From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 1/2] ignore AMDs HWCR register access to set the FFDIS bit Date: Wed, 24 Jun 2009 12:58:28 +0300 Message-ID: <4A41F8C4.6080102@redhat.com> References: <1245709224-974-1-git-send-email-andre.przywara@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Andre Przywara Return-path: Received: from mx2.redhat.com ([66.187.237.31]:47182 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751338AbZFXJ50 (ORCPT ); Wed, 24 Jun 2009 05:57:26 -0400 In-Reply-To: <1245709224-974-1-git-send-email-andre.przywara@amd.com> Sender: kvm-owner@vger.kernel.org List-ID: On 06/23/2009 01:20 AM, Andre Przywara wrote: > Linux tries to disable the flush filter on all AMD K8 CPUs. Since KVM > does not handle the needed MSR, the injected #GP will panic the Linux > kernel. Ignore setting of the HWCR.FFDIS bit in this MSR to let Linux > boot with an AMD K8 family guest CPU. > > Signed-off-by: Andre Przywara > --- > arch/x86/kvm/x86.c | 7 +++++++ > 1 files changed, 7 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 5a66bb9..4c19c24 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -796,6 +796,13 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data) > case MSR_EFER: > set_efer(vcpu, data); > break; > + case MSR_K7_HWCR: > + if (data != 0x40) { > + pr_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n", > + data); > + return 1; > + } > + break; > Won't that printk() if writing a zero? Just mask out that bit. I also see some HWCR handling in svm.c, can probably be removed. -- error compiling committee.c: too many arguments to function