From 4c84926e229e0efdafa2756d7e6c4ae2fb0b7945 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Tue, 14 Sep 2021 18:48:19 +0300 Subject: [PATCH] KVM: x86: SVM: add module param to control LBR virtualization This is useful for debug and also makes it consistent with the rest of the SVM optional features. Signed-off-by: Maxim Levitsky Message-Id: <20210914154825.104886-9-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/svm.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index c770dce55ba8..270a091d57b0 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -186,6 +186,10 @@ module_param(vls, int, 0444); static int vgif = true; module_param(vgif, int, 0444); +/* enable/disable LBR virtualization */ +static int lbrv = true; +module_param(lbrv, int, 0444); + /* * enable / disable AVIC. Because the defaults differ for APICv * support between VMX and SVM we cannot use module_param_named. @@ -1059,6 +1063,13 @@ static __init int svm_hardware_setup(void) pr_info("Virtual GIF supported\n"); } + if (lbrv) { + if (!boot_cpu_has(X86_FEATURE_LBRV)) + lbrv = false; + else + pr_info("LBR virtualization supported\n"); + } + svm_set_cpu_caps(); /* @@ -2923,7 +2934,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) svm->tsc_aux = data; break; case MSR_IA32_DEBUGCTLMSR: - if (!boot_cpu_has(X86_FEATURE_LBRV)) { + if (!lbrv) { vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTL 0x%llx, nop\n", __func__, data); break;