On Thu, Mar 03, 2016 at 01:19:47PM +0100, Andrea Bolognani wrote:
> On Thu, 2016-03-03 at 16:21 +0800, Peter Xu wrote:
> > For emulated ARM VM, only gicv2 is supported. We need to add gicv3
> in
> > when emulated gicv3 ready. For KVM accelerated ARM VM, we detect the
> > capability bits using ioctls.
> >
> > if we want to
> know GIC kernel capabilities, we need to make sure we have
> > enabled KVM when querying (like, with "-enable-kvm").
> >
> >
> Signed-off-by: Peter Xu <pet...@redhat.com>
> > ---
> > target-arm/machine.c | 48
> +++++++++++++++++++++++++++++++++++++++++++++++-
> > 1 file changed, 47 insertions(+), 1 deletion(-)
>
> Sorry for not catching this earlier, but I'm afraid this is not
> going to work -- libvirt doesn't pass either -enable-kvm or the
> machine option accel=kvm when probing for capabilities, which
> means that, with the current implementation, it will only get
> information about emulated GIC.
>
> Is there a way to make probing work without requiring KVM to
> be enabled?
Ah.. If so, this is a good point...
I can do this, but I just feel it a bit hacky if I do ioctl()s
directly in one QMP command handle:
qmp_query_gic_capability()
{
kvm = open("/dev/kvm");
vm = ioctl(KVM_CREATE_VM);
...test create devices using KVM_CREATE_DEVICE ioctls...
close(vm);
close(kvm);
}
Rather than leveraging current KVMState stuffs (of course, I can
make things a little bit prettier than above...).
Another way to do is to generalize kvm_init() maybe? That's some
work too.
Andrea, do you know how much effort we need to add this support for
libvirt, say, we can specify "accel=" or "-enable-kvm" as extra
parameter when probing?
Or, does anyone on the list has suggestion on how to better do this?
Thanks.
Peter
