Re: [RFT][PATCH v1 3/6] vfio: Pass in starting IOVA to vfio_pin/unpin_pages API

[Christoph Hellwig]

On Thu, Jun 16, 2022 at 04:52:09PM -0700, Nicolin Chen wrote:
> +	ret = vfio_unpin_pages(&vgpu->vfio_device, gfn << PAGE_SHIFT, npage);
> +	drm_WARN_ON(&i915->drm, ret != npage);

The shifting of gfn seems to happen bother here and in the callers.

Also this is the only caller that does anything withthe vfio_unpin_pages
return value.  Given that you touch the API here we might as well
not return any value, and turn the debug checks that can return errors
into WARN_ON_ONCE calls the vfio/iommu_type1 code.

> +extern int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
>  			  int npage, int prot, unsigned long *phys_pfn);
> -extern int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
> +extern int vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova,
>  			    int npage);

This will clash with the extern removal patch that Alex has sent.