include/asm/kvm_page_track.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_KVM_PAGE_TRACK_H
0003 #define _ASM_X86_KVM_PAGE_TRACK_H
0004
0005 enum kvm_page_track_mode {
0006     KVM_PAGE_TRACK_WRITE,
0007     KVM_PAGE_TRACK_MAX,
0008 };
0009
0010 /*
0011  * The notifier represented by @kvm_page_track_notifier_node is linked into
0012  * the head which will be notified when guest is triggering the track event.
0013  *
0014  * Write access on the head is protected by kvm->mmu_lock, read access
0015  * is protected by track_srcu.
0016  */
0017 struct kvm_page_track_notifier_head {
0018     struct srcu_struct track_srcu;
0019     struct hlist_head track_notifier_list;
0020 };
0021
0022 struct kvm_page_track_notifier_node {
0023     struct hlist_node node;
0024
0025     /*
0026      * It is called when guest is writing the write-tracked page
0027      * and write emulation is finished at that time.
0028      *
0029      * @vcpu: the vcpu where the write access happened.
0030      * @gpa: the physical address written by guest.
0031      * @new: the data was written to the address.
0032      * @bytes: the written length.
0033      * @node: this node
0034      */
0035     void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
0036                 int bytes, struct kvm_page_track_notifier_node *node);
0037     /*
0038      * It is called when memory slot is being moved or removed
0039      * users can drop write-protection for the pages in that memory slot
0040      *
0041      * @kvm: the kvm where memory slot being moved or removed
0042      * @slot: the memory slot being moved or removed
0043      * @node: this node
0044      */
0045     void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot,
0046                 struct kvm_page_track_notifier_node *node);
0047 };
0048
0049 int kvm_page_track_init(struct kvm *kvm);
0050 void kvm_page_track_cleanup(struct kvm *kvm);
0051
0052 bool kvm_page_track_write_tracking_enabled(struct kvm *kvm);
0053 int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot);
0054
0055 void kvm_page_track_free_memslot(struct kvm_memory_slot *slot);
0056 int kvm_page_track_create_memslot(struct kvm *kvm,
0057                   struct kvm_memory_slot *slot,
0058                   unsigned long npages);
0059
0060 void kvm_slot_page_track_add_page(struct kvm *kvm,
0061                   struct kvm_memory_slot *slot, gfn_t gfn,
0062                   enum kvm_page_track_mode mode);
0063 void kvm_slot_page_track_remove_page(struct kvm *kvm,
0064                      struct kvm_memory_slot *slot, gfn_t gfn,
0065                      enum kvm_page_track_mode mode);
0066 bool kvm_slot_page_track_is_active(struct kvm *kvm,
0067                    const struct kvm_memory_slot *slot,
0068                    gfn_t gfn, enum kvm_page_track_mode mode);
0069
0070 void
0071 kvm_page_track_register_notifier(struct kvm *kvm,
0072                  struct kvm_page_track_notifier_node *n);
0073 void
0074 kvm_page_track_unregister_notifier(struct kvm *kvm,
0075                    struct kvm_page_track_notifier_node *n);
0076 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
0077               int bytes);
0078 void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
0079 #endif