Re: [PATCH v4 03/13] iommu/vt-d: Refactor the pasid setup helpers

Yi Liu
2024-11-06T09:18:21Z

On 2024/11/6 15:14, Tian, Kevin wrote:
>> From: Liu, Yi L <yi.l.liu@intel.com>
>> Sent: Monday, November 4, 2024 9:19 PM
>>
>> As iommu driver is going to support pasid replacement, the new pasid
>> replace
>> helpers need to config the pasid entry as well. Hence, there are quite a few
>> code to be shared with existing pasid setup helpers. This moves the pasid
>> config codes into helpers which can be used by existing pasid setup helpers
>> and the future new pasid replace helpers.
>
> hmm probably you can add a link to the discussion which suggested
> to have separate replace/setup helpers. It's not intuitive to require
> this if just talking about "to support pasid replacement"

this came from the offline chat with Baolu. He shared this idea to me
and it makes sense that we use pasid replace helpers instead of extending
the setup helpers. How about:

This driver is going to support pasid replacement. A choice is to extend
the existing pasid setup helpers which is for creating a pasid entry.
However, it might change some assumption on the setup helpers. So adding
separate pasid replace helpers is chosen. Then we need to split the common
code that manipulate the pasid entry out from the setup helpers, hence it
can be used by the replace helpers as well.

>>
>> No functional change is intended.
>>
>> Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

--
Regards,
Yi Liu