Re: [PATCH v6 1/3] i915/gvt: Introduce the mmio table to support VFIO new mdev API

[Wang, Zhi A]

On 2/9/22 9:04 AM, Jani Nikula wrote:
> On Wed, 09 Feb 2022, Christoph Hellwig <hch@xxxxxx> wrote:
>> On Tue, Feb 08, 2022 at 05:15:00PM +0200, Jani Nikula wrote:
>>>>  #ifdef CONFIG_DRM_I915_GVT
>>>> +
>>>> +#define D_BDW   (1 << 0)
>>>> +#define D_SKL	(1 << 1)
>>>> +#define D_KBL	(1 << 2)
>>>> +#define D_BXT	(1 << 3)
>>>> +#define D_CFL	(1 << 4)
>>>> +
>>>> +#define D_GEN9PLUS	(D_SKL | D_KBL | D_BXT | D_CFL)
>>>> +#define D_GEN8PLUS	(D_BDW | D_SKL | D_KBL | D_BXT | D_CFL)
>>>> +
>>>> +#define D_SKL_PLUS	(D_SKL | D_KBL | D_BXT | D_CFL)
>>>> +#define D_BDW_PLUS	(D_BDW | D_SKL | D_KBL | D_BXT | D_CFL)
>>>> +
>>>> +#define D_PRE_SKL	(D_BDW)
>>>> +#define D_ALL		(D_BDW | D_SKL | D_KBL | D_BXT | D_CFL)
>>>
>>> If these really need to be in a header in i915/, I think they need to be
>>> longer with some namespacing or something. I do wish these could be
>>> hidden though.
>>
>> I think we could actually kill them off entirely.  They are used as
>> arguments to the macros that setup the mmio table.
>>
>> Thefunctions to build these tabls are already organized by families,
>> so we'd need relatively few conditions to just build them the right
>> way.  There also are some runtime checks in the callbacks, but they
>> seem entirely superflous as far as I can tell.
>>
>> Only the cmd parser is a bit messy.  So maybe we could keep these
>> constants just for the cmd parser inside of gvt for now (and clean
>> that up later) and remove them entirely from the mmio table.
> 
> I'm fine with cleaning this up in follow-up, provided the follow-up
> actually happens! ;)

Thanks so much for the comments and the support. :)

> 
> BR,
> Jani.
> 
>