From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] x86, kvm: Add MSR_AMD64_BU_CFG2 to the list of ignored MSRs Date: Wed, 13 Feb 2013 14:10:02 +0200 Message-ID: <20130213121002.GD9817@redhat.com> References: <1360755761-725-1-git-send-email-bp@alien8.de> <20130213114747.GC9817@redhat.com> <20130213115526.GA15210@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Borislav Petkov , kvm@vger.kernel.org, LKML , X86 ML , Borislav Petkov , Boris Ostrovsky , Andre Przywara , Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60763 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933821Ab3BMMLP (ORCPT ); Wed, 13 Feb 2013 07:11:15 -0500 Content-Disposition: inline In-Reply-To: <20130213115526.GA15210@pd.tnic> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Feb 13, 2013 at 12:55:26PM +0100, Borislav Petkov wrote: > On Wed, Feb 13, 2013 at 01:47:47PM +0200, Gleb Natapov wrote: > > On Wed, Feb 13, 2013 at 12:42:41PM +0100, Borislav Petkov wrote: > > > From: Borislav Petkov > > > > > > The "x86, AMD: Enable WC+ memory type on family 10 processors" patch > > > currently in -tip added a workaround for AMD F10h CPUs which #GPs my > > > guest when booted in kvm. This is because it accesses MSR_AMD64_BU_CFG2 > > > which is not currently ignored by kvm. Do that because this MSR is only > > > baremetal-relevant anyway. While at it, move the ignored MSRs at the > > > beginning of kvm_set_msr_common so that we exit then and there. > > > > > Is your guest compiled without PV support? With PV Linux traps #GP for > > all MSRs and it saves us in more than one places. > > Yes, CONFIG_PARAVIRT_GUEST is not set on the guest kernel. > Thanks. It does not mean that the patch should not be applied though. I cannot seems to find the documentation for the MSR anywhere, do you have a pointer? -- Gleb.