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Date:   Wed, 5 Aug 2020 08:51:56 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     Jason Wang <jasowang@redhat.com>
Cc:     virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, rob.miller@broadcom.com,
        lingshan.zhu@intel.com, eperezma@redhat.com, lulu@redhat.com,
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        gdawar@xilinx.com, saugatm@xilinx.com, vmireyno@marvell.com,
        zhangweining@ruijie.com.cn, eli@mellanox.com
Subject: Re: [PATCH 1/4] vdpa: introduce config op to get valid iova range
Message-ID: <20200805085035-mutt-send-email-mst@kernel.org>
References: <20200617032947.6371-1-jasowang@redhat.com>
 <20200617032947.6371-2-jasowang@redhat.com>
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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@redhat.com>
> ---
>  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