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#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 */
35static inline u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm)
36{
37 return 0;
38}
39
40static inline bool kvm_use_dirty_bitmap(struct kvm *kvm)
41{
42 return true;
43}
44
45static inline int kvm_dirty_ring_alloc(struct kvm *kvm, struct kvm_dirty_ring *ring,
46 int index, u32 size)
47{
48 return 0;
49}
50
51static inline int kvm_dirty_ring_reset(struct kvm *kvm,
52 struct kvm_dirty_ring *ring,
53 int *nr_entries_reset)
54{
55 return -ENOENT;
56}
57
58static inline void kvm_dirty_ring_push(struct kvm_vcpu *vcpu,
59 u32 slot, u64 offset)
60{
61}
62
63static inline struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring,
64 u32 offset)
65{
66 return NULL;
67}
68
69static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
70{
71}
72
73#else /* CONFIG_HAVE_KVM_DIRTY_RING */
74
75int kvm_cpu_dirty_log_size(struct kvm *kvm);
76bool kvm_use_dirty_bitmap(struct kvm *kvm);
77bool kvm_arch_allow_write_without_running_vcpu(struct kvm *kvm);
78u32 kvm_dirty_ring_get_rsvd_entries(struct kvm *kvm);
79int kvm_dirty_ring_alloc(struct kvm *kvm, struct kvm_dirty_ring *ring,
80 int index, u32 size);
81int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring,
82 int *nr_entries_reset);
83void kvm_dirty_ring_push(struct kvm_vcpu *vcpu, u32 slot, u64 offset);
84
85bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu);
86
87/* for use in vm_operations_struct */
88struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);
89
90void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
91
92#endif /* CONFIG_HAVE_KVM_DIRTY_RING */
93
94#endif /* KVM_DIRTY_RING_H */
95

source code of linux/include/linux/kvm_dirty_ring.h