From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] Write to read-only msr MSR_IA32_PERF_STATUS is harmless, ignore it! Date: Tue, 31 Aug 2010 19:28:22 +0300 Message-ID: <4C7D2DA6.40105@redhat.com> References: <1283257029-24102-1-git-send-email-Jes.Sorensen@redhat.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: Jes.Sorensen@redhat.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:7073 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753970Ab0HaQui (ORCPT ); Tue, 31 Aug 2010 12:50:38 -0400 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o7VGoaVm029265 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 31 Aug 2010 12:50:38 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx08.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o7VGSNa4004971 for ; Tue, 31 Aug 2010 12:28:24 -0400 In-Reply-To: <1283257029-24102-1-git-send-email-Jes.Sorensen@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 08/31/2010 03:17 PM, Jes.Sorensen@redhat.com wrote: > From: Jes Sorensen > > We regularly see bug reports over this one, however it is a write to > a read-only register which some operating systems (including Linux) > tend to write to once in a while. > > Ignore the writes since they do no harm. > Does Linux write it with wrmsr_safe()? If not, I don't see how it works. If it does, then we shouldn't ignore the write, instead issue the #GP as usual, but be silent about it. -- error compiling committee.c: too many arguments to function