[ovirt-users] Network profile filtering

I am using ovirt 4.3. I am in need to isolate all my VM from each other (without using VLAN) except to a virtual gateway which is also the DHCP server. Basically only allowing traffic from 1 MAC address to another MAC address. Everything else should be filter out by ovirt filtering subsystem How will I go about that? I can see in network profile the ability to set different filter but can't find a way to create new filter. Thanks for your help Pascal