Eventually I faced problem with macvtap device that was disappered from virt-manager. It happened after I installed openstack-compute-node by tasksel from debian mirror and version of libvirtd becomes 2.6.9 but it was 2.6.8 in Juno. I cannot downgrade because of dependencies. I upgrade libvirtd to next 2.6.10 manually from tarball to try struggling with some known bug (undefined tag while creating domain) for 2.6.9.

But for libvirtd 2.6.10 build --with-macvtap=true macvtap device is disappeared in virt-manager. Macvtap kernel module is loaded.

I wonder if I can work without macvtap devices but using shared device with bridge only? By the way instances work like this if I check dumpxml or details of vm in virt-manager.

Again my question is: using macvtap driver is mandatory (or recommended) or shared device with bridge is enough?

Some macvtap blog is appreciated.