[PATCH 06/21] KVM: SEV: Lock all vCPUs for the duration of SEV-ES VMSA synchronization

[Sean Christopherson <seanjc@google.com>]

Lock and unlock all vCPUs in a single batch when synchronizing SEV-ES VMSAs
during launch finish, partly to dedup the code by a tiny amount, but mostly
so that sev_launch_update_vmsa() uses the same logic/flow as all other SEV
ioctls that lock all vCPUs.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/svm/sev.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index c10c71608208..1bdcc5bef7c3 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1035,19 +1035,18 @@ static int sev_launch_update_vmsa(struct kvm *kvm, struct kvm_sev_cmd *argp)
 	if (kvm_is_vcpu_creation_in_progress(kvm))
 		return -EBUSY;
 
-	kvm_for_each_vcpu(i, vcpu, kvm) {
-		ret = mutex_lock_killable(&vcpu->mutex);
-		if (ret)
-			return ret;
+	ret = kvm_lock_all_vcpus(kvm);
+	if (ret)
+		return ret;
 
+	kvm_for_each_vcpu(i, vcpu, kvm) {
 		ret = __sev_launch_update_vmsa(kvm, vcpu, &argp->error);
-
-		mutex_unlock(&vcpu->mutex);
 		if (ret)
-			return ret;
+			break;
 	}
 
-	return 0;
+	kvm_unlock_all_vcpus(kvm);
+	return ret;
 }
 
 static int sev_launch_measure(struct kvm *kvm, struct kvm_sev_cmd *argp)
-- 
2.53.0.473.g4a7958ca14-goog