creating specific cpu model

Greetings, I want to create a new cpu model which is a cross section of cpu flags of 2 different cpus and libvirt capabilites. I've extracted the supported cpu flags of each cpu using lscpu. I've created a cross section of both. I've pulled the suppored cpu flags from libvirt and created a cross section of it with the subset from above. now I want to create a new cpu model out of it. I assume that creating a xml file at /usr/share/libvirt/cpu_map/ with the x86_ prefix that matches the format listed there will suffice for libvirt and later for qemu? Thanks, Dagg.