I have used KVM Virtualization and the Virtual Machine Manager (VMM) GUI application years and I am still learning. I am troubleshooting a system that I did not install so I have to discover why it does not have the default NAT interface in VMM. After finding fragments of the answeronline I went looking for books on KVM Virtualization. After a quick review I bought two e-books from <packt> (https://www.packtpub.com/en-us).
KVM Virtualization Cookbook By Konstantin Ivanov
I found an example of what the configuration file looks like and where it is located in the file system.
Mastering KVM Virtualization - Second Edition By Vedran Dakic ,
Humble Devassy Chirammal , Prasad Mukhedkar ,
Anil Vettathu
A deep dive on all things KVM.
Life is better with good reference material.
Having Fun,
Roger M. Jenson