Commit 4eb87460 authored Mar 02, 2020 by Sean Christopherson Committed by Paolo Bonzini Mar 16, 2020

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>

parent a50718cc

arch/x86/kvm/svm.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -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;

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