[CentOS-virt] Centos 7 KVM questions

Clean install of centos 7 and I have most things working, however the default virbr0 interface is not getting any addressing. The interface in network manager just spins and spins and never gets an address. I thought at first it was something about firewalld which I am trying to come up to speed with but I do not believe that is the issues.

I guess the questions that I have is what is the correct way to add KVM and all of the virt packages to a minimal centos 7 installation. I would like to understand bridged interfaces vs the nat interfaces what what needs to be installed/configured.

Thanks in advance.