Enable administration of VMs as non root user
Edit file /etc/libvirt/libvirtd.conf.
unix_sock_group = "libvirt"
unix_sock_rw_perms = "0770"
Add current user to libvirt group.
sudo usermod -a -G libvirt $USER
Log out and log in again.
By default libvirt firewalld zone is used in the host machine for the virtual NIC connected to the VMs' network.