[dpdk-dev] [RFC v3] net/i40e: enable multi-queue Rx interrupt for VF

[Zhang, Qi Z]

> -----Original Message-----
> From: Cui, LunyuanX
> Sent: Monday, September 16, 2019 10:43 PM
> To: Yang, Qiming <qiming.yang at intel.com>; Wu, Jingjing
> <jingjing.wu at intel.com>; Xing, Beilei <beilei.xing at intel.com>; Zhang, Qi Z
> <qi.z.zhang at intel.com>; Wang, ShougangX <shougangx.wang at intel.com>;
> Stillwell Jr, Paul M <paul.m.stillwell.jr at intel.com>
> Cc: dev at dpdk.org; Cui, LunyuanX <lunyuanx.cui at intel.com>
> Subject: [RFC v3] net/i40e: enable multi-queue Rx interrupt for VF
> 
> Current implementation is that only one Rx queue can support interrupt,
> because all queues are mapped in the same vector id in vfio_enable_msix().
> So VF can not support multi-queue Rx interrupt in the interrupt mode.
> 
> In this patch, if the packet I/O interrupt on datapath is enabled
> (rte_intr_dp_is_en(intr_handle) is true), we map different interrupt vectors to
> each queue and send this map to PF.
> After PF sets the map to the register,
> all Rx queue interrupts will be received.
> 
> In addition, because of the i40e performance in ioctl(), the maximum
> supported interrupt vector id is 4.
> If vector id is more than 4, i40e driver will fail to start.
> So when queue number is more than 4,
> we set up a loop of interrupt vectors map from 1 to 4.

Don't know why we need to limit max interrupt to 4, why i40e driver will fail to start, could share more detail?
I think you can do the similar implementation as iavf driver does (ref iavf_config_irq_map)

> 
> Signed-off-by: Lunyuan Cui <lunyuanx.cui at intel.com>
> ---
> v3:
> * combined 2 lines into 1 line
>   before:
> 	map_info->vecmap[i].rxq_map = 0;
> 	map_info->vecmap[i].rxq_map |= 1 << i;
>   after:
> 	map_info->vecmap[i].rxq_map = 1 << i;
> 
> v2:
> * set up a loop of interrupt vectors map from 1 to 4, and sent
>   message from VF to PF by one time.
> ---
>  drivers/net/i40e/i40e_ethdev_vf.c | 27 +++++++++++++++++----------
>  1 file changed, 17 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> b/drivers/net/i40e/i40e_ethdev_vf.c
> index 308fb9835..abb2d1353 100644
> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> @@ -645,13 +645,15 @@ i40evf_configure_vsi_queues(struct rte_eth_dev
> *dev)
>  	return ret;
>  }
> 
> +#define RTE_LIBRTE_I40E_IRQ_NUM_PER_VF  4
> +
>  static int
>  i40evf_config_irq_map(struct rte_eth_dev *dev)  {
>  	struct i40e_vf *vf =
> I40EVF_DEV_PRIVATE_TO_VF(dev->data->dev_private);
>  	struct vf_cmd_info args;
>  	uint8_t cmd_buffer[sizeof(struct virtchnl_irq_map_info) + \
> -		sizeof(struct virtchnl_vector_map)];
> +		sizeof(struct virtchnl_vector_map) * dev->data->nb_rx_queues];
>  	struct virtchnl_irq_map_info *map_info;
>  	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
>  	struct rte_intr_handle *intr_handle = &pci_dev->intr_handle; @@ -665,18
> +667,23 @@ i40evf_config_irq_map(struct rte_eth_dev *dev)
>  		vector_id = I40E_MISC_VEC_ID;
> 
>  	map_info = (struct virtchnl_irq_map_info *)cmd_buffer;
> -	map_info->num_vectors = 1;
> -	map_info->vecmap[0].rxitr_idx = I40E_ITR_INDEX_DEFAULT;
> -	map_info->vecmap[0].vsi_id = vf->vsi_res->vsi_id;
> -	/* Alway use default dynamic MSIX interrupt */
> -	map_info->vecmap[0].vector_id = vector_id;
> -	/* Don't map any tx queue */
> -	map_info->vecmap[0].txq_map = 0;
> -	map_info->vecmap[0].rxq_map = 0;
> +	map_info->num_vectors = dev->data->nb_rx_queues;
>  	for (i = 0; i < dev->data->nb_rx_queues; i++) {
> -		map_info->vecmap[0].rxq_map |= 1 << i;
> +		map_info->vecmap[i].rxitr_idx = I40E_ITR_INDEX_DEFAULT;
> +		map_info->vecmap[i].vsi_id = vf->vsi_res->vsi_id;
> +		/* Alway use default dynamic MSIX interrupt */
> +		map_info->vecmap[i].vector_id = vector_id;
> +		/* Don't map any tx queue */
> +		map_info->vecmap[i].txq_map = 0;
> +		map_info->vecmap[i].rxq_map = 1 << i;
>  		if (rte_intr_dp_is_en(intr_handle))
>  			intr_handle->intr_vec[i] = vector_id;
> +		if (vector_id > I40E_MISC_VEC_ID) {
> +			if (vector_id < RTE_LIBRTE_I40E_IRQ_NUM_PER_VF)
> +				vector_id++;
> +			else
> +				vector_id = I40E_RX_VEC_START;
> +		}
>  	}
> 
>  	args.ops = VIRTCHNL_OP_CONFIG_IRQ_MAP;
> --
> 2.17.1