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 	 * @vcpu: the vcpu where the write access happened.
30 	 * @gpa: the physical address written by guest.
31 	 * @new: the data was written to the address.
32 	 * @bytes: the written length.
33 	 * @node: this node
34 	 */
35 	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
36 			    int bytes, struct kvm_page_track_notifier_node *node);
37 	/*
38 	 * It is called when memory slot is being moved or removed
39 	 * users can drop write-protection for the pages in that memory slot
40 	 *
41 	 * @kvm: the kvm where memory slot being moved or removed
42 	 * @slot: the memory slot being moved or removed
43 	 * @node: this node
44 	 */
45 	void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot,
46 			    struct kvm_page_track_notifier_node *node);
47 };
48 
49 int kvm_page_track_init(struct kvm *kvm);
50 void kvm_page_track_cleanup(struct kvm *kvm);
51 
52 bool kvm_page_track_write_tracking_enabled(struct kvm *kvm);
53 int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot);
54 
55 void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
56 int kvm_page_track_create_memslot(struct kvm *kvm,
57 				  struct kvm_memory_slot *slot,
58 				  unsigned long npages);
59 
60 void kvm_slot_page_track_add_page(struct kvm *kvm,
61 				  struct kvm_memory_slot *slot, gfn_t gfn,
62 				  enum kvm_page_track_mode mode);
63 void kvm_slot_page_track_remove_page(struct kvm *kvm,
64 				     struct kvm_memory_slot *slot, gfn_t gfn,
65 				     enum kvm_page_track_mode mode);
66 bool kvm_slot_page_track_is_active(struct kvm_vcpu *vcpu,
67 				   struct kvm_memory_slot *slot, gfn_t gfn,
68 				   enum kvm_page_track_mode mode);
69 
70 void
71 kvm_page_track_register_notifier(struct kvm *kvm,
72 				 struct kvm_page_track_notifier_node *n);
73 void
74 kvm_page_track_unregister_notifier(struct kvm *kvm,
75 				   struct kvm_page_track_notifier_node *n);
76 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
77 			  int bytes);
78 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
79 #endif
80