From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933436Ab3BSSWa (ORCPT ); Tue, 19 Feb 2013 13:22:30 -0500 Received: from terminus.zytor.com ([198.137.202.10]:44917 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933160Ab3BSSW3 (ORCPT ); Tue, 19 Feb 2013 13:22:29 -0500 Message-ID: <5123C28F.50405@zytor.com> Date: Tue, 19 Feb 2013 10:21:03 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Boris Ostrovsky CC: Ingo Molnar , Konrad Rzeszutek Wilk , Borislav Petkov , Linus Torvalds , linux-kernel@vger.kernel.org, Thomas Gleixner , Andrew Morton Subject: Re: [GIT PULL] x86/cpu changes for v3.9 References: <20130219152503.GA14862@gmail.com> <20130219153655.GD26748@pd.tnic> <20130219154721.GA15876@gmail.com> <5123B897.9010607@zytor.com> <20130219174758.GB4465@pd.tnic> <20130219175726.GA18244@phenom.dumpdata.com> <5123C217.3040609@oracle.com> In-Reply-To: <5123C217.3040609@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/2013 10:19 AM, Boris Ostrovsky wrote: > On 02/19/2013 12:57 PM, Konrad Rzeszutek Wilk wrote: >> On Tue, Feb 19, 2013 at 06:47:58PM +0100, Borislav Petkov wrote: >>> On Tue, Feb 19, 2013 at 09:38:31AM -0800, H. Peter Anvin wrote: >>>> My fault... I was tracking the fix and lost track of the thread. >>>> >>>> The problem is that the fix is necessary but not sufficient, as it >>>> introduces an undesirable host-guest dependency. In order to allow >>>> neerw guests to work on older hosts we also should use the >>>> {rd,wr}msr_safe() functions to manipulate this MSR, with a comment >>>> as to why. >>>> >>>> Boris, could you prepare such a patch, please? >>> I don't think Boris O. is at AMD anymore. Want me to add that to my fix >>> for kvm or prep a separate patch? >> CC-ing Boris. > > BorisP's patch is what I should have done. Can you take it? > As I stated: >>>> The problem is that the fix is necessary but not sufficient, as it >>>> introduces an undesirable host-guest dependency. In order to allow >>>> neerw guests to work on older hosts we also should use the >>>> {rd,wr}msr_safe() functions to manipulate this MSR, with a comment >>>> as to why. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.