We download the latest release of pfSense as a gzipped ISO, then extract it and pass it to virt-install to get the VM up and running. Interactive portions of setup are handled with a VNC viewer because the pfSense installer doesn't seem to be able to work with virt-install's native console redirection, at least not out of the box. I'd love a tip from anyone if it's possible to fix that somehow.
CentOS 8 instructions are this way.
Find the latest release here.
