From 2cdef91cf882abc74dd2f6bfae16db782b44c6ce Mon Sep 17 00:00:00 2001 From: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Date: Thu, 5 Nov 2020 16:39:32 +0100 Subject: [PATCH] KVM: x86: handle MSR_IA32_DEBUGCTLMSR with report_ignored_msrs Windows2016 guest tries to enable LBR by setting the corresponding bits in MSR_IA32_DEBUGCTLMSR. KVM does not emulate MSR_IA32_DEBUGCTLMSR and spams the host kernel logs with error messages like: kvm [...]: vcpu1, guest rIP: 0xfffff800a8b687d3 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop" This patch fixes this by enabling error logging only with 'report_ignored_msrs=1'. Signed-off-by: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Message-Id: <20201105153932.24316-1-pankaj.gupta.linux@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/x86.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index d9651faabe6833..447edc0d1d5a68 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3065,9 +3065,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) /* Values other than LBR and BTF are vendor-specific, thus reserved and should throw a #GP */ return 1; - } - vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", - __func__, data); + } else if (report_ignored_msrs) + vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n", + __func__, data); break; case 0x200 ... 0x2ff: return kvm_mtrr_set_msr(vcpu, msr, data); -- GitLab