include/linux/kvm_dirty_ring.h

   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  */
  21 struct 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 #ifndef CONFIG_HAVE_KVM_DIRTY_RING
  31 /*
  32  * If CONFIG_HAVE_HVM_DIRTY_RING not defined, kvm_dirty_ring.o should
  33  * not be included as well, so define these nop functions for the arch.
  34  */
  35 static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
  36 {
  37         return 0;
  38 }
  39
  40 static inline bool kvm_use_dirty_bitmap(struct kvm *kvm)
  41 {
  42         return true;
  43 }
  44
  45 static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
  46                                        int index, u32 size)
  47 {
  48         return 0;
  49 }
  50
  51 static inline int kvm_dirty_ring_reset(struct kvm *kvm,
  52                                        struct kvm_dirty_ring *ring)
  53 {
  54         return 0;
  55 }
  56
  57 static inline void kvm_dirty_ring_push(struct kvm_vcpu *vcpu,
  58                                        u32 slot, u64 offset)
  59 {
  60 }
  61
  62 static inline struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring,
  63                                                    u32 offset)
  64 {
  65         return NULL;
  66 }
  67
  68 static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
  69 {
  70 }
  71
  72 #else /* CONFIG_HAVE_KVM_DIRTY_RING */
  73
  74 int kvm_cpu_dirty_log_size(void);
  75 bool kvm_use_dirty_bitmap(struct kvm *kvm);
  76 bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm);
  77 u32 kvm_dirty_ring_get_rsvd_entries(void);
  78 int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
  79
  80 /*
  81  * called with kvm->slots_lock held, returns the number of
  82  * processed pages.
  83  */
  84 int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring);
  85
  86 /*
  87  * returns =0: successfully pushed
  88  *         <0: unable to push, need to wait
  89  */
  90 void kvm_dirty_ring_push(struct kvm_vcpu *vcpu, u32 slot, u64 offset);
  91
  92 bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu);
  93
  94 /* for use in vm_operations_struct */
  95 struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);
  96
  97 void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
  98
  99 #endif /* CONFIG_HAVE_KVM_DIRTY_RING */
 100
 101 #endif  /* KVM_DIRTY_RING_H */