I tried with qemu 2.10 and libvirt 3.6.0: not bug, it works.
I tried with raw and qcow2 format, both works.
I used this repository: https://launchpad.net/~ubuntu-cloud-archive/+archive/ubuntu/pike-staging
But it's a staging version, i didn't find a stable qemu/libvirt repository for Ubuntu Xenial with those versions
I tried with qemu 2.10 and libvirt 3.6.0: not bug, it works.
I tried with raw and qcow2 format, both works.
I used this repository: https:/ /launchpad. net/~ubuntu- cloud-archive/ +archive/ ubuntu/ pike-staging
But it's a staging version, i didn't find a stable qemu/libvirt repository for Ubuntu Xenial with those versions