Re: [PATCH v1 06/29] xen/asm-generic: introduce stub header grant_table.h

[Jan Beulich <jbeulich@suse.com>]

On 23.10.2023 12:32, Oleksii wrote:
> On Thu, 2023-10-19 at 11:19 +0200, Jan Beulich wrote:
>> On 14.09.2023 16:56, Oleksii Kurochko wrote:
>>> --- /dev/null
>>> +++ b/xen/include/asm-generic/grant_table.h
>>> @@ -0,0 +1,14 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +#ifndef __ASM_GENERIC_GRANTTABLE_H__
>>> +#define __ASM_GENERIC_GRANTTABLE_H__
>>> +
>>> +#endif /* __ASM_GENERIC_GRANTTABLE_H__ */
>>
>> This isn't going to work with CONFIG_GRANT_TABLE=y, is it?
> Yes, it won't work with CONFIG_GRANT_TABLE=y. Missed that as
> CONFIG_GRANT_TABLE is disabled for RISC-V.
> 
> It looks like it should be moved to arch specific folder but as I
> mentioned before I don't see a lot of sense to introduce an empty
> header for new arch each time when it will be needed to enable full Xen
> build.

Here I'm okay with an almost empty header in asm-generic/, so long as
it properly rejects CONFIG_GRANT_TABLE=y (indicating in the diagnostic
that for this to build an arch needs to have its own header).

However, then the question again arises where it wouldn't be possible
to have xen/grant_table.h avoid including asm/grant_table.h when
!CONFIG_GRANT_TABLE, eliminating the question whether to have a fallback
header in asm-generic/. If that's not possible, the reason may be a good
thing to put in the description here.

Jan