Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752210AbXJUMjJ (ORCPT ); Sun, 21 Oct 2007 08:39:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751468AbXJUMi6 (ORCPT ); Sun, 21 Oct 2007 08:38:58 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:42099 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321AbXJUMi5 convert rfc822-to-8bit (ORCPT ); Sun, 21 Oct 2007 08:38:57 -0400 Message-ID: <471B483D.90305@bull.net> Date: Sun, 21 Oct 2007 14:38:21 +0200 From: Laurent Vivier Organization: Bull S.A.S. User-Agent: IceDove 1.5.0.12 (X11/20070606) MIME-Version: 1.0 To: Avi Kivity Cc: kvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [kvm-devel] [PATCH 00/11] KVM updates for Linux 2.6.24-rc review References: <1192964892617-git-send-email-avi@qumranet.com> <471B340C.5010800@qumranet.com> <471B3DD3.3080107@bull.net> <471B40E4.4060204@qumranet.com> In-Reply-To: <471B40E4.4060204@qumranet.com> X-MIMETrack: Itemize by SMTP Server on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 21/10/2007 14:45:28, Serialize by Router on ECN002/FR/BULL(Release 5.0.12 |February 13, 2003) at 21/10/2007 14:45:30, Serialize complete at 21/10/2007 14:45:30 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset=iso-8859-1; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2555 Lines: 69 Avi Kivity a ?crit : > Laurent Vivier wrote: >> Avi Kivity a ?crit : >>> Avi Kivity wrote: >>>> The following patches fix fallout from the main 2.6.24 KVM merge. An >>>> exception is the movnti emulation patch, which adds support for Linux >>>> 2.6.16 guests. >>>> >>>> The patches can be found in kvm.git in the branch kvm-updates-2.6.24. >>>> There is also a branch kvm-updates-2.6.25 which will form the basis of >>>> the next merge window submission. >>>> >>>> Please review the patches and let me know if something is wrong or if >>>> a patch is missing. >>>> >>>> >>> >>> Laurent, I believe the following patch (in kvm-updates-2.6.25) needs >>> to go into 2.6.24 as well. Can you comment on this? >> What kind of comment do you want ? > > Well, whether it needs to go into .24. > >> What are the requirements to go in 2.6.24 instead of 2.6.25 ? >> >> Is a bug correction enough ? :-P >> > > It has to fix something real-life, in a real guest. > >> This patch correct a bad behavior of x86_emulate_insn() in case of >> error with a REP prefix. >> >> This patch is needed because, without it, when REP prefix is used with >> an instruction failing for some reasons (like IO or page fault) we >> don't restore all modified registers (like RSI and RDI), but only ECX >> and EIP, so when we re-enter in x86_emulate_insn() we modify again an >> already modified value. Moreover, this patch manages correctly the >> case where the instruction fails in writeback(). >> > > Okay, I guess it is needed. Can you backport it to the branch? It's > very different from kvm-updates-2.6.24... > Well, in fact it is not needed in 2.6.24, because this patch correct a bad behavior introduced by commit 57f4e446ebca4aad5c11364baf8477c8cfcb16a4 (which is not in kvm-update-2.6.24): KVM: Call x86_decode_insn() only when needed Move emulate_ctxt to kvm_vcpu to keep emulate context when we exit from kvm module. Call x86_decode_insn() only when needed. Modify x86_emulate_insn() to not modify the context if it must be re-entered. So, in fact, the answer is (after correctly understanding the question): no, this patch is not needed in kvm-update-2.6.24. Regards, Laurent -- ---------------- Laurent.Vivier@bull.net ----------------- "Given enough eyeballs, all bugs are shallow" E. S. Raymond - 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/