Re: [Qemu-devel] Re: [STAGING]: Block migration segfaults

[Anthony Liguori <anthony@codemonkey.ws>]

Jan Kiszka wrote:
> Luiz Capitulino wrote:
>   
>> On Thu, 03 Dec 2009 19:36:15 +0100
>> Jan Kiszka <jan.kiszka@siemens.com> wrote:
>>
>>     
>>> Luiz Capitulino wrote:
>>>       
>>>>  Hi there,
>>>>
>>>>  Got this while testing block migration in staging:
>>>>
>>>> """
>>>> Program terminated with signal 11, Segmentation fault.
>>>> #0  0x0000000000410cf9 in monitor_vprintf (mon=0x0, fmt=0x5ae5e7 "Start full migration for %s\n",
>>>> ap=0x7fff1f830a40) at /home/lcapitulino/src/aliguori-queue/monitor.c:192
>>>> 192         if (mon->mc && !mon->mc->print_enabled) {
>>>> """
>>>>
>>>>  The problem here is that init_blk_migration() calls monitor_printf() with
>>>> a NULL 'mon' and the backtrace shows that this is true for the entire call
>>>> chain.
>>>>         
>>> What is the backtrace? And how did you start the migration?
>>>       
>>  Started the source VM with:
>>
>> # qemu -hda disks/fedora-11-kratos-i386.img -enable-kvm -snapshot \
>>        -balloon virtio -m 1G -S
>>
>>  and the destination one with:
>>
>> # qemu -hda disks/fedora-11-kratos-i386.img -enable-kvm -snapshot \
>>        -balloon virtio -m 1G -S -incoming tcp:0:4444
>>
>>  Migration command issued:
>>
>> (QEMU) migrate -d -b tcp:0:4444
>>
>>     
>
> Ah, forgot '-d'! Yes, that was precisely the use case for suppressing
> monitor output I was talking about. This depends on the monitor services
> catching NULL properly, so please push the corresponding patch.
>   

Man I really hate detach.  Okay, I agree re: a patch.

Regards,

Anthony Liguori