[PATCH v2 3/3] KVM: x86: Remove the unused page track hook track_flush_slot

[Yan Zhao <yan.y.zhao@xxxxxxxxx>]

There's no users of hook track_remove_slot any more and no external page
tracker user cares about slot flush.
So remove this hook.

Cc: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
---
 arch/x86/include/asm/kvm_page_track.h | 11 -----------
 arch/x86/kvm/mmu/page_track.c         | 26 --------------------------
 arch/x86/kvm/x86.c                    |  2 --
 3 files changed, 39 deletions(-)

diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index 046b024d1813..4f1d3c91fdc7 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -34,16 +34,6 @@ struct kvm_page_track_notifier_node {
 	 */
 	void (*track_write)(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
 			    int bytes, struct kvm_page_track_notifier_node *node);
-	/*
-	 * It is called when memory slot is being moved or removed
-	 * users can drop write-protection for the pages in that memory slot
-	 *
-	 * @kvm: the kvm where memory slot being moved or removed
-	 * @slot: the memory slot being moved or removed
-	 * @node: this node
-	 */
-	void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    struct kvm_page_track_notifier_node *node);
 	/*
 	 * It is called when memory slot is moved or removed
 	 * users can drop write-protection for the pages in that memory slot
@@ -85,6 +75,5 @@ kvm_page_track_unregister_notifier(struct kvm *kvm,
 				   struct kvm_page_track_notifier_node *n);
 void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
 			  int bytes);
-void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
 void kvm_page_track_remove_slot(struct kvm *kvm, struct kvm_memory_slot *slot);
 #endif
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 4d6bab1d61c9..f783aea618f8 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -275,32 +275,6 @@ void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new,
 	srcu_read_unlock(&head->track_srcu, idx);
 }
 
-/*
- * Notify the node that memory slot is being removed or moved so that it can
- * drop write-protection for the pages in the memory slot.
- *
- * The node should figure out it has any write-protected pages in this slot
- * by itself.
- */
-void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
-{
-	struct kvm_page_track_notifier_head *head;
-	struct kvm_page_track_notifier_node *n;
-	int idx;
-
-	head = &kvm->arch.track_notifier_head;
-
-	if (hlist_empty(&head->track_notifier_list))
-		return;
-
-	idx = srcu_read_lock(&head->track_srcu);
-	hlist_for_each_entry_srcu(n, &head->track_notifier_list, node,
-				srcu_read_lock_held(&head->track_srcu))
-		if (n->track_flush_slot)
-			n->track_flush_slot(kvm, slot, n);
-	srcu_read_unlock(&head->track_srcu, idx);
-}
-
 /*
  * Notify the node that memory slot is removed or moved so that it can
  * drop write-protection for the pages in the memory slot.
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a24a4a2ad1a0..260288f4d741 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12872,8 +12872,6 @@ void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
 				   struct kvm_memory_slot *slot)
 {
 	kvm_mmu_zap_all_fast(kvm);
-
-	kvm_page_track_flush_slot(kvm, slot);
 }
 
 static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
-- 
2.17.1