Re: [RESEND][PATCH v2 5/7] xen: include xen/guest_access.h rather than asm/guest_access.h

[Jan Beulich <jbeulich@suse.com>]

On 18.08.2020 18:20, Julien Grall wrote:
> 
> 
> On 18/08/2020 17:04, Jan Beulich wrote:
>> On 18.08.2020 15:14, Julien Grall wrote:
>>>
>>>
>>> On 18/08/2020 12:32, Jan Beulich wrote:
>>>> On 18.08.2020 10:58, Julien Grall wrote:
>>>>>> One option. Personally I'd prefer to avoid introduction of yet another
>>>>>> constant, by leveraging __XEN_GUEST_ACCESS_H__ instead.
>>>>>
>>>>> I thought about it but it doesn't prevent new inclusions of asm/guest_access.h. For instance, the following would still compile:
>>>>>
>>>>> #include <xen/guest_access.h>
>>>>>
>>>>> [...]
>>>>>
>>>>> #include <asm/guest_access.h>
>>>>
>>>> But where's the problem with this? The first #include will already
>>>> have resulted in the inclusion of asm/guest_access.h, so the second
>>>> #include is simply a no-op.
>>>
>>> A couple of reasons:
>>>     1) I don't consider this solving completely your original request [1]
>>>     2) I don't see how this is more important to prevent including <asm/guest_access.h> before and not after. Both will still compile fine, we just want to avoid it.
>>>
>>>
>>> [1] "Is there any chance you could take measures to avoid new inclusions of asm/guest_access.h to appear?"
>>
>> Is
>>
>> #include <xen/guest_access.h>
>> [...]
>> #include <asm/guest_access.h>
>>
>> actually a problem (as opposed to an asm/ include without any include
>> of the xen/ one at all)?
> 
> Neither of them are really a problem today. So it is not entirely clear why we would want to prevent one and not the other.

If neither is a problem, why the conversion?

Jan