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 #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 */
kvm_dirty_ring_get_rsvd_entries(void)35 static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
36 {
37 return 0;
38 }
39
kvm_dirty_ring_alloc(struct kvm_dirty_ring * ring,int index,u32 size)40 static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
41 int index, u32 size)
42 {
43 return 0;
44 }
45
kvm_dirty_ring_get(struct kvm * kvm)46 static inline struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm)
47 {
48 return NULL;
49 }
50
kvm_dirty_ring_reset(struct kvm * kvm,struct kvm_dirty_ring * ring)51 static inline int kvm_dirty_ring_reset(struct kvm *kvm,
52 struct kvm_dirty_ring *ring)
53 {
54 return 0;
55 }
56
kvm_dirty_ring_push(struct kvm_dirty_ring * ring,u32 slot,u64 offset)57 static inline void kvm_dirty_ring_push(struct kvm_dirty_ring *ring,
58 u32 slot, u64 offset)
59 {
60 }
61
kvm_dirty_ring_get_page(struct kvm_dirty_ring * ring,u32 offset)62 static inline struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring,
63 u32 offset)
64 {
65 return NULL;
66 }
67
kvm_dirty_ring_free(struct kvm_dirty_ring * ring)68 static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
69 {
70 }
71
kvm_dirty_ring_soft_full(struct kvm_dirty_ring * ring)72 static 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
79 u32 kvm_dirty_ring_get_rsvd_entries(void);
80 int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
81 struct 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 */
87 int 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 */
93 void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);
94
95 /* for use in vm_operations_struct */
96 struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);
97
98 void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
99 bool 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