On Fri, Aug 17, 2012 at 06:51:22 -0600, Eric Blake wrote: > On 08/17/2012 06:20 AM, Jiri Denemark wrote: > > Change device type of a virtio channel from/to spicevmc is not a user > > visible change. However, spicevmc channels use different default target > > name than other virtio channels. To maintain ABI stability during this > > change target name must be explicitly specified (and equal) in both > > configurations. > > Can we go from 'non-spice, no name' to 'spice, explicit name that > matches old non-spice default name'? Can we go from 'spice, no name' to > 'non-spice, explicit name that matches old spice default name'? Your > patch prevents those, even if it is technically possible. > For that matter, can we even go from 'non-spice, no name' to 'non-spice, > explicit default name'? If we can, then the user can achieve the > earlier task through two steps. In theory, both can be done but both cases are forbidden by ABI stability checks. The main reason is that ABI stability check is a generic code which has no idea what the default values are. Moving the defaults from qemu driver to conf is certainly doable but I think we should avoid doing so unless we absolutely have to. Jirka -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list