1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_KVM_PAGE_TRACK_H
3#define _ASM_X86_KVM_PAGE_TRACK_H
4
5enum 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 */
17struct kvm_page_track_notifier_head {
18	struct srcu_struct track_srcu;
19	struct hlist_head track_notifier_list;
20};
21
22struct 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
49int kvm_page_track_init(struct kvm *kvm);
50void kvm_page_track_cleanup(struct kvm *kvm);
51
52void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
53int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
54				  unsigned long npages);
55
56void kvm_slot_page_track_add_page(struct kvm *kvm,
57				  struct kvm_memory_slot *slot, gfn_t gfn,
58				  enum kvm_page_track_mode mode);
59void kvm_slot_page_track_remove_page(struct kvm *kvm,
60				     struct kvm_memory_slot *slot, gfn_t gfn,
61				     enum kvm_page_track_mode mode);
62bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn,
63			      enum kvm_page_track_mode mode);
64
65void
66kvm_page_track_register_notifier(struct kvm *kvm,
67				 struct kvm_page_track_notifier_node *n);
68void
69kvm_page_track_unregister_notifier(struct kvm *kvm,
70				   struct kvm_page_track_notifier_node *n);
71void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
72			  int bytes);
73void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
74#endif
75