Re: [Qemu-devel] [PATCH v6 2/5] hpet: enable to entitle more irq pins for hpet

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Oct 11, 2013 at 05:18:30PM +0800, liu ping fan wrote:
> On Fri, Oct 11, 2013 at 4:38 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> > Il 11/10/2013 04:59, liu ping fan ha scritto:
> >> On Thu, Oct 10, 2013 at 7:41 PM, Michael S. Tsirkin <mst@redhat.com> wrote:
> >>> On Thu, Oct 10, 2013 at 11:46:42AM +0200, Paolo Bonzini wrote:
> >>>> Il 10/10/2013 11:41, Michael S. Tsirkin ha scritto:
> >>>>>>> Are you sure?  This is not done for any other compat property.
> >>>>>>>
> >>>>>>> Paolo
> >>>>> It's done if we use the property from C.
> >>>>> See PCI_HOST_PROP_PCI_HOLE64_SIZE.
> >>>>>
> >>>>> You want compiler to catch errors, that's
> >>>>> much better than a runtime failure.
> >>>>
> >>>> I agree, but I think there should be no need to use the property from C.
> >>>>
> >>>> Paolo
> >>>
> >>> Well this patchset does use it from C.
> >>> If it's done it needs a macro.
> >>
> >> hpet.h is the ideal place to put the macro, so pc.c can see it. But
> >> what about PC_COMPAT_1_7 in pc.h? I think it is not right to include
> >> hpet.h. So can I do not use marco in pc.h?
> >
> > I think you shouldn't need the macro (no need to use the property from
> > C, only from compat properties).
> >
> We need to tell the compat and then decide to set "intcap" in
> pc_basic_device_init()
> 
>                 uint8_t compat = object_property_get_int(OBJECT(hpet),
>                         "intcap", NULL);
>                 if (!compat) {
>                     qdev_prop_set_uint32(hpet, "intcap", 0xff0104);
>                 }
> 
> Regards,
> Ping Fan

So if you use it from C, please use a macro.
If not, no need to.