KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c07dbcc..26110c2 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4120,6 +4120,13 @@
msr_info->data = svm->spec_ctrl;
break;
+ case MSR_AMD64_VIRT_SPEC_CTRL:
+ if (!msr_info->host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+ return 1;
+
+ msr_info->data = svm->virt_spec_ctrl;
+ break;
case MSR_F15H_IC_CFG: {
int family, model;
@@ -4251,6 +4258,16 @@
break;
set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1);
break;
+ case MSR_AMD64_VIRT_SPEC_CTRL:
+ if (!msr->host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD))
+ return 1;
+
+ if (data & ~SPEC_CTRL_SSBD)
+ return 1;
+
+ svm->virt_spec_ctrl = data;
+ break;
case MSR_STAR:
svm->vmcb->save.star = data;
break;
@@ -5791,7 +5808,7 @@
return false;
}
-static bool svm_has_high_real_mode_segbase(void)
+static bool svm_has_emulated_msr(int index)
{
return true;
}
@@ -7017,7 +7034,7 @@
.hardware_enable = svm_hardware_enable,
.hardware_disable = svm_hardware_disable,
.cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr,
- .cpu_has_high_real_mode_segbase = svm_has_high_real_mode_segbase,
+ .has_emulated_msr = svm_has_emulated_msr,
.vcpu_create = svm_create_vcpu,
.vcpu_free = svm_free_vcpu,