[PATCH 4/6] KVM: SEV: use mutex guard in sev_mem_enc_unregister_region()

["Carlos López" <clopez@suse.de>]

Simplify the error paths in sev_mem_enc_unregister_region() by using a
mutex guard, allowing early return instead of using gotos.

Signed-off-by: Carlos López <clopez@suse.de>
---
 arch/x86/kvm/svm/sev.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 253f2ae24bfc..47ff5267ab01 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2746,35 +2746,25 @@ int sev_mem_enc_unregister_region(struct kvm *kvm,
 				  struct kvm_enc_region *range)
 {
 	struct enc_region *region;
-	int ret;
 
 	/* If kvm is mirroring encryption context it isn't responsible for it */
 	if (is_mirroring_enc_context(kvm))
 		return -EINVAL;
 
-	mutex_lock(&kvm->lock);
+	guard(mutex)(&kvm->lock);
 
-	if (!sev_guest(kvm)) {
-		ret = -ENOTTY;
-		goto failed;
-	}
+	if (!sev_guest(kvm))
+		return -ENOTTY;
 
 	region = find_enc_region(kvm, range);
-	if (!region) {
-		ret = -EINVAL;
-		goto failed;
-	}
+	if (!region)
+		return -EINVAL;
 
 	sev_writeback_caches(kvm);
 
 	__unregister_enc_region_locked(kvm, region);
 
-	mutex_unlock(&kvm->lock);
 	return 0;
-
-failed:
-	mutex_unlock(&kvm->lock);
-	return ret;
 }
 
 int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
-- 
2.51.0