Re: [PATCH V3 07/10] vfio: Enable cdev noiommu mode under iommufd

[Jason Gunthorpe]

On Thu, Apr 02, 2026 at 10:11:43PM -0700, Jacob Pan wrote:
> @@ -392,6 +398,16 @@ void vfio_unregister_group_dev(struct vfio_device *device)
>  	bool interrupted = false;
>  	long rc;
>  
> +	/*
> +	 * For noiommu devices without a container, thus no dummy group,
> +	 * simply delete and unregister to balance refcount.
> +	 */
> +	if (device->noiommu && !vfio_device_has_group(device)) {
> +		vfio_device_del(device);
> +		vfio_device_put_registration(device);
> +		return;
> +	}
> +

Sashiko points out this can't just skip the waiting even for no-iommu
mode, it isn't linked to groups and containers but the lifecylce of
the open FD.

Maybe just stick a !group inside vfio_device_group_unregister() is
sufficient?

Jason