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authorTom Lendacky <thomas.lendacky@amd.com>2018-05-10 22:06:39 +0200
committerThomas Gleixner <tglx@linutronix.de>2018-05-17 17:09:21 +0200
commitbc226f07dcd3c9ef0b7f6236fe356ea4a9cb4769 (patch)
tree59513d5643fe684d8f08ffdc3c31c681608d30a6 /arch/x86/kvm/svm.c
parent47c61b3955cf712cadfc25635bf9bc174af030ea (diff)
downloadlinux-bc226f07dcd3c9ef0b7f6236fe356ea4a9cb4769.tar.gz
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>
Diffstat (limited to 'arch/x86/kvm/svm.c')
-rw-r--r--arch/x86/kvm/svm.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index c07dbcc6d449..26110c202b19 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4120,6 +4120,13 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 		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 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
 			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 @@ static bool svm_cpu_has_accelerated_tpr(void)
 	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 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = {
 	.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,