RE: [PATCH v4 02/23] iommu: Pass in a driver-level user data structure to viommu_alloc op

Tian, Kevin
2025-05-15T05:44:50Z

> From: Nicolin Chen <nicolinc@nvidia.com>
> Sent: Friday, May 9, 2025 11:02 AM
>
> The new type of vIOMMU for tegra241-cmdqv allows user space VM to use
> one
> of its virtual command queue HW resources exclusively. This requires user
> space to mmap the corresponding MMIO page from kernel space for direct
> HW
> control.
>
> To forward the mmap info (offset and length), iommufd should add a driver
> specific data structure to the IOMMUFD_CMD_VIOMMU_ALLOC ioctl, for
> driver
> to output the info during the allocation back to user space.
>
> Similar to the existing ioctls and their IOMMU handlers, add a user_data
> to viommu_alloc op to bridge between iommufd and drivers.
>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
> Reviewed-by: Pranjal Shrivastava <praan@google.com>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>

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