kvm: add guest_state_{enter,exit}_irqoff()

[linux-2.6-microblaze.git] / include / linux / kvm_host.h

/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __KVM_HOST_H
#define __KVM_HOST_H


#include <linux/types.h>
#include <linux/hardirq.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/sched/stat.h>
#include <linux/bug.h>
#include <linux/minmax.h>
#include <linux/mm.h>
#include <linux/mmu_notifier.h>
#include <linux/preempt.h>
#include <linux/msi.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/rcupdate.h>
#include <linux/ratelimit.h>
#include <linux/err.h>
#include <linux/irqflags.h>
#include <linux/context_tracking.h>
#include <linux/irqbypass.h>
#include <linux/rcuwait.h>
#include <linux/refcount.h>
#include <linux/nospec.h>
#include <linux/notifier.h>
#include <linux/ftrace.h>
#include <linux/hashtable.h>
#include <linux/instrumentation.h>
#include <linux/interval_tree.h>
#include <linux/rbtree.h>
#include <linux/xarray.h>
#include <asm/signal.h>

#include <linux/kvm.h>
#include <linux/kvm_para.h>

#include <linux/kvm_types.h>

#include <asm/kvm_host.h>
#include <linux/kvm_dirty_ring.h>

#ifndef KVM_MAX_VCPU_IDS
#define KVM_MAX_VCPU_IDS KVM_MAX_VCPUS
#endif

/*
 * The bit 16 ~ bit 31 of kvm_memory_region::flags are internally used
 * in kvm, other bits are visible for userspace which are defined in
 * include/linux/kvm_h.
 */
#define KVM_MEMSLOT_INVALID     (1UL << 16)

/*
 * Bit 63 of the memslot generation number is an "update in-progress flag",
 * e.g. is temporarily set for the duration of install_new_memslots().
 * This flag effectively creates a unique generation number that is used to
 * mark cached memslot data, e.g. MMIO accesses, as potentially being stale,
 * i.e. may (or may not) have come from the previous memslots generation.
 *
 * This is necessary because the actual memslots update is not atomic with
 * respect to the generation number update.  Updating the generation number
 * first would allow a vCPU to cache a spte from the old memslots using the
 * new generation number, and updating the generation number after switching
 * to the new memslots would allow cache hits using the old generation number
 * to reference the defunct memslots.
 *
 * This mechanism is used to prevent getting hits in KVM's caches while a
 * memslot update is in-progress, and to prevent cache hits *after* updating
 * the actual generation number against accesses that were inserted into the
 * cache *before* the memslots were updated.
 */
#define KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS      BIT_ULL(63)

/* Two fragments for cross MMIO pages. */
#define KVM_MAX_MMIO_FRAGMENTS  2

#ifndef KVM_ADDRESS_SPACE_NUM
#define KVM_ADDRESS_SPACE_NUM   1
#endif

/*
 * For the normal pfn, the highest 12 bits should be zero,
 * so we can mask bit 62 ~ bit 52  to indicate the error pfn,
 * mask bit 63 to indicate the noslot pfn.
 */
#define KVM_PFN_ERR_MASK        (0x7ffULL << 52)
#define KVM_PFN_ERR_NOSLOT_MASK (0xfffULL << 52)
#define KVM_PFN_NOSLOT          (0x1ULL << 63)

#define KVM_PFN_ERR_FAULT       (KVM_PFN_ERR_MASK)
#define KVM_PFN_ERR_HWPOISON    (KVM_PFN_ERR_MASK + 1)
#define KVM_PFN_ERR_RO_FAULT    (KVM_PFN_ERR_MASK + 2)

/*
 * error pfns indicate that the gfn is in slot but faild to
 * translate it to pfn on host.
 */
static inline bool is_error_pfn(kvm_pfn_t pfn)
{
        return !!(pfn & KVM_PFN_ERR_MASK);
}

/*
 * error_noslot pfns indicate that the gfn can not be
 * translated to pfn - it is not in slot or failed to
 * translate it to pfn.
 */
static inline bool is_error_noslot_pfn(kvm_pfn_t pfn)
{
        return !!(pfn & KVM_PFN_ERR_NOSLOT_MASK);
}

/* noslot pfn indicates that the gfn is not in slot. */
static inline bool is_noslot_pfn(kvm_pfn_t pfn)
{
        return pfn == KVM_PFN_NOSLOT;
}

/*
 * architectures with KVM_HVA_ERR_BAD other than PAGE_OFFSET (e.g. s390)
 * provide own defines and kvm_is_error_hva
 */
#ifndef KVM_HVA_ERR_BAD

#define KVM_HVA_ERR_BAD         (PAGE_OFFSET)
#define KVM_HVA_ERR_RO_BAD      (PAGE_OFFSET + PAGE_SIZE)

static inline bool kvm_is_error_hva(unsigned long addr)
{
        return addr >= PAGE_OFFSET;
}

#endif

#define KVM_ERR_PTR_BAD_PAGE    (ERR_PTR(-ENOENT))

static inline bool is_error_page(struct page *page)
{
        return IS_ERR(page);
}

#define KVM_REQUEST_MASK           GENMASK(7,0)
#define KVM_REQUEST_NO_WAKEUP      BIT(8)
#define KVM_REQUEST_WAIT           BIT(9)
/*
 * Architecture-independent vcpu->requests bit members
 * Bits 4-7 are reserved for more arch-independent bits.
 */
#define KVM_REQ_TLB_FLUSH         (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_MMU_RELOAD        (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_UNBLOCK           2
#define KVM_REQ_UNHALT            3
#define KVM_REQ_VM_DEAD           (4 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_GPC_INVALIDATE    (5 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQUEST_ARCH_BASE     8

#define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \
        BUILD_BUG_ON((unsigned)(nr) >= (sizeof_field(struct kvm_vcpu, requests) * 8) - KVM_REQUEST_ARCH_BASE); \
        (unsigned)(((nr) + KVM_REQUEST_ARCH_BASE) | (flags)); \
})
#define KVM_ARCH_REQ(nr)           KVM_ARCH_REQ_FLAGS(nr, 0)

bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
                                 unsigned long *vcpu_bitmap);
bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
                                      struct kvm_vcpu *except);
bool kvm_make_cpus_request_mask(struct kvm *kvm, unsigned int req,
                                unsigned long *vcpu_bitmap);

#define KVM_USERSPACE_IRQ_SOURCE_ID             0
#define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID        1

extern struct mutex kvm_lock;
extern struct list_head vm_list;

struct kvm_io_range {
        gpa_t addr;
        int len;
        struct kvm_io_device *dev;
};

#define NR_IOBUS_DEVS 1000

struct kvm_io_bus {
        int dev_count;
        int ioeventfd_count;
        struct kvm_io_range range[];
};

enum kvm_bus {
        KVM_MMIO_BUS,
        KVM_PIO_BUS,
        KVM_VIRTIO_CCW_NOTIFY_BUS,
        KVM_FAST_MMIO_BUS,
        KVM_NR_BUSES
};

int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
                     int len, const void *val);
int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
                            gpa_t addr, int len, const void *val, long cookie);
int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
                    int len, void *val);
int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
                            int len, struct kvm_io_device *dev);
int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
                              struct kvm_io_device *dev);
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
                                         gpa_t addr);

#ifdef CONFIG_KVM_ASYNC_PF
struct kvm_async_pf {
        struct work_struct work;
        struct list_head link;
        struct list_head queue;
        struct kvm_vcpu *vcpu;
        struct mm_struct *mm;
        gpa_t cr2_or_gpa;
        unsigned long addr;
        struct kvm_arch_async_pf arch;
        bool   wakeup_all;
        bool notpresent_injected;
};

void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
                        unsigned long hva, struct kvm_arch_async_pf *arch);
int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
#endif

#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
struct kvm_gfn_range {
        struct kvm_memory_slot *slot;
        gfn_t start;
        gfn_t end;
        pte_t pte;
        bool may_block;
};
bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
#endif

enum {
        OUTSIDE_GUEST_MODE,
        IN_GUEST_MODE,
        EXITING_GUEST_MODE,
        READING_SHADOW_PAGE_TABLES,
};

#define KVM_UNMAPPED_PAGE       ((void *) 0x500 + POISON_POINTER_DELTA)

struct kvm_host_map {
        /*
         * Only valid if the 'pfn' is managed by the host kernel (i.e. There is
         * a 'struct page' for it. When using mem= kernel parameter some memory
         * can be used as guest memory but they are not managed by host
         * kernel).
         * If 'pfn' is not managed by the host kernel, this field is
         * initialized to KVM_UNMAPPED_PAGE.
         */
        struct page *page;
        void *hva;
        kvm_pfn_t pfn;
        kvm_pfn_t gfn;
};

/*
 * Used to check if the mapping is valid or not. Never use 'kvm_host_map'
 * directly to check for that.
 */
static inline bool kvm_vcpu_mapped(struct kvm_host_map *map)
{
        return !!map->hva;
}

static inline bool kvm_vcpu_can_poll(ktime_t cur, ktime_t stop)
{
        return single_task_running() && !need_resched() && ktime_before(cur, stop);
}

/*
 * Sometimes a large or cross-page mmio needs to be broken up into separate
 * exits for userspace servicing.
 */
struct kvm_mmio_fragment {
        gpa_t gpa;
        void *data;
        unsigned len;
};

struct kvm_vcpu {
        struct kvm *kvm;
#ifdef CONFIG_PREEMPT_NOTIFIERS
        struct preempt_notifier preempt_notifier;
#endif
        int cpu;
        int vcpu_id; /* id given by userspace at creation */
        int vcpu_idx; /* index in kvm->vcpus array */
        int srcu_idx;
        int mode;
        u64 requests;
        unsigned long guest_debug;

        struct mutex mutex;
        struct kvm_run *run;

#ifndef __KVM_HAVE_ARCH_WQP
        struct rcuwait wait;
#endif
        struct pid __rcu *pid;
        int sigset_active;
        sigset_t sigset;
        unsigned int halt_poll_ns;
        bool valid_wakeup;

#ifdef CONFIG_HAS_IOMEM
        int mmio_needed;
        int mmio_read_completed;
        int mmio_is_write;
        int mmio_cur_fragment;
        int mmio_nr_fragments;
        struct kvm_mmio_fragment mmio_fragments[KVM_MAX_MMIO_FRAGMENTS];
#endif

#ifdef CONFIG_KVM_ASYNC_PF
        struct {
                u32 queued;
                struct list_head queue;
                struct list_head done;
                spinlock_t lock;
        } async_pf;
#endif

#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
        /*
         * Cpu relax intercept or pause loop exit optimization
         * in_spin_loop: set when a vcpu does a pause loop exit
         *  or cpu relax intercepted.
         * dy_eligible: indicates whether vcpu is eligible for directed yield.
         */
        struct {
                bool in_spin_loop;
                bool dy_eligible;
        } spin_loop;
#endif
        bool preempted;
        bool ready;
        struct kvm_vcpu_arch arch;
        struct kvm_vcpu_stat stat;
        char stats_id[KVM_STATS_NAME_SIZE];
        struct kvm_dirty_ring dirty_ring;

        /*
         * The most recently used memslot by this vCPU and the slots generation
         * for which it is valid.
         * No wraparound protection is needed since generations won't overflow in
         * thousands of years, even assuming 1M memslot operations per second.
         */
        struct kvm_memory_slot *last_used_slot;
        u64 last_used_slot_gen;
};

/*
 * Start accounting time towards a guest.
 * Must be called before entering guest context.
 */
static __always_inline void guest_timing_enter_irqoff(void)
{
        /*
         * This is running in ioctl context so its safe to assume that it's the
         * stime pending cputime to flush.
         */
        instrumentation_begin();
        vtime_account_guest_enter();
        instrumentation_end();
}

/*
 * Enter guest context and enter an RCU extended quiescent state.
 *
 * Between guest_context_enter_irqoff() and guest_context_exit_irqoff() it is
 * unsafe to use any code which may directly or indirectly use RCU, tracing
 * (including IRQ flag tracing), or lockdep. All code in this period must be
 * non-instrumentable.
 */
static __always_inline void guest_context_enter_irqoff(void)
{
        /*
         * KVM does not hold any references to rcu protected data when it
         * switches CPU into a guest mode. In fact switching to a guest mode
         * is very similar to exiting to userspace from rcu point of view. In
         * addition CPU may stay in a guest mode for quite a long time (up to
         * one time slice). Lets treat guest mode as quiescent state, just like
         * we do with user-mode execution.
         */
        if (!context_tracking_guest_enter()) {
                instrumentation_begin();
                rcu_virt_note_context_switch(smp_processor_id());
                instrumentation_end();
        }
}

/*
 * Deprecated. Architectures should move to guest_timing_enter_irqoff() and
 * guest_state_enter_irqoff().
 */
static __always_inline void guest_enter_irqoff(void)
{
        guest_timing_enter_irqoff();
        guest_context_enter_irqoff();
}

/**
 * guest_state_enter_irqoff - Fixup state when entering a guest
 *
 * Entry to a guest will enable interrupts, but the kernel state is interrupts
 * disabled when this is invoked. Also tell RCU about it.
 *
 * 1) Trace interrupts on state
 * 2) Invoke context tracking if enabled to adjust RCU state
 * 3) Tell lockdep that interrupts are enabled
 *
 * Invoked from architecture specific code before entering a guest.
 * Must be called with interrupts disabled and the caller must be
 * non-instrumentable.
 * The caller has to invoke guest_timing_enter_irqoff() before this.
 *
 * Note: this is analogous to exit_to_user_mode().
 */
static __always_inline void guest_state_enter_irqoff(void)
{
        instrumentation_begin();
        trace_hardirqs_on_prepare();
        lockdep_hardirqs_on_prepare(CALLER_ADDR0);
        instrumentation_end();

        guest_context_enter_irqoff();
        lockdep_hardirqs_on(CALLER_ADDR0);
}

/*
 * Exit guest context and exit an RCU extended quiescent state.
 *
 * Between guest_context_enter_irqoff() and guest_context_exit_irqoff() it is
 * unsafe to use any code which may directly or indirectly use RCU, tracing
 * (including IRQ flag tracing), or lockdep. All code in this period must be
 * non-instrumentable.
 */
static __always_inline void guest_context_exit_irqoff(void)
{
        context_tracking_guest_exit();
}

/*
 * Stop accounting time towards a guest.
 * Must be called after exiting guest context.
 */
static __always_inline void guest_timing_exit_irqoff(void)
{
        instrumentation_begin();
        /* Flush the guest cputime we spent on the guest */
        vtime_account_guest_exit();
        instrumentation_end();
}

/*
 * Deprecated. Architectures should move to guest_state_exit_irqoff() and
 * guest_timing_exit_irqoff().
 */
static __always_inline void guest_exit_irqoff(void)
{
        guest_context_exit_irqoff();
        guest_timing_exit_irqoff();
}

static inline void guest_exit(void)
{
        unsigned long flags;

        local_irq_save(flags);
        guest_exit_irqoff();
        local_irq_restore(flags);
}

/**
 * guest_state_exit_irqoff - Establish state when returning from guest mode
 *
 * Entry from a guest disables interrupts, but guest mode is traced as
 * interrupts enabled. Also with NO_HZ_FULL RCU might be idle.
 *
 * 1) Tell lockdep that interrupts are disabled
 * 2) Invoke context tracking if enabled to reactivate RCU
 * 3) Trace interrupts off state
 *
 * Invoked from architecture specific code after exiting a guest.
 * Must be invoked with interrupts disabled and the caller must be
 * non-instrumentable.
 * The caller has to invoke guest_timing_exit_irqoff() after this.
 *
 * Note: this is analogous to enter_from_user_mode().
 */
static __always_inline void guest_state_exit_irqoff(void)
{
        lockdep_hardirqs_off(CALLER_ADDR0);
        guest_context_exit_irqoff();

        instrumentation_begin();
        trace_hardirqs_off_finish();
        instrumentation_end();
}

static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
{
        /*
         * The memory barrier ensures a previous write to vcpu->requests cannot
         * be reordered with the read of vcpu->mode.  It pairs with the general
         * memory barrier following the write of vcpu->mode in VCPU RUN.
         */
        smp_mb__before_atomic();
        return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
}

/*
 * Some of the bitops functions do not support too long bitmaps.
 * This number must be determined not to exceed such limits.
 */
#define KVM_MEM_MAX_NR_PAGES ((1UL << 31) - 1)

/*
 * Since at idle each memslot belongs to two memslot sets it has to contain
 * two embedded nodes for each data structure that it forms a part of.
 *
 * Two memslot sets (one active and one inactive) are necessary so the VM
 * continues to run on one memslot set while the other is being modified.
 *
 * These two memslot sets normally point to the same set of memslots.
 * They can, however, be desynchronized when performing a memslot management
 * operation by replacing the memslot to be modified by its copy.
 * After the operation is complete, both memslot sets once again point to
 * the same, common set of memslot data.
 *
 * The memslots themselves are independent of each other so they can be
 * individually added or deleted.
 */
struct kvm_memory_slot {
        struct hlist_node id_node[2];
        struct interval_tree_node hva_node[2];
        struct rb_node gfn_node[2];
        gfn_t base_gfn;
        unsigned long npages;
        unsigned long *dirty_bitmap;
        struct kvm_arch_memory_slot arch;
        unsigned long userspace_addr;
        u32 flags;
        short id;
        u16 as_id;
};

static inline bool kvm_slot_dirty_track_enabled(const struct kvm_memory_slot *slot)
{
        return slot->flags & KVM_MEM_LOG_DIRTY_PAGES;
}

static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
{
        return ALIGN(memslot->npages, BITS_PER_LONG) / 8;
}

static inline unsigned long *kvm_second_dirty_bitmap(struct kvm_memory_slot *memslot)
{
        unsigned long len = kvm_dirty_bitmap_bytes(memslot);

        return memslot->dirty_bitmap + len / sizeof(*memslot->dirty_bitmap);
}

#ifndef KVM_DIRTY_LOG_MANUAL_CAPS
#define KVM_DIRTY_LOG_MANUAL_CAPS KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE
#endif

struct kvm_s390_adapter_int {
        u64 ind_addr;
        u64 summary_addr;
        u64 ind_offset;
        u32 summary_offset;
        u32 adapter_id;
};

struct kvm_hv_sint {
        u32 vcpu;
        u32 sint;
};

struct kvm_xen_evtchn {
        u32 port;
        u32 vcpu;
        u32 priority;
};

struct kvm_kernel_irq_routing_entry {
        u32 gsi;
        u32 type;
        int (*set)(struct kvm_kernel_irq_routing_entry *e,
                   struct kvm *kvm, int irq_source_id, int level,
                   bool line_status);
        union {
                struct {
                        unsigned irqchip;
                        unsigned pin;
                } irqchip;
                struct {
                        u32 address_lo;
                        u32 address_hi;
                        u32 data;
                        u32 flags;
                        u32 devid;
                } msi;
                struct kvm_s390_adapter_int adapter;
                struct kvm_hv_sint hv_sint;
                struct kvm_xen_evtchn xen_evtchn;
        };
        struct hlist_node link;
};

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
struct kvm_irq_routing_table {
        int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
        u32 nr_rt_entries;
        /*
         * Array indexed by gsi. Each entry contains list of irq chips
         * the gsi is connected to.
         */
        struct hlist_head map[];
};
#endif

#ifndef KVM_PRIVATE_MEM_SLOTS
#define KVM_PRIVATE_MEM_SLOTS 0
#endif

#define KVM_MEM_SLOTS_NUM SHRT_MAX
#define KVM_USER_MEM_SLOTS (KVM_MEM_SLOTS_NUM - KVM_PRIVATE_MEM_SLOTS)

#ifndef __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
{
        return 0;
}
#endif

struct kvm_memslots {
        u64 generation;
        atomic_long_t last_used_slot;
        struct rb_root_cached hva_tree;
        struct rb_root gfn_tree;
        /*
         * The mapping table from slot id to memslot.
         *
         * 7-bit bucket count matches the size of the old id to index array for
         * 512 slots, while giving good performance with this slot count.
         * Higher bucket counts bring only small performance improvements but
         * always result in higher memory usage (even for lower memslot counts).
         */
        DECLARE_HASHTABLE(id_hash, 7);
        int node_idx;
};

struct kvm {
#ifdef KVM_HAVE_MMU_RWLOCK
        rwlock_t mmu_lock;
#else
        spinlock_t mmu_lock;
#endif /* KVM_HAVE_MMU_RWLOCK */

        struct mutex slots_lock;

        /*
         * Protects the arch-specific fields of struct kvm_memory_slots in
         * use by the VM. To be used under the slots_lock (above) or in a
         * kvm->srcu critical section where acquiring the slots_lock would
         * lead to deadlock with the synchronize_srcu in
         * install_new_memslots.
         */
        struct mutex slots_arch_lock;
        struct mm_struct *mm; /* userspace tied to this vm */
        unsigned long nr_memslot_pages;
        /* The two memslot sets - active and inactive (per address space) */
        struct kvm_memslots __memslots[KVM_ADDRESS_SPACE_NUM][2];
        /* The current active memslot set for each address space */
        struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
        struct xarray vcpu_array;

        /* Used to wait for completion of MMU notifiers.  */
        spinlock_t mn_invalidate_lock;
        unsigned long mn_active_invalidate_count;
        struct rcuwait mn_memslots_update_rcuwait;

        /* For management / invalidation of gfn_to_pfn_caches */
        spinlock_t gpc_lock;
        struct list_head gpc_list;

        /*
         * created_vcpus is protected by kvm->lock, and is incremented
         * at the beginning of KVM_CREATE_VCPU.  online_vcpus is only
         * incremented after storing the kvm_vcpu pointer in vcpus,
         * and is accessed atomically.
         */
        atomic_t online_vcpus;
        int created_vcpus;
        int last_boosted_vcpu;
        struct list_head vm_list;
        struct mutex lock;
        struct kvm_io_bus __rcu *buses[KVM_NR_BUSES];
#ifdef CONFIG_HAVE_KVM_EVENTFD
        struct {
                spinlock_t        lock;
                struct list_head  items;
                struct list_head  resampler_list;
                struct mutex      resampler_lock;
        } irqfds;
        struct list_head ioeventfds;
#endif
        struct kvm_vm_stat stat;
        struct kvm_arch arch;
        refcount_t users_count;
#ifdef CONFIG_KVM_MMIO
        struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
        spinlock_t ring_lock;
        struct list_head coalesced_zones;
#endif

        struct mutex irq_lock;
#ifdef CONFIG_HAVE_KVM_IRQCHIP
        /*
         * Update side is protected by irq_lock.
         */
        struct kvm_irq_routing_table __rcu *irq_routing;
#endif
#ifdef CONFIG_HAVE_KVM_IRQFD
        struct hlist_head irq_ack_notifier_list;
#endif

#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
        struct mmu_notifier mmu_notifier;
        unsigned long mmu_notifier_seq;
        long mmu_notifier_count;
        unsigned long mmu_notifier_range_start;
        unsigned long mmu_notifier_range_end;
#endif
        struct list_head devices;
        u64 manual_dirty_log_protect;
        struct dentry *debugfs_dentry;
        struct kvm_stat_data **debugfs_stat_data;
        struct srcu_struct srcu;
        struct srcu_struct irq_srcu;
        pid_t userspace_pid;
        unsigned int max_halt_poll_ns;
        u32 dirty_ring_size;
        bool vm_bugged;
        bool vm_dead;

#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
        struct notifier_block pm_notifier;
#endif
        char stats_id[KVM_STATS_NAME_SIZE];
};

#define kvm_err(fmt, ...) \
        pr_err("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_info(fmt, ...) \
        pr_info("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_debug(fmt, ...) \
        pr_debug("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_debug_ratelimited(fmt, ...) \
        pr_debug_ratelimited("kvm [%i]: " fmt, task_pid_nr(current), \
                             ## __VA_ARGS__)
#define kvm_pr_unimpl(fmt, ...) \
        pr_err_ratelimited("kvm [%i]: " fmt, \
                           task_tgid_nr(current), ## __VA_ARGS__)

/* The guest did something we don't support. */
#define vcpu_unimpl(vcpu, fmt, ...)                                     \
        kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt,                  \
                        (vcpu)->vcpu_id, kvm_rip_read(vcpu), ## __VA_ARGS__)

#define vcpu_debug(vcpu, fmt, ...)                                      \
        kvm_debug("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
#define vcpu_debug_ratelimited(vcpu, fmt, ...)                          \
        kvm_debug_ratelimited("vcpu%i " fmt, (vcpu)->vcpu_id,           \
                              ## __VA_ARGS__)
#define vcpu_err(vcpu, fmt, ...)                                        \
        kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)

static inline void kvm_vm_dead(struct kvm *kvm)
{
        kvm->vm_dead = true;
        kvm_make_all_cpus_request(kvm, KVM_REQ_VM_DEAD);
}

static inline void kvm_vm_bugged(struct kvm *kvm)
{
        kvm->vm_bugged = true;
        kvm_vm_dead(kvm);
}


#define KVM_BUG(cond, kvm, fmt...)                              \
({                                                              \
        int __ret = (cond);                                     \
                                                                \
        if (WARN_ONCE(__ret && !(kvm)->vm_bugged, fmt))         \
                kvm_vm_bugged(kvm);                             \
        unlikely(__ret);                                        \
})

#define KVM_BUG_ON(cond, kvm)                                   \
({                                                              \
        int __ret = (cond);                                     \
                                                                \
        if (WARN_ON_ONCE(__ret && !(kvm)->vm_bugged))           \
                kvm_vm_bugged(kvm);                             \
        unlikely(__ret);                                        \
})

static inline bool kvm_dirty_log_manual_protect_and_init_set(struct kvm *kvm)
{
        return !!(kvm->manual_dirty_log_protect & KVM_DIRTY_LOG_INITIALLY_SET);
}

static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
{
        return srcu_dereference_check(kvm->buses[idx], &kvm->srcu,
                                      lockdep_is_held(&kvm->slots_lock) ||
                                      !refcount_read(&kvm->users_count));
}

static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
{
        int num_vcpus = atomic_read(&kvm->online_vcpus);
        i = array_index_nospec(i, num_vcpus);

        /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu.  */
        smp_rmb();
        return xa_load(&kvm->vcpu_array, i);
}

#define kvm_for_each_vcpu(idx, vcpup, kvm)                 \
        xa_for_each_range(&kvm->vcpu_array, idx, vcpup, 0, \
                          (atomic_read(&kvm->online_vcpus) - 1))

static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
{
        struct kvm_vcpu *vcpu = NULL;
        unsigned long i;

        if (id < 0)
                return NULL;
        if (id < KVM_MAX_VCPUS)
                vcpu = kvm_get_vcpu(kvm, id);
        if (vcpu && vcpu->vcpu_id == id)
                return vcpu;
        kvm_for_each_vcpu(i, vcpu, kvm)
                if (vcpu->vcpu_id == id)
                        return vcpu;
        return NULL;
}

static inline int kvm_vcpu_get_idx(struct kvm_vcpu *vcpu)
{
        return vcpu->vcpu_idx;
}

void kvm_destroy_vcpus(struct kvm *kvm);

void vcpu_load(struct kvm_vcpu *vcpu);
void vcpu_put(struct kvm_vcpu *vcpu);

#ifdef __KVM_HAVE_IOAPIC
void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm);
void kvm_arch_post_irq_routing_update(struct kvm *kvm);
#else
static inline void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm)
{
}
static inline void kvm_arch_post_irq_routing_update(struct kvm *kvm)
{
}
#endif

#ifdef CONFIG_HAVE_KVM_IRQFD
int kvm_irqfd_init(void);
void kvm_irqfd_exit(void);
#else
static inline int kvm_irqfd_init(void)
{
        return 0;
}

static inline void kvm_irqfd_exit(void)
{
}
#endif
int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
                  struct module *module);
void kvm_exit(void);

void kvm_get_kvm(struct kvm *kvm);
bool kvm_get_kvm_safe(struct kvm *kvm);
void kvm_put_kvm(struct kvm *kvm);
bool file_is_kvm(struct file *file);
void kvm_put_kvm_no_destroy(struct kvm *kvm);

static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
{
        as_id = array_index_nospec(as_id, KVM_ADDRESS_SPACE_NUM);
        return srcu_dereference_check(kvm->memslots[as_id], &kvm->srcu,
                        lockdep_is_held(&kvm->slots_lock) ||
                        !refcount_read(&kvm->users_count));
}

static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
{
        return __kvm_memslots(kvm, 0);
}

static inline struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu)
{
        int as_id = kvm_arch_vcpu_memslots_id(vcpu);

        return __kvm_memslots(vcpu->kvm, as_id);
}

static inline bool kvm_memslots_empty(struct kvm_memslots *slots)
{
        return RB_EMPTY_ROOT(&slots->gfn_tree);
}

#define kvm_for_each_memslot(memslot, bkt, slots)                             \
        hash_for_each(slots->id_hash, bkt, memslot, id_node[slots->node_idx]) \
                if (WARN_ON_ONCE(!memslot->npages)) {                         \
                } else

static inline
struct kvm_memory_slot *id_to_memslot(struct kvm_memslots *slots, int id)
{
        struct kvm_memory_slot *slot;
        int idx = slots->node_idx;

        hash_for_each_possible(slots->id_hash, slot, id_node[idx], id) {
                if (slot->id == id)
                        return slot;
        }

        return NULL;
}

/* Iterator used for walking memslots that overlap a gfn range. */
struct kvm_memslot_iter {
        struct kvm_memslots *slots;
        struct rb_node *node;
        struct kvm_memory_slot *slot;
};

static inline void kvm_memslot_iter_next(struct kvm_memslot_iter *iter)
{
        iter->node = rb_next(iter->node);
        if (!iter->node)
                return;

        iter->slot = container_of(iter->node, struct kvm_memory_slot, gfn_node[iter->slots->node_idx]);
}

static inline void kvm_memslot_iter_start(struct kvm_memslot_iter *iter,
                                          struct kvm_memslots *slots,
                                          gfn_t start)
{
        int idx = slots->node_idx;
        struct rb_node *tmp;
        struct kvm_memory_slot *slot;

        iter->slots = slots;

        /*
         * Find the so called "upper bound" of a key - the first node that has
         * its key strictly greater than the searched one (the start gfn in our case).
         */
        iter->node = NULL;
        for (tmp = slots->gfn_tree.rb_node; tmp; ) {
                slot = container_of(tmp, struct kvm_memory_slot, gfn_node[idx]);
                if (start < slot->base_gfn) {
                        iter->node = tmp;
                        tmp = tmp->rb_left;
                } else {
                        tmp = tmp->rb_right;
                }
        }

        /*
         * Find the slot with the lowest gfn that can possibly intersect with
         * the range, so we'll ideally have slot start <= range start
         */
        if (iter->node) {
                /*
                 * A NULL previous node means that the very first slot
                 * already has a higher start gfn.
                 * In this case slot start > range start.
                 */
                tmp = rb_prev(iter->node);
                if (tmp)
                        iter->node = tmp;
        } else {
                /* a NULL node below means no slots */
                iter->node = rb_last(&slots->gfn_tree);
        }

        if (iter->node) {
                iter->slot = container_of(iter->node, struct kvm_memory_slot, gfn_node[idx]);

                /*
                 * It is possible in the slot start < range start case that the
                 * found slot ends before or at range start (slot end <= range start)
                 * and so it does not overlap the requested range.
                 *
                 * In such non-overlapping case the next slot (if it exists) will
                 * already have slot start > range start, otherwise the logic above
                 * would have found it instead of the current slot.
                 */
                if (iter->slot->base_gfn + iter->slot->npages <= start)
                        kvm_memslot_iter_next(iter);
        }
}

static inline bool kvm_memslot_iter_is_valid(struct kvm_memslot_iter *iter, gfn_t end)
{
        if (!iter->node)
                return false;

        /*
         * If this slot starts beyond or at the end of the range so does
         * every next one
         */
        return iter->slot->base_gfn < end;
}

/* Iterate over each memslot at least partially intersecting [start, end) range */
#define kvm_for_each_memslot_in_gfn_range(iter, slots, start, end)      \
        for (kvm_memslot_iter_start(iter, slots, start);                \
             kvm_memslot_iter_is_valid(iter, end);                      \
             kvm_memslot_iter_next(iter))

/*
 * KVM_SET_USER_MEMORY_REGION ioctl allows the following operations:
 * - create a new memory slot
 * - delete an existing memory slot
 * - modify an existing memory slot
 *   -- move it in the guest physical memory space
 *   -- just change its flags
 *
 * Since flags can be changed by some of these operations, the following
 * differentiation is the best we can do for __kvm_set_memory_region():
 */
enum kvm_mr_change {
        KVM_MR_CREATE,
        KVM_MR_DELETE,
        KVM_MR_MOVE,
        KVM_MR_FLAGS_ONLY,
};

int kvm_set_memory_region(struct kvm *kvm,
                          const struct kvm_userspace_memory_region *mem);
int __kvm_set_memory_region(struct kvm *kvm,
                            const struct kvm_userspace_memory_region *mem);
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot);
void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                const struct kvm_memory_slot *old,
                                struct kvm_memory_slot *new,
                                enum kvm_mr_change change);
void kvm_arch_commit_memory_region(struct kvm *kvm,
                                struct kvm_memory_slot *old,
                                const struct kvm_memory_slot *new,
                                enum kvm_mr_change change);
/* flush all memory translations */
void kvm_arch_flush_shadow_all(struct kvm *kvm);
/* flush memory translations pointing to 'slot' */
void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
                                   struct kvm_memory_slot *slot);

int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
                            struct page **pages, int nr_pages);

struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable);
unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn,
                                      bool *writable);
void kvm_release_page_clean(struct page *page);
void kvm_release_page_dirty(struct page *page);
void kvm_set_page_accessed(struct page *page);

kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
                      bool *writable);
kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn);
kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn);
kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn,
                               bool atomic, bool *async, bool write_fault,
                               bool *writable, hva_t *hva);

void kvm_release_pfn_clean(kvm_pfn_t pfn);
void kvm_release_pfn_dirty(kvm_pfn_t pfn);
void kvm_set_pfn_dirty(kvm_pfn_t pfn);
void kvm_set_pfn_accessed(kvm_pfn_t pfn);

void kvm_release_pfn(kvm_pfn_t pfn, bool dirty);
int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
                        int len);
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);
int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                           void *data, unsigned long len);
int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                                 void *data, unsigned int offset,
                                 unsigned long len);
int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
                         int offset, int len);
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
                    unsigned long len);
int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                           void *data, unsigned long len);
int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                                  void *data, unsigned int offset,
                                  unsigned long len);
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                              gpa_t gpa, unsigned long len);

#define __kvm_get_guest(kvm, gfn, offset, v)                            \
({                                                                      \
        unsigned long __addr = gfn_to_hva(kvm, gfn);                    \
        typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
        int __ret = -EFAULT;                                            \
                                                                        \
        if (!kvm_is_error_hva(__addr))                                  \
                __ret = get_user(v, __uaddr);                           \
        __ret;                                                          \
})

#define kvm_get_guest(kvm, gpa, v)                                      \
({                                                                      \
        gpa_t __gpa = gpa;                                              \
        struct kvm *__kvm = kvm;                                        \
                                                                        \
        __kvm_get_guest(__kvm, __gpa >> PAGE_SHIFT,                     \
                        offset_in_page(__gpa), v);                      \
})

#define __kvm_put_guest(kvm, gfn, offset, v)                            \
({                                                                      \
        unsigned long __addr = gfn_to_hva(kvm, gfn);                    \
        typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
        int __ret = -EFAULT;                                            \
                                                                        \
        if (!kvm_is_error_hva(__addr))                                  \
                __ret = put_user(v, __uaddr);                           \
        if (!__ret)                                                     \
                mark_page_dirty(kvm, gfn);                              \
        __ret;                                                          \
})

#define kvm_put_guest(kvm, gpa, v)                                      \
({                                                                      \
        gpa_t __gpa = gpa;                                              \
        struct kvm *__kvm = kvm;                                        \
                                                                        \
        __kvm_put_guest(__kvm, __gpa >> PAGE_SHIFT,                     \
                        offset_in_page(__gpa), v);                      \
})

int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len);
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);
bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn);
unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn);
void mark_page_dirty_in_slot(struct kvm *kvm, const struct kvm_memory_slot *memslot, gfn_t gfn);
void mark_page_dirty(struct kvm *kvm, gfn_t gfn);

struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu);
struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn);
kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn);
kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map);
struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn);
void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty);
unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn);
unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable);
int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset,
                             int len);
int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
                               unsigned long len);
int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
                        unsigned long len);
int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, const void *data,
                              int offset, int len);
int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
                         unsigned long len);
void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn);

/**
 * kvm_gfn_to_pfn_cache_init - prepare a cached kernel mapping and HPA for a
 *                             given guest physical address.
 *
 * @kvm:           pointer to kvm instance.
 * @gpc:           struct gfn_to_pfn_cache object.
 * @vcpu:          vCPU to be used for marking pages dirty and to be woken on
 *                 invalidation.
 * @guest_uses_pa: indicates that the resulting host physical PFN is used while
 *                 @vcpu is IN_GUEST_MODE so invalidations should wake it.
 * @kernel_map:    requests a kernel virtual mapping (kmap / memremap).
 * @gpa:           guest physical address to map.
 * @len:           sanity check; the range being access must fit a single page.
 * @dirty:         mark the cache dirty immediately.
 *
 * @return:        0 for success.
 *                 -EINVAL for a mapping which would cross a page boundary.
 *                 -EFAULT for an untranslatable guest physical address.
 *
 * This primes a gfn_to_pfn_cache and links it into the @kvm's list for
 * invalidations to be processed. Invalidation callbacks to @vcpu using
 * %KVM_REQ_GPC_INVALIDATE will occur only for MMU notifiers, not for KVM
 * memslot changes. Callers are required to use kvm_gfn_to_pfn_cache_check()
 * to ensure that the cache is valid before accessing the target page.
 */
int kvm_gfn_to_pfn_cache_init(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
                              struct kvm_vcpu *vcpu, bool guest_uses_pa,
                              bool kernel_map, gpa_t gpa, unsigned long len,
                              bool dirty);

/**
 * kvm_gfn_to_pfn_cache_check - check validity of a gfn_to_pfn_cache.
 *
 * @kvm:           pointer to kvm instance.
 * @gpc:           struct gfn_to_pfn_cache object.
 * @gpa:           current guest physical address to map.
 * @len:           sanity check; the range being access must fit a single page.
 * @dirty:         mark the cache dirty immediately.
 *
 * @return:        %true if the cache is still valid and the address matches.
 *                 %false if the cache is not valid.
 *
 * Callers outside IN_GUEST_MODE context should hold a read lock on @gpc->lock
 * while calling this function, and then continue to hold the lock until the
 * access is complete.
 *
 * Callers in IN_GUEST_MODE may do so without locking, although they should
 * still hold a read lock on kvm->scru for the memslot checks.
 */
bool kvm_gfn_to_pfn_cache_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
                                gpa_t gpa, unsigned long len);

/**
 * kvm_gfn_to_pfn_cache_refresh - update a previously initialized cache.
 *
 * @kvm:           pointer to kvm instance.
 * @gpc:           struct gfn_to_pfn_cache object.
 * @gpa:           updated guest physical address to map.
 * @len:           sanity check; the range being access must fit a single page.
 * @dirty:         mark the cache dirty immediately.
 *
 * @return:        0 for success.
 *                 -EINVAL for a mapping which would cross a page boundary.
 *                 -EFAULT for an untranslatable guest physical address.
 *
 * This will attempt to refresh a gfn_to_pfn_cache. Note that a successful
 * returm from this function does not mean the page can be immediately
 * accessed because it may have raced with an invalidation. Callers must
 * still lock and check the cache status, as this function does not return
 * with the lock still held to permit access.
 */
int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
                                 gpa_t gpa, unsigned long len, bool dirty);

/**
 * kvm_gfn_to_pfn_cache_unmap - temporarily unmap a gfn_to_pfn_cache.
 *
 * @kvm:           pointer to kvm instance.
 * @gpc:           struct gfn_to_pfn_cache object.
 *
 * This unmaps the referenced page and marks it dirty, if appropriate. The
 * cache is left in the invalid state but at least the mapping from GPA to
 * userspace HVA will remain cached and can be reused on a subsequent
 * refresh.
 */
void kvm_gfn_to_pfn_cache_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);

/**
 * kvm_gfn_to_pfn_cache_destroy - destroy and unlink a gfn_to_pfn_cache.
 *
 * @kvm:           pointer to kvm instance.
 * @gpc:           struct gfn_to_pfn_cache object.
 *
 * This removes a cache from the @kvm's list to be processed on MMU notifier
 * invocation.
 */
void kvm_gfn_to_pfn_cache_destroy(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);

void kvm_sigset_activate(struct kvm_vcpu *vcpu);
void kvm_sigset_deactivate(struct kvm_vcpu *vcpu);

void kvm_vcpu_halt(struct kvm_vcpu *vcpu);
bool kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu);
bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
int kvm_vcpu_yield_to(struct kvm_vcpu *target);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible);

void kvm_flush_remote_tlbs(struct kvm *kvm);
void kvm_reload_remote_mmus(struct kvm *kvm);

#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc);
void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc);
void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
#endif

void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
                                   unsigned long end);
void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
                                   unsigned long end);

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg);
long kvm_arch_vcpu_ioctl(struct file *filp,
                         unsigned int ioctl, unsigned long arg);
vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf);

int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext);

void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
                                        struct kvm_memory_slot *slot,
                                        gfn_t gfn_offset,
                                        unsigned long mask);
void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot);

#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
                                        const struct kvm_memory_slot *memslot);
#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
                      int *is_dirty, struct kvm_memory_slot **memslot);
#endif

int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
                        bool line_status);
int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
                            struct kvm_enable_cap *cap);
long kvm_arch_vm_ioctl(struct file *filp,
                       unsigned int ioctl, unsigned long arg);

int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu);
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu);

int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
                                    struct kvm_translation *tr);

int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                  struct kvm_sregs *sregs);
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                  struct kvm_sregs *sregs);
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state);
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state);
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                                        struct kvm_guest_debug *dbg);
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu);

int kvm_arch_init(void *opaque);
void kvm_arch_exit(void);

void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id);
int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);

#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state);
#endif

#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
#endif

int kvm_arch_hardware_enable(void);
void kvm_arch_hardware_disable(void);
int kvm_arch_hardware_setup(void *opaque);
void kvm_arch_hardware_unsetup(void);
int kvm_arch_check_processor_compat(void *opaque);
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);
bool kvm_arch_dy_runnable(struct kvm_vcpu *vcpu);
bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu);
int kvm_arch_post_init_vm(struct kvm *kvm);
void kvm_arch_pre_destroy_vm(struct kvm *kvm);
int kvm_arch_create_vm_debugfs(struct kvm *kvm);

#ifndef __KVM_HAVE_ARCH_VM_ALLOC
/*
 * All architectures that want to use vzalloc currently also
 * need their own kvm_arch_alloc_vm implementation.
 */
static inline struct kvm *kvm_arch_alloc_vm(void)
{
        return kzalloc(sizeof(struct kvm), GFP_KERNEL);
}
#endif

static inline void __kvm_arch_free_vm(struct kvm *kvm)
{
        kvfree(kvm);
}

#ifndef __KVM_HAVE_ARCH_VM_FREE
static inline void kvm_arch_free_vm(struct kvm *kvm)
{
        __kvm_arch_free_vm(kvm);
}
#endif

#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
{
        return -ENOTSUPP;
}
#endif

#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
bool kvm_arch_has_noncoherent_dma(struct kvm *kvm);
#else
static inline void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
{
}

static inline void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
{
}

static inline bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
{
        return false;
}
#endif
#ifdef __KVM_HAVE_ARCH_ASSIGNED_DEVICE
void kvm_arch_start_assignment(struct kvm *kvm);
void kvm_arch_end_assignment(struct kvm *kvm);
bool kvm_arch_has_assigned_device(struct kvm *kvm);
#else
static inline void kvm_arch_start_assignment(struct kvm *kvm)
{
}

static inline void kvm_arch_end_assignment(struct kvm *kvm)
{
}

static inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
{
        return false;
}
#endif

static inline struct rcuwait *kvm_arch_vcpu_get_wait(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_WQP
        return vcpu->arch.waitp;
#else
        return &vcpu->wait;
#endif
}

/*
 * Wake a vCPU if necessary, but don't do any stats/metadata updates.  Returns
 * true if the vCPU was blocking and was awakened, false otherwise.
 */
static inline bool __kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
{
        return !!rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu));
}

static inline bool kvm_vcpu_is_blocking(struct kvm_vcpu *vcpu)
{
        return rcuwait_active(kvm_arch_vcpu_get_wait(vcpu));
}

#ifdef __KVM_HAVE_ARCH_INTC_INITIALIZED
/*
 * returns true if the virtual interrupt controller is initialized and
 * ready to accept virtual IRQ. On some architectures the virtual interrupt
 * controller is dynamically instantiated and this is not always true.
 */
bool kvm_arch_intc_initialized(struct kvm *kvm);
#else
static inline bool kvm_arch_intc_initialized(struct kvm *kvm)
{
        return true;
}
#endif

int kvm_arch_init_vm(struct kvm *kvm, unsigned long type);
void kvm_arch_destroy_vm(struct kvm *kvm);
void kvm_arch_sync_events(struct kvm *kvm);

int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);

bool kvm_is_reserved_pfn(kvm_pfn_t pfn);
bool kvm_is_zone_device_pfn(kvm_pfn_t pfn);

struct kvm_irq_ack_notifier {
        struct hlist_node link;
        unsigned gsi;
        void (*irq_acked)(struct kvm_irq_ack_notifier *kian);
};

int kvm_irq_map_gsi(struct kvm *kvm,
                    struct kvm_kernel_irq_routing_entry *entries, int gsi);
int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin);

int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
                bool line_status);
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *irq_entry, struct kvm *kvm,
                int irq_source_id, int level, bool line_status);
int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
                               struct kvm *kvm, int irq_source_id,
                               int level, bool line_status);
bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_notify_acked_gsi(struct kvm *kvm, int gsi);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
                                   struct kvm_irq_ack_notifier *kian);
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
                                   struct kvm_irq_ack_notifier *kian);
int kvm_request_irq_source_id(struct kvm *kvm);
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);

/*
 * Returns a pointer to the memslot if it contains gfn.
 * Otherwise returns NULL.
 */
static inline struct kvm_memory_slot *
try_get_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
{
        if (!slot)
                return NULL;

        if (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages)
                return slot;
        else
                return NULL;
}

/*
 * Returns a pointer to the memslot that contains gfn. Otherwise returns NULL.
 *
 * With "approx" set returns the memslot also when the address falls
 * in a hole. In that case one of the memslots bordering the hole is
 * returned.
 */
static inline struct kvm_memory_slot *
search_memslots(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
        struct kvm_memory_slot *slot;
        struct rb_node *node;
        int idx = slots->node_idx;

        slot = NULL;
        for (node = slots->gfn_tree.rb_node; node; ) {
                slot = container_of(node, struct kvm_memory_slot, gfn_node[idx]);
                if (gfn >= slot->base_gfn) {
                        if (gfn < slot->base_gfn + slot->npages)
                                return slot;
                        node = node->rb_right;
                } else
                        node = node->rb_left;
        }

        return approx ? slot : NULL;
}

static inline struct kvm_memory_slot *
____gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
        struct kvm_memory_slot *slot;

        slot = (struct kvm_memory_slot *)atomic_long_read(&slots->last_used_slot);
        slot = try_get_memslot(slot, gfn);
        if (slot)
                return slot;

        slot = search_memslots(slots, gfn, approx);
        if (slot) {
                atomic_long_set(&slots->last_used_slot, (unsigned long)slot);
                return slot;
        }

        return NULL;
}

/*
 * __gfn_to_memslot() and its descendants are here to allow arch code to inline
 * the lookups in hot paths.  gfn_to_memslot() itself isn't here as an inline
 * because that would bloat other code too much.
 */
static inline struct kvm_memory_slot *
__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
{
        return ____gfn_to_memslot(slots, gfn, false);
}

static inline unsigned long
__gfn_to_hva_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
{
        /*
         * The index was checked originally in search_memslots.  To avoid
         * that a malicious guest builds a Spectre gadget out of e.g. page
         * table walks, do not let the processor speculate loads outside
         * the guest's registered memslots.
         */
        unsigned long offset = gfn - slot->base_gfn;
        offset = array_index_nospec(offset, slot->npages);
        return slot->userspace_addr + offset * PAGE_SIZE;
}

static inline int memslot_id(struct kvm *kvm, gfn_t gfn)
{
        return gfn_to_memslot(kvm, gfn)->id;
}

static inline gfn_t
hva_to_gfn_memslot(unsigned long hva, struct kvm_memory_slot *slot)
{
        gfn_t gfn_offset = (hva - slot->userspace_addr) >> PAGE_SHIFT;

        return slot->base_gfn + gfn_offset;
}

static inline gpa_t gfn_to_gpa(gfn_t gfn)
{
        return (gpa_t)gfn << PAGE_SHIFT;
}

static inline gfn_t gpa_to_gfn(gpa_t gpa)
{
        return (gfn_t)(gpa >> PAGE_SHIFT);
}

static inline hpa_t pfn_to_hpa(kvm_pfn_t pfn)
{
        return (hpa_t)pfn << PAGE_SHIFT;
}

static inline struct page *kvm_vcpu_gpa_to_page(struct kvm_vcpu *vcpu,
                                                gpa_t gpa)
{
        return kvm_vcpu_gfn_to_page(vcpu, gpa_to_gfn(gpa));
}

static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
{
        unsigned long hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));

        return kvm_is_error_hva(hva);
}

enum kvm_stat_kind {
        KVM_STAT_VM,
        KVM_STAT_VCPU,
};

struct kvm_stat_data {
        struct kvm *kvm;
        const struct _kvm_stats_desc *desc;
        enum kvm_stat_kind kind;
};

struct _kvm_stats_desc {
        struct kvm_stats_desc desc;
        char name[KVM_STATS_NAME_SIZE];
};

#define STATS_DESC_COMMON(type, unit, base, exp, sz, bsz)                      \
        .flags = type | unit | base |                                          \
                 BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) |              \
                 BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) |              \
                 BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK),               \
        .exponent = exp,                                                       \
        .size = sz,                                                            \
        .bucket_size = bsz

#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz)            \
        {                                                                      \
                {                                                              \
                        STATS_DESC_COMMON(type, unit, base, exp, sz, bsz),     \
                        .offset = offsetof(struct kvm_vm_stat, generic.stat)   \
                },                                                             \
                .name = #stat,                                                 \
        }
#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz)          \
        {                                                                      \
                {                                                              \
                        STATS_DESC_COMMON(type, unit, base, exp, sz, bsz),     \
                        .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
                },                                                             \
                .name = #stat,                                                 \
        }
#define VM_STATS_DESC(stat, type, unit, base, exp, sz, bsz)                    \
        {                                                                      \
                {                                                              \
                        STATS_DESC_COMMON(type, unit, base, exp, sz, bsz),     \
                        .offset = offsetof(struct kvm_vm_stat, stat)           \
                },                                                             \
                .name = #stat,                                                 \
        }
#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, bsz)                  \
        {                                                                      \
                {                                                              \
                        STATS_DESC_COMMON(type, unit, base, exp, sz, bsz),     \
                        .offset = offsetof(struct kvm_vcpu_stat, stat)         \
                },                                                             \
                .name = #stat,                                                 \
        }
/* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, bsz)                \
        SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, bsz)

#define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent)               \
        STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE,                     \
                unit, base, exponent, 1, 0)
#define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent)                  \
        STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT,                        \
                unit, base, exponent, 1, 0)
#define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent)                     \
        STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK,                           \
                unit, base, exponent, 1, 0)
#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, bsz)     \
        STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST,                    \
                unit, base, exponent, sz, bsz)
#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz)             \
        STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST,                       \
                unit, base, exponent, sz, 0)

/* Cumulative counter, read/write */
#define STATS_DESC_COUNTER(SCOPE, name)                                        \
        STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_NONE,                \
                KVM_STATS_BASE_POW10, 0)
/* Instantaneous counter, read only */
#define STATS_DESC_ICOUNTER(SCOPE, name)                                       \
        STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_NONE,                   \
                KVM_STATS_BASE_POW10, 0)
/* Peak counter, read/write */
#define STATS_DESC_PCOUNTER(SCOPE, name)                                       \
        STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_NONE,                      \
                KVM_STATS_BASE_POW10, 0)

/* Cumulative time in nanosecond */
#define STATS_DESC_TIME_NSEC(SCOPE, name)                                      \
        STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,             \
                KVM_STATS_BASE_POW10, -9)
/* Linear histogram for time in nanosecond */
#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bsz)                     \
        STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS,            \
                KVM_STATS_BASE_POW10, -9, sz, bsz)
/* Logarithmic histogram for time in nanosecond */
#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz)                          \
        STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS,               \
                KVM_STATS_BASE_POW10, -9, sz)

#define KVM_GENERIC_VM_STATS()                                                 \
        STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush),                      \
        STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush_requests)

#define KVM_GENERIC_VCPU_STATS()                                               \
        STATS_DESC_COUNTER(VCPU_GENERIC, halt_successful_poll),                \
        STATS_DESC_COUNTER(VCPU_GENERIC, halt_attempted_poll),                 \
        STATS_DESC_COUNTER(VCPU_GENERIC, halt_poll_invalid),                   \
        STATS_DESC_COUNTER(VCPU_GENERIC, halt_wakeup),                         \
        STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_success_ns),              \
        STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns),                 \
        STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_wait_ns),                      \
        STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_success_hist,     \
                        HALT_POLL_HIST_COUNT),                                 \
        STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_hist,        \
                        HALT_POLL_HIST_COUNT),                                 \
        STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_wait_hist,             \
                        HALT_POLL_HIST_COUNT),                                 \
        STATS_DESC_ICOUNTER(VCPU_GENERIC, blocking)

extern struct dentry *kvm_debugfs_dir;

ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
                       const struct _kvm_stats_desc *desc,
                       void *stats, size_t size_stats,
                       char __user *user_buffer, size_t size, loff_t *offset);

/**
 * kvm_stats_linear_hist_update() - Update bucket value for linear histogram
 * statistics data.
 *
 * @data: start address of the stats data
 * @size: the number of bucket of the stats data
 * @value: the new value used to update the linear histogram's bucket
 * @bucket_size: the size (width) of a bucket
 */
static inline void kvm_stats_linear_hist_update(u64 *data, size_t size,
                                                u64 value, size_t bucket_size)
{
        size_t index = div64_u64(value, bucket_size);

        index = min(index, size - 1);
        ++data[index];
}

/**
 * kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
 * statistics data.
 *
 * @data: start address of the stats data
 * @size: the number of bucket of the stats data
 * @value: the new value used to update the logarithmic histogram's bucket
 */
static inline void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
{
        size_t index = fls64(value);

        index = min(index, size - 1);
        ++data[index];
}

#define KVM_STATS_LINEAR_HIST_UPDATE(array, value, bsize)                      \
        kvm_stats_linear_hist_update(array, ARRAY_SIZE(array), value, bsize)
#define KVM_STATS_LOG_HIST_UPDATE(array, value)                                \
        kvm_stats_log_hist_update(array, ARRAY_SIZE(array), value)


extern const struct kvm_stats_header kvm_vm_stats_header;
extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
extern const struct kvm_stats_header kvm_vcpu_stats_header;
extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[];

#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
{
        if (unlikely(kvm->mmu_notifier_count))
                return 1;
        /*
         * Ensure the read of mmu_notifier_count happens before the read
         * of mmu_notifier_seq.  This interacts with the smp_wmb() in
         * mmu_notifier_invalidate_range_end to make sure that the caller
         * either sees the old (non-zero) value of mmu_notifier_count or
         * the new (incremented) value of mmu_notifier_seq.
         * PowerPC Book3s HV KVM calls this under a per-page lock
         * rather than under kvm->mmu_lock, for scalability, so
         * can't rely on kvm->mmu_lock to keep things ordered.
         */
        smp_rmb();
        if (kvm->mmu_notifier_seq != mmu_seq)
                return 1;
        return 0;
}

static inline int mmu_notifier_retry_hva(struct kvm *kvm,
                                         unsigned long mmu_seq,
                                         unsigned long hva)
{
        lockdep_assert_held(&kvm->mmu_lock);
        /*
         * If mmu_notifier_count is non-zero, then the range maintained by
         * kvm_mmu_notifier_invalidate_range_start contains all addresses that
         * might be being invalidated. Note that it may include some false
         * positives, due to shortcuts when handing concurrent invalidations.
         */
        if (unlikely(kvm->mmu_notifier_count) &&
            hva >= kvm->mmu_notifier_range_start &&
            hva < kvm->mmu_notifier_range_end)
                return 1;
        if (kvm->mmu_notifier_seq != mmu_seq)
                return 1;
        return 0;
}
#endif

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING

#define KVM_MAX_IRQ_ROUTES 4096 /* might need extension/rework in the future */

bool kvm_arch_can_set_irq_routing(struct kvm *kvm);
int kvm_set_irq_routing(struct kvm *kvm,
                        const struct kvm_irq_routing_entry *entries,
                        unsigned nr,
                        unsigned flags);
int kvm_set_routing_entry(struct kvm *kvm,
                          struct kvm_kernel_irq_routing_entry *e,
                          const struct kvm_irq_routing_entry *ue);
void kvm_free_irq_routing(struct kvm *kvm);

#else

static inline void kvm_free_irq_routing(struct kvm *kvm) {}

#endif

int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);

#ifdef CONFIG_HAVE_KVM_EVENTFD

void kvm_eventfd_init(struct kvm *kvm);
int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args);

#ifdef CONFIG_HAVE_KVM_IRQFD
int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args);
void kvm_irqfd_release(struct kvm *kvm);
void kvm_irq_routing_update(struct kvm *);
#else
static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
{
        return -EINVAL;
}

static inline void kvm_irqfd_release(struct kvm *kvm) {}
#endif

#else

static inline void kvm_eventfd_init(struct kvm *kvm) {}

static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
{
        return -EINVAL;
}

static inline void kvm_irqfd_release(struct kvm *kvm) {}

#ifdef CONFIG_HAVE_KVM_IRQCHIP
static inline void kvm_irq_routing_update(struct kvm *kvm)
{
}
#endif

static inline int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
{
        return -ENOSYS;
}

#endif /* CONFIG_HAVE_KVM_EVENTFD */

void kvm_arch_irq_routing_update(struct kvm *kvm);

static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
{
        /*
         * Ensure the rest of the request is published to kvm_check_request's
         * caller.  Paired with the smp_mb__after_atomic in kvm_check_request.
         */
        smp_wmb();
        set_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}

static inline bool kvm_request_pending(struct kvm_vcpu *vcpu)
{
        return READ_ONCE(vcpu->requests);
}

static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu)
{
        return test_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}

static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
{
        clear_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}

static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
{
        if (kvm_test_request(req, vcpu)) {
                kvm_clear_request(req, vcpu);

                /*
                 * Ensure the rest of the request is visible to kvm_check_request's
                 * caller.  Paired with the smp_wmb in kvm_make_request.
                 */
                smp_mb__after_atomic();
                return true;
        } else {
                return false;
        }
}

extern bool kvm_rebooting;

extern unsigned int halt_poll_ns;
extern unsigned int halt_poll_ns_grow;
extern unsigned int halt_poll_ns_grow_start;
extern unsigned int halt_poll_ns_shrink;

struct kvm_device {
        const struct kvm_device_ops *ops;
        struct kvm *kvm;
        void *private;
        struct list_head vm_node;
};

/* create, destroy, and name are mandatory */
struct kvm_device_ops {
        const char *name;

        /*
         * create is called holding kvm->lock and any operations not suitable
         * to do while holding the lock should be deferred to init (see
         * below).
         */
        int (*create)(struct kvm_device *dev, u32 type);

        /*
         * init is called after create if create is successful and is called
         * outside of holding kvm->lock.
         */
        void (*init)(struct kvm_device *dev);

        /*
         * Destroy is responsible for freeing dev.
         *
         * Destroy may be called before or after destructors are called
         * on emulated I/O regions, depending on whether a reference is
         * held by a vcpu or other kvm component that gets destroyed
         * after the emulated I/O.
         */
        void (*destroy)(struct kvm_device *dev);

        /*
         * Release is an alternative method to free the device. It is
         * called when the device file descriptor is closed. Once
         * release is called, the destroy method will not be called
         * anymore as the device is removed from the device list of
         * the VM. kvm->lock is held.
         */
        void (*release)(struct kvm_device *dev);

        int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
        int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
        int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
        long (*ioctl)(struct kvm_device *dev, unsigned int ioctl,
                      unsigned long arg);
        int (*mmap)(struct kvm_device *dev, struct vm_area_struct *vma);
};

void kvm_device_get(struct kvm_device *dev);
void kvm_device_put(struct kvm_device *dev);
struct kvm_device *kvm_device_from_filp(struct file *filp);
int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type);
void kvm_unregister_device_ops(u32 type);

extern struct kvm_device_ops kvm_mpic_ops;
extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
extern struct kvm_device_ops kvm_arm_vgic_v3_ops;

#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT

static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
{
        vcpu->spin_loop.in_spin_loop = val;
}
static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
{
        vcpu->spin_loop.dy_eligible = val;
}

#else /* !CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */

static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
{
}

static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
{
}
#endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */

static inline bool kvm_is_visible_memslot(struct kvm_memory_slot *memslot)
{
        return (memslot && memslot->id < KVM_USER_MEM_SLOTS &&
                !(memslot->flags & KVM_MEMSLOT_INVALID));
}

struct kvm_vcpu *kvm_get_running_vcpu(void);
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);

#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
bool kvm_arch_has_irq_bypass(void);
int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
                           struct irq_bypass_producer *);
void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *,
                           struct irq_bypass_producer *);
void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *);
void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *);
int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
                                  uint32_t guest_irq, bool set);
bool kvm_arch_irqfd_route_changed(struct kvm_kernel_irq_routing_entry *,
                                  struct kvm_kernel_irq_routing_entry *);
#endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */

#ifdef CONFIG_HAVE_KVM_INVALID_WAKEUPS
/* If we wakeup during the poll time, was it a sucessful poll? */
static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu)
{
        return vcpu->valid_wakeup;
}

#else
static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu)
{
        return true;
}
#endif /* CONFIG_HAVE_KVM_INVALID_WAKEUPS */

#ifdef CONFIG_HAVE_KVM_NO_POLL
/* Callback that tells if we must not poll */
bool kvm_arch_no_poll(struct kvm_vcpu *vcpu);
#else
static inline bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
{
        return false;
}
#endif /* CONFIG_HAVE_KVM_NO_POLL */

#ifdef CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL
long kvm_arch_vcpu_async_ioctl(struct file *filp,
                               unsigned int ioctl, unsigned long arg);
#else
static inline long kvm_arch_vcpu_async_ioctl(struct file *filp,
                                             unsigned int ioctl,
                                             unsigned long arg)
{
        return -ENOIOCTLCMD;
}
#endif /* CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL */

void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
                                            unsigned long start, unsigned long end);

#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu);
#else
static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
{
        return 0;
}
#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */

typedef int (*kvm_vm_thread_fn_t)(struct kvm *kvm, uintptr_t data);

int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
                                uintptr_t data, const char *name,
                                struct task_struct **thread_ptr);

#ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
{
        vcpu->run->exit_reason = KVM_EXIT_INTR;
        vcpu->stat.signal_exits++;
}
#endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */

/*
 * This defines how many reserved entries we want to keep before we
 * kick the vcpu to the userspace to avoid dirty ring full.  This
 * value can be tuned to higher if e.g. PML is enabled on the host.
 */
#define  KVM_DIRTY_RING_RSVD_ENTRIES  64

/* Max number of entries allowed for each kvm dirty ring */
#define  KVM_DIRTY_RING_MAX_ENTRIES  65536

#endif