Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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 */