Qemu can not parse long fqdns during drive-mirror

During migration of an openstack booted instance, I got the following error:

Apr 12 10:55:22 cmp1 libvirtd[4133]: 2018-04-12 10:55:22.133+0000: 4139: error : qemuMonitorJSONCheckError:392 : internal error: unable to execute QEMU command 'drive-mirror': error parsing address 'cmp0.sandriichenko-deploy-heat-virtual-mcp-pike-ovs-76.bud-mk.local:49153'

A bit more info in libvirt bug https://bugzilla.redhat.com/show_bug.cgi?id=1568939

To reproduce it with qemu only, I followed the guide at https://github.com/qemu/qemu/blob/master/docs/interop/live-block-operations.rst#id21. On dest and source compute nodes, I launched an instance:

qemu-system-x86_64 -display none -nodefconfig -M q35 -nodefaults -m 512 -blockdev node-name=node-TargetDisk,driver=qcow2,file.driver=file,file.node-name=file,file.filename=./test-instance-mirror.qcow2 -device virtio-blk,drive=node-TargetDisk,id=virtio0 -S -monitor stdio -qmp unix:./qmp-sock,server,nowait -incoming tcp:localhost:6666

Then on dest node I launched nbd server:

(qemu) nbd_server_start cmp0:49153
(qemu) nbd_server_add -w node-TargetDisk

On the source node:

(qemu) drive_mirror -n  node-TargetDisk nbd:cmp0.vdrok-deploy-heat-virtual-mcp-pike-ovs-foobarbuzz.bud-mk.local:49153:exportname=node-TargetDisk
error parsing address 'cmp0.vdrok-deploy-heat-virtual-mcp-pike-ovs-foobarbuzz.bud-mk.local:49153'

When using short host name instead of FQDN address seems to be parsed fine:

(qemu) drive_mirror -n  node-TargetDisk nbd:cmp0:49153:exportname=node-TargetDisk qcow2
Image is not in qcow2 format

(not sure why it is not a qcow2 format, as I have qcow2 image with raw backing file, but this is unrelated)

QEMU version is 2.11.1 from bionic

As Daniel asked in [1] making this abug report against Qemu (upstream).

[1]: https://bugzilla.redhat.com/show_bug.cgi?id=1568939 

Ubuntu task is not actionable until we settled on how to change the parsing code for long strings upstream, so I set it to confirmed but wishlist (until we know what size a patch - or actions a recommendation on handling differently has).

The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.

If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.

Thank you and sorry for the inconvenience.


[Expired for QEMU because there has been no activity for 60 days.]

[Expired for qemu (Ubuntu) because there has been no activity for 60 days.]