Re: [PATCH 1/4] vdpa: introduce config op to get valid iova range

From: Michael S. Tsirkin
Date: Wed Aug 05 2020 - 13:25:21 EST


On Wed, Jun 17, 2020 at 11:29:44AM +0800, Jason Wang wrote:
> This patch introduce a config op to get valid iova range from the vDPA
> device.
>
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
> include/linux/vdpa.h | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 239db794357c..b7633ed2500c 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -41,6 +41,16 @@ struct vdpa_device {
> unsigned int index;
> };
>
> +/**
> + * vDPA IOVA range - the IOVA range support by the device
> + * @start: start of the IOVA range
> + * @end: end of the IOVA range
> + */
> +struct vdpa_iova_range {
> + u64 start;
> + u64 end;
> +};
> +


This is ambiguous. Is end in the range or just behind it?
How about first/last?



> /**
> * vDPA_config_ops - operations for configuring a vDPA device.
> * Note: vDPA device drivers are required to implement all of the
> @@ -134,6 +144,9 @@ struct vdpa_device {
> * @get_generation: Get device config generation (optional)
> * @vdev: vdpa device
> * Returns u32: device generation
> + * @get_iova_range: Get supported iova range (on-chip IOMMU)
> + * @vdev: vdpa device
> + * Returns the iova range supported by the device
> * @set_map: Set device memory mapping (optional)
> * Needed for device that using device
> * specific DMA translation (on-chip IOMMU)
> @@ -195,6 +208,7 @@ struct vdpa_config_ops {
> void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
> const void *buf, unsigned int len);
> u32 (*get_generation)(struct vdpa_device *vdev);
> + struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
>
> /* DMA ops */
> int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
> --
> 2.20.1