[RFC PATCH v2 07/10] iommu/riscv: support nested iommu for creating domains owned by userspace

[Joao Martins]

On 14/06/2024 15:21, Zong Li wrote:
> +static struct iommu_domain *
> +riscv_iommu_domain_alloc_user(struct device *dev, u32 flags,
> +			      struct iommu_domain *parent,
> +			      const struct iommu_user_data *user_data)
> +{
> +	struct iommu_domain *domain;
> +	struct riscv_iommu_domain *riscv_domain;
> +
> +	/* Allocate stage-1 domain if it has stage-2 parent domain */
> +	if (parent)
> +		return riscv_iommu_domain_alloc_nested(dev, parent, user_data);
> +
> +	if (flags & ~((IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
> +		return ERR_PTR(-EOPNOTSUPP);
> +

IOMMU_HWPT_ALLOC_DIRTY_TRACKING flag check should be dropped if it's not
supported in code (which looks to be the case in your series) e.g.

	if (flags & ~((IOMMU_HWPT_ALLOC_NEST_PARENT)))
		return ERR_PTR(-EOPNOTSUPP);