libvirt users - May 2017 - nwfilter and address of network ip address

Hi,

I am running a webserver on the libvirt host and would like to add 
a nwfilter such that a VM can access that server. The 
corresponding iptables rule would look like this:

iptables --append INPUT --in-interface virbr0 --destination 192.168.122.1
--protocol tcp --dport 80 --jump ACCEPT

where the network is using virbr0 and sits at 192.168.122.1. I 
don't want to hardcode the host IP address in the nwfilter so that 
I can use that filter for other networks. Is it possible to 
reference the host's IP address in the filter?

Thanks!

Nick