RE: [PATCH v5 21/29] iommufd: Allow an input data_type via iommu_hw_info

Tian, Kevin
2025-05-23T08:21:56Z

> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Sunday, May 18, 2025 11:22 AM
>
> The iommu_hw_info can output via the out_data_type field the vendor data
> type from a driver, but this only allows driver to report one data type.
>
> Now, with SMMUv3 having a Tegra241 CMDQV implementation, it has two
> sets
> of types and data structs to report.
>
> One way to support that is to use the same type field bidirectionally.
>
> Rename "out_data_type" to simply "data_type", to allow an input for user
> space to request for a specific type and to get the corresponding data.
>
> For backward compatibility, since the ioctl handler has never checked an
> input value, add a new IOMMU_HW_INFO_FLAG_INPUT_TYPE to switch
> between
> the old output-only field and the new bidirectional field.
>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>

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