| Message ID | 20230907162449.1739785-1-pgonda@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V3] KVM: SEV: Update SEV-ES shutdown intercepts with more metadata | expand |
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@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> > --- > 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;
On Thu, 07 Sep 2023 09:24:49 -0700, 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. > > > [...] Applied to kvm-x86 svm, thanks! [1/1] KVM: SEV: Update SEV-ES shutdown intercepts with more metadata https://github.com/kvm-x86/linux/commit/bc3d7c5570a0 -- https://github.com/kvm-x86/linux/tree/next
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;
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@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 --- arch/x86/kvm/svm/svm.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)