Re: [Xen-devel] [XenARM] XEN tools for ARM with Virtualization Extensions

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Wed, 10 Jul 2013, Eric Trudeau wrote:
> > > What functions should I call to implement  XEN_DOMCTL_bind_pt_irq on
> > ARM?
> > 
> > I think we would probably need to introduce a new hypercall because
> > neither PHYSDEVOP_map_pirq nor XEN_DOMCTL_bind_pt_irq fit our model
> > very well.
> > The first one creates the mapping (as in allows the guest to receive the
> > interrupt but only as an event channel notification), the second one
> > sets up the emulation.
> > For HVM guests on x86 we need to call both. For PV guests, just the
> > first one.
> > 
> > On ARM we would need to introduce something similar to
> > PHYSDEVOP_map_pirq that instead of returning a pirq returns the guest
> > irq.
> > We could actually use PHYSDEVOP_map_pirq, if we mandate that on ARM pirq
> > means guest irq, but I wouldn't recommend it because it could lead to
> > confusion.
> 
> Will I need to implement other PHYSDEVOP_* operations, like x86 which has
> PHYSDEVOP_eoi and PHYSDEVOP_irq_status_query?
> 

Good question. The answer is no, because we don't use pirqs. The two
hypercalls that you mentioned are both part of the same mechanism that
allows a PV guest to receive hardware interrupts as event channels on
x86. We don't need it on ARM because we can inject hardware interrupts
directly thanks to the gic/vgic.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel