Re: [PATCH v1 11/14] vfio/type1: Register device notifier

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

> +
> +		if (!dma->pfnmap) {
> +			struct vfio_device *device;
> +			unsigned long base_pfn;
> +			struct pfnmap_obj *pfnmap;

Please factor this whole block into a separate helper to keep it
readable.