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

On Fri, Jun 22, 2018 at 04:19:29PM +0200, Markus Armbruster wrote: > Kevin Wolf <kwolf(a)redhat.com&gt; writes: > > > 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. > > > > Thanks for bringing this up. libvirt should fix this before QEMU 3.0 is > > released. > > > > Sadly, it also shows that deprecation warnings in log files go > > unnoticed. > > Nobody reads log files until things have gone belly up, and even then > unrelated log entries get ignored. > > The way to get deprecation warnings noticed it to have the management > application fail its "make check". > > Perhaps we could use a more structured notification, to make detecting > use of deprecated features programmatically trivial. A QMP event might > do. Libvirt currently has CI that is largely focused on unit testing. We recently did some work, however, to get our functional test suite working properly again (Sys-Virt-TCK) and are trying to get some new CI hardware. So if we get that running, we coud run tests on real QEMU versions and check the /var/log/libvirt/qemu/$GUEST.logs to make sure we're not triggering unexpected warnings from QEMU