Re: [PATCH v3 for-4.14] pvcalls: Document correctly and explicitely the padding for all arches

[Julien Grall <julien@xxxxxxx>]

On 16/06/2020 09:26, Jan Beulich wrote:
> On 13.06.2020 20:41, Julien Grall wrote:
> > @@ -73,10 +76,18 @@ struct xen_pvcalls_request {
> >               uint32_t flags;
> >               grant_ref_t ref;
> >               uint32_t evtchn;
> > +#ifndef __i386__
> > +            uint8_t pad[4];
> > +#endif
> Where possible I think uint32_t would be slightly better to use.
OOI, why?

> >           } connect;
> >           struct xen_pvcalls_release {
> >               uint64_t id;
> >               uint8_t reuse;
> > +#ifndef __i386__
> > +            uint8_t pad[7];
> > +#else
> > +            uint8_t pad[3];
> > +#endif
> For this I'd recommend uniform "uint8_t pad[3];" (i.e. outside
> of any #ifdef) followed by a uint32_t again inside the #ifdef.
Same question here. The more the padding cannot be re-used.

> Expressing everything through e.g. alignof() would seem even
> better, but I can't currently think of a way to do so cleanly.
I am afraid I don't have time to look at how alignof() can work nicely. 
Feel free to send a follow-up or pick-up the patch is you really want 
alignof().
Cheers,

--
Julien Grall