Re: [RFC PATCH 10/24] vdpa: introduce config operations for associating ASID to a virtqueue group

[Eli Cohen]

On Thu, Sep 24, 2020 at 11:21:11AM +0800, Jason Wang wrote:
> This patch introduces a new bus operation to allow the vDPA bus driver
> to associate an ASID to a virtqueue group.
>

So in case of virtio_net, I would expect that all the data virtqueues
will be associated with the same address space identifier. Moreover,
this assignment should be provided before the set_map call that provides
the iotlb for the address space, correct?

> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
>  include/linux/vdpa.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 1e1163daa352..e2394995a3cd 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -160,6 +160,12 @@ struct vdpa_device {
>   * @get_generation:		Get device config generation (optional)
>   *				@vdev: vdpa device
>   *				Returns u32: device generation
> + * @set_group_asid:		Set address space identifier for a
> + *				virtqueue group
> + *				@vdev: vdpa device
> + *				@group: virtqueue group
> + *				@asid: address space id for this group
> + *				Returns integer: success (0) or error (< 0)
>   * @set_map:			Set device memory mapping (optional)
>   *				Needed for device that using device
>   *				specific DMA translation (on-chip IOMMU)
> @@ -237,6 +243,10 @@ struct vdpa_config_ops {
>  		       u64 iova, u64 size, u64 pa, u32 perm);
>  	int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
>  			 u64 iova, u64 size);
> +	int (*set_group_asid)(struct vdpa_device *vdev, unsigned int group,
> +			      unsigned int asid);
> +
> +

Extra space
>  
>  	/* Free device resources */
>  	void (*free)(struct vdpa_device *vdev);
> -- 
> 2.20.1
>