text: /* 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/bug.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/swait.h>
  #include <linux/refcount.h>
  #include <linux/nospec.h>
  #include <asm/signal.h>
  
  #include <linux/kvm.h>
  #include <linux/kvm_para.h>
  
  #include <linux/kvm_types.h>
  
  #include <asm/kvm_host.h>
  
  #ifndef KVM_MAX_VCPU_ID
  #define KVM_MAX_VCPU_ID 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_PENDING_TIMER     2
  #define KVM_REQ_UNHALT            3
  #define KVM_REQUEST_ARCH_BASE     8
  
  #define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \
  	BUILD_BUG_ON((unsigned)(nr) >= (FIELD_SIZEOF(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)
  
  #define KVM_USERSPACE_IRQ_SOURCE_ID		0
  #define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID	1
  
  extern struct kmem_cache *kvm_vcpu_cache;
  
  extern spinlock_t 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);
  void 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;
  	gva_t gva;
  	unsigned long addr;
  	struct kvm_arch_async_pf arch;
  	bool   wakeup_all;
  };
  
  void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
  void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
  int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, unsigned long hva,
  		       struct kvm_arch_async_pf *arch);
  int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
  #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;
  }
  
  /*
   * 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;
  	int srcu_idx;
  	int mode;
  	u64 requests;
  	unsigned long guest_debug;
  
  	int pre_pcpu;
  	struct list_head blocked_vcpu_list;
  
  	struct mutex mutex;
  	struct kvm_run *run;
  
  	int guest_xcr0_loaded;
  	struct swait_queue_head wq;
  	struct pid __rcu *pid;
  	int sigset_active;
  	sigset_t sigset;
  	struct kvm_vcpu_stat stat;
  	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;
  	struct kvm_vcpu_arch arch;
  	struct dentry *debugfs_dentry;
  };
  
  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)
  
  struct kvm_memory_slot {
  	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;
  };
  
  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);
  }
  
  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_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 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[0];
  };
  #endif
  
  #ifndef KVM_PRIVATE_MEM_SLOTS
  #define KVM_PRIVATE_MEM_SLOTS 0
  #endif
  
  #ifndef KVM_MEM_SLOTS_NUM
  #define KVM_MEM_SLOTS_NUM (KVM_USER_MEM_SLOTS + KVM_PRIVATE_MEM_SLOTS)
  #endif
  
  #ifndef __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
  static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
  {
  	return 0;
  }
  #endif
  
  /*
   * Note:
   * memslots are not sorted by id anymore, please use id_to_memslot()
   * to get the memslot by its id.
   */
  struct kvm_memslots {
  	u64 generation;
  	struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM];
  	/* The mapping table from slot id to the index in memslots[]. */
  	short id_to_index[KVM_MEM_SLOTS_NUM];
  	atomic_t lru_slot;
  	int used_slots;
  };
  
  struct kvm {
  	spinlock_t mmu_lock;
  	struct mutex slots_lock;
  	struct mm_struct *mm; /* userspace tied to this vm */
  	struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
  	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
  
  	/*
  	 * 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;
  #endif
  	long tlbs_dirty;
  	struct list_head devices;
  	bool 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;
  };
  
  #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 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 kvm->vcpus[i];
  }
  
  #define kvm_for_each_vcpu(idx, vcpup, kvm) \
  	for (idx = 0; \
  	     idx < atomic_read(&kvm->online_vcpus) && \
  	     (vcpup = kvm_get_vcpu(kvm, idx)) != NULL; \
  	     idx++)
  
  static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
  {
  	struct kvm_vcpu *vcpu = NULL;
  	int 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)
  {
  	struct kvm_vcpu *tmp;
  	int idx;
  
  	kvm_for_each_vcpu(idx, tmp, vcpu->kvm)
  		if (tmp == vcpu)
  			return idx;
  	BUG();
  }
  
  #define kvm_for_each_memslot(memslot, slots)	\
  	for (memslot = &slots->memslots[0];	\
  	      memslot < slots->memslots + KVM_MEM_SLOTS_NUM && memslot->npages;\
  		memslot++)
  
  int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id);
  void kvm_vcpu_uninit(struct kvm_vcpu *vcpu);
  
  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);
  void kvm_put_kvm(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 struct kvm_memory_slot *
  id_to_memslot(struct kvm_memslots *slots, int id)
  {
  	int index = slots->id_to_index[id];
  	struct kvm_memory_slot *slot;
  
  	slot = &slots->memslots[index];
  
  	WARN_ON(slot->id != id);
  	return slot;
  }
  
  /*
   * 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 *free,
  			   struct kvm_memory_slot *dont);
  int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
  			    unsigned long npages);
  void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
  int kvm_arch_prepare_memory_region(struct kvm *kvm,
  				struct kvm_memory_slot *memslot,
  				const struct kvm_userspace_memory_region *mem,
  				enum kvm_mr_change change);
  void kvm_arch_commit_memory_region(struct kvm *kvm,
  				const struct kvm_userspace_memory_region *mem,
  				const struct kvm_memory_slot *old,
  				const struct kvm_memory_slot *new,
  				enum kvm_mr_change change);
  bool kvm_largepages_enabled(void);
  void kvm_disable_largepages(void);
  /* 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_atomic(struct kvm *kvm, gfn_t gfn);
  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(struct kvm_memory_slot *slot, gfn_t gfn);
  kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn);
  kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
  			       bool atomic, bool *async, bool write_fault,
  			       bool *writable);
  
  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_get_pfn(kvm_pfn_t pfn);
  
  int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
  			int len);
  int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
  			  unsigned long 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_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);
  int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
  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);
  unsigned long kvm_host_page_size(struct kvm *kvm, 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);
  
  void kvm_sigset_activate(struct kvm_vcpu *vcpu);
  void kvm_sigset_deactivate(struct kvm_vcpu *vcpu);
  
  void 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);
  
  bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
  				 unsigned long *vcpu_bitmap, cpumask_var_t tmp);
  bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
  
  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);
  
  int kvm_get_dirty_log(struct kvm *kvm,
  			struct kvm_dirty_log *log, int *is_dirty);
  
  int kvm_get_dirty_log_protect(struct kvm *kvm,
  			      struct kvm_dirty_log *log, bool *flush);
  int kvm_clear_dirty_log_protect(struct kvm *kvm,
  				struct kvm_clear_dirty_log *log, bool *flush);
  
  void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
  					struct kvm_memory_slot *slot,
  					gfn_t gfn_offset,
  					unsigned long mask);
  
  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
  				struct kvm_dirty_log *log);
  int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
  				  struct kvm_clear_dirty_log *log);
  
  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, struct kvm_run *kvm_run);
  
  int kvm_arch_init(void *opaque);
  void kvm_arch_exit(void);
  
  int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu);
  void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu);
  
  void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
  
  void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu);
  void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
  void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
  struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id);
  int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu);
  void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
  void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
  
  bool kvm_arch_has_vcpu_debugfs(void);
  int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu);
  
  int kvm_arch_hardware_enable(void);
  void kvm_arch_hardware_disable(void);
  int kvm_arch_hardware_setup(void);
  void kvm_arch_hardware_unsetup(void);
  void kvm_arch_check_processor_compat(void *rtn);
  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);
  
  #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);
  }
  
  static inline void kvm_arch_free_vm(struct kvm *kvm)
  {
  	kfree(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 swait_queue_head *kvm_arch_vcpu_wq(struct kvm_vcpu *vcpu)
  {
  #ifdef __KVM_HAVE_ARCH_WQP
  	return vcpu->arch.wqp;
  #else
  	return &vcpu->wq;
  #endif
  }
  
  #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);
  void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
  
  bool kvm_is_reserved_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);
  
  /*
   * search_memslots() and __gfn_to_memslot() are here because they are
   * used in non-modular code in arch/powerpc/kvm/book3s_hv_rm_mmu.c.
   * gfn_to_memslot() itself isn't here as an inline because that would
   * bloat other code too much.
   */
  static inline struct kvm_memory_slot *
  search_memslots(struct kvm_memslots *slots, gfn_t gfn)
  {
  	int start = 0, end = slots->used_slots;
  	int slot = atomic_read(&slots->lru_slot);
  	struct kvm_memory_slot *memslots = slots->memslots;
  
  	if (gfn >= memslots[slot].base_gfn &&
  	    gfn < memslots[slot].base_gfn + memslots[slot].npages)
  		return &memslots[slot];
  
  	while (start < end) {
  		slot = start + (end - start) / 2;
  
  		if (gfn >= memslots[slot].base_gfn)
  			end = slot;
  		else
  			start = slot + 1;
  	}
  
  	if (gfn >= memslots[start].base_gfn &&
  	    gfn < memslots[start].base_gfn + memslots[start].npages) {
  		atomic_set(&slots->lru_slot, start);
  		return &memslots[start];
  	}
  
  	return NULL;
  }
  
  static inline struct kvm_memory_slot *
  __gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
  {
  	return search_memslots(slots, gfn);
  }
  
  static inline unsigned long
  __gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
  {
  	return slot->userspace_addr + (gfn - slot->base_gfn) * 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 {
  	int offset;
  	struct kvm *kvm;
  };
  
  struct kvm_stats_debugfs_item {
  	const char *name;
  	int offset;
  	enum kvm_stat_kind kind;
  };
  extern struct kvm_stats_debugfs_item debugfs_entries[];
  extern struct dentry *kvm_debugfs_dir;
  
  #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;
  }
  #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 {
  	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(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 */
  
  #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);
  #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 */
  
  int kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
  		unsigned long start, unsigned long end, bool blockable);
  
  #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 */
  
  #endif
  