1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_KVM_PAGE_TRACK_H
3 #define _ASM_X86_KVM_PAGE_TRACK_H
4 
5 enum kvm_page_track_mode {
6 	KVM_PAGE_TRACK_WRITE,
7 	KVM_PAGE_TRACK_MAX,
8 };
9 
10 /*
11  * The notifier represented by @kvm_page_track_notifier_node is linked into
12  * the head which will be notified when guest is triggering the track event.
13  *
14  * Write access on the head is protected by kvm->mmu_lock, read access
15  * is protected by track_srcu.
16  */
17 struct kvm_page_track_notifier_head {
18 	struct srcu_struct track_srcu;
19 	struct hlist_head track_notifier_list;
20 };
21 
22 struct kvm_page_track_notifier_node {
23 	struct hlist_node node;
24 
25 	/*
26 	 * It is called when guest is writing the write-tracked page
27 	 * and write emulation is finished at that time.
28 	 *
29 	 * @gpa: the physical address written by guest.
30 	 * @new: the data was written to the address.
31 	 * @bytes: the written length.
32 	 * @node: this node
33 	 */
34 	void (*track_write)(gpa_t gpa, const u8 *new, int bytes,
35 			    struct kvm_page_track_notifier_node *node);
36 	/*
37 	 * It is called when memory slot is being moved or removed
38 	 * users can drop write-protection for the pages in that memory slot
39 	 *
40 	 * @kvm: the kvm where memory slot being moved or removed
41 	 * @slot: the memory slot being moved or removed
42 	 * @node: this node
43 	 */
44 	void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot,
45 			    struct kvm_page_track_notifier_node *node);
46 };
47 
48 int kvm_page_track_init(struct kvm *kvm);
49 void kvm_page_track_cleanup(struct kvm *kvm);
50 
51 bool kvm_page_track_write_tracking_enabled(struct kvm *kvm);
52 int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot);
53 
54 void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
55 int kvm_page_track_create_memslot(struct kvm *kvm,
56 				  struct kvm_memory_slot *slot,
57 				  unsigned long npages);
58 
59 void kvm_slot_page_track_add_page(struct kvm *kvm,
60 				  struct kvm_memory_slot *slot, gfn_t gfn,
61 				  enum kvm_page_track_mode mode);
62 void kvm_slot_page_track_remove_page(struct kvm *kvm,
63 				     struct kvm_memory_slot *slot, gfn_t gfn,
64 				     enum kvm_page_track_mode mode);
65 bool kvm_slot_page_track_is_active(struct kvm *kvm,
66 				   const struct kvm_memory_slot *slot,
67 				   gfn_t gfn, enum kvm_page_track_mode mode);
68 
69 void
70 kvm_page_track_register_notifier(struct kvm *kvm,
71 				 struct kvm_page_track_notifier_node *n);
72 void
73 kvm_page_track_unregister_notifier(struct kvm *kvm,
74 				   struct kvm_page_track_notifier_node *n);
75 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
76 			  int bytes);
77 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
78 #endif
79