Re: [Qemu-devel] A crash problem about "loadvm"

[Gerd Hoffmann]

On 04/08/13 14:07, Stefan Hajnoczi wrote:
> On Mon, Apr 01, 2013 at 07:56:33AM +0000, Liuji (Jeremy) wrote:
>> I delete the "dev->sin = NULL;" in the last of "spice_char_device_reset" 
>> function. And the "loadvm" is OK.
>>
>> But I don't know whether this change will lead to other problems. Who can 
>> give me some advice?
> 
> See the ./MAINTAINERS file to find out who is responsible for a QEMU
> subsystem.
> 
> I have CCed Gerd Hoffmann, who is the maintainer.

Adding spice-devel to cc

> Stefan
> 
>>  Best Regards,
>>  
>>  Jeremy Liu
>>
>>> Hello, everyone
>>>
>>> I found a problem about "loadvm", when I use Spice.
>>>
>>> Host OS: Fedora 17
>>> Qemu: 1.4.0
>>> Spice: 0.12.2
>>> Quest OS: WinXP
>>>
>>> 1) Use the following command to start the VM:
>>>     qemu-kvm -enable-kvm -name winxp -M pc-0.15 -m 1024 -smp 2 -boot c 
>>> -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 
>>>     -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive 
>>> file=/home/test/winxp.qcow2,if=virtio,index=0,format=qcow2 
>>>     -net nic,model=virtio,macaddr=52:54:00:05:11:12 -monitor stdio -chardev 
>>> spicevmc,id=charchannel0,name=vdagent 
>>>     -device 
>>> virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0
>>>  -chardev pty,id=charchannel1 
>>>     -device 
>>> virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=arbitrary.virtio.serial.port.name
>>>  -device usb-tablet,id=input0 
>>>     -spice 
>>> port=3001,addr=186.100.8.131,disable-ticketing,plaintext-channel=main,plaintext-channel=playback,plaintext-channel=record,image-compression=auto_glz
>>>  
>>>     -vga qxl -global qxl-vga.vram_size=67108864 -device 
>>> AC97,id=sound0,bus=pci.0,addr=0x4
>>> 2) Use spice client to connect the VM.
>>> 3) Exec the "savevm" command in the qemu monitor.
>>> 4) List snapshot information:
>>>     info snapshots 
>>>     ID        TAG                 VM SIZE                DATE       VM CLOCK
>>>     1         vm-20130330181626      224M 2013-03-30 18:16:26   00:00:17.294
>>>
>>> 5) Load the snapshot. But the process crashed:
>>>     loadvm vm-20130330181626
>>>     red_dispatcher_loadvm_commands: 
>>>     Segmentation fault (core dumped)
>>>
>>> I use the GDB to analyze the core-dump file:
>>>     #0  0x00007f6cbdc37a15 in spice_char_device_write_to_device 
>>> (dev=0x7f6cc5248320) at char_device.c:439
>>>     439      sif = SPICE_CONTAINEROF(dev->sin->base.sif, 
>>> SpiceCharDeviceInterface, base);
>>>     (gdb) p dev
>>>     $1 = (SpiceCharDeviceState *) 0x7f6cc5248320
>>>     (gdb) p dev->sin
>>>     $2 = (SpiceCharDeviceInstance *) 0x0
>>>
>>> I have always found this problem after the 
>>> commit(fc24f3bd2ed4c97c99ad40e747732ae46dff2009 "spice: notify spice server 
>>> on vm start/stop").
>>>
>>> Could you give me some advices to debug this problem?
>>>
>>>
>>> ------------------
>>> Best Regards,
>>>
>>> Jeremy Liu
>>