lkml.org 
[lkml]   [2023]   [Oct]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op
From
On 2023/9/27 09:08, Tian, Kevin wrote:
>> From: Jason Gunthorpe <jgg@nvidia.com>
>> Sent: Wednesday, September 27, 2023 12:29 AM
>>
>> On Tue, Sep 26, 2023 at 06:37:55AM +0000, Tian, Kevin wrote:
>>>> From: Robin Murphy <robin.murphy@arm.com>
>>>> Sent: Friday, September 22, 2023 5:48 PM
>>>>
>>>> I could go on enjoying myself, but basically yeah, "default" can't be a
>>>> type in itself (at best it would be a meta-type which could be
>>>> requested, such that it resolves to some real type to actually
>>>> allocate), so a good name should reflect what the type functionally
>>>> *means* to the user. IIUC the important distinction is that it's an
>>>> abstract kernel-owned pagetable for the user to indirectly control via
>>>> the API, rather than one it owns and writes directly (and thus has to be
>>>> in a specific agreed format).
>>>>
>>>
>>> IOMMU_HWPT_TYPE_KERNEL then?
>>>
>>> IOMMU_HWPT_TYPE_GENERIC also doesn't sound a straight word.
>>
>> At the end of the day this enum is the type tag for:
>>
>> struct iommu_hwpt_alloc {
>> __u32 size;
>> __u32 pt_id;
>> __u32 out_hwpt_id;
>> __u32 __reserved;
>> + __u32 hwpt_type;
>> + __u32 data_len;
>> + __aligned_u64 data_uptr;
>> };
>>
>> That pointer.
>>
>> IOMMU_HWPT_ALLOC_DATA_NONE = 0
>> IOMMU_HWPT_ALLOC_DATA_INTEL_VTD
>> IOMMU_HWPT_ALLOC_DATA_ARM_SMMUV3
>>
>> etc?
>>
>> DATA_NONE requires data_len == 0
>>
>
> Looks good. Probably hwpt_type can be also renamed to data_type
> to better match this interpretation.

ack.

--
Regards,
Yi Liu

\
 
 \ /
  Last update: 2023-10-07 11:40    [W:1.183 / U:0.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site