From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751378AbdH1Old convert rfc822-to-8bit (ORCPT ); Mon, 28 Aug 2017 10:41:33 -0400 Received: from mout.gmx.net ([212.227.17.22]:64910 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbdH1Olc (ORCPT ); Mon, 28 Aug 2017 10:41:32 -0400 Message-ID: <1503931275.5701.7.camel@gmx.de> Subject: Re: 4.13-rc7: WARNING at arch/x86/kvm/mmu.c:717 (and a crash thereafter) From: Mike Galbraith To: Takashi Iwai , Paolo Bonzini Cc: kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Date: Mon, 28 Aug 2017 16:41:15 +0200 In-Reply-To: <1503928376.5709.11.camel@gmx.de> References: <1503928376.5709.11.camel@gmx.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:97o2nCqdqGilJ2ArQe9aLh4hbFpXusMySQPEqPRQQm8CtB16iCW t+3QJe7QaYhoK5uHiWbdwMpcyj8J7gV/EriydErGO3Ls2NQxDHtUtfbvWg5k/aBmmzj2lqc qw5QT9JaLOu3K5uwAxLjeuOhalsFCBqYv/QJnfyV0D2jB8tcrFNNXZ5j0nFguLvoxte9egR mgmXYvYlKmy0TuWGQoBQA== X-UI-Out-Filterresults: notjunk:1;V01:K0:XoJBPyhiJCk=:9mnR82a9FXPLQgJt4qImqn gngk3eDOiYbcinZwcB/Nd4wQcVtclFt/03/8Kb18B4jbWU2QCIT5vhDVHmRMt3l4cE+h2ycA3 4PGkZ8Ahx74xcU8DW3vCNcGPBr58XxZeal05HywTX9D12ozGdyB9Aor6Amgz/yoMhfH6nZmCm Sbmf4iR8Hq77C141VuXGcGkNMHVgUYyZN9Bkl+2Azd/8/ehNPoFTXLbGIGBgqly0ZskN/NIQH pHk0J6UQ6bao9ra++QoMr3iHNtMeQ2Kue/GP5oR+oGC9DmZHjQ29TYthcYy5e5da9DYYwxQcP HV03kVIJQKuGlojVR2rbqWLW6g8P+hu8SmSn1GoIGGQSZj2LgINmX2Srl7Fq4Wr9mU7WDwoBR 0pXgaW4Br8vMQahl64ZZ8qurw45BcMrClW4OlTYLgpjBOm3BajUURVXFiddQwWNq4kvC1CreO gniqSBp6N63UuH8rxK9gfE7ER3Tr6gIHmKGRu80y8oo47N6N2GZDHwoJ8hXv1yLr3B+Z3X0/J MMUiwIAIqGQGh9EIhR3MMJd1St72366FtG6lCCZkv/h6C8OeRS0SIWcjhc4qWP4Gzapqi+/8B RwRUqnuL/yCcdsqpnc1sU+c9OwDIYvq/axVhyg9mK/Q3PBDX3MwW53uNHt7xKt7dAD81mb0Ob u0rKf2D0JxrxdD0nJVZIP9bq3A6gg9h13r4osMeMCEeBae3abxxRfaz+Sc49OYDKh6zsxKmHf lBUvq1oi0SXZTtQT0r+km6ilXtAost3GV2kFVzbyng/uVG+wYNc1nk45vUi4SMWHJ41a9r9iF +j9xnyF5pkAzK0h3i071h9ayslr2gGWZVLOk385kJZvR77E/MY= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2017-08-28 at 15:52 +0200, Mike Galbraith wrote: > On Mon, 2017-08-28 at 14:26 +0200, Takashi Iwai wrote: > > Hi, > > > > I seem to get a kernel warning when running KVM on Dell desktop with > > IvyBridge like below. As you can see, a bad page BUG is triggered > > after that, too. The problem is not triggered always, but it happens > > occasionally. > > > > I haven't seen this on 4.13-rc4 at all, and IIRC, it started happening > > since rc5. So this might be a regression at rc5. But, as it doesn't > > happen always, I can't be 100% sure about it, and it's quite difficult > > to bisect (the test case isn't reliable), unfortunately. > > > > Any hint for further debugging this? > > Maybe a way to make failure more likely.  This is an RT kernel, but > trying to build a fat kernel over NFS from a KVM clone of my > workstation (full topology, half of ram) didn't survive one build. Bah, plain master in guest/host survived. -Mike