Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754181AbdHUT6j (ORCPT ); Mon, 21 Aug 2017 15:58:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54500 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754135AbdHUT6h (ORCPT ); Mon, 21 Aug 2017 15:58:37 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 32B1283F42 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=rkrcmar@redhat.com Date: Mon, 21 Aug 2017 21:58:34 +0200 From: Radim =?utf-8?B?S3LEjW3DocWZ?= To: Adam Borowski Cc: Wanpeng Li , Paolo Bonzini , kvm , "linux-kernel@vger.kernel.org" Subject: Re: kvm splat in mmu_spte_clear_track_bits Message-ID: <20170821195833.GA696@flask> References: <20170820231302.s732zclznrqxwr46@angband.pl> <20170821191203.jospdwqpnixlotx3@angband.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170821191203.jospdwqpnixlotx3@angband.pl> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Mon, 21 Aug 2017 19:58:37 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1225 Lines: 28 2017-08-21 21:12+0200, Adam Borowski: > On Mon, Aug 21, 2017 at 09:26:57AM +0800, Wanpeng Li wrote: > > 2017-08-21 7:13 GMT+08:00 Adam Borowski : > > > Hi! > > > I'm afraid I keep getting a quite reliable, but random, splat when running > > > KVM: > > > > I reported something similar before. https://lkml.org/lkml/2017/6/29/64 > > Your problem seems to require OOM; I don't have any memory pressure at all: > running a single 2GB guest while there's nothing big on the host (bloatfox, > xfce, xorg, terminals + some minor junk); 8GB + (untouched) swap. There's > no memory pressure inside the guest either -- none was Linux (I wanted to > test something on hurd, kfreebsd) and I doubt they even got to use all of > their frames. I even tried hurd, but couldn't reproduce ... what is your qemu command line and the output of host's `grep . /sys/module/kvm*/parameters/*`? > Also, it doesn't reproduce for me on 4.12. Great info ... the most suspicious between v4.12 and v4.13-rc5 is the series with dcdca5fed5f6 ("x86: kvm: mmu: make spte mmio mask more explicit"), does reverting it help? `git revert ce00053b1cfca312c22e2a6465451f1862561eab~1..995f00a619584e65e53eff372d9b73b121a7bad5` Thanks.