Re: [Qemu-discuss] qemu hangs

[Peter Maydell]

On 16 August 2016 at 19:45, Nerijus Baliūnas
<address@hidden> wrote:
> 2016-08-16 21:21, Nerijus Baliūnas rašė:
>>
>> I've tried gdb without daemonize on a working PC and got the same
>> backtrace. So it seems it is daemonize code which has a problem.
>
>
> Debugging the child revealed the problem:

> #11 0x00007fffd162778c in  () at /usr/lib64/nvidia-304xx/libGL.so.1
> #12 0x00007fffcb4440cf in  () at
> /usr/lib64/nvidia-304xx/libnvidia-glcore.so.304.131
> #13 0x00007fffd160220d in  () at /usr/lib64/nvidia-304xx/libGL.so.1
> #14 0x00007fffd160958f in  () at /usr/lib64/nvidia-304xx/libGL.so.1
> #15 0x00007fffd16096c4 in  () at /usr/lib64/nvidia-304xx/libGL.so.1
> #16 0x00007fffd1609e4f in  () at /usr/lib64/nvidia-304xx/libGL.so.1
> #17 0x00007fffda8b9a0e in __libc_fork () at ../sysdeps/nptl/fork.c:211
> #18 0x00005555557d6324 in os_daemonize () at
> /usr/src/debug/qemu-2.7.0-rc2/os-posix.c:216
> #19 0x000055555573ac9e in main (argc=<optimized out>, argv=<optimized out>,
> envp=<optimized out>)
>     at /usr/src/debug/qemu-2.7.0-rc2/vl.c:3989
>
> It is nvidia binary driver. Running LD_PRELOAD=/usr/lib64/libGL.so.1
> /usr/bin/qemu-system-alpha -S...
> works OK.

Aha, thanks for tracking down the cause.

> Is there something that can be done/workarounded in qemu or should I just
> patch libvirtd systemd unit file to include
> LD_PRELOAD=/usr/lib64/libGL.so.1?

QEMU's just doing fork() and fork is supposed to work. If this driver
is supplied by Fedora I would suggest reporting the bug to them and
they can decide whether they want to get the driver fixed or work
around it in libvirt.

Otherwise if I were you I would uninstall the binary blob :-)

thanks
-- PMM