On Fri, Mar 01, 2013 at 03:58:18PM -0300, Eduardo Habkost wrote: > On Fri, Mar 01, 2013 at 07:31:46PM +0100, Andreas Färber wrote: > > Am 01.03.2013 14:12, schrieb Jiri Denemark: > > > On Thu, Feb 21, 2013 at 11:58:18 -0300, Eduardo Habkost wrote: > > >> = Listing CPU models = > > >> > > >> Requirement: libvirt needs to know which CPU models are available to be used > > >> with the "-cpu" option. > > >> > > >> Current problem: libvirt relies on help output parsing for that. > > > > query-cpu-definitions is the QMP command to retrieve values compatible > > with -cpu. > > > > And if libvirt is not using it, I really don't understand why the work > > of maintaining this crappy interface has been pushed onto us in the > > first place? There is no reuse between -cpu ? and QMP implementations so > > it's just extra work, there is no communicated or implemented way to > > extend the arch_query_cpu_definitions() implementation to become more > > usable for command line output implementation (e.g., associating a PVR > > value with the model name for ppc) and, while we're at it, it uses > > global functions plus a stub rather than a CPUState hook with a no-op > > default implementation in qom/cpu.c... > > I have the same questions you have. :-) > > But my main complaint about query-cpu-definitions is not about the > implementation: it's that the interface was introduced without taking > into account the requirements of libvirt regarding CPU features. It was > found to be not appropriate for what libvirt needs[1], but somehow it > got applied anyway. The requirement at the time we did this was just to have a straight adaptation of the stuff libvirt parsed from -help, into QMP format. The query-cpu-definitions command served that purpose fine. It was expected that some of this may be sub-optimal in the long term. This is fine - we can either extend the existing data, or introduce brand new commands to deal with the problems. The key thing was just to get 100% into the QMP world for capabilities at that time, and then iterate to improve things. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list