Description of problem: libvirt is starting dnsmasq even if there isn't any related record in configuration. It is regression against libvirt in F11, which allowed me to run custom dnsmasq service (now dnsmasq started by libvirt opens important ports and blocks other instances). Version-Release number of selected component (if applicable): libvirt-0.7.1-15.fc12.x86_64 Expected results: libvirt doesn't start dnsmasq if not explicitly requested in configuration (as previous version did it). Alternatively libvirt allows full control over dnsmasq instance.
This change is intentional. libvirt will always start dnsmasq because it is necessary to provide DNS and TFTPBoot services to guests using static IP config instead of DHCP. The libvirt virtual network capability is not intended to allow arbitrary end user customization. If you require that, then the recommendation is to configure it directly, and use type=bridge in libvirt guest domain config for NICs, instead of type=network.