[Intel-gfx] [PATCH v4 2/9] vfio-iommufd: Create iommufd_access for noiommu devices

[Tian, Kevin]

> From: Liu, Yi L <yi.l.liu at intel.com>
> Sent: Wednesday, April 26, 2023 10:54 PM
> @@ -121,7 +128,8 @@ static void vfio_emulated_unmap(void *data,
> unsigned long iova,
>  {
>  	struct vfio_device *vdev = data;
> 
> -	if (vdev->ops->dma_unmap)
> +	/* noiommu devices cannot do map/unmap */
> +	if (vdev->noiommu && vdev->ops->dma_unmap)
>  		vdev->ops->dma_unmap(vdev, iova, length);

Is it necessary? All mdev devices implementing @dma_unmap won't
set noiommu flag.

Instead in the future if we allow noiommu userspace to pin pages
we'd need similar logic too.