Re: [PATCH v1 00/29] Introduce stub headers necessary for full Xen build

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Mon, 2023-09-18 at 11:29 +0200, Jan Beulich wrote:
> On 18.09.2023 10:51, Oleksii wrote:
> > On Thu, 2023-09-14 at 17:08 +0200, Jan Beulich wrote:
> > > On 14.09.2023 16:56, Oleksii Kurochko wrote:
> > > > Based on two patch series [1] and [2], the idea of which is to
> > > > provide minimal
> > > > amount of things for a complete Xen build, a large amount of
> > > > headers are the same
> > > > or almost the same, so it makes sense to move them to asm-
> > > > generic.
> > > > 
> > > > Also, providing such stub headers should help future
> > > > architectures
> > > > to add
> > > > a full Xen build.
> > > > 
> > > > [1]
> > > > https://lore.kernel.org/xen-devel/cover.1694543103.git.sanastasio@xxxxxxxxxxxxxxxxxxxxx/
> > > > [2]
> > > > https://lore.kernel.org/xen-devel/cover.1692181079.git.oleksii.kurochko@xxxxxxxxx/
> > > > 
> > > > Oleksii Kurochko (29):
> > > >   xen/asm-generic: introduce stub header spinlock.h
> > > 
> > > At the example of this, personally I think this goes too far.
> > > Headers
> > > in
> > > asm-generic should be for the case where an arch elects to not
> > > implement
> > > certain functionality. Clearly spinlocks are required uniformly.
> > It makes sense. Then I will back to the option [2] where I
> > introduced
> > all this headers as part of RISC-V architecture. 
> 
> You did see though that in a reply to my own mail I said I take back
> the
> comment, at least as far as this header (and perhaps several others)
> are
> concerned.
> 
I missed that comment on the patch about spinlock.

Well, then, I don't fully understand the criteria.

What about empty headers or temporary empty headers?

For example, asm/xenoprof.h is empty for all arches except x86, so it
is a good candidate for asm-generic.
But asm/grant_table.h is empty for PPC and RISC-V for now but won't be
empty in the future. Does it make sense to put them to asm-generic? The
only benefit I see is that in future architecture if they follow the
same way of adding support for the arch to Xen, they will face the same
issue: building full Xen requires this empty header.

So, should I wait for some time on other patches of the patch series?

~ Oleksii