The xen_overlay device (and later similar devices for event channels and
grant tables) need to be instantiated. Do this from a kvm_type method on
the PC machine derivatives, since KVM is only way to support Xen emulation
for now.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
e21be724ea