From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 3/4] KVM: MMU: notrap it if gpte's reserved is set Date: Mon, 15 Nov 2010 11:17:25 +0200 Message-ID: <4CE0FAA5.3040902@redhat.com> References: <4CDD173E.8010706@cn.fujitsu.com> <4CDD1841.9010300@cn.fujitsu.com> <4CDFC04A.8010907@redhat.com> <4CE0C7F0.2040407@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM To: Xiao Guangrong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:17488 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754082Ab0KOJRe (ORCPT ); Mon, 15 Nov 2010 04:17:34 -0500 In-Reply-To: <4CE0C7F0.2040407@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: 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? Ideally we'd have a test case to catch this, but it may be hard to write. -- error compiling committee.c: too many arguments to function