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