Re: [PATCH v2 2/8] iommu: Introduce iommu_paging_domain_alloc_flags()

[Baolu Lu <baolu.lu@linux.intel.com>]

On 9/11/24 6:19 PM, Vasant Hegde wrote:
>   /**
> - * iommu_paging_domain_alloc() - Allocate a paging domain
> + * iommu_paging_domain_alloc_flags() - Allocate a paging domain
>    * @dev: device for which the domain is allocated
> + * @flags: Bitmap of iommufd_hwpt_alloc_flags
>    *
>    * Allocate a paging domain which will be managed by a kernel driver. Return
>    * allocated domain if successful, or a ERR pointer for failure.
>    */
> -struct iommu_domain *iommu_paging_domain_alloc(struct device *dev)
> +struct iommu_domain *iommu_paging_domain_alloc_flags(struct device *dev,
> +						     unsigned int flags)
>   {
> +	const struct iommu_ops *ops;
> +	struct iommu_domain *domain;
> +
>   	if (!dev_has_iommu(dev))
>   		return ERR_PTR(-ENODEV);
>   
> -	return __iommu_domain_alloc(dev_iommu_ops(dev), dev, IOMMU_DOMAIN_UNMANAGED);
> +	ops = dev_iommu_ops(dev);
> +
> +	if (ops->domain_alloc_paging && !flags)
> +		domain = ops->domain_alloc_paging(dev);
> +	else if (ops->domain_alloc_user)
> +		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
> +	else if (ops->domain_alloc && !flags)
> +		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
> +	else
> +		return ERR_PTR(-EOPNOTSUPP);

How about

	if (flags) {
		if (!ops->domain_alloc_user)
			return ERR_PTR(-EOPNOTSUPP);
		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
	} else if (ops->domain_alloc_paging) {
		domain = ops->domain_alloc_paging(dev);
	} else if (ops->domain_alloc) {
		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
	} else {
		return ERR_PTR(-EOPNOTSUPP);
	}

?

> +
> +	if (IS_ERR(domain))
> +		return domain;
> +	if (!domain)
> +		return ERR_PTR(-ENOMEM);
> +
> +	iommu_domain_init(domain, IOMMU_DOMAIN_UNMANAGED, ops);
> +	return domain;
>   }
> -EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc);
> +EXPORT_SYMBOL_GPL(iommu_paging_domain_alloc_flags);

Thanks,
baolu