Re: [PATCH v3 7/7] xen/arm: introduce new xen,enhanced property value

[Julien Grall <julien@xxxxxxx>]

Hi Bertrand,

On 02/09/2022 15:51, Bertrand Marquis wrote:
> > On 1 Sep 2022, at 19:15, Julien Grall <julien@xxxxxxx> wrote:
> > AFAIU, it is not possible to have *_xenstore = true and *_enhanced = false. I 
> > think it would be clearer if ``dom0less_enhanced`` is turned to an enum with 3 
> > values:
> > - None
> > - NOXENSTORE/BASIC
> > - FULLY_ENHANCED
> >
> > If we want to be future proof, I would use a field 'flags' where non-zero means 
> > enhanced. Each bit would indicate which features of Xen is exposed.
> I think that could be a good solution if we do it this way:
> - define a dom0less feature field and have defines like the following:
> #define DOM0LESS_GNTTAB
> #define DOM0LESS_EVENTCHN
> #define DOM0LESS_XENSTORE >
> - define dom0less enhanced as the right combination:
> #define DOM0LESS_ENHANCED = (DOM0LESS_GNTTAB| DOM0LESS_EVENTCHN| 
> DOM0LESS_XENSTORE)
I would rather introduce DOM0LESS_ENHANCED_BASIC (or similar) instead of 
defining a bit for gnttab and evtchn. This will avoid the question of 
why we are introducing bits for both features but not the hypercall...
As this is an internal interface, it would be easier to modify afterwards.

Cheers,

--
Julien Grall