Re: [PATCH v7 3/3] iommu/vt-d: Add iotlb flush for nested domain

[Jason Gunthorpe]

On Fri, Nov 17, 2023 at 05:18:16AM -0800, Yi Liu wrote:
> +static int intel_nested_cache_invalidate_user(struct iommu_domain *domain,
> +					      struct iommu_user_data_array *array,
> +					      u32 *cerror_idx)
> +{
> +	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> +	struct iommu_hwpt_vtd_s1_invalidate inv_info;
> +	u32 index;
> +	int ret;
> +
> +	/* REVISIT:
> +	 * VT-d has defined ITE, ICE, IQE for invalidation failure per hardware,
> +	 * but no error code yet, so just set the error code to be 0.
> +	 */
> +	*cerror_idx = 0;
> +
> +	for (index = 0; index < array->entry_num; index++) {
> +		ret = iommu_copy_struct_from_user_array(&inv_info, array,
> +							IOMMU_HWPT_DATA_VTD_S1,
> +							index, __reserved);
> +		if (ret) {
> +			pr_err_ratelimited("Failed to fetch invalidation request\n");
> +			break;

No error prints on ioctls!

> +		if (inv_info.addr == 0 && inv_info.npages == -1)
> +			intel_flush_iotlb_all(domain);

-1 is clearer written as U64_MAX - same remark for the comment
documenting it.

Jason