On 25/04/2025 2:13 pm, Jan Beulich wrote:
> On 25.04.2025 15:05, Andrew Cooper wrote:
>> On 25/04/2025 1:48 pm, Jan Beulich wrote:
>>> On 25.04.2025 13:24, Andrew Cooper wrote:
>>>> The type used for pagetable attributes/permissions is currently unsigned
>>>> int,
>>>> but needs to become architecture dependent as PPC needs unsigned long.
>>>>
>>>> Introduce mm-types.h to house pte_attr_t.
>>>>
>>>> Given the new toolchain baseline, we can use __has_include() now to remove
>>>> the
>>>> need for boilerplate on most architectures.
>>> That's true now, when it's just pte_attr_t that's there. Memory management,
>>> however, is pretty different between architectures, so I wonder if in the
>>> longer run any one will remain that actually can use the common header.
>> Anything in xen/mm.h is common and needs architectures to provide (or
>> use the defaults) the bits required.
>>
>> asm/mm{,-types.h} still exist (when necessary) to provide the
>> arch-specific extensions.
> Sure, but you kind of avoid my question: Are you reasonably certain more than
> one arch will still be able to use the defaults, once a few more things appear
> in this header? (IOW: Won't we be better off having each arch have its
> asm/mm-types.h right away?)
I can't predict the future, but my gut feeling is that it's not going to
diverge very much.
If needs be, we can go to conditional override for specific bits. Or,
if I'm wrong, I'm wrong. It's not hard to change.
~Andrew
