RE: [PATCH v2 0/7] iommu/vt-d: Add page request draining support

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Wednesday, April 15, 2020 1:26 PM
> 
> 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 register level interface
> for page request draining is defined in 7.11 of the VT-d spec.
> This series adds the support for page requests draining.

7.11 doesn't include register-level interface. It just talks about
the general requirements on system software, endpoint device
and its driver.

Thanks
Kevin

> 
> This includes two parts:
>  - PATCH 1/7 ~ 3/7: refactor the qi_submit_sync() to support
>    multiple descriptors per submission which will be used by
>    PATCH 6/7.
>  - PATCH 4/7 ~ 7/7: add page request drain support after a
>    pasid entry is torn down due to an unbind operation.
> 
> Please help to review.
> 
> Best regards,
> baolu
> 
> Change log:
>  v1->v2:
>   - Fix race between multiple prq handling threads
> 
> Lu Baolu (7):
>   iommu/vt-d: Refactor parameters for qi_submit_sync()
>   iommu/vt-d: Multiple descriptors per qi_submit_sync()
>   iommu/vt-d: debugfs: Add support to show inv queue internals
>   iommu/vt-d: Refactor prq_event_thread()
>   iommu/vt-d: Save prq descriptors in an internal list
>   iommu/vt-d: Add page request draining support
>   iommu/vt-d: Remove redundant IOTLB flush
> 
>  drivers/iommu/dmar.c                |  63 +++--
>  drivers/iommu/intel-iommu-debugfs.c |  62 +++++
>  drivers/iommu/intel-pasid.c         |   4 +-
>  drivers/iommu/intel-svm.c           | 383 ++++++++++++++++++----------
>  drivers/iommu/intel_irq_remapping.c |   2 +-
>  include/linux/intel-iommu.h         |  12 +-
>  6 files changed, 369 insertions(+), 157 deletions(-)
> 
> --
> 2.17.1