Re: [Qemu-devel] [libvirt] [PULL 25/26] block: Remove deprecated -drive option serial

[Kevin Wolf]

Am 25.06.2018 um 11:53 hat Daniel P. Berrangé geschrieben:
> On Fri, Jun 22, 2018 at 03:31:46PM +0100, Daniel P. Berrangé wrote:
> > On Fri, Jun 22, 2018 at 04:25:13PM +0200, Kevin Wolf wrote:
> > > Am 22.06.2018 um 15:36 hat Christian Borntraeger geschrieben:
> > > > 
> > > > 
> > > > On 06/22/2018 02:55 PM, Kevin Wolf wrote:
> > > > > Am 22.06.2018 um 13:38 hat Christian Borntraeger geschrieben:
> > > > >>
> > > > >> 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.
> > > > 
> > > > To me it seems that this is also broken on x86.
> > > > > 
> > > > > Thanks for bringing this up. libvirt should fix this before QEMU 3.0 
> > > > > is
> > > > > released.
> > > > 
> > > > I think this is definitely too short notice. We should not break 
> > > > existing
> > > > setups just by insisting that users have to update libvirt when they 
> > > > update
> > > > QEMU. Yes, this might be our policy, but doing so "just because we can"
> > > > is certainly a very bad attitude. I see no fundamental technical reason 
> > > > why
> > > > we should not revert this change.
> > > 
> > > This was in fact one release longer than our deprecation policy says.
> > > Are we serious about the deprecation policy or aren't we?
> > > 
> > > I might consider reverting a change if it turned out that this requires
> > > some massive work in libvirt. But I think this one should be rather easy
> > > to fix in libvirt until 3.0 is released.
> > 
> > It is probably even possible for us to fix it in our July 1st
> > release
> 
> Fix posted here:
> 
> https://www.redhat.com/archives/libvir-list/2018-June/msg01598.html

Thanks!

I'll look into werror/rerror support for usb-storage. It shouldn't be
too hard, though it's strictly speaking a separate problem related to
using -blockdev rather than option deprecation.

If Peter wants to wait for QEMU support before converting werror/rerror
to -device, maybe it would make sense to split your patch for v2 so that
geometry and serial can get fixed right away?

Kevin