1 files changed, 45 insertions, 8 deletions

diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 269f11f92fd0..cc4eb5b7fb76 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -19,6 +19,12 @@
 #include "mmu.h"
 #include "mmu_internal.h"
 
+bool kvm_page_track_write_tracking_enabled(struct kvm *kvm)
+{
+	return IS_ENABLED(CONFIG_KVM_EXTERNAL_WRITE_TRACKING) ||
+	       !tdp_enabled || kvm_shadow_root_allocated(kvm);
+}
+
 void kvm_page_track_free_memslot(struct kvm_memory_slot *slot)
 {
 	int i;
@@ -29,12 +35,17 @@ void kvm_page_track_free_memslot(struct kvm_memory_slot *slot)
 	}
 }
 
-int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
+int kvm_page_track_create_memslot(struct kvm *kvm,
+				  struct kvm_memory_slot *slot,
 				  unsigned long npages)
 {
-	int  i;
+	int i;
 
 	for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
+		if (i == KVM_PAGE_TRACK_WRITE &&
+		    !kvm_page_track_write_tracking_enabled(kvm))
+			continue;
+
 		slot->arch.gfn_track[i] =
 			kvcalloc(npages, sizeof(*slot->arch.gfn_track[i]),
 				 GFP_KERNEL_ACCOUNT);
@@ -57,6 +68,21 @@ static inline bool page_track_mode_is_valid(enum kvm_page_track_mode mode)
 	return true;
 }
 
+int kvm_page_track_write_tracking_alloc(struct kvm_memory_slot *slot)
+{
+	unsigned short *gfn_track;
+
+	if (slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE])
+		return 0;
+
+	gfn_track = kvcalloc(slot->npages, sizeof(*gfn_track), GFP_KERNEL_ACCOUNT);
+	if (gfn_track == NULL)
+		return -ENOMEM;
+
+	slot->arch.gfn_track[KVM_PAGE_TRACK_WRITE] = gfn_track;
+	return 0;
+}
+
 static void update_gfn_track(struct kvm_memory_slot *slot, gfn_t gfn,
 			     enum kvm_page_track_mode mode, short count)
 {
@@ -92,6 +118,10 @@ void kvm_slot_page_track_add_page(struct kvm *kvm,
 	if (WARN_ON(!page_track_mode_is_valid(mode)))
 		return;
 
+	if (WARN_ON(mode == KVM_PAGE_TRACK_WRITE &&
+		    !kvm_page_track_write_tracking_enabled(kvm)))
+		return;
+
 	update_gfn_track(slot, gfn, mode, 1);
 
 	/*
@@ -126,6 +156,10 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm,
 	if (WARN_ON(!page_track_mode_is_valid(mode)))
 		return;
 
+	if (WARN_ON(mode == KVM_PAGE_TRACK_WRITE &&
+		    !kvm_page_track_write_tracking_enabled(kvm)))
+		return;
+
 	update_gfn_track(slot, gfn, mode, -1);
 
 	/*
@@ -139,19 +173,22 @@ EXPORT_SYMBOL_GPL(kvm_slot_page_track_remove_page);
 /*
  * check if the corresponding access on the specified guest page is tracked.
  */
-bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn,
-			      enum kvm_page_track_mode mode)
+bool kvm_slot_page_track_is_active(struct kvm_vcpu *vcpu,
+				   struct kvm_memory_slot *slot, gfn_t gfn,
+				   enum kvm_page_track_mode mode)
 {
-	struct kvm_memory_slot *slot;
 	int index;
 
 	if (WARN_ON(!page_track_mode_is_valid(mode)))
 		return false;
 
-	slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
 	if (!slot)
 		return false;
 
+	if (mode == KVM_PAGE_TRACK_WRITE &&
+	    !kvm_page_track_write_tracking_enabled(vcpu->kvm))
+		return false;
+
 	index = gfn_to_index(gfn, slot->base_gfn, PG_LEVEL_4K);
 	return !!READ_ONCE(slot->arch.gfn_track[mode][index]);
 }
@@ -164,13 +201,13 @@ void kvm_page_track_cleanup(struct kvm *kvm)
 	cleanup_srcu_struct(&head->track_srcu);
 }
 
-void kvm_page_track_init(struct kvm *kvm)
+int kvm_page_track_init(struct kvm *kvm)
 {
 	struct kvm_page_track_notifier_head *head;
 
 	head = &kvm->arch.track_notifier_head;
-	init_srcu_struct(&head->track_srcu);
 	INIT_HLIST_HEAD(&head->track_notifier_list);
+	return init_srcu_struct(&head->track_srcu);
 }
 
 /*