A few weeks back we migrated our ovirt environment to a new ovirt 4.0 environment. We had a hook in place to remove the CPU model for some Solaris servers.
After the migration we noticed that the Solaris servers didn’t had any network connectivity. Thanks to google we found the probable issue (https://bugzilla.redhat.com/show_bug.cgi?id=1040500) but there wasn’t an easy fix available. That’s why we wrote a new hook to disable the x2apic on the CPU for KVM.
You can find our hook on https://github.com/47b/ovirt-hooks