6.6-stable review patch. If anyone has any objections, please let me know.
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From: Peter Gonda pgonda@google.com
[ Upstream commit bc3d7c5570a03ab45bde4bae83697c80900fb714 ]
Currently if an SEV-ES VM shuts down userspace sees KVM_RUN struct with only errno=EINVAL. This is a very limited amount of information to debug the situation. Instead return KVM_EXIT_SHUTDOWN to alert userspace the VM is shutting down and is not usable any further.
Signed-off-by: Peter Gonda pgonda@google.com Suggested-by: Sean Christopherson seanjc@google.com Suggested-by: Tom Lendacky thomas.lendacky@amd.com Cc: Paolo Bonzini pbonzini@redhat.com Cc: Sean Christopherson seanjc@google.com Cc: Tom Lendacky thomas.lendacky@amd.com Cc: Joerg Roedel joro@8bytes.org Cc: Borislav Petkov bp@alien8.de Cc: x86@kernel.org Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Tom Lendacky thomas.lendacky@amd.com Link: https://lore.kernel.org/r/20230907162449.1739785-1-pgonda@google.com [sean: tweak changelog] Signed-off-by: Sean Christopherson seanjc@google.com Stable-dep-of: a2620f8932fa ("KVM: SVM: Forcibly leave SMM mode on SHUTDOWN interception") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 29c1be65cb71a..0c01887124b6c 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2211,12 +2211,6 @@ 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 @@ -2225,9 +2219,14 @@ 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;