KVM: arm64: Use __gfn_to_page() when copying MTE tags to/from userspace

Use __gfn_to_page() instead when copying MTE tags between guest and
userspace.  This will eventually allow removing gfn_to_pfn_prot(),
gfn_to_pfn(), kvm_pfn_to_refcounted_page(), and related APIs.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20241010182427.1434605-78-seanjc@google.com>

Author: sean-jc

arch/arm64/kvm/guest.c

@@ -1051,20 +1051,18 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
 	}
 
 	while (length > 0) {
-		kvm_pfn_t pfn = gfn_to_pfn_prot(kvm, gfn, write, NULL);
+		struct page *page = __gfn_to_page(kvm, gfn, write);
 		void *maddr;
 		unsigned long num_tags;
-		struct page *page;
 
-		if (is_error_noslot_pfn(pfn)) {
+		if (!page) {
 			ret = -EFAULT;
 			goto out;
 		}
 
-		page = pfn_to_online_page(pfn);
-		if (!page) {
+		if (!pfn_to_online_page(page_to_pfn(page))) {
 			/* Reject ZONE_DEVICE memory */
-			kvm_release_pfn_clean(pfn);
+			kvm_release_page_unused(page);
 			ret = -EFAULT;
 			goto out;
 		}
@@ -1078,7 +1076,7 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
 				/* No tags in memory, so write zeros */
 				num_tags = MTE_GRANULES_PER_PAGE -
 					clear_user(tags, MTE_GRANULES_PER_PAGE);
-			kvm_release_pfn_clean(pfn);
+			kvm_release_page_clean(page);
 		} else {
 			/*
 			 * Only locking to serialise with a concurrent
@@ -1093,8 +1091,7 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
 			if (num_tags != MTE_GRANULES_PER_PAGE)
 				mte_clear_page_tags(maddr);
 			set_page_mte_tagged(page);
-
-			kvm_release_pfn_dirty(pfn);
+			kvm_release_page_dirty(page);
 		}
 
 		if (num_tags != MTE_GRANULES_PER_PAGE) {