Re: [Qemu-devel] [libvirt] ARM KVM GICv3 Support

[Andrea Bolognani]

On Tue, 2016-02-02 at 16:58 +0100, Christoffer Dall wrote:
> ok, so that would mean we need to implement a QMP command to tell us
> which gic versions are supported for a given machine.  Current
> possible responses are "2", "3" and "2,3"
> 
> and we also need to add code to libvirt to try that QMP command, and
> if it doesn't exist, fall back to not specifying gic-version, using
> the old-qemu compatible default of providing a gicv2 to guests, and if
> the QMP command exists, use the newest gic-version.
> 
> users can then always override this behavior by directly specifying a
> gic version "host", "2", or "3" in their xml file.
> 
> any objections?

Dan voiced his preference for probing the host GIC versions from
libvirt and just passing that to QEMU dealing with any failure later
on, but I think that was mostly to keep things simple and not
because the QMP command approach was wrong?

IOW Dan, if we went ahead with the QMP command approach, would you
oppose it? Peter Xu has posted some RFC QEMU patches yesterday...

Cheers.

-- 
Andrea Bolognani
Software Engineer - Virtualization Team