Re: [PATCH v1 13/14] xen/arm: Fixed error when PCI device is assigned to guest

[Julien Grall <julien@xxxxxxx>]

Hi,

On 19/08/2021 13:12, Jan Beulich wrote:
> On 19.08.2021 14:02, Rahul Singh wrote:
> > --- a/xen/arch/arm/domctl.c
> > +++ b/xen/arch/arm/domctl.c
> > @@ -173,6 +173,8 @@ long arch_do_domctl(struct xen_domctl *domctl, struct 
> > domain *d,
> >   
> >           return rc;
> >       }
> > +    case XEN_DOMCTL_ioport_permission:
> > +        return 0;
> I don't think returning success for something that doesn't make
> much sense in the first place (there aren't truly "I/O ports" on
> Arm afaik) is a good idea.
They are memory mapped. IIRC, there is a region that is reserved to fake 
them (for PCI cards that still using them).
> Instead I think the tool stack should
> avoid making arch-specific calls in an arch-independent way.
+1. The current approach means that it will be impossible to implement 
those sub operations without breaking Xen if we ever needs it.
Cheers,

--
Julien Grall