I was working on some MTU testing for OpenShift, and I realized that, while libvirt does allow specifying the MTU of the bridge interface, it doesn't plumb it through the DHCP server.
This is really easy - it's just an extra line in the dnsmasq.conf file, e.g.:
Any interest in this as a patch? And, apologies if this has been discussed to death (though I searched around and didn't find anything).
-- Casey C.