Re: [PATCH 8/9] iommufd: Accept a DMABUF through IOMMU_IOAS_MAP_FILE

[Nicolin Chen <nicolinc@nvidia.com>]

On Fri, Nov 07, 2025 at 12:49:40PM -0400, Jason Gunthorpe wrote:
> Finally call iopt_alloc_dmabuf_pages() if the user passed in a DMABUF
> through IOMMU_IOAS_MAP_FILE. This makes the feature visible to userspace.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>

With a nit:

> -struct iopt_pages *iopt_alloc_file_pages(struct file *file, unsigned long start,
> +struct iopt_pages *iopt_alloc_file_pages(struct file *file,
> +					 unsigned long start_byte,
> +					 unsigned long start,
>  					 unsigned long length, bool writable);

Passing in start_byte looks like a cleanup to me, aligning with
what iopt_map_common() has.

Since we are doing this cleanup, maybe we could follow the same
sequence: xxx, start, length, start_byte, writable?

Thanks
Nicolin