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 /* 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)
 #define KVM_REQUEST_NO_ACTION      BIT(10)
 /*
  * 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_VM_DEAD           (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 #define KVM_REQ_UNBLOCK           2
 #define KVM_REQ_UNHALT            3
 #define KVM_REQUEST_ARCH_BASE     8
 
 /*
  * KVM_REQ_OUTSIDE_GUEST_MODE exists is purely as way to force the vCPU to
  * OUTSIDE_GUEST_MODE.  KVM_REQ_OUTSIDE_GUEST_MODE differs from a vCPU "kick"
  * in that it ensures the vCPU has reached OUTSIDE_GUEST_MODE before continuing
  * on.  A kick only guarantees that the vCPU is on its way out, e.g. a previous
  * kick may have set vcpu->mode to EXITING_GUEST_MODE, and so there's no
  * guarantee the vCPU received an IPI and has actually exited guest mode.
  */
 #define KVM_REQ_OUTSIDE_GUEST_MODE  (KVM_REQUEST_NO_ACTION | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
 
 #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; /* Don't use this directly.  You've been warned. */
 #ifdef CONFIG_PROVE_RCU
     int srcu_depth;
 #endif
     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();
     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_id;
     int vcpu_idx;
     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_INTERNAL_MEM_SLOTS
 #define KVM_INTERNAL_MEM_SLOTS 0
 #endif
 
 #define KVM_MEM_SLOTS_NUM SHRT_MAX
 #define KVM_USER_MEM_SLOTS (KVM_MEM_SLOTS_NUM - KVM_INTERNAL_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 max_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_invalidate_seq;
     long mmu_invalidate_in_progress;
     unsigned long mmu_invalidate_range_start;
     unsigned long mmu_invalidate_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 void kvm_vcpu_srcu_read_lock(struct kvm_vcpu *vcpu)
 {
 #ifdef CONFIG_PROVE_RCU
     WARN_ONCE(vcpu->srcu_depth++,
           "KVM: Illegal vCPU srcu_idx LOCK, depth=%d", vcpu->srcu_depth - 1);
 #endif
     vcpu->____srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 }
 
 static inline void kvm_vcpu_srcu_read_unlock(struct kvm_vcpu *vcpu)
 {
     srcu_read_unlock(&vcpu->kvm->srcu, vcpu->____srcu_idx);
 
 #ifdef CONFIG_PROVE_RCU
     WARN_ONCE(--vcpu->srcu_depth,
           "KVM: Illegal vCPU srcu_idx UNLOCK, depth=%d", vcpu->srcu_depth);
 #endif
 }
 
 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;
 }
 
 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);
 
 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);
 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.
  * @usage:     indicates if the resulting host physical PFN is used while
  *         the @vcpu is IN_GUEST_MODE (in which case invalidation of 
  *         the cache from MMU notifiers---but not for KVM memslot
  *         changes!---will also force @vcpu to exit the guest and
  *         refresh the cache); and/or if the PFN used directly
  *         by KVM (and thus needs a kernel virtual mapping).
  * @gpa:       guest physical address to map.
  * @len:       sanity check; the range being access must fit a single page.
  *
  * @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.  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, enum pfn_cache_usage usage,
                   gpa_t gpa, unsigned long len);
 
 /**
  * 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.
  *
  * @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.
  *
  * @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);
 
 /**
  * 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. 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);
 
 #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_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, 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_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
                   unsigned long end);
 void kvm_mmu_invalidate_end(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);
 #else
 static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
 #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 __always_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
 
 #ifdef CONFIG_GUEST_PERF_EVENTS
 unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu);
 
 void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void));
 void kvm_unregister_perf_callbacks(void);
 #else
 static inline void kvm_register_perf_callbacks(void *ign) {}
 static inline void kvm_unregister_perf_callbacks(void) {}
 #endif /* CONFIG_GUEST_PERF_EVENTS */
 
 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);
 
 struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn);
 bool kvm_is_zone_device_page(struct page *page);
 
 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 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)
 
 /* Instantaneous boolean value, read only */
 #define STATS_DESC_IBOOLEAN(SCOPE, name)                       \
     STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BOOLEAN,            \
         KVM_STATS_BASE_POW10, 0)
 /* Peak (sticky) boolean value, read/write */
 #define STATS_DESC_PBOOLEAN(SCOPE, name)                       \
     STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_BOOLEAN,               \
         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_IBOOLEAN(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_invalidate_retry(struct kvm *kvm, unsigned long mmu_seq)
 {
     if (unlikely(kvm->mmu_invalidate_in_progress))
         return 1;
     /*
      * Ensure the read of mmu_invalidate_in_progress happens before
      * the read of mmu_invalidate_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_invalidate_in_progress or the new (incremented) value of
      * mmu_invalidate_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_invalidate_seq != mmu_seq)
         return 1;
     return 0;
 }
 
 static inline int mmu_invalidate_retry_hva(struct kvm *kvm,
                        unsigned long mmu_seq,
                        unsigned long hva)
 {
     lockdep_assert_held(&kvm->mmu_lock);
     /*
      * If mmu_invalidate_in_progress 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_invalidate_in_progress) &&
         hva >= kvm->mmu_invalidate_range_start &&
         hva < kvm->mmu_invalidate_range_end)
         return 1;
     if (kvm->mmu_invalidate_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 __always_inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
 {
     /*
      * Request that don't require vCPU action should never be logged in
      * vcpu->requests.  The vCPU won't clear the request, so it will stay
      * logged indefinitely and prevent the vCPU from entering the guest.
      */
     BUILD_BUG_ON(!__builtin_constant_p(req) ||
              (req & KVM_REQUEST_NO_ACTION));
 
     __kvm_make_request(req, vcpu);
 }
 
 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);
 
 void kvm_arch_guest_memory_reclaimed(struct kvm *kvm);
 
 #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

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