Message ID | 20220325152758.335626-1-pgonda@google.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v2] Add KVM_EXIT_SHUTDOWN metadata for SEV-ES | expand |
On 3/25/22 16:27, Peter Gonda wrote: > SEV-ES guests can request termination using the GHCB's MSR protocol. See > AMD's GHCB spec section '4.1.13 Termination Request'. Currently when a > guest does this the userspace VMM sees an KVM_EXIT_UNKNOWN (-EVINAL) > return code from KVM_RUN. By adding a KVM_EXIT_SHUTDOWN_ENTRY to kvm_run > struct the userspace VMM can clear see the guest has requested a SEV-ES > termination including the termination reason code set and reason code. > > Signed-off-by: Peter Gonda <pgonda@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Tom Lendacky <thomas.lendacky@amd.com> > Cc: Brijesh Singh <brijesh.singh@amd.com> > Cc: Joerg Roedel <jroedel@suse.de> > Cc: Marc Orr <marcorr@google.com> > Cc: Sean Christopherson <seanjc@google.com> > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org This is missing an update to Documentation/. Paolo > --- > > V2 > * Add KVM_CAP_EXIT_SHUTDOWN_REASON check for KVM_CHECK_EXTENSION. > > Tested by making an SEV-ES guest call sev_es_terminate() with hardcoded > reason code set and reason code and then observing the codes from the > userspace VMM in the kvm_run.shutdown.data fields. > > --- > arch/x86/kvm/svm/sev.c | 9 +++++++-- > include/uapi/linux/kvm.h | 13 +++++++++++++ > virt/kvm/kvm_main.c | 1 + > 3 files changed, 21 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c > index 75fa6dd268f0..5f9d37dd3f6f 100644 > --- a/arch/x86/kvm/svm/sev.c > +++ b/arch/x86/kvm/svm/sev.c > @@ -2735,8 +2735,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) > pr_info("SEV-ES guest requested termination: %#llx:%#llx\n", > reason_set, reason_code); > > - ret = -EINVAL; > - break; > + vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; > + vcpu->run->shutdown.reason = KVM_SHUTDOWN_SEV_TERM; > + vcpu->run->shutdown.ndata = 2; > + vcpu->run->shutdown.data[0] = reason_set; > + vcpu->run->shutdown.data[1] = reason_code; > + > + return 0; > } > default: > /* Error, keep GHCB MSR value as-is */ > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > index 8616af85dc5d..017c03421c48 100644 > --- a/include/uapi/linux/kvm.h > +++ b/include/uapi/linux/kvm.h > @@ -271,6 +271,12 @@ struct kvm_xen_exit { > #define KVM_EXIT_XEN 34 > #define KVM_EXIT_RISCV_SBI 35 > > +/* For KVM_EXIT_SHUTDOWN */ > +/* Standard VM shutdown request. No additional metadata provided. */ > +#define KVM_SHUTDOWN_REQ 0 > +/* SEV-ES termination request */ > +#define KVM_SHUTDOWN_SEV_TERM 1 > + > /* For KVM_EXIT_INTERNAL_ERROR */ > /* Emulate instruction failed. */ > #define KVM_INTERNAL_ERROR_EMULATION 1 > @@ -311,6 +317,12 @@ struct kvm_run { > struct { > __u64 hardware_exit_reason; > } hw; > + /* KVM_EXIT_SHUTDOWN */ > + struct { > + __u64 reason; > + __u32 ndata; > + __u64 data[16]; > + } shutdown; > /* KVM_EXIT_FAIL_ENTRY */ > struct { > __u64 hardware_entry_failure_reason; > @@ -1145,6 +1157,7 @@ struct kvm_ppc_resize_hpt { > #define KVM_CAP_PMU_CAPABILITY 212 > #define KVM_CAP_DISABLE_QUIRKS2 213 > #define KVM_CAP_VM_TSC_CONTROL 214 > +#define KVM_CAP_EXIT_SHUTDOWN_REASON 215 > > #ifdef KVM_CAP_IRQ_ROUTING > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 70e05af5ebea..03b6e472f32c 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -4299,6 +4299,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) > case KVM_CAP_CHECK_EXTENSION_VM: > case KVM_CAP_ENABLE_CAP_VM: > case KVM_CAP_HALT_POLL: > + case KVM_CAP_EXIT_SHUTDOWN_REASON: > return 1; > #ifdef CONFIG_KVM_MMIO > case KVM_CAP_COALESCED_MMIO:
On Fri, Mar 25, 2022 at 9:29 AM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 3/25/22 16:27, Peter Gonda wrote: > > SEV-ES guests can request termination using the GHCB's MSR protocol. See > > AMD's GHCB spec section '4.1.13 Termination Request'. Currently when a > > guest does this the userspace VMM sees an KVM_EXIT_UNKNOWN (-EVINAL) > > return code from KVM_RUN. By adding a KVM_EXIT_SHUTDOWN_ENTRY to kvm_run > > struct the userspace VMM can clear see the guest has requested a SEV-ES > > termination including the termination reason code set and reason code. > > > > Signed-off-by: Peter Gonda <pgonda@google.com> > > Cc: Paolo Bonzini <pbonzini@redhat.com> > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: Tom Lendacky <thomas.lendacky@amd.com> > > Cc: Brijesh Singh <brijesh.singh@amd.com> > > Cc: Joerg Roedel <jroedel@suse.de> > > Cc: Marc Orr <marcorr@google.com> > > Cc: Sean Christopherson <seanjc@google.com> > > Cc: kvm@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > This is missing an update to Documentation/. > My mistake. I'll send another revision. Is the behavior of KVM_CAP_EXIT_SHUTDOWN_REASON OK? Or should we only return 1 for SEV-ES guests?
On 3/25/22 16:31, Peter Gonda wrote: > On Fri, Mar 25, 2022 at 9:29 AM Paolo Bonzini <pbonzini@redhat.com> wrote: >> >> On 3/25/22 16:27, Peter Gonda wrote: >>> SEV-ES guests can request termination using the GHCB's MSR protocol. See >>> AMD's GHCB spec section '4.1.13 Termination Request'. Currently when a >>> guest does this the userspace VMM sees an KVM_EXIT_UNKNOWN (-EVINAL) >>> return code from KVM_RUN. By adding a KVM_EXIT_SHUTDOWN_ENTRY to kvm_run >>> struct the userspace VMM can clear see the guest has requested a SEV-ES >>> termination including the termination reason code set and reason code. >>> >>> Signed-off-by: Peter Gonda <pgonda@google.com> >>> Cc: Paolo Bonzini <pbonzini@redhat.com> >>> Cc: Borislav Petkov <bp@alien8.de> >>> Cc: Tom Lendacky <thomas.lendacky@amd.com> >>> Cc: Brijesh Singh <brijesh.singh@amd.com> >>> Cc: Joerg Roedel <jroedel@suse.de> >>> Cc: Marc Orr <marcorr@google.com> >>> Cc: Sean Christopherson <seanjc@google.com> >>> Cc: kvm@vger.kernel.org >>> Cc: linux-kernel@vger.kernel.org >> >> This is missing an update to Documentation/. >> > > My mistake. I'll send another revision. Is the behavior of > KVM_CAP_EXIT_SHUTDOWN_REASON OK? Or should we only return 1 for SEV-ES > guests? No, you can return 1 unconditionally, but you should also set reason and clear ndata in the other cases that return KVM_EXIT_SHUTDOWN. Paolo
On Fri, Mar 25, 2022 at 10:53 AM Paolo Bonzini <pbonzini@redhat.com> wrote: > > On 3/25/22 16:31, Peter Gonda wrote: > > On Fri, Mar 25, 2022 at 9:29 AM Paolo Bonzini <pbonzini@redhat.com> wrote: > >> > >> On 3/25/22 16:27, Peter Gonda wrote: > >>> SEV-ES guests can request termination using the GHCB's MSR protocol. See > >>> AMD's GHCB spec section '4.1.13 Termination Request'. Currently when a > >>> guest does this the userspace VMM sees an KVM_EXIT_UNKNOWN (-EVINAL) > >>> return code from KVM_RUN. By adding a KVM_EXIT_SHUTDOWN_ENTRY to kvm_run > >>> struct the userspace VMM can clear see the guest has requested a SEV-ES > >>> termination including the termination reason code set and reason code. > >>> > >>> Signed-off-by: Peter Gonda <pgonda@google.com> > >>> Cc: Paolo Bonzini <pbonzini@redhat.com> > >>> Cc: Borislav Petkov <bp@alien8.de> > >>> Cc: Tom Lendacky <thomas.lendacky@amd.com> > >>> Cc: Brijesh Singh <brijesh.singh@amd.com> > >>> Cc: Joerg Roedel <jroedel@suse.de> > >>> Cc: Marc Orr <marcorr@google.com> > >>> Cc: Sean Christopherson <seanjc@google.com> > >>> Cc: kvm@vger.kernel.org > >>> Cc: linux-kernel@vger.kernel.org > >> > >> This is missing an update to Documentation/. > >> > > > > My mistake. I'll send another revision. Is the behavior of > > KVM_CAP_EXIT_SHUTDOWN_REASON OK? Or should we only return 1 for SEV-ES > > guests? > > No, you can return 1 unconditionally, but you should also set reason and > clear ndata in the other cases that return KVM_EXIT_SHUTDOWN. Sounds good! Done in V3, thanks
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 75fa6dd268f0..5f9d37dd3f6f 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2735,8 +2735,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm) pr_info("SEV-ES guest requested termination: %#llx:%#llx\n", reason_set, reason_code); - ret = -EINVAL; - break; + vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; + vcpu->run->shutdown.reason = KVM_SHUTDOWN_SEV_TERM; + vcpu->run->shutdown.ndata = 2; + vcpu->run->shutdown.data[0] = reason_set; + vcpu->run->shutdown.data[1] = reason_code; + + return 0; } default: /* Error, keep GHCB MSR value as-is */ diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 8616af85dc5d..017c03421c48 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -271,6 +271,12 @@ struct kvm_xen_exit { #define KVM_EXIT_XEN 34 #define KVM_EXIT_RISCV_SBI 35 +/* For KVM_EXIT_SHUTDOWN */ +/* Standard VM shutdown request. No additional metadata provided. */ +#define KVM_SHUTDOWN_REQ 0 +/* SEV-ES termination request */ +#define KVM_SHUTDOWN_SEV_TERM 1 + /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ #define KVM_INTERNAL_ERROR_EMULATION 1 @@ -311,6 +317,12 @@ struct kvm_run { struct { __u64 hardware_exit_reason; } hw; + /* KVM_EXIT_SHUTDOWN */ + struct { + __u64 reason; + __u32 ndata; + __u64 data[16]; + } shutdown; /* KVM_EXIT_FAIL_ENTRY */ struct { __u64 hardware_entry_failure_reason; @@ -1145,6 +1157,7 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_PMU_CAPABILITY 212 #define KVM_CAP_DISABLE_QUIRKS2 213 #define KVM_CAP_VM_TSC_CONTROL 214 +#define KVM_CAP_EXIT_SHUTDOWN_REASON 215 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 70e05af5ebea..03b6e472f32c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4299,6 +4299,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) case KVM_CAP_CHECK_EXTENSION_VM: case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_HALT_POLL: + case KVM_CAP_EXIT_SHUTDOWN_REASON: return 1; #ifdef CONFIG_KVM_MMIO case KVM_CAP_COALESCED_MMIO:
SEV-ES guests can request termination using the GHCB's MSR protocol. See AMD's GHCB spec section '4.1.13 Termination Request'. Currently when a guest does this the userspace VMM sees an KVM_EXIT_UNKNOWN (-EVINAL) return code from KVM_RUN. By adding a KVM_EXIT_SHUTDOWN_ENTRY to kvm_run struct the userspace VMM can clear see the guest has requested a SEV-ES termination including the termination reason code set and reason code. Signed-off-by: Peter Gonda <pgonda@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Marc Orr <marcorr@google.com> Cc: Sean Christopherson <seanjc@google.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- V2 * Add KVM_CAP_EXIT_SHUTDOWN_REASON check for KVM_CHECK_EXTENSION. Tested by making an SEV-ES guest call sev_es_terminate() with hardcoded reason code set and reason code and then observing the codes from the userspace VMM in the kvm_run.shutdown.data fields. --- arch/x86/kvm/svm/sev.c | 9 +++++++-- include/uapi/linux/kvm.h | 13 +++++++++++++ virt/kvm/kvm_main.c | 1 + 3 files changed, 21 insertions(+), 2 deletions(-)