RE: [PATCH v2 02/10] iommu: Introduce a new iommu_group_replace_domain() API

[Tian, Kevin]

> From: Nicolin Chen <nicolinc@xxxxxxxxxx>
> Sent: Wednesday, February 8, 2023 5:18 AM
> 
> +int iommu_group_replace_domain(struct iommu_group *group,
> +			       struct iommu_domain *new_domain)
> +{
> +	int ret;
> +
> +	if (!new_domain)
> +		return -EINVAL;

Is there value of allowing NULL new domain so this plays like
iommu_detach_group() then iommufd only needs call one
function in both attach/detach path?

> +
> +	mutex_lock(&group->mutex);
> +	ret = __iommu_group_set_domain(group, new_domain);
> +	if (ret)
> +		__iommu_group_set_domain(group, group->domain);
> +	mutex_unlock(&group->mutex);
> +	return ret;
> +}
> +EXPORT_SYMBOL_NS_GPL(iommu_group_replace_domain,
> IOMMUFD_INTERNAL);
> +
>  static int iommu_group_do_set_platform_dma(struct device *dev, void
> *data)
>  {
>  	const struct iommu_ops *ops = dev_iommu_ops(dev);
> --
> 2.39.1
>