kvm with bridge: is there a way to limit network bandwith or to prioritize requests of the host vs. guest OS?

Running an instance of TW on another instance of TW, but is valid for all hosts: is there a way to make sure the host has always enough bandwith no matther what the guest does (e.g. an upgrade with hundreds of package) so that e.g. my mail is not timing out? So can I prioritize the requests of the host vs guest. Thank you.