = kvm_handle_cp15_32,
        [HSR_EC_CP15_64]        = kvm_handle_cp15_64,
        [HSR_EC_CP14_MR]        = kvm_handle_cp14_access,
        [HSR_EC_CP14_LS]        = kvm_handle_cp14_load_store,
        [HSR_EC_CP14_64]        = kvm_handle_cp14_access,
        [HSR_EC_CP_0_13]        = kvm_handle_cp_0_13_access,
        [HSR_EC_CP10_ID]        = kvm_handle_cp10_id,
        [HSR_EC_SVC_HYP]        = handle_svc_hyp,
        [HSR_EC_HVC]            = handle_hvc,
        [HSR_EC_SMC]            = handle_smc,
        [HSR_EC_IABT]           = kvm_handle_guest_abort,
        [HSR_EC_IABT_HYP]       = handle_pabt_hyp,
        [HSR_EC_DABT]           = kvm_handle_guest_abort,
        [HSR_EC_DABT_HYP]       = handle_dabt_hyp,
};

/*
 * A conditional instruction is allowed to trap, even though it
 * wouldn't be executed.  So let's re-implement the hardware, in
 * software!
 */
static bool kvm_condition_valid(struct kvm_vcpu *vcpu)
{
        unsigned long cpsr, cond, insn;

        /*
         * Exception Code 0 can only happen if we set HCR.TGE to 1, to
         * catch undefined instructions, and then we won't get past
         * the arm_exit_handlers test anyway.
         */
        BUG_ON(((vcpu->arch.hsr & HSR_EC) >> HSR_EC_SHIFT) == 0);

        /* Top two bits non-zero?  Unconditional. */
        if (vcpu->arch.hsr >> 30)
                return true;

        cpsr = *vcpu_cpsr(vcpu);

        /* Is condition field valid? */
        if ((vcpu->arch.hsr & HSR_CV) >> HSR_CV_SHIFT)
                cond = (vcpu->arch.hsr & HSR_COND) >> HSR_COND_SHIFT;
        else {
                /* This can happen in Thumb mode: examine IT state. */
                unsigned long it;

                it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3);

                /* it == 0 => unconditional. */
                if (it == 0)
                        return true;

                /* The cond for this insn works out as the top 4 bits. */
                cond = (it >> 4);
        }

        /* Shift makes it look like an ARM-mode instruction */
        insn = cond << 28;
        return arm_check_condition(insn, cpsr) != ARM_OPCODE_CONDTEST_FAIL;
}

/*
 * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
 * proper exit to QEMU.
 */
static int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
                       int exception_index)
{
        unsigned long hsr_ec;

        switch (exception_index) {
        case ARM_EXCEPTION_IRQ:
                return 1;
        case ARM_EXCEPTION_UNDEFINED:
                kvm_err("Undefined exception in Hyp mode at: %#08x\n",
                        vcpu->arch.hyp_pc);
                BUG();
                panic("KVM: Hypervisor undefined exception!\n");
        case ARM_EXCEPTION_DATA_ABORT:
        case ARM_EXCEPTION_PREF_ABORT:
        case ARM_EXCEPTION_HVC:
                hsr_ec = (vcpu->arch.hsr & HSR_EC) >> HSR_EC_SHIFT;

                if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers)
                    || !arm_exit_handlers[hsr_ec]) {
                        kvm_err("Unkown exception class: %#08lx, "
                                "hsr: %#08x\n", hsr_ec,
                                (unsigned int)vcpu->arch.hsr);
                        BUG();
                }

                /*
                 * See ARM ARM B1.14.1: "Hyp traps on instructions
                 * that fail their condition code check"
                 */
                if (!kvm_condition_valid(vcpu)) {
                        bool is_wide = vcpu->arch.hsr & HSR_IL;
                        kvm_skip_instr(vcpu, is_wide);
                        return 1;
                }

                return arm_exit_handlers[hsr_ec](vcpu, run);
        default:
                kvm_pr_unimpl("Unsupported exception type: %d",
                              exception_index);
                run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                return 0;
        }
}

static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
{
        if (likely(vcpu->arch.has_run_once))
                return 0;

        vcpu->arch.has_run_once = true;

        /*
         * Initialize the VGIC before running a vcpu the first time on
         * this VM.
         */
        if (irqchip_in_kernel(vcpu->kvm) &&
            unlikely(!vgic_initialized(vcpu->kvm))) {
                int ret = kvm_vgic_init(vcpu->kvm);
                if (ret)
                        return ret;
        }

        /*
         * Handle the "start in power-off" case by calling into the
         * PSCI code.
         */
        if (test_and_clear_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) {
                *vcpu_reg(vcpu, 0) = KVM_PSCI_FN_CPU_OFF;
                kvm_psci_call(vcpu);
        }

        return 0;
}

static void vcpu_pause(struct kvm_vcpu *vcpu)
{
        wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);

        wait_event_interruptible(*wq, !vcpu->arch.pause);
}

/**
 * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
 * @vcpu:       The VCPU pointer
 * @run:        The kvm_run structure pointer used for userspace state exchange
 *
 * This function is called through the VCPU_RUN ioctl called from user space. It
 * will execute VM code in a loop until the time slice for the process is used
 * or some emulation is needed from user space in which case the function will
 * return with return value 0 and with the kvm_run structure filled in with the
 * required data for the requested emulation.
 */
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        int ret;
        sigset_t sigsaved;

        /* Make sure they initialize the vcpu with KVM_ARM_VCPU_INIT */
        if (unlikely(vcpu->arch.target < 0))
                return -ENOEXEC;

        ret = kvm_vcpu_first_run_init(vcpu);
        if (ret)
                return ret;

        if (run->exit_reason == KVM_EXIT_MMIO) {
                ret = kvm_handle_mmio_return(vcpu, vcpu->run);
                if (ret)
                        return ret;
        }

        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);

        ret = 1;
        run->exit_reason = KVM_EXIT_UNKNOWN;
        while (ret > 0) {
                /*
                 * Check conditions before entering the guest
                 */
                cond_resched();

                update_vttbr(vcpu->kvm);

                if (vcpu->arch.pause)
                        vcpu_pause(vcpu);

                kvm_vgic_flush_hwstate(vcpu);
                kvm_timer_flush_hwstate(vcpu);

                local_irq_disable();

                /*
                 * Re-check atomic conditions
                 */
                if (signal_pending(current)) {
                        ret = -EINTR;
                        run->exit_reason = KVM_EXIT_INTR;
                }

                if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
                        local_irq_enable();
                        kvm_timer_sync_hwstate(vcpu);
                        kvm_vgic_sync_hwstate(vcpu);
                        continue;
                }

                /**************************************************************
                 * Enter the guest
                 */
                trace_kvm_entry(*vcpu_pc(vcpu));
                kvm_guest_enter();
                vcpu->mode = IN_GUEST_MODE;

                ret = kvm_call_hyp(__kvm_vcpu_run, vcpu);

                vcpu->mode = OUTSIDE_GUEST_MODE;
                vcpu->arch.last_pcpu = smp_processor_id();
                kvm_guest_exit();
                trace_kvm_exit(*vcpu_pc(vcpu));
                /*
                 * We may have taken a host interrupt in HYP mode (ie
                 * while executing the guest). This interrupt is still
                 * pending, as we haven't serviced it yet!
                 *
                 * We're now back in SVC mode, with interrupts
                 * disabled.  Enabling the interrupts now will have
                 * the effect of taking the interrupt again, in SVC
                 * mode this time.
                 */
                local_irq_enable();

                /*
                 * Back from guest
                 *************************************************************/

                kvm_timer_sync_hwstate(vcpu);
                kvm_vgic_sync_hwstate(vcpu);

                ret = handle_exit(vcpu, run, ret);
        }

        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);
        return ret;
}

static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
{
        int bit_index;
        bool set;
        unsigned long *ptr;

        if (number == KVM_ARM_IRQ_CPU_IRQ)
                bit_index = __ffs(HCR_VI);
        else /* KVM_ARM_IRQ_CPU_FIQ */
                bit_index = __ffs(HCR_VF);

        ptr = (unsigned long *)&vcpu->arch.irq_lines;
        if (level)
                set = test_and_set_bit(bit_index, ptr);
        else
                set = test_and_clear_bit(bit_index, ptr);

        /*
         * If we didn't change anything, no need to wake up or kick other CPUs
         */
        if (set == level)
                return 0;

        /*
         * The vcpu irq_lines field was updated, wake up sleeping VCPUs and
         * trigger a world-switch round on the running physical CPU to set the
         * virtual IRQ/FIQ fields in the HCR appropriately.
         */
        kvm_vcpu_kick(vcpu);

        return 0;
}

int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level)
{
        u32 irq = irq_level->irq;
        unsigned int irq_type, vcpu_idx, irq_num;
        int nrcpus = atomic_read(&kvm->online_vcpus);
        struct kvm_vcpu *vcpu = NULL;
        bool level = irq_level->level;

        irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
        vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
        irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;

        trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level);

        switch (irq_type) {
        case KVM_ARM_IRQ_TYPE_CPU:
                if (irqchip_in_kernel(kvm))
                        return -ENXIO;

                if (vcpu_idx >= nrcpus)
                        return -EINVAL;

                vcpu = kvm_get_vcpu(kvm, vcpu_idx);
                if (!vcpu)
                        return -EINVAL;

                if (irq_num > KVM_ARM_IRQ_CPU_FIQ)
                        return -EINVAL;

                return vcpu_interrupt_line(vcpu, irq_num, level);
        case KVM_ARM_IRQ_TYPE_PPI:
                if (!irqchip_in_kernel(kvm))
                        return -ENXIO;

                if (vcpu_idx >= nrcpus)
                        return -EINVAL;

                vcpu = kvm_get_vcpu(kvm, vcpu_idx);
                if (!vcpu)
                        return -EINVAL;

                if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
                        return -EINVAL;

                return kvm_vgic_inject_irq(kvm, vcpu->vcpu_id, irq_num, level);
        case KVM_ARM_IRQ_TYPE_SPI:
                if (!irqchip_in_kernel(kvm))
                        return -ENXIO;

                if (irq_num < VGIC_NR_PRIVATE_IRQS ||
                    irq_num > KVM_ARM_IRQ_GIC_MAX)
                        return -EINVAL;

                return kvm_vgic_inject_irq(kvm, 0, irq_num, level);
        }

        return -EINVAL;
}

long kvm_arch_vcpu_ioctl(struct file *filp,
                         unsigned int ioctl, unsigned long arg)
{
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;

        switch (ioctl) {
        case KVM_ARM_VCPU_INIT: {
                struct kvm_vcpu_init init;

                if (copy_from_user(&init, argp, sizeof(init)))
                        return -EFAULT;

                return kvm_vcpu_set_target(vcpu, &init);

        }
        case KVM_SET_ONE_REG:
        case KVM_GET_ONE_REG: {
                struct kvm_one_reg reg;
                if (copy_from_user(&reg, argp, sizeof(reg)))
                        return -EFAULT;
                if (ioctl == KVM_SET_ONE_REG)
                        return kvm_arm_set_reg(vcpu, &reg);
                else
                        return kvm_arm_get_reg(vcpu, &reg);
        }
        case KVM_GET_REG_LIST: {
                struct kvm_reg_list __user *user_list = argp;
                struct kvm_reg_list reg_list;
                unsigned n;

                if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
                        return -EFAULT;
                n = reg_list.n;
                reg_list.n = kvm_arm_num_regs(vcpu);
                if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
                        return -EFAULT;
                if (n < reg_list.n)
                        return -E2BIG;
                return kvm_arm_copy_reg_indices(vcpu, user_list->reg);
        }
        default:
                return -EINVAL;
        }
}

int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
{
        return -EINVAL;
}

static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
                                        struct kvm_arm_device_addr *dev_addr)
{
        unsigned long dev_id, type;

        dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >>
                KVM_ARM_DEVICE_ID_SHIFT;
        type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >>
                KVM_ARM_DEVICE_TYPE_SHIFT;

        switch (dev_id) {
        case KVM_ARM_DEVICE_VGIC_V2:
                if (!vgic_present)
                        return -ENXIO;
                return kvm_vgic_set_addr(kvm, type, dev_addr->addr);
        default:
                return -ENODEV;
        }
}

long kvm_arch_vm_ioctl(struct file *filp,
                       unsigned int ioctl, unsigned long arg)
{
        struct kvm *kvm = filp->private_data;
        void __user *argp = (void __user *)arg;

        switch (ioctl) {
        case KVM_CREATE_IRQCHIP: {
                if (vgic_present)
                        return kvm_vgic_create(kvm);
                else
                        return -ENXIO;
        }
        case KVM_ARM_SET_DEVICE_ADDR: {
                struct kvm_arm_device_addr dev_addr;

                if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
                        return -EFAULT;
                return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
        }
        default:
                return -EINVAL;
        }
}

static void cpu_init_hyp_mode(void *vector)
{
        unsigned long long pgd_ptr;
        unsigned long pgd_low, pgd_high;
        unsigned long hyp_stack_ptr;
        unsigned long stack_page;
        unsigned long vector_ptr;

        /* Switch from the HYP stub to our own HYP init vector */
        __hyp_set_vectors((unsigned long)vector);

        pgd_ptr = (unsigned long long)kvm_mmu_get_httbr();
        pgd_low = (pgd_ptr & ((1ULL << 32) - 1));
        pgd_high = (pgd_ptr >> 32ULL);
        stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
        hyp_stack_ptr = stack_page + PAGE_SIZE;
        vector_ptr = (unsigned long)__kvm_hyp_vector;

        /*
         * Call initialization code, and switch to the full blown
         * HYP code. The init code doesn't need to preserve these registers as
         * r1-r3 and r12 are already callee save according to the AAPCS.
         * Note that we slightly misuse the prototype by casing the pgd_low to
         * a void *.
         */
        kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr);
}

/**
 * Inits Hyp-mode on all online CPUs
 */
static int init_hyp_mode(void)
{
        phys_addr_t init_phys_addr;
        int cpu;
        int err = 0;

        /*
         * Allocate Hyp PGD and setup Hyp identity mapping
         */
        err = kvm_mmu_init();
        if (err)
                goto out_err;

        /*
         * It is probably enough to obtain the default on one
         * CPU. It's unlikely to be different on the others.
         */
        hyp_default_vectors = __hyp_get_vectors();

        /*
         * Allocate stack pages for Hypervisor-mode
         */
        for_each_possible_cpu(cpu) {
                unsigned long stack_page;

                stack_page = __get_free_page(GFP_KERNEL);
                if (!stack_page) {
                        err = -ENOMEM;
                        goto out_free_stack_pages;
                }

                per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
        }

        /*
         * Execute the init code on each CPU.
         *
         * Note: The stack is not mapped yet, so don't do anything else than
         * initializing the hypervisor mode on each CPU using a local stack
         * space for temporary storage.
         */
        init_phys_addr = virt_to_phys(__kvm_hyp_init);
        for_each_online_cpu(cpu) {
                smp_call_function_single(cpu, cpu_init_hyp_mode,
                                         (void *)(long)init_phys_addr, 1);
        }

        /*
         * Unmap the identity mapping
         */
        kvm_clear_hyp_idmap();

        /*
         * Map the Hyp-code called directly from the host
         */
        err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);
        if (err) {
                kvm_err("Cannot map world-switch code\n");
                goto out_free_mappings;
        }

        /*
         * Map the Hyp stack pages
         */
        for_each_possible_cpu(cpu) {
                char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
                err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE);

                if (err) {
                        kvm_err("Cannot map hyp stack\n");
                        goto out_free_mappings;
                }
        }

        /*
         * Map the host VFP structures
         */
        kvm_host_vfp_state = alloc_percpu(struct vfp_hard_struct);
        if (!kvm_host_vfp_state) {
                err = -ENOMEM;
                kvm_err("Cannot allocate host VFP state\n");
                goto out_free_mappings;
        }

        for_each_possible_cpu(cpu) {
                struct vfp_hard_struct *vfp;

                vfp = per_cpu_ptr(kvm_host_vfp_state, cpu);
                err = create_hyp_mappings(vfp, vfp + 1);

                if (err) {
                        kvm_err("Cannot map host VFP state: %d\n", err);
                        goto out_free_vfp;
                }
        }

        /*
         * Init HYP view of VGIC
         */
        err = kvm_vgic_hyp_init();
        if (err)
                goto out_free_vfp;

#ifdef CONFIG_KVM_ARM_VGIC
                vgic_present = true;
#endif

        /*
         * Init HYP architected timer support
         */
        err = kvm_timer_hyp_init();
        if (err)
                goto out_free_mappings;

        kvm_info("Hyp mode initialized successfully\n");
        return 0;
out_free_vfp:
        free_percpu(kvm_host_vfp_state);
out_free_mappings:
        free_hyp_pmds();
out_free_stack_pages:
        for_each_possible_cpu(cpu)
                free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
out_err:
        kvm_err("error initializing Hyp mode: %d\n", err);
        return err;
}

/**
 * Initialize Hyp-mode and memory mappings on all CPUs.
 */
int kvm_arch_init(void *opaque)
{
        int err;

        if (!is_hyp_mode_available()) {
                kvm_err("HYP mode not available\n");
                return -ENODEV;
        }

        if (kvm_target_cpu() < 0) {
                kvm_err("Target CPU not supported!\n");
                return -ENODEV;
        }

        err = init_hyp_mode();
        if (err)
                goto out_err;

        kvm_coproc_table_init();
        return 0;
out_err:
        return err;
}

/* NOP: Compiling as a module not supported */
void kvm_arch_exit(void)
{
}

static int arm_init(void)
{
        int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
        return rc;
}

module_init(arm_init);