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 clearly see the guest has requested a SEV-ES
termination including the termination reason code set and reason code.
Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
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 | 12 ++++++++++++
2 files changed, 19 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..12138b8f290c 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_ENTRY */
+ struct {
+ __u64 reason;
+ __u32 ndata;
+ __u64 data[16];
+ } shutdown;
/* KVM_EXIT_FAIL_ENTRY */
struct {
__u64 hardware_entry_failure_reason;
--
2.35.1.894.gb6a874cedc-goog
