[libvirt] [qemu-s390x] request a revert for "block: Remove deprecated -drive option serial" (was block: Remove deprecated -drive option serial)

[Thomas Huth]

On 22.06.2018 14:51, Christian Borntraeger wrote:
> adding more CC.
> 
> On 06/22/2018 01:38 PM, Christian Borntraeger wrote:
>>
>> On 06/15/2018 04:21 PM, Kevin Wolf wrote:
>>> The -drive option serial was deprecated in QEMU 2.10. It's time to
>>> remove it.
>>>
>>> Tests need to be updated to set the serial number with -global instead
>>> of using the -drive option.
>>
>> libvirt 4.5 still creates those (at least on s390x)
>>
>>     <disk type='file' device='disk'>
>>       <driver name='qemu' type='qcow2' cache='none' io='native' iothread='1'/>
>>       <source file='/var/lib/libvirt/qemu/image.zhyp137'/>
>>       <target dev='hda' bus='virtio'/>
>>       <serial>skel</serial>
>>       <boot order='1'/>
>>       <address type='ccw' cssid='0xfe' ssid='0x0' devno='0x0000'/>
>>     </disk>
>> -> 
>> [...]
>> -drive file=/var/lib/libvirt/qemu/image.zhyp137,format=qcow2,if=none,id=drive-virtio-disk0,serial=skel,cache=none,aio=native -device virtio-blk-ccw,iothread=iothread1,scsi=off,devno=fe.0.0000,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,write-cache=on 
>> [...]
>>
>> 2018-06-22T11:25:20.946024Z qemu-system-s390x: -drive file=/var/lib/libvirt/qemu/image.zhyp137,format=qcow2,if=none,id=drive-virtio-disk0,serial=skel,cache=none,aio=native: Block format 'qcow2' does not support the option 'serial'
>> 2018-06-22 11:25:21.098+0000: shutting down, reason=failed
>>
>> So it seems that this breaks s390x.

I wonder why nobody noticed the deprecation messages before?

> So what about reverting commit b0083267444a5e0f28391f6c2831a539f878d424
> "block: Remove deprecated -drive option serial" and redo the removal in
> qemu 3.1 (or 3.2) ?
> Even if we fix libvirt today, this is certainly a too short period of 
> time to get things fixed in the field.

Agreed, reverting that commit is likely the best thing we can do right
now, and then kill it in a later QEMU release. Note that you also need
to revert 6266e900b8083945cb766b45c124fb3c42932cb3 first.

 Thomas