Re: [PATCH V2 5/9] iommufd: IOMMU_IOAS_MAP_FILE implementation

[Nicolin Chen <nicolinc@nvidia.com>]

On Tue, Sep 24, 2024 at 08:05:34AM -0700, Steve Sistare wrote:
> diff --git a/drivers/iommu/iommufd/io_pagetable.c b/drivers/iommu/iommufd/io_pagetable.c
> index a0a66f1..1e14a0f 100644
> --- a/drivers/iommu/iommufd/io_pagetable.c
> +++ b/drivers/iommu/iommufd/io_pagetable.c
> @@ -259,7 +259,10 @@ static int iopt_alloc_area_pages(struct io_pagetable *iopt,
>                 /* Use the first entry to guess the ideal IOVA alignment */
>                 elm = list_first_entry(pages_list, struct iopt_pages_list,
>                                        next);
> -               start = elm->start_byte + (uintptr_t)elm->pages->uptr;
> +               if (elm->pages->type == IOPT_ADDRESS_FILE)
> +                       start = elm->start_byte + elm->pages->start;
> +               else
> +                       start = elm->start_byte + (uintptr_t)elm->pages->uptr;

	switch (elm->pages->type) {
	case IOPT_ADDRESS_USER: ...
	case IOPT_ADDRESS_FILE: ...
	}

Would make it easier for us to add other types.
 
> +/**
> + * iopt_map_file_pages() - Like iopt_map_user_pages, but map a file.

Could we just write "Map a user FILE to an..."? It's not that long :)

>  int iommufd_ioas_map_file(struct iommufd_ucmd *ucmd)
>  {
[...]
> +       rc = iopt_map_file_pages(ucmd->ictx, &ioas->iopt, &iova,
> +                                file, cmd->start,
> +                                cmd->length,

We could merge cmd->length to the previous line.

Thanks
Nicolin