Re: [Qemu-devel] weird qdev error

[Anthony Liguori]

On 02/12/2012 11:31 AM, Michael S. Tsirkin wrote:
> On Sun, Feb 12, 2012 at 07:07:43PM +0200, Michael S. Tsirkin wrote:
> > I got this assert when working on qemu: pci hotplug
> > callback failed so qdev_free was called.
> >
> > (gdb) where
> > #0  0x00007ffff5fa1905 in raise () from /lib64/libc.so.6
> > #1  0x00007ffff5fa30e5 in abort () from /lib64/libc.so.6
> > #2  0x00007ffff7413a7f in g_assertion_message () from
> > /lib64/libglib-2.0.so.0
> > #3  0x00007ffff7414020 in g_assertion_message_expr () from
> > /lib64/libglib-2.0.so.0
> > #4  0x00007ffff7e452a9 in object_delete (obj=0x7ffff9124e60) at
> > qom/object.c:375
> > #5  0x00007ffff7e2f5d4 in qdev_free (dev=0x7ffff9124e60)
> >      at /home/mst/scm/qemu/hw/qdev.c:250
> > #6  qdev_init (dev=0x7ffff9124e60) at /home/mst/scm/qemu/hw/qdev.c:149
> > #7  0x00007ffff7e2a7fe in qdev_device_add (opts=0x7ffff8b0d3a0)
> >      at /home/mst/scm/qemu/hw/qdev-monitor.c:473
> > #8  0x00007ffff7e06da9 in device_init_func (opts=<value optimized out>,
> >      opaque=<value optimized out>) at /home/mst/scm/qemu/vl.c:1754
> > #9  0x00007ffff7e3737a in qemu_opts_foreach (list=<value optimized out>,
> > func=
> >      0x7ffff7e06d90<device_init_func>, opaque=0x0,
> >      abort_on_failure=<value optimized out>) at qemu-option.c:1048
> > #10 0x00007ffff7e09cdb in main (argc=<value optimized out>, argv=<value
> > optimized out>,
> >      envp=<value optimized out>) at /home/mst/scm/qemu/vl.c:3407
> > (gdb) frame 6
> > #6  qdev_init (dev=0x7ffff9124e60) at /home/mst/scm/qemu/hw/qdev.c:149
> > 149             qdev_free(dev);
> >
> > The problems seems to be that
> > pci_qdev_init calls do_pci_unregister_device on
> > hotplug  error which will free the device twice?
>
> Here's a reproducer to a similar error in property parsing:
>
> qemu-system-x86_64  -enable-kvm -m 1G -drive file=/home/mst/rhel6.qcow2
> -netdev user,id=bar -net
> nic,netdev=bar,model=e1000,macaddr=52:54:00:12:34:57  -redir
> tcp:8022::22 -device virtio-net-pci,netdev=foo,mac=5854:00:12:34:56
> -netdev
> tap,id=foo,ifname=msttap0,script=/home/mst/ifup,downscript=no,vhost=on
> -vnc :1 -monitor stdio

Here's the fix.  I need to do some regression testing and then I'll post as a 
proper top-level patch.

Thanks for the report.

Regards,

Anthony Liguori

> > --
> > MST

0001-device_add-don-t-add-a-peripheral-link-until-init-is.patch
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