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

[Stefan Hajnoczi <stefanha@gmail.com>]

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.

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
>