Re: [RFC PATCH] libacpi: Fix cross building x86 on arm

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

> On 24 Aug 2022, at 08:37, Jan Beulich <jbeulich@xxxxxxxx> wrote:
> 
> On 23.08.2022 17:56, Bertrand Marquis wrote:
>>> On 23 Aug 2022, at 16:45, Jan Beulich <jbeulich@xxxxxxxx> wrote:
>>> On 23.08.2022 17:09, Bertrand Marquis wrote:
>>>> How about moving those to a xen-acpi.h header and include that one in 
>>>> xen.h ?
>>> 
>>> In principle okay, if there wasn't the need for HVM_MAX_VCPUS. With a
>>> suitable comment it may be okay to live there. I'd be curious what
>>> others think.
>> 
>> The problem with this already exists in the current status as this is 
>> defined in
>> hvm_info_table.h which is never included from arch-x86/xen.h
> 
> You're referring to it being necessary to explicitly include both headers.
> That's not what I'm referring to, though: The tool imo shouldn't include
> hvm_info_table.h, and hence the HVM_MAX_VCPUS would need to move as well.

Any suggestion where ?
The more I dig, the more I find that everything is including xen.h and going 
round.
Arch-x86_*.h headers are including arch-x86/xen.h including xen.h

> 
>> Including hvm_info_table.h from xen-acpi.h could create include path issues.
> 
> Include path issues? Both are / would be public headers. But as said, I
> don't think any new header introduced for the purpose at hand should
> include _any_ other public header.

For now I can create a arch-x86/xen-acpi.h and move there the XEN_ACPI_*
definitions and include that one instead in mk_dsdt.h.
The change will be small and should not have much impact.

Modifying HVM_MAX_VCPUS is not per say needed and I think would not be
enough to make the situation cleaner.

> 
>> But as those are used nowhere apart from mk_dsdt, I would probably skip the
>> include of xen-acpi.h from xen.h.
> 
> Hmm, yes, that's reasonable I guess as far as XEN_ACPI_* go. Of course
> HVM_MAX_VCPUS is a different matter.
> 
>> Any chance that those XEN_ACPI_ are needed by some external tools that
>> could get broken by this modification ?
> 
> Requiring them to include another header is, I think, a tolerable form
> of breakage, the more that such breakage isn't very likely anyway.

Then if you are ok with it, I will just submit the xen-acpi.h creation patch 
and fix
mk_dsdt compilation for x86 on arm.

The rest would require more thinking and I do not think it should be done now.

Can you confirm you agree ?

Cheers
Bertrand

> 
> Jan