KVM: SVM: Cannot re-initialize the VMCB after shutdown with SEV-ES

When a SHUTDOWN VMEXIT is encountered, normally the VMCB is re-initialized
so that the guest can be re-launched. But when a guest is running as an
SEV-ES guest, the VMSA cannot be re-initialized because it has been
encrypted. For now, just return -EINVAL to prevent a possible attempt at
a guest reset.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <aa6506000f6f3a574de8dbcdab0707df844cb00c.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cade703..19d1c97 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2010,6 +2010,13 @@ static int shutdown_interception(struct vcpu_svm *svm)
 {
        struct kvm_run *kvm_run = svm->vcpu.run;
 
+       /*
+        * The VM save area has already been encrypted so it
+        * cannot be reinitialized - just terminate.
+        */
+       if (sev_es_guest(svm->vcpu.kvm))
+               return -EINVAL;
+
        /*
         * VMCB is undefined after a SHUTDOWN intercept
         * so reinitialize it.