I poked around some more on google and this link seems to explain it all.
https://www.happyassassin.net/2014/07/23/bridged-networking-for-libvirt-with-networkmanager-2014-fedora-21/

Rob

2014-09-29 8:00 GMT+02:00 Rob Verduijn <rob.verduijn@gmail.com>:
Hello,

I was wondering if anybody could tell me how to set up firewalld together with kvm.

For example a fedora 20 host running a centos6.5 guest.
The guest is using bridge0 which is connected to eth0.

What devices do I need to which zone.
Do the virtual devices like vnet1 and vnet2 need to be added to a zone ?

I keep running into walls here (firewalls to be precise), the only thing I can find on this subject is 'switch back to iptables'.
But I would like to know how to fix this with firewalld.

Anybody who has any ideas on this ?

Cheers
Rob