Re: [RFC 10/20] iommu/iommufd: Add IOMMU_DEVICE_GET_INFO

Alex Williamson
2021-09-22T21:24:17Z

On Sun, 19 Sep 2021 14:38:38 +0800
Liu Yi L <yi.l.liu@intel.com> wrote:

> +struct iommu_device_info {
> + __u32 argsz;
> + __u32 flags;
> +#define IOMMU_DEVICE_INFO_ENFORCE_SNOOP (1 << 0) /* IOMMU enforced snoop */

Is this too PCI specific, or perhaps too much of the mechanism rather
than the result? ie. should we just indicate if the IOMMU guarantees
coherent DMA? Thanks,

Alex

> +#define IOMMU_DEVICE_INFO_PGSIZES (1 << 1) /* supported page sizes */
> +#define IOMMU_DEVICE_INFO_ADDR_WIDTH (1 << 2) /* addr_wdith field valid */
> + __u64 dev_cookie;
> + __u64 pgsize_bitmap;
> + __u32 addr_width;
> +};
> +
> +#define IOMMU_DEVICE_GET_INFO _IO(IOMMU_TYPE, IOMMU_BASE + 1)
>
> #define IOMMU_FAULT_PERM_READ (1 << 0) /* read */
> #define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */