From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] use upstream cpuid code Date: Mon, 03 Aug 2009 17:06:28 +0300 Message-ID: <4A76EEE4.5090403@redhat.com> References: <1248811515-6877-1-git-send-email-glommer@redhat.com> <4A76D0BB.3080000@redhat.com> <20090803132226.GC4374@poweredge.glommer> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Glauber Costa Return-path: Received: from mx2.redhat.com ([66.187.237.31]:42806 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754926AbZHCOBO (ORCPT ); Mon, 3 Aug 2009 10:01:14 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n73E1D6K001709 for ; Mon, 3 Aug 2009 10:01:15 -0400 In-Reply-To: <20090803132226.GC4374@poweredge.glommer> Sender: kvm-owner@vger.kernel.org List-ID: On 08/03/2009 04:22 PM, Glauber Costa wrote: > On Mon, Aug 03, 2009 at 02:57:47PM +0300, Avi Kivity wrote: > >> On 07/28/2009 11:05 PM, Glauber Costa wrote: >> >>> use cpuid code from upstream. By doing that, we lose the following snippet >>> in kvm_get_supported_cpuid(): >>> >>> ret |= 1<< 12; /* MTRR */ >>> ret |= 1<< 16; /* PAT */ >>> ret |= 1<< 7; /* MCE */ >>> ret |= 1<< 14; /* MCA */ >>> >>> A quick search in mailing lists says this code is not really necessary, and we're >>> keeping it just for backwards compatibility. This is not that important, because >>> we'd lose it anyway in the golden day in which we totally merge with qemu. >>> Anyway, if it do _is_ important, we can send a patch to qemu with it. >>> >>> >> It is important. Please don't introduce regressions (if you do, >> introduce them in separate patches). The procedure to drop such >> workarounds for kernel bugs is to verify that major distros have the >> kernel fixes in their supported kernels. >> > Since this was introduced to fix a bug that did not even existed in Windows, > I can't see what you mean by "distro kernels" here. > If qemu-kvm with this patch works on Fedora 10 (latest kernel) and the equivalent opensuse and Ubuntu kernels, then we can safely remove the bug workaround. If not, if we apply the patch we just cause users needless pain. -- error compiling committee.c: too many arguments to function