The libvirt test driver is a per-process fake hypervisor driver.
The driver maintains all its state in memory. It can start with a pre-configured default config, or be given a path to an alternate config. Some example connection URIs for the libvirt driver are:
test:///default (local access, default config) test:///path/to/driver/config.xml (local access, custom config) test+unix:///default (local access, default config, via daemon) test://example.com/default (remote access, TLS/x509) test+tcp://example.com/default (remote access, SASl/Kerberos) test+ssh://root@example.com/default (remote access, SSH tunnelled)