Re: Definition of mfn_t in x86's hvm/grant_table.h

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 16/10/2023 13:20, Jan Beulich wrote:
> On 29.09.2023 10:51, Nicola Vetrini wrote:
> > while fixing a violation of R8.4 related to a missing include in
> > x86/hvm/grant_table.c
> > I included <asm/hvm/grant_table.h>, since that file contains just the
> > declarations needed
> > by the .c file. However, since the declaration uses the type mfn_t,
> > which is defined in an
> > header not included from hvm/grant_table.h I'm wondering what is
> > preferred:
> > 1. include #include <asm/paging.h> in asm/hvm/grant_table.h, so that
> > mfn_t can be used
> >    without relying on other headers using this one to provide it.
> > 2. include <asm/grant_table.h> in x86/hvm/grant_table.c, which 
> > includes
> > more declarations
> >    than needed, but has all type definitions.
> >
> > I prefer (1), but (2) does not have major downsides either.
> Why asm/paging.h? xen/mm-frame.h is what you need for mfn_t. I'd be 
> fine
> with (1) in that case, but if it was asm/paging.h that's needed (for
> another reason) I guess I'd prefer (2).
>
> Jan
This is part of a patch series now [1].
I put asm/paging because asm/grant_table uses it and I wasn't entirely 
sure whether including
mm-frame directly was the right thing to do. I don't remember whether I 
actually tested that
solution, but changing the included header should not be problematic.

[1] 
https://lore.kernel.org/xen-devel/d49c648e940a651790fa6075a3fde40009501262.1696833629.git.nicola.vetrini@xxxxxxxxxxx/
--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)