LXR linux/include/linux/kvm_dirty

   1#ifndef KVM_DIRTY_RING_H
   2#define KVM_DIRTY_RING_H
   3
   4#include <linux/kvm.h>
   5
   6/**
   7 * kvm_dirty_ring: KVM internal dirty ring structure
   8 *
   9 * @dirty_index: free running counter that points to the next slot in
  10 *               dirty_ring->dirty_gfns, where a new dirty page should go
  11 * @reset_index: free running counter that points to the next dirty page
  12 *               in dirty_ring->dirty_gfns for which dirty trap needs to
  13 *               be reenabled
  14 * @size:        size of the compact list, dirty_ring->dirty_gfns
  15 * @soft_limit:  when the number of dirty pages in the list reaches this
  16 *               limit, vcpu that owns this ring should exit to userspace
  17 *               to allow userspace to harvest all the dirty pages
  18 * @dirty_gfns:  the array to keep the dirty gfns
  19 * @index:       index of this dirty ring
  20 */
  21struct kvm_dirty_ring {
  22        u32 dirty_index;
  23        u32 reset_index;
  24        u32 size;
  25        u32 soft_limit;
  26        struct kvm_dirty_gfn *dirty_gfns;
  27        int index;
  28};
  29
  30#if (KVM_DIRTY_LOG_PAGE_OFFSET == 0)
  31/*
  32 * If KVM_DIRTY_LOG_PAGE_OFFSET not defined, kvm_dirty_ring.o should
  33 * not be included as well, so define these nop functions for the arch.
  34 */
  35static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
  36{
  37        return 0;
  38}
  39
  40static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
  41                                       int index, u32 size)
  42{
  43        return 0;
  44}
  45
  46static inline struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm)
  47{
  48        return NULL;
  49}
  50
  51static inline int kvm_dirty_ring_reset(struct kvm *kvm,
  52                                       struct kvm_dirty_ring *ring)
  53{
  54        return 0;
  55}
  56
  57static inline void kvm_dirty_ring_push(struct kvm_dirty_ring *ring,
  58                                       u32 slot, u64 offset)
  59{
  60}
  61
  62static inline struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring,
  63                                                   u32 offset)
  64{
  65        return NULL;
  66}
  67
  68static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
  69{
  70}
  71
  72static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
  73{
  74        return true;
  75}
  76
  77#else /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */
  78
  79u32 kvm_dirty_ring_get_rsvd_entries(void);
  80int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
  81struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm);
  82
  83/*
  84 * called with kvm->slots_lock held, returns the number of
  85 * processed pages.
  86 */
  87int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring);
  88
  89/*
  90 * returns =0: successfully pushed
  91 *         <0: unable to push, need to wait
  92 */
  93void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);
  94
  95/* for use in vm_operations_struct */
  96struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);
  97
  98void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
  99bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring);
 100
 101#endif /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */
 102
 103#endif  /* KVM_DIRTY_RING_H */
 104