Dedicate physical eth to KVM

Hi All,

I have a KVM which needs to have a physical eth dedicated to it, so that it can see/work with all VLAN's. I cannot use a fixed numbered solution (specifying the VLAN's in the host and then creating bridges up to the KVM); as the VLAN's can change regularly.

How can I get the KVM to link directly to the physical eth (no other KVM is using it) so that it can work with VLAN's.

Thanks
Anubis