On 9/7/23 11:24, Peter Gonda wrote:
Currently if an SEV-ES VM shuts down userspace sees KVM_RUN struct with
only the INVALID_ARGUMENT. This is a very limited amount of information
to debug the situation. Instead KVM can return a
KVM_EXIT_SHUTDOWN to alert userspace the VM is shutting down and
is not usable any further.
Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Suggested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/kvm/svm/svm.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 956726d867aa..114afc897465 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2127,12 +2127,6 @@ static int shutdown_interception(struct kvm_vcpu *vcpu)
struct kvm_run *kvm_run = vcpu->run;
struct vcpu_svm *svm = to_svm(vcpu);
- /*
- * The VM save area has already been encrypted so it
- * cannot be reinitialized - just terminate.
- */
- if (sev_es_guest(vcpu->kvm))
- return -EINVAL;
/*
* VMCB is undefined after a SHUTDOWN intercept. INIT the vCPU to put
@@ -2141,9 +2135,14 @@ static int shutdown_interception(struct kvm_vcpu *vcpu)
* userspace. At a platform view, INIT is acceptable behavior as
* there exist bare metal platforms that automatically INIT the CPU
* in response to shutdown.
+ *
+ * The VM save area for SEV-ES guests has already been encrypted so it
+ * cannot be reinitialized, i.e. synthesizing INIT is futile.
*/
- clear_page(svm->vmcb);
- kvm_vcpu_reset(vcpu, true);
+ if (!sev_es_guest(vcpu->kvm)) {
+ clear_page(svm->vmcb);
+ kvm_vcpu_reset(vcpu, true);
+ }
kvm_run->exit_reason = KVM_EXIT_SHUTDOWN;
return 0;
