Re: [PATCH for-next 2/6] xen/common: Guard iommu symbols with CONFIG_HAS_PASSTHROUGH

[Jan Beulich <jbeulich@xxxxxxxx>]

On 26.02.2021 03:54, Connor Davis wrote:
> On Thu, Feb 25, 2021 at 04:45:15PM +0100, Jan Beulich wrote:
>> On 25.02.2021 16:24, Connor Davis wrote:
>>> --- a/xen/common/domain.c
>>> +++ b/xen/common/domain.c
>>> @@ -501,7 +501,9 @@ static int sanitise_domain_config(struct 
>>> xen_domctl_createdomain *config)
>>>              return -EINVAL;
>>>          }
>>>  
>>> +#ifdef CONFIG_HAS_PASSTHROUGH
>>>          if ( !iommu_enabled )
>>> +#endif
>>>          {
>>>              dprintk(XENLOG_INFO, "IOMMU requested but not available\n");
>>>              return -EINVAL;
>>
>> Where possible - to avoid such #ifdef-ary - the symbol instead should
>> get #define-d to a sensible value ("false" in this case) in the header.
>> The other cases here may indeed need to remain as you have them.
>>
> Do you prefer the #define in the same function near the if or
> somwhere near the top of the file?

Neither, if I understand you correctly. It should be in the same header
where the extern declaration lives, for the whole code base to consume.

Jan