From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752016Ab2IEFfZ (ORCPT ); Wed, 5 Sep 2012 01:35:25 -0400 Received: from mga14.intel.com ([143.182.124.37]:61682 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750800Ab2IEFfY (ORCPT ); Wed, 5 Sep 2012 01:35:24 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,372,1344236400"; d="scan'208";a="188922516" Message-ID: <5046E47C.2020405@intel.com> Date: Wed, 05 Sep 2012 13:34:52 +0800 From: Alex Shi User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:9.0) Gecko/20111229 Thunderbird/9.0 MIME-Version: 1.0 To: Jan Beulich CC: Konrad Rzeszutek Wilk , tglx@linutronix.de, mingo@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com, "Ren, Yongjie" Subject: Re: [PATCH] xen: fix logical error in tlb flushing References: <1345798513-3566-1-git-send-email-alex.shi@intel.com> <5037A8E7020000780008A78B@nat28.tlf.novell.com> <20120824181721.GC15167@konrad-lan.dumpdata.com> <5037E7ED020000780008A7BD@nat28.tlf.novell.com> In-Reply-To: <5037E7ED020000780008A7BD@nat28.tlf.novell.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/25/2012 03:45 AM, Jan Beulich wrote: >>>> On 24.08.12 at 20:17, Konrad Rzeszutek Wilk wrote: >> On Fri, Aug 24, 2012 at 04:16:39PM +0100, Jan Beulich wrote: >>>>>> On 24.08.12 at 10:55, Alex Shi wrote: >>>> While TLB_FLUSH_ALL gets passed as 'end' argument to >>>> flush_tlb_others(), the Xen code was made to check its 'start' >>>> parameter. That may give a incorrect op.cmd to MMUEXT_INVLPG_MULTI >>>> instead of MMUEXT_TLB_FLUSH_MULTI. Then it causes some page can not >>>> be flushed from TLB. >>>> >>>> This patch fixed this issue. >>>> >>>> Reported-by: Jan Beulich >>>> Signed-off-by: Alex Shi >>> >>> Acked-by: Jan Beulich CC to Yongjie, Could you like to test this patch on PV guest >> >> How can I reproduce this > > I don't know, I spotted this while looking at the code. Again, since the old buggy code doesn't cause trouble in PV guest, guess the hypercall for MMUEXT_INVLPG_MULTI was translated or treated as MMUEXT_TLB_FLUSH_MULTI. If so, believe correct this will bring a big performance benefit.