Re: [PATCH v6 13/13] iommu/amd: Add support for nested domain attach/detach

[Jason Gunthorpe]

On Thu, Jan 15, 2026 at 06:08:14AM +0000, Suravee Suthikulpanit wrote:
> +static int nested_attach_device(struct iommu_domain *dom, struct device *dev,
> +				struct iommu_domain *old)
> +{
> +	struct dev_table_entry new = {0};
> +	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
> +	struct amd_iommu *iommu = get_amd_iommu_from_dev_data(dev_data);
> +	int ret = 0;
> +
> +	/*
> +	 * Needs to make sure PASID is not enabled
> +	 * for this attach path.
> +	 */
> +	if (WARN_ON(dev_data->pasid_enabled))
> +		return -EINVAL;

Well, that's one way, but a rather big hammer as we do want to support
assigning PASID capable functions to VMs.

You have it on your list to fix it up properly?

Jason