From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60921) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVMI4-0000Rx-1p for qemu-devel@nongnu.org; Wed, 02 Apr 2014 10:37:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WVMHk-0001UM-C3 for qemu-devel@nongnu.org; Wed, 02 Apr 2014 10:37:20 -0400 Received: from mail-bk0-f42.google.com ([209.85.214.42]:53275) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WVMHk-0001UG-3C for qemu-devel@nongnu.org; Wed, 02 Apr 2014 10:37:00 -0400 Received: by mail-bk0-f42.google.com with SMTP id mx12so51479bkb.15 for ; Wed, 02 Apr 2014 07:36:58 -0700 (PDT) Message-ID: <533C208E.7010703@m2r.biz> Date: Wed, 02 Apr 2014 16:37:02 +0200 From: Fabio Fantoni MIME-Version: 1.0 References: <533AD4BE.8080101@m2r.biz> <533AE841.1000606@redhat.com> <533BF0DB.70100@m2r.biz> <533C114B.8020902@redhat.com> In-Reply-To: <533C114B.8020902@redhat.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Qemu 2.0 regression with xen: qemu crash on any domUs S.O. start List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laszlo Ersek , xen-devel , "qemu-devel@nongnu.org" Il 02/04/2014 15:31, Laszlo Ersek ha scritto: > On 04/02/14 13:13, Fabio Fantoni wrote: >> Il 01/04/2014 18:24, Laszlo Ersek ha scritto: >>> On 04/01/14 17:01, Fabio Fantoni wrote: >>>> Today I tried latest qemu 2.0 compiled from git (commit >>>> 63678e17cf399ff81b93417fe7bee8d6ef6b6b1b) on this dom0: >>>> Debian 7 (Wheezy) 64 bit with kernel from package >>>> linux-image-3.2.0-4-amd64 version 3.2.54-2 and all dependency packages >>>> for xen, spice and usb redirection. >>>> Seabios 1.7.3-3, spice 0.12.4-0nocelt2 and usbredir 0.6-2 compiled from >>>> debian unstable sources. >>>> The xen-unstable upstream commit is >>>> 4787f667bcee205c56a27da59b766a53e1e929eb, plus these patches not >>>> upstream: >>>> tools: various things just to build test >>>> tools: Improve make debball >>>> libxl: Add qxl vga interface support for upstream qemu >>>> libxl: add basic spice support for pv domUs >>>> >>>> Qemu crashes always on domU S.O. start, on both pv and hvm domUs. > I may have misunderstood you (hence my gdb suggestion may not have been > appropriate) -- does the guest kernel crash *in* qemu, or does the qemu > host-side process crash? I understood your message to imply the latter. > >>>> Same dom0 with qemu 1.6 from xen-unstable repository used for some tests >>>> yesterday and was full working. >>>> I also update seabios to 1.7.4-4 compiled from debian unstable sources >>>> but the problem persists. >>>> >>>> I looked on dom0 logs, qemu logs and xl dmesg and I found only a qemu >>>> segfault related on each domU in dom0 syslog, for example the latest: >>>> [ 844.273170] qemu-system-i38[3545]: segfault at 8 ip 00007fa905dcc4c1 >>>> sp 00007fff41220810 error 4 in qemu-system-i386[7fa905ad5000+598000] > Can you reproduce this qemu process SIGSEGV while running qemu in > (host-)gdb? Or else, can you save a coredump and look into it with gdb? > > The steps you describe with gdbserver target the guest OS as debuggee. I > suggested that the host side qemu process be debugged (because that's > what crashes). > > Laszlo The gdbserver target in my previous test was /usr/lib/xen/bin/qemu-system-i386.bak on dom0 which is called by xl create and crashes with segfault. I don't understand how doing that would target the guest OS as debuggee. Can you describe the steps to target the right process? Thanks for any reply. > >>>> If you need more informations, tests and/or logs tell me and I'll post >>>> them. >>> Whoever looks into this would be greatly helped: >>> - if you bisected the issue (between 1.6 and 2.0-rcX), >> I tried time ago qemu 1.7 and qemu 2.0 on start of development without >> problem on domUs start but I'll retry. >> >>> - if you posted qemu's backtrace at the sigsegv. >> I tried to use gdb following this old post: >> https://lists.gnu.org/archive/html/qemu-devel/2011-12/msg02575.html >> but with same changes: >> >> /usr/lib/xen/bin# vi qemu-system-i386 >> #!/bin/sh >> exec gdbserver 0.0.0.0:1234 /usr/lib/xen/bin/qemu-system-i386.bak "$@" >> >> gdb /usr/lib/xen/bin/qemu-system-i386.bak >> target remote localhost:1234 >> >> This command with gdb on qemu fails: >> xl -vvv create /etc/xen/wheezy.cfg >> ... >> libxl: error: libxl_dm.c:1378:device_model_spawn_outcome: domain 13 >> device model: spawn failed (rc=-3) >> libxl: error: libxl_create.c:1207:domcreate_devmodel_started: device >> model did not start: -3 >> libxl: debug: libxl_dm.c:1485:kill_device_model: Device Model signaled >> ... >> >> the dom0 syslog show segfault also in this case and the qemu log is >> different on first lines (probably for gdbserver): >> less /var/log/xen/qemu-dm-wheezy.log >> Process /usr/lib/xen/bin/qemu-system-i386.bak created; pid = 8238 >> Listening on port 1234 >> Remote debugging from host 127.0.0.1 >> xc: error: linux_gnttab_set_max_grants: ioctl SET_MAX_GRANTS failed (22 >> = Invalid argument): Internal error >> xen be: qdisk-51712: xc_gnttab_set_max_grants failed: Invalid argument >> >> >> gdb on xl create show: >> (gdb) target remote localhost:1234 >> Remote debugging using localhost:1234 >> Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols >> found)...done. >> Loaded symbols for /lib64/ld-linux-x86-64.so.2 >> 0x00007ffff7dddaf0 in ?? () from /lib64/ld-linux-x86-64.so.2 >> (gdb) >> >> (gdb) bt full >> #0 0x00007ffff7dddaf0 in ?? () from /lib64/ld-linux-x86-64.so.2 >> No symbol table info available. >> #1 0x0000000000000013 in ?? () >> No symbol table info available. >> #2 0x00007fffffffe871 in ?? () >> No symbol table info available. >> #3 0x00007fffffffe897 in ?? () >> No symbol table info available. >> #4 0x00007fffffffe8a2 in ?? () >> No symbol table info available. >> #5 0x00007fffffffe8a5 in ?? () >> No symbol table info available. >> #6 0x00007fffffffe8ae in ?? () >> No symbol table info available. >> #7 0x00007fffffffe8ef in ?? () >> No symbol table info available. >> #8 0x00007fffffffe8f4 in ?? () >> No symbol table info available. >> #9 0x00007fffffffe913 in ?? () >> No symbol table info available. >> #10 0x00007fffffffe91f in ?? () >> No symbol table info available. >> #11 0x00007fffffffe92b in ?? () >> No symbol table info available. >> #12 0x00007fffffffe931 in ?? () >> ---Type to continue, or q to quit--- >> >> the qemu include debug and is not stripped: >> file /usr/lib/xen/bin/qemu-system-i386.bak >> /usr/lib/xen/bin/qemu-system-i386.bak: ELF 64-bit LSB shared object, >> x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for >> GNU/Linux 2.6.26, >> BuildID[sha1]=0x5aa043b5524d74d166ead62527343080384d586b, not stripped >> and I also tried: >> aptitude install libc6-dbg >> but same result. >> >> I not understand what I missed for correct xl create and/or gdb >> informations. >> Can someone help me please? >> >> Thanks for any reply >> >>> Laszlo >>> >>>