diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index e66e620c3bed9eafde705b0315ff977fb158d031..539333ac4b38082f01e0407908441aa39b9ca136 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -81,7 +81,6 @@ struct kvm_ioapic {
 	unsigned long irq_states[IOAPIC_NUM_PINS];
 	struct kvm_io_device dev;
 	struct kvm *kvm;
-	void (*ack_notifier)(void *opaque, int irq);
 	spinlock_t lock;
 	struct rtc_status rtc_status;
 	struct delayed_work eoi_inject;
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 650642b18d151083e7120b81ef51dae690090333..c2d7cfe82d004b1ae4d9518b0a73a0755114bedd 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -56,7 +56,6 @@ struct kvm_pic {
 	struct kvm_io_device dev_master;
 	struct kvm_io_device dev_slave;
 	struct kvm_io_device dev_elcr;
-	void (*ack_notifier)(void *opaque, int irq);
 	unsigned long irq_states[PIC_NUM_PINS];
 };
 
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 3be9beea838d134a077a67e05f12a1c9aaa7c2ef..0c839ee1282c10d956105ab6bd452dfbef3d221e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1582,7 +1582,7 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
 		flush = kvm_handle_gfn_range(kvm, range, kvm_unmap_rmapp);
 
 	if (is_tdp_mmu_enabled(kvm))
-		flush |= kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);
+		flush = kvm_tdp_mmu_unmap_gfn_range(kvm, range, flush);
 
 	return flush;
 }
@@ -5854,7 +5854,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm,
 void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
 				   const struct kvm_memory_slot *slot)
 {
-	bool flush = false;
+	bool flush;
 
 	if (kvm_memslots_have_rmaps(kvm)) {
 		write_lock(&kvm->mmu_lock);
@@ -5871,7 +5871,7 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm,
 
 	if (is_tdp_mmu_enabled(kvm)) {
 		read_lock(&kvm->mmu_lock);
-		flush = kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot, flush);
+		flush = kvm_tdp_mmu_zap_collapsible_sptes(kvm, slot, false);
 		if (flush)
 			kvm_arch_flush_remote_tlbs_memslot(kvm, slot);
 		read_unlock(&kvm->mmu_lock);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index a54c3491af42c9fba8a894619ee7bd5c7f3f4628..1f8c9f783b7852bc5d6770f86cb04d2acd26b300 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -317,9 +317,6 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt,
 	struct kvm_mmu_page *sp = sptep_to_sp(rcu_dereference(pt));
 	int level = sp->role.level;
 	gfn_t base_gfn = sp->gfn;
-	u64 old_child_spte;
-	u64 *sptep;
-	gfn_t gfn;
 	int i;
 
 	trace_kvm_mmu_prepare_zap_page(sp);
@@ -327,8 +324,9 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt,
 	tdp_mmu_unlink_page(kvm, sp, shared);
 
 	for (i = 0; i < PT64_ENT_PER_PAGE; i++) {
-		sptep = rcu_dereference(pt) + i;
-		gfn = base_gfn + i * KVM_PAGES_PER_HPAGE(level);
+		u64 *sptep = rcu_dereference(pt) + i;
+		gfn_t gfn = base_gfn + i * KVM_PAGES_PER_HPAGE(level);
+		u64 old_child_spte;
 
 		if (shared) {
 			/*
@@ -374,7 +372,7 @@ static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt,
 				    shared);
 	}
 
-	kvm_flush_remote_tlbs_with_address(kvm, gfn,
+	kvm_flush_remote_tlbs_with_address(kvm, base_gfn,
 					   KVM_PAGES_PER_HPAGE(level + 1));
 
 	call_rcu(&sp->rcu_head, tdp_mmu_free_sp_rcu_callback);
@@ -1034,8 +1032,8 @@ bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range,
 	struct kvm_mmu_page *root;
 
 	for_each_tdp_mmu_root(kvm, root, range->slot->as_id)
-		flush |= zap_gfn_range(kvm, root, range->start, range->end,
-				       range->may_block, flush, false);
+		flush = zap_gfn_range(kvm, root, range->start, range->end,
+				      range->may_block, flush, false);
 
 	return flush;
 }
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9646bb9112c101ea0398f7d447bd563d2008de50..6c5083f2eb505d15a453b7e52d200055b91b7e65 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1531,11 +1531,10 @@ static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old,
 
 static int kvm_set_memslot(struct kvm *kvm,
 			   const struct kvm_userspace_memory_region *mem,
-			   struct kvm_memory_slot *old,
 			   struct kvm_memory_slot *new, int as_id,
 			   enum kvm_mr_change change)
 {
-	struct kvm_memory_slot *slot;
+	struct kvm_memory_slot *slot, old;
 	struct kvm_memslots *slots;
 	int r;
 
@@ -1566,7 +1565,7 @@ static int kvm_set_memslot(struct kvm *kvm,
 		 * Note, the INVALID flag needs to be in the appropriate entry
 		 * in the freshly allocated memslots, not in @old or @new.
 		 */
-		slot = id_to_memslot(slots, old->id);
+		slot = id_to_memslot(slots, new->id);
 		slot->flags |= KVM_MEMSLOT_INVALID;
 
 		/*
@@ -1597,6 +1596,26 @@ static int kvm_set_memslot(struct kvm *kvm,
 		kvm_copy_memslots(slots, __kvm_memslots(kvm, as_id));
 	}
 
+	/*
+	 * Make a full copy of the old memslot, the pointer will become stale
+	 * when the memslots are re-sorted by update_memslots(), and the old
+	 * memslot needs to be referenced after calling update_memslots(), e.g.
+	 * to free its resources and for arch specific behavior.  This needs to
+	 * happen *after* (re)acquiring slots_arch_lock.
+	 */
+	slot = id_to_memslot(slots, new->id);
+	if (slot) {
+		old = *slot;
+	} else {
+		WARN_ON_ONCE(change != KVM_MR_CREATE);
+		memset(&old, 0, sizeof(old));
+		old.id = new->id;
+		old.as_id = as_id;
+	}
+
+	/* Copy the arch-specific data, again after (re)acquiring slots_arch_lock. */
+	memcpy(&new->arch, &old.arch, sizeof(old.arch));
+
 	r = kvm_arch_prepare_memory_region(kvm, new, mem, change);
 	if (r)
 		goto out_slots;
@@ -1604,14 +1623,18 @@ static int kvm_set_memslot(struct kvm *kvm,
 	update_memslots(slots, new, change);
 	slots = install_new_memslots(kvm, as_id, slots);
 
-	kvm_arch_commit_memory_region(kvm, mem, old, new, change);
+	kvm_arch_commit_memory_region(kvm, mem, &old, new, change);
+
+	/* Free the old memslot's metadata.  Note, this is the full copy!!! */
+	if (change == KVM_MR_DELETE)
+		kvm_free_memslot(kvm, &old);
 
 	kvfree(slots);
 	return 0;
 
 out_slots:
 	if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
-		slot = id_to_memslot(slots, old->id);
+		slot = id_to_memslot(slots, new->id);
 		slot->flags &= ~KVM_MEMSLOT_INVALID;
 		slots = install_new_memslots(kvm, as_id, slots);
 	} else {
@@ -1626,7 +1649,6 @@ static int kvm_delete_memslot(struct kvm *kvm,
 			      struct kvm_memory_slot *old, int as_id)
 {
 	struct kvm_memory_slot new;
-	int r;
 
 	if (!old->npages)
 		return -EINVAL;
@@ -1639,12 +1661,7 @@ static int kvm_delete_memslot(struct kvm *kvm,
 	 */
 	new.as_id = as_id;
 
-	r = kvm_set_memslot(kvm, mem, old, &new, as_id, KVM_MR_DELETE);
-	if (r)
-		return r;
-
-	kvm_free_memslot(kvm, old);
-	return 0;
+	return kvm_set_memslot(kvm, mem, &new, as_id, KVM_MR_DELETE);
 }
 
 /*
@@ -1672,7 +1689,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	id = (u16)mem->slot;
 
 	/* General sanity checks */
-	if (mem->memory_size & (PAGE_SIZE - 1))
+	if ((mem->memory_size & (PAGE_SIZE - 1)) ||
+	    (mem->memory_size != (unsigned long)mem->memory_size))
 		return -EINVAL;
 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
 		return -EINVAL;
@@ -1718,7 +1736,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	if (!old.npages) {
 		change = KVM_MR_CREATE;
 		new.dirty_bitmap = NULL;
-		memset(&new.arch, 0, sizeof(new.arch));
 	} else { /* Modify an existing slot. */
 		if ((new.userspace_addr != old.userspace_addr) ||
 		    (new.npages != old.npages) ||
@@ -1732,9 +1749,8 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		else /* Nothing to change. */
 			return 0;
 
-		/* Copy dirty_bitmap and arch from the current memslot. */
+		/* Copy dirty_bitmap from the current memslot. */
 		new.dirty_bitmap = old.dirty_bitmap;
-		memcpy(&new.arch, &old.arch, sizeof(new.arch));
 	}
 
 	if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
@@ -1760,7 +1776,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 			bitmap_set(new.dirty_bitmap, 0, new.npages);
 	}
 
-	r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change);
+	r = kvm_set_memslot(kvm, mem, &new, as_id, change);
 	if (r)
 		goto out_bitmap;