This is useful for debug and also makes it consistent with the rest of the SVM optional features.
Signed-off-by: Maxim Levitsky mlevitsk@redhat.com --- arch/x86/kvm/svm/svm.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index deeebd05f682..b08c5d826208 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -186,6 +186,11 @@ 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 +1064,13 @@ 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();
/* @@ -2920,7 +2932,7 @@ 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;