Re: [PATCH v1 02/29] xen/asm-generic: introduce stub header paging.h

[Jan Beulich <jbeulich@xxxxxxxx>]

On 23.10.2023 11:40, Oleksii wrote:
> On Thu, 2023-10-19 at 11:05 +0200, Jan Beulich wrote:
>> On 14.09.2023 16:56, Oleksii Kurochko wrote:
>>> The patch introduces stub header needed for full Xen build.
>>>
>>> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
>>> ---
>>>  xen/include/asm-generic/paging.h | 17 +++++++++++++++++
>>>  1 file changed, 17 insertions(+)
>>>  create mode 100644 xen/include/asm-generic/paging.h
>>>
>>> diff --git a/xen/include/asm-generic/paging.h b/xen/include/asm-
>>> generic/paging.h
>>> new file mode 100644
>>> index 0000000000..2aab63b536
>>> --- /dev/null
>>> +++ b/xen/include/asm-generic/paging.h
>>> @@ -0,0 +1,17 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +#ifndef __ASM_GENERIC_PAGING_H__
>>> +#define __ASM_GENERIC_PAGING_H__
>>> +
>>> +#define paging_mode_translate(d)       (1)
>>> +#define paging_mode_external(d)                (1)
>>> +
>>> +#endif /* __ASM_GENERIC_PAGING_H__ */
>>
>> Looks okay, but wants accompanying by dropping (i.e. effectively
>> moving)
>> Arm's respective header. The description than also wants adjusting
>> (it
>> wasn't quite suitable anyway, as there's missing context).
> If I understand you correctly, I'll re-use ARM's header, but I am not
> sure I know how the description should be changed except that it can be
> more specific regarding which one header is introduced.

Well, first of all context is missing in "full Xen build" - PPC has recently
reached that point already, and both Arm and x86 have been fully building
for quite some time. And then, as said elsewhere, imo headers needed solely
for building (but being otherwise non-functional) shouldn't be introduced.
At which point it may make sense to give a pointer as to where the
definitions are needed, and clarify why what is introduced is sufficient /
appropriate as fallback for a certain "common" default case of operation.

Jan