Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753337Ab1EQJQq (ORCPT ); Tue, 17 May 2011 05:16:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37245 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752232Ab1EQJQp (ORCPT ); Tue, 17 May 2011 05:16:45 -0400 Message-ID: <4DD23CB6.3050503@redhat.com> Date: Tue, 17 May 2011 12:15:34 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc14 Lightning/1.0b3pre Thunderbird/3.1.10 MIME-Version: 1.0 To: Ingo Molnar CC: "H. Peter Anvin" , Fenghua Yu , Thomas Gleixner , Asit K Mallick , Linus Torvalds , Arjan van de Ven , Andrew Morton , Andi Kleen , linux-kernel , Pekka Enberg Subject: Re: [PATCH v2 0/4] Enable SMEP CPU Feature References: <1305581685-5144-1-git-send-email-fenghua.yu@intel.com> <4DD19C81.8000902@zytor.com> <20110517070527.GD22305@elte.hu> In-Reply-To: <20110517070527.GD22305@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1256 Lines: 33 On 05/17/2011 10:05 AM, Ingo Molnar wrote: > * H. Peter Anvin wrote: > > > On 05/16/2011 02:34 PM, Fenghua Yu wrote: > > > > > > Note: This patch set doesn't enable the SMEP feature in KVM. If it's needed, > > > another patch will be pushed for enabling the feature in KVM. > > > > > > > Hi Avi, > > > > Could you comment on if this needs to be a gating factor? It should certainly not be a gating factor. Note that smep will be disabled when switching to the guest, so there are no compatibility issues. > I think KVM would benefit from the native kernel playing guinea pig whether > SMEP is really, truly 100% trouble-free to enable by default (for Linux) ;-) > > Some programmable configurability seems necessary on the KVM side, as KVM has > no control over how sane the guest kernel is. We should simply expose the cpuid bit and cr4.smep. If the guest kernel feels it is up to it, it can enable smep itself. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/