RE: [PATCH v8 02/10] iommufd: Add IOMMU_HWPT_INVALIDATE

[Tian, Kevin]

> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Thursday, December 28, 2023 12:14 AM
> 
> In nested translation, the stage-1 page table is user-managed but cached
> by the IOMMU hardware, so an update on present page table entries in the
> stage-1 page table should be followed with a cache invalidation.
> 
> Add an IOMMU_HWPT_INVALIDATE ioctl to support such a cache
> invalidation.
> It takes hwpt_id to specify the iommu_domain, and a multi-entry array to
> support multiple invalidation data in one ioctl.
> 
> enum iommu_hwpt_invalidate_data_type is defined to tag the data type of
> the entries in the multi-entry array.
> 
> Co-developed-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>