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 */
102
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