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 >>> >>> 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 <return> to continue, or q <return> 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 >> >> >