Re: [Qemu-devel] weird qdev error

["Michael S. Tsirkin" <mst@redhat.com>]

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



> -- 
> MST