On Tue, Jan 05, 2016 at 07:26:54PM +0100, Andrea Bolognani wrote: > On Tue, 2016-01-05 at 18:14 +0000, Peter Maydell wrote: > > > > Why can libvirt not just run the tool and parse its output? That's what > > > > I understood was done for other things, but perhaps I misunderstood. > > > > > > It's the other way around: the tool uses libvirt to implement its > > > checks. Running a command and parsing its output makes sense when the > > > binary (as is the case for QEMU) is developed by a third party; if > > > you control both pieces, it's usually better to stick to C and avoid > > > spawning extra processes. > > > > That argument suggests libvirt should just go ahead and do the > > ioctls to check for GICv2/v3 support, rather than spawning a > > separate QEMU binary to do the check for it ? > > libvirt already has to spawn QEMU and run QMP commands to probe for > dozens of other capabilities, so we have very robust code to do that. > > Most importantly, as I wrote in a previous mail, if the check is done > by QEMU we remove the risk of it and libvirt ever disagreeing. > So do I understand correct that what you're looking for is a QMP command to query for host GIC capabilities? -Christoffer -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list