From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934000Ab0KQBks (ORCPT ); Tue, 16 Nov 2010 20:40:48 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:64200 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S933968Ab0KQBkq (ORCPT ); Tue, 16 Nov 2010 20:40:46 -0500 Message-ID: <4CE3339F.4020200@cn.fujitsu.com> Date: Wed, 17 Nov 2010 09:45:03 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: Re: [PATCH 3/4] KVM: MMU: notrap it if gpte's reserved is set References: <4CDD173E.8010706@cn.fujitsu.com> <4CDD1841.9010300@cn.fujitsu.com> <4CDFC04A.8010907@redhat.com> <4CE0C7F0.2040407@cn.fujitsu.com> <4CE0FAA5.3040902@redhat.com> In-Reply-To: <4CE0FAA5.3040902@redhat.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-17 09:41:07, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2010-11-17 09:41:07, Serialize complete at 2010-11-17 09:41:07 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/15/2010 05:17 PM, Avi Kivity wrote: > On 11/15/2010 07:41 AM, Xiao Guangrong wrote: >> On 11/14/2010 06:56 PM, Avi Kivity wrote: >> > On 11/12/2010 12:34 PM, Xiao Guangrong wrote: >> >> We can past the page fault to guest directly if gpte's reserved >> >> is set >> >> >> > >> > How can that work? shadow_notrap_nonpresent_pte causes a fault with >> > PFEC.P=PFEC.RSVD=0, while we need PFEC.P=PFEC.RSVD=1. >> > >> >> Ah, i missed it for a long time, thanks for you point it out. >> >> The same mistake is in 'prefetch' path, i'll fix it in the v2 version. > > Doesn't access.flat catch this? Unfortunately, it can't catch this. > > Ideally we'd have a test case to catch this, but it may be hard to write. > Um. i'll do it later.