KVM: nSVM: Advertise and enable NRIPS for L1 iff nrips is enabled

Set NRIPS in KVM capabilities if and only if nrips=true, which naturally
incorporates the boot_cpu_has() check, and set nrips_enabled only if the
KVM capability is enabled.

Note, previously KVM would set nrips_enabled based purely on userspace
input, but at worst that would cause KVM to propagate garbage into L1,
i.e. userspace would simply be hosing its VM.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm.c

@@ -1375,7 +1375,7 @@ static __init void svm_set_cpu_caps(void)
 	if (nested) {
 		kvm_cpu_cap_set(X86_FEATURE_SVM);
 
-		if (boot_cpu_has(X86_FEATURE_NRIPS))
+		if (nrips)
 			kvm_cpu_cap_set(X86_FEATURE_NRIPS);
 
 		if (npt_enabled)
@@ -6029,7 +6029,8 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
 				    boot_cpu_has(X86_FEATURE_XSAVES);
 
 	/* Update nrips enabled cache */
-	svm->nrips_enabled = !!guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS);
+	svm->nrips_enabled = kvm_cpu_cap_has(X86_FEATURE_NRIPS) &&
+			     guest_cpuid_has(&svm->vcpu, X86_FEATURE_NRIPS);
 
 	if (!kvm_vcpu_apicv_active(vcpu))
 		return;