From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: segfault at start with latest qemu-kvm.git Date: Thu, 04 Mar 2010 09:28:09 +0100 Message-ID: <4B8F6F19.7070803@web.de> References: <4B8ECC79.8040205@cisco.com> <4B8EEC07.2040803@web.de> <4B8EECB5.7030609@cisco.com> <4B8EEEA8.8070902@web.de> <4B8EEF76.8030205@cisco.com> <4B8EF701.10208@web.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigF94EB108D27F0D9520A54F3E" Cc: kvm-devel To: "David S. Ahern" Return-path: Received: from fmmailgate02.web.de ([217.72.192.227]:58212 "EHLO fmmailgate02.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754152Ab0CDI2K (ORCPT ); Thu, 4 Mar 2010 03:28:10 -0500 In-Reply-To: <4B8EF701.10208@web.de> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigF94EB108D27F0D9520A54F3E Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Jan Kiszka wrote: > David S. Ahern wrote: >> On 03/03/2010 04:20 PM, Jan Kiszka wrote: >>> David S. Ahern wrote: >>>> >>>> On 03/03/2010 04:08 PM, Jan Kiszka wrote: >>>>> David S. Ahern wrote: >>>>>> With latest qemu-kvm.git I am getting a segfault at start: >>>>>> >>>>>> /tmp/qemu-kvm-test/bin/qemu-system-x86_64 -m 1024 -smp 2 \ >>>>>> -drive file=3D/images/f12-x86_64.img,if=3Dvirtio,cache=3Dnone,bo= ot=3Don >>>>>> >>>>>> kvm_create_vcpu: Invalid argument >>>>>> Segmentation fault (core dumped) >>>>>> >>>>>> >>>>>> git bisect points to: >>>>>> >>>>>> Bisecting: 0 revisions left to test after this (roughly 0 steps) >>>>>> [52b03dd70261934688cb00768c4b1e404716a337] qemu-kvm: Move >>>>>> kvm_set_boot_cpu_id >>>>>> >>>>>> >>>>>> $ git show >>>>>> commit 7811d4e8ec057d25db68f900be1f09a142faca49 >>>>>> Author: Marcelo Tosatti >>>>>> Date: Mon Mar 1 21:36:31 2010 -0300 >>>>>> >>>>>> >>>>>> If I manually back out the patch it will boot fine. >>>>>> >>>>> Problem persists after removing the build directory and doing a fre= sh >>>>> configure && make? I'm asking before taking the bug (which would be= >>>>> mine, likely) as I recently spent some hours "debugging" a volatile= >>>>> build system issue. >>>>> >>>>> Jan >>>>> >>>> Before sending the email I pulled a fresh clone in a completely >>>> different directory (/tmp) to determine if it was something I >>>> introduced. I then went back to my usual location, unapplied the pat= ch >>>> and it worked fine. >>> OK, that reason can be excluded. What's your host kernel kvm version?= >>> >>> (Of course, the issue does not show up here. But virtio currently doe= s >>> not boot for me - independent of my patch.) >>> >>> Jan >>> >> Fedora Core 12, >> >> Linux daahern-lx 2.6.31.12-174.2.22.fc12.x86_64 #1 SMP Fri Feb 19 >> 18:55:03 UTC 2010 x86_64 x86_64 x86_64 GNU/Linux >> >=20 > Reproduced after switching back to kvm-kmod-2.6.31, will debug. >=20 Subtle memory corruption: qemu_malloc is returning a pointer that happens to become kvm_state twice. I bet my patch just exchanges some of the involved parties and exposes the issue more prominently. Trying to understand malloc's issue now... Jan --------------enigF94EB108D27F0D9520A54F3E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkuPbxkACgkQitSsb3rl5xTqRwCfQfYLfEzS6mOIP0rIVOg+fJtk vxUAn1S/0RhvtVjTBwW7k6TF6BSIguf6 =VumK -----END PGP SIGNATURE----- --------------enigF94EB108D27F0D9520A54F3E--