KVM: x86: Change parameter of kvm_mmu_slot_remove_write_access

This patch changes the second parameter of kvm_mmu_slot_remove_write_access from
'slot id' to 'struct kvm_memory_slot *' to align with kvm_x86_ops dirty logging
hooks, which will be introduced in further patch.

Better way is to change second parameter of kvm_arch_commit_memory_region from
'struct kvm_userspace_memory_region *' to 'struct kvm_memory_slot * new', but it
requires changes on other non-x86 ARCH too, so avoid it now.
Signed-off-by: Kai Huang <kai.huang@linux.intel.com>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -834,7 +834,8 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
 		u64 dirty_mask, u64 nx_mask, u64 x_mask);
 
 void kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
-void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
+void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
+				      struct kvm_memory_slot *memslot);
 void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot);
 void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm,

arch/x86/kvm/mmu.c

@@ -4408,14 +4408,13 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
 	init_kvm_mmu(vcpu);
 }
 
-void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
+void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
+				      struct kvm_memory_slot *memslot)
 {
-	struct kvm_memory_slot *memslot;
 	gfn_t last_gfn;
 	int i;
 	bool flush = false;
 
-	memslot = id_to_memslot(kvm->memslots, slot);
 	last_gfn = memslot->base_gfn + memslot->npages - 1;
 
 	spin_lock(&kvm->mmu_lock);

arch/x86/kvm/x86.c

@@ -7538,7 +7538,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 				const struct kvm_memory_slot *old,
 				enum kvm_mr_change change)
 {
-
+	struct kvm_memory_slot *new;
 	int nr_mmu_pages = 0;
 
 	if ((mem->slot >= KVM_USER_MEM_SLOTS) && (change == KVM_MR_DELETE)) {
@@ -7557,6 +7557,10 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 
 	if (nr_mmu_pages)
 		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+
+	/* It's OK to get 'new' slot here as it has already been installed */
+	new = id_to_memslot(kvm->memslots, mem->slot);
+
 	/*
 	 * Write protect all pages for dirty logging.
 	 *
@@ -7566,8 +7570,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 	 *
 	 * See the comments in fast_page_fault().
 	 */
-	if ((change != KVM_MR_DELETE) && (mem->flags & KVM_MEM_LOG_DIRTY_PAGES))
-		kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+	if ((change != KVM_MR_DELETE) && (new->flags & KVM_MEM_LOG_DIRTY_PAGES))
+		kvm_mmu_slot_remove_write_access(kvm, new);
 }
 
 void kvm_arch_flush_shadow_all(struct kvm *kvm)