RE: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op

[Tian, Kevin]

> From: Yi Liu <yi.l.liu@xxxxxxxxx>
> Sent: Thursday, September 21, 2023 3:51 PM
> +
> +/**
> + * iommu_copy_user_data - Copy iommu driver specific user space data
> + * @dst_data: Pointer to an iommu driver specific user data that is defined
> in
> + *            include/uapi/linux/iommufd.h
> + * @src_data: Pointer to a struct iommu_user_data for user space data info
> + * @data_len: Length of current user data structure, i.e. sizeof(struct _dst)
> + * @min_len: Initial length of user data structure for backward compatibility.
> + *           This should be offsetofend using the last member in the user data
> + *           struct that was initially added to include/uapi/linux/iommufd.h
> + */
> +static inline int iommu_copy_user_data(void *dst_data,
> +				       const struct iommu_user_data *src_data,
> +				       size_t data_len, size_t min_len)

iommu_copy_struct_from_user()?

btw given the confusion raised on how this would be used is it clearer
to move it to the patch together with the 1st user?