From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f170.google.com ([209.85.216.170]:51616 "EHLO mail-qc0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751312AbaJJPzh (ORCPT ); Fri, 10 Oct 2014 11:55:37 -0400 Received: by mail-qc0-f170.google.com with SMTP id m20so2174513qcx.1 for ; Fri, 10 Oct 2014 08:55:36 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <5437F1F5.3010706@maya.org> References: <20140923210318.498dacbd@dualc.maya.org> <1411502866.24563.8.camel@ul30vt.home> <5437A958.3000201@maya.org> <5437F1F5.3010706@maya.org> From: Bjorn Helgaas Date: Fri, 10 Oct 2014 09:55:16 -0600 Message-ID: Subject: Re: Hard and silent lock up since linux 3.14 with PCIe pass through (vfio) To: Andreas Hartmann Cc: Alex Williamson , linux-pci Content-Type: text/plain; charset=UTF-8 Sender: linux-pci-owner@vger.kernel.org List-ID: On Fri, Oct 10, 2014 at 8:49 AM, Andreas Hartmann wrote: > Bjorn Helgaas schrieb: >> On Fri, Oct 10, 2014 at 3:39 AM, Andreas Hartmann >> wrote: >>> shortly: I retested w/ qemu 2.1.0 and Linux 3.17.0 - no change in behaviour. >>> >>> Alex Williamson wrote: >>>> On Tue, 2014-09-23 at 21:03 +0200, Andreas Hartmann wrote: >>>>> Hello! >>>>> >>>>> Since long time now, I'm using w/o any problem PCIe pass through with a >>>>> Gigabyte GA-990XA-UD3/GA-990XA-UD3 mainboard (AMD 990X chipset) and >>>>> enabled IOMMU with vfio-pci. >>>>> >>>>> The last kernel working w/o any problem is kernel 3.13.7 (I didn't use >>>>> .8 and .9, but I do not think they would have been problematic). >>>>> >>>>> Since 3.14.19 (I didn't test any 3.14 kernel before) I'm encountering a >>>>> hard and silent lock up of the complete machine when starting the VM >>>>> with the PCIe card passed through. >> >> Since we're not really making any progress on this yet, would it be >> possible to bisect it? We already know that 3.13.7 works and 3.14.19 >> fails, and "git bisect start v3.14 v3.13" says it's about 13 steps. I >> know that's still quite a bit of work, but at least it sounds like the >> problem is easy to reproduce. > > Which git repository should I use best? The linux-stable repository [1] contains both the v3.13.x and the v3.14.x branches, but apparently you can't bisect directly between v3.13.7 and v3.14.19: $ git bisect start v3.14.19 v3.13.7 Bisecting: a merge base must be tested [d8ec26d7f8287f5788a494f56e8814210f0e64be] Linux 3.13 I'm not an expert at bisecting, but here's what I would try: - Clone the repo from [1] (this same repo can be used for all your testing) - Checkout, build, and test v3.14 - If v3.14 works (unlikely), bisect between v3.14 and v3.14.19 to see which change broke it - If v3.14 fails, checkout, build, and test v3.13 - If v3.13 fails (very unlikely), bisect between v3.13 and v3.13.7 to see which change fixed it - If v3.13 works and v3.14 fails (most likely), bisect between v3.13 and v3.14 Bjorn [1] git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git