Re: [PATCH v3 01/10] iommufd: Add data structure for Intel VT-d stage-1 domain allocation

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, May 11, 2023 at 07:51:01AM -0700, Yi Liu wrote:
> This adds IOMMU_HWPT_TYPE_VTD_S1 for stage-1 hw_pagetable of Intel VT-d
> +/**
> + * struct iommu_hwpt_intel_vtd - Intel VT-d specific user-managed
> + *                               stage-1 page table info
> + * @flags: Combination of enum iommu_hwpt_intel_vtd_flags
> + * @pgtbl_addr: The base address of the user-managed stage-1 page table.
> + * @pat: Page attribute table data to compute effective memory type
> + * @emt: Extended memory type
> + * @addr_width: The address width of the untranslated addresses that are
> + *              subjected to the user-managed stage-1 page table.
> + * @__reserved: Must be 0
> + *
> + * The Intel VT-d specific data for creating hw_pagetable to represent
> + * the user-managed stage-1 page table that is used in nested translation.
> + *
> + * In nested translation, the stage-1 page table locates in the address
> + * space that defined by the corresponding stage-2 page table. Hence the
> + * stage-1 page table base address value should not be higher than the
> + * maximum untranslated address of stage-2 page table.
> + *
> + * The paging level of the stage-1 page table should be compatible with
> + * the hardware iommu. Otherwise, the allocation would be failed.
> + */
> +struct iommu_hwpt_intel_vtd {
> +	__u64 flags;
> +	__u64 pgtbl_addr;

__aligned_u64

> +	__u32 pat;
> +	__u32 emt;
> +	__u32 addr_width;
> +	__u32 __reserved;
>  };
>  
>  /**
> @@ -391,6 +446,8 @@ enum iommu_hwpt_type {
>   * +------------------------------+-------------------------------------+-----------+
>   * | IOMMU_HWPT_TYPE_DEFAULT      |               N/A                   |    IOAS   |
>   * +------------------------------+-------------------------------------+-----------+
> + * | IOMMU_HWPT_TYPE_VTD_S1       |      struct iommu_hwpt_intel_vtd    |    HWPT   |
> + * +------------------------------+-------------------------------------+-----------+

Please don't make ascii art tables.

Note beside the struct what enum it is for

Jason