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

[Christian Borntraeger]

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.

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.