Re: [PATCH v3 0/4] iommu/vt-d: Add page request draining support

[Lu Baolu]

Hi Kevin,

On 2020/4/22 16:06, Lu Baolu wrote:
> When a PASID is stopped or terminated, there can be pending PRQs
> (requests that haven't received responses) in the software and
> remapping hardware. The pending page requests must be drained
> so that the pasid could be reused. The chapter 7.10 in the VT-d
> specification specifies the software steps to drain pending page
> requests and responses.
>
> This includes two parts:
>   - PATCH 1/4 ~ 2/4: refactor the qi_submit_sync() to support multiple
>     descriptors per submission which will be used in the following
>     patch.
>   - PATCH 3/4 ~ 4/4: add page request drain support after a pasid entry
>     is torn down.
>
> Please help to review.
>
> Best regards,
> baolu
>
> Change log:
>   v2->v3:
>    - Address Kevin's review comments
>      - Squash the first 2 patches together;
>      - The prq thread is serialized, no need to consider reentrance;
>      - Ensure no new-coming prq before drain prq in queue;
>      - Handle page request overflow case.

Very appreciated for your review comments.

How about these changes? Any comments?

Best regards,
baolu