From: Paolo Bonzini <pbonzini@redhat.com>
To: Peter Gonda <pgonda@google.com>, kvm@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
Brijesh Singh <brijesh.singh@amd.com>,
Joerg Roedel <jroedel@suse.de>, Marc Orr <marcorr@google.com>,
Sean Christopherson <seanjc@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] Add KVM_EXIT_SHUTDOWN metadata for SEV-ES
Date: Fri, 25 Mar 2022 16:28:54 +0100 [thread overview]
Message-ID: <d0366a14-6492-d2b9-215e-2ee310d9f8ae@redhat.com> (raw)
In-Reply-To: <20220325152758.335626-1-pgonda@google.com>
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:
next prev parent reply other threads:[~2022-03-25 15:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-25 15:27 [PATCH v2] Add KVM_EXIT_SHUTDOWN metadata for SEV-ES Peter Gonda
2022-03-25 15:28 ` Paolo Bonzini [this message]
2022-03-25 15:31 ` Peter Gonda
2022-03-25 16:53 ` Paolo Bonzini
2022-03-30 18:30 ` Peter Gonda
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