[PATCH 24/24] KVM: nSVM: enable GMET for guests

[Paolo Bonzini]

All that needs to be done is moving the GMET bit from vmcs12 to
vmcs02.  The only new thing is that __nested_svm_check_controls
now ensures that ignored-if-unavailable bits are zero in
svm->nested.ctl.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
 arch/x86/kvm/svm/nested.c | 6 ++++++
 arch/x86/kvm/svm/svm.c    | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 4c7bc0e7f908..235477bac7e7 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -343,6 +343,8 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)
 static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
 					 struct vmcb_ctrl_area_cached *control)
 {
+	struct vcpu_svm *svm = to_svm(vcpu);
+
 	if (CC(!vmcb12_is_intercept(control, INTERCEPT_VMRUN)))
 		return false;
 
@@ -364,6 +366,9 @@ static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
 		return false;
 	}
 
+	if (!gmet_enabled || !guest_cpu_cap_has(vcpu, X86_FEATURE_GMET))
+		svm->nested.ctl.nested_ctl &= ~SVM_NESTED_CTL_GMET_ENABLE;
+
 	return true;
 }
 
@@ -832,6 +837,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm,
 	/* Use vmcb01 MMU and format if guest does not use nNPT */
 	if (nested_npt_enabled(svm)) {
 		vmcb02->control.nested_ctl &= ~SVM_NESTED_CTL_GMET_ENABLE;
+		vmcb02->control.nested_ctl |= (svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_GMET_ENABLE);
 
 		nested_svm_init_mmu_context(vcpu);
 	}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 700090c3408c..430e4f4ef55b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -5372,6 +5372,9 @@ static __init void svm_set_cpu_caps(void)
 		if (boot_cpu_has(X86_FEATURE_PFTHRESHOLD))
 			kvm_cpu_cap_set(X86_FEATURE_PFTHRESHOLD);
 
+		if (boot_cpu_has(X86_FEATURE_GMET))
+			kvm_cpu_cap_set(X86_FEATURE_GMET);
+
 		if (vgif)
 			kvm_cpu_cap_set(X86_FEATURE_VGIF);
 
-- 
2.53.0