Re: [PATCH] public: xen: Define missing guest handle for int32_t

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 26 Apr 2024, Jan Beulich wrote:
> On 26.04.2024 00:39, Stefano Stabellini wrote:
> > On Mon, 22 Apr 2024, Julien Grall wrote:
> >> Hi Stefano,
> >>
> >> On 17/04/2024 19:49, Stefano Stabellini wrote:
> >>> On Wed, 17 Apr 2024, Julien Grall wrote:
> >>>> Hi Michal,
> >>>>
> >>>> On 17/04/2024 13:14, Michal Orzel wrote:
> >>>>> Commit afab29d0882f ("public: s/int/int32_t") replaced int with int32_t
> >>>>> in XEN_GUEST_HANDLE() in memory.h but there is no guest handle defined
> >>>>> for it. This results in a build failure. Example on Arm:
> >>>>>
> >>>>> ./include/public/arch-arm.h:205:41: error: unknown type name
> >>>>> ‘__guest_handle_64_int32_t’
> >>>>>     205 | #define __XEN_GUEST_HANDLE(name)        __guest_handle_64_ ##
> >>>>> name
> >>>>>         |                                         ^~~~~~~~~~~~~~~~~~
> >>>>> ./include/public/arch-arm.h:206:41: note: in expansion of macro
> >>>>> ‘__XEN_GUEST_HANDLE’
> >>>>>     206 | #define XEN_GUEST_HANDLE(name)
> >>>>> __XEN_GUEST_HANDLE(name)
> >>>>>         |                                         ^~~~~~~~~~~~~~~~~~
> >>>>> ./include/public/memory.h:277:5: note: in expansion of macro
> >>>>> ‘XEN_GUEST_HANDLE’
> >>>>>     277 |     XEN_GUEST_HANDLE(int32_t) errs;
> >>>>>
> >>>>> Fix it. Also, drop guest handle definition for int given no further use.
> >>>>>
> >>>>> Fixes: afab29d0882f ("public: s/int/int32_t")
> >>>>> Signed-off-by: Michal Orzel <michal.orzel@xxxxxxx>
> >>>
> >>> Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> >>>
> >>>
> >>>> So it turned out that I committed v1 from Stefano. I was meant to commit
> >>>> the
> >>>> patch at all, but I think I started with a dirty staging :(. Sorry for
> >>>> that.
> >>>>
> >>>> I have reverted Stefano's commit for now so we can take the correct 
> >>>> patch.
> >>>>
> >>>> Now, from my understanding, Andrew suggested on Matrix that this solution
> >>>> may
> >>>> actually be a good way to handle GUEST_HANLDEs (they were removed in v2).
> >>>> Maybe this can be folded in Stefano's patch?
> >>>
> >>> v1 together with Michal's fix is correct. Also v2 alone is correct, or
> >>> v2 with Michal's fix is also correct.
> >>
> >> I am slightly confused, v2 + Michal's fix means that XEN_GUEST_HANDLE(int) 
> >> is
> >> removed and we introduce XEN_GUEST_INT(int32_t) with no user. So wouldn't 
> >> this
> > 
> > You are right I apologize. I looked at Michal's patch too quickly and
> > I thought it was just adding XEN_GUEST_INT(int32_t) without removing
> > anything.
> > 
> > In that case, if you are OK with it, please ack and commit v2 only.
> 
> Just to mention it: Committing would apparently be premature, as I can't spot
> any response to comments I gave to the patch. I'm okay with those being
> addressed verbally only, but imo they cannot be dropped on the floor.

I agree with your comments but I prefer to keep this patch smaller and
focused on doing one thing only. I don't want to mix non-mechanical
changes with the mechanical substitutions. For sure, there will be
follow ups to address your comments and other outstanding issues.