kvm_host.h

#ifndef __KVM_HOST_H
#define __KVM_HOST_H

/*
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 */

#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/mm.h>
#include <linux/preempt.h>
#include <linux/msi.h>
#include <linux/slab.h>
#include <linux/rcupdate.h>
#include <linux/ratelimit.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_MMIO_SIZE
#define KVM_MMIO_SIZE 8
#endif

/*
 * vcpu->requests bit members
 */
#define KVM_REQ_TLB_FLUSH          0
#define KVM_REQ_MIGRATE_TIMER      1
#define KVM_REQ_REPORT_TPR_ACCESS  2
#define KVM_REQ_MMU_RELOAD         3
#define KVM_REQ_TRIPLE_FAULT       4
#define KVM_REQ_PENDING_TIMER      5
#define KVM_REQ_UNHALT             6
#define KVM_REQ_MMU_SYNC           7
#define KVM_REQ_CLOCK_UPDATE       8
#define KVM_REQ_KICK               9
#define KVM_REQ_DEACTIVATE_FPU    10
#define KVM_REQ_EVENT             11
#define KVM_REQ_APF_HALT          12
#define KVM_REQ_STEAL_UPDATE      13
#define KVM_REQ_NMI               14
#define KVM_REQ_IMMEDIATE_EXIT    15

#define KVM_USERSPACE_IRQ_SOURCE_ID	0

struct kvm;
struct kvm_vcpu;
extern struct kmem_cache *kvm_vcpu_cache;

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

struct kvm_io_bus {
	int                   dev_count;
#define NR_IOBUS_DEVS 300
	struct kvm_io_range range[NR_IOBUS_DEVS];
};

enum kvm_bus {
	KVM_MMIO_BUS,
	KVM_PIO_BUS,
	KVM_NR_BUSES
};

int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
		     int len, const void *val);
int kvm_io_bus_read(struct kvm *kvm, 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);

#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;
	struct page *page;
	bool done;
};

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, gfn_t gfn,
		       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
};

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;
	unsigned long requests;
	unsigned long guest_debug;

	struct mutex mutex;
	struct kvm_run *run;

	int fpu_active;
	int guest_fpu_loaded, guest_xcr0_loaded;
	wait_queue_head_t wq;
	struct pid *pid;
	int sigset_active;
	sigset_t sigset;
	struct kvm_vcpu_stat stat;

#ifdef CONFIG_HAS_IOMEM
	int mmio_needed;
	int mmio_read_completed;
	int mmio_is_write;
	int mmio_size;
	int mmio_index;
	unsigned char mmio_data[KVM_MMIO_SIZE];
	gpa_t mmio_phys_addr;
#endif

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

	struct kvm_vcpu_arch arch;
};

static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
{
	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_lpage_info {
	unsigned long rmap_pde;
	int write_count;
};

struct kvm_memory_slot {
	gfn_t base_gfn;
	unsigned long npages;
	unsigned long flags;
	unsigned long *rmap;
	unsigned long *dirty_bitmap;
	unsigned long *dirty_bitmap_head;
	struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1];
	unsigned long userspace_addr;
	int user_alloc;
	int id;
};

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

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);
	union {
		struct {
			unsigned irqchip;
			unsigned pin;
		} irqchip;
		struct msi_msg msi;
	};
	struct hlist_node link;
};

#ifdef __KVM_HAVE_IOAPIC

struct kvm_irq_routing_table {
	int chip[KVM_NR_IRQCHIPS][KVM_IOAPIC_NUM_PINS];
	struct kvm_kernel_irq_routing_entry *rt_entries;
	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];
};

#else

struct kvm_irq_routing_table {};

#endif

struct kvm_memslots {
	int nmemslots;
	u64 generation;
	struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS +
					KVM_PRIVATE_MEM_SLOTS];
};

struct kvm {
	spinlock_t mmu_lock;
	struct mutex slots_lock;
	struct mm_struct *mm; /* userspace tied to this vm */
	struct kvm_memslots *memslots;
	struct srcu_struct srcu;
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
	u32 bsp_vcpu_id;
	struct kvm_vcpu *bsp_vcpu;
#endif
	struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
	atomic_t online_vcpus;
	int last_boosted_vcpu;
	struct list_head vm_list;
	struct mutex lock;
	struct kvm_io_bus *buses[KVM_NR_BUSES];
#ifdef CONFIG_HAVE_KVM_EVENTFD
	struct {
		spinlock_t        lock;
		struct list_head  items;
	} irqfds;
	struct list_head ioeventfds;
#endif
	struct kvm_vm_stat stat;
	struct kvm_arch arch;
	atomic_t users_count;
#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
	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 and,
	 * if configured, irqfds.lock.
	 */
	struct kvm_irq_routing_table __rcu *irq_routing;
	struct hlist_head mask_notifier_list;
	struct hlist_head irq_ack_notifier_list;
#endif

#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
	struct mmu_notifier mmu_notifier;
	unsigned long mmu_notifier_seq;
	long mmu_notifier_count;
#endif
	long tlbs_dirty;
};

/* The guest did something we don't support. */
#define pr_unimpl(vcpu, fmt, ...)					\
	pr_err_ratelimited("kvm: %i: cpu%i " fmt,			\
			   current->tgid, (vcpu)->vcpu_id , ## __VA_ARGS__)

#define kvm_printf(kvm, fmt ...) printk(KERN_DEBUG fmt)
#define vcpu_printf(vcpu, fmt...) kvm_printf(vcpu->kvm, fmt)

static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
{
	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++)

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);

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)
{
	return rcu_dereference_check(kvm->memslots,
			srcu_read_lock_held(&kvm->srcu)
			|| lockdep_is_held(&kvm->slots_lock));
}

#define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
#define HPA_ERR_MASK ((hpa_t)1 << HPA_MSB)
static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; }

extern struct page *bad_page;
extern struct page *fault_page;

extern pfn_t bad_pfn;
extern pfn_t fault_pfn;

int is_error_page(struct page *page);
int is_error_pfn(pfn_t pfn);
int is_hwpoison_pfn(pfn_t pfn);
int is_fault_pfn(pfn_t pfn);
int is_noslot_pfn(pfn_t pfn);
int is_invalid_pfn(pfn_t pfn);
int kvm_is_error_hva(unsigned long addr);
int kvm_set_memory_region(struct kvm *kvm,
			  struct kvm_userspace_memory_region *mem,
			  int user_alloc);
int __kvm_set_memory_region(struct kvm *kvm,
			    struct kvm_userspace_memory_region *mem,
			    int user_alloc);
int kvm_arch_prepare_memory_region(struct kvm *kvm,
				struct kvm_memory_slot *memslot,
				struct kvm_memory_slot old,
				struct kvm_userspace_memory_region *mem,
				int user_alloc);
void kvm_arch_commit_memory_region(struct kvm *kvm,
				struct kvm_userspace_memory_region *mem,
				struct kvm_memory_slot old,
				int user_alloc);
void kvm_disable_largepages(void);
void kvm_arch_flush_shadow(struct kvm *kvm);

int gfn_to_page_many_atomic(struct kvm *kvm, 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);
void kvm_release_page_clean(struct page *page);
void kvm_release_page_dirty(struct page *page);
void kvm_set_page_dirty(struct page *page);
void kvm_set_page_accessed(struct page *page);

pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr);
pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn);
pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
		       bool write_fault, bool *writable);
pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn);
pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
		      bool *writable);
pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
			 struct kvm_memory_slot *slot, gfn_t gfn);
void kvm_release_pfn_dirty(pfn_t);
void kvm_release_pfn_clean(pfn_t pfn);
void kvm_set_pfn_dirty(pfn_t pfn);
void kvm_set_pfn_accessed(pfn_t pfn);
void kvm_get_pfn(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_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
			      gpa_t gpa);
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);
int 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);
void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
			     gfn_t gfn);

void kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu);
void kvm_resched(struct kvm_vcpu *vcpu);
void kvm_load_guest_fpu(struct kvm_vcpu *vcpu);
void kvm_put_guest_fpu(struct kvm_vcpu *vcpu);

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

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);

int kvm_dev_ioctl_check_extension(long ext);

int kvm_get_dirty_log(struct kvm *kvm,
			struct kvm_dirty_log *log, int *is_dirty);
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
				struct kvm_dirty_log *log);

int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
				   struct
				   kvm_userspace_memory_region *mem,
				   int user_alloc);
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_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_destroy(struct kvm_vcpu *vcpu);

int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu);
int kvm_arch_hardware_enable(void *garbage);
void kvm_arch_hardware_disable(void *garbage);
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);

void kvm_free_physmem(struct kvm *kvm);

#ifndef __KVM_HAVE_ARCH_VM_ALLOC
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

int kvm_arch_init_vm(struct kvm *kvm);
void kvm_arch_destroy_vm(struct kvm *kvm);
void kvm_free_all_assigned_devices(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);

int kvm_is_mmio_pfn(pfn_t pfn);

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

struct kvm_assigned_dev_kernel {
	struct kvm_irq_ack_notifier ack_notifier;
	struct list_head list;
	int assigned_dev_id;
	int host_segnr;
	int host_busnr;
	int host_devfn;
	unsigned int entries_nr;
	int host_irq;
	bool host_irq_disabled;
	struct msix_entry *host_msix_entries;
	int guest_irq;
	struct msix_entry *guest_msix_entries;
	unsigned long irq_requested_type;
	int irq_source_id;
	int flags;
	struct pci_dev *dev;
	struct kvm *kvm;
	spinlock_t intx_lock;
	char irq_name[32];
	struct pci_saved_state *pci_saved_state;
};

struct kvm_irq_mask_notifier {
	void (*func)(struct kvm_irq_mask_notifier *kimn, bool masked);
	int irq;
	struct hlist_node link;
};

void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
				    struct kvm_irq_mask_notifier *kimn);
void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
				      struct kvm_irq_mask_notifier *kimn);
void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
			     bool mask);

#ifdef __KVM_HAVE_IOAPIC
void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,
				   union kvm_ioapic_redirect_entry *entry,
				   unsigned long *deliver_bitmask);
#endif
int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level);
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *irq_entry, struct kvm *kvm,
		int irq_source_id, int level);
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);

/* For vcpu->arch.iommu_flags */
#define KVM_IOMMU_CACHE_COHERENCY	0x1

#ifdef CONFIG_IOMMU_API
int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot);
int kvm_iommu_map_guest(struct kvm *kvm);
int kvm_iommu_unmap_guest(struct kvm *kvm);
int kvm_assign_device(struct kvm *kvm,
		      struct kvm_assigned_dev_kernel *assigned_dev);
int kvm_deassign_device(struct kvm *kvm,
			struct kvm_assigned_dev_kernel *assigned_dev);
#else /* CONFIG_IOMMU_API */
static inline int kvm_iommu_map_pages(struct kvm *kvm,
				      struct kvm_memory_slot *slot)
{
	return 0;
}

static inline int kvm_iommu_map_guest(struct kvm *kvm)
{
	return -ENODEV;
}

static inline int kvm_iommu_unmap_guest(struct kvm *kvm)
{
	return 0;
}

static inline int kvm_assign_device(struct kvm *kvm,
		struct kvm_assigned_dev_kernel *assigned_dev)
{
	return 0;
}

static inline int kvm_deassign_device(struct kvm *kvm,
		struct kvm_assigned_dev_kernel *assigned_dev)
{
	return 0;
}
#endif /* CONFIG_IOMMU_API */

static inline void kvm_guest_enter(void)
{
	BUG_ON(preemptible());
	account_system_vtime(current);
	current->flags |= PF_VCPU;
	/* 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 userspase 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.
	 */
	rcu_virt_note_context_switch(smp_processor_id());
}

static inline void kvm_guest_exit(void)
{
	account_system_vtime(current);
	current->flags &= ~PF_VCPU;
}

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

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 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(pfn_t pfn)
{
	return (hpa_t)pfn << PAGE_SHIFT;
}

static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
	set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);
}

enum kvm_stat_kind {
	KVM_STAT_VM,
	KVM_STAT_VCPU,
};

struct kvm_stats_debugfs_item {
	const char *name;
	int offset;
	enum kvm_stat_kind kind;
	struct dentry *dentry;
};
extern struct kvm_stats_debugfs_item debugfs_entries[];
extern struct dentry *kvm_debugfs_dir;

#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
static inline int mmu_notifier_retry(struct kvm_vcpu *vcpu, unsigned long mmu_seq)
{
	if (unlikely(vcpu->kvm->mmu_notifier_count))
		return 1;
	/*
	 * Both reads happen under the mmu_lock and both values are
	 * modified under mmu_lock, so there's no need of smb_rmb()
	 * here in between, otherwise mmu_notifier_count should be
	 * read before mmu_notifier_seq, see
	 * mmu_notifier_invalidate_range_end write side.
	 */
	if (vcpu->kvm->mmu_notifier_seq != mmu_seq)
		return 1;
	return 0;
}
#endif

#ifdef CONFIG_HAVE_KVM_IRQCHIP

#define KVM_MAX_IRQ_ROUTES 1024

int kvm_setup_default_irq_routing(struct kvm *kvm);
int kvm_set_irq_routing(struct kvm *kvm,
			const struct kvm_irq_routing_entry *entries,
			unsigned nr,
			unsigned flags);
void kvm_free_irq_routing(struct kvm *kvm);

#else

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

#endif

#ifdef CONFIG_HAVE_KVM_EVENTFD

void kvm_eventfd_init(struct kvm *kvm);
int kvm_irqfd(struct kvm *kvm, int fd, int gsi, int flags);
void kvm_irqfd_release(struct kvm *kvm);
void kvm_irq_routing_update(struct kvm *, struct kvm_irq_routing_table *);
int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args);

#else

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

static inline int kvm_irqfd(struct kvm *kvm, int fd, int gsi, int flags)
{
	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,
					  struct kvm_irq_routing_table *irq_rt)
{
	rcu_assign_pointer(kvm->irq_routing, irq_rt);
}
#endif

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

#endif /* CONFIG_HAVE_KVM_EVENTFD */

#ifdef CONFIG_KVM_APIC_ARCHITECTURE
static inline bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
{
	return vcpu->kvm->bsp_vcpu_id == vcpu->vcpu_id;
}
#endif

#ifdef __KVM_HAVE_DEVICE_ASSIGNMENT

long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
				  unsigned long arg);

#else

static inline long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
						unsigned long arg)
{
	return -ENOTTY;
}

#endif

static inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
{
	set_bit(req, &vcpu->requests);
}

static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
{
	if (test_bit(req, &vcpu->requests)) {
		clear_bit(req, &vcpu->requests);
		return true;
	} else {
		return false;
	}
}

#endif