[RFC,v2] net/i40e: enable multi-queue Rx interrupt for VF

  This patch enables VF to support multi-queue Rx interrupt.

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 everytime.
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.

Signed-off-by: Lunyuan Cui <lunyuanx.cui@intel.com>
---
 drivers/net/i40e/i40e_ethdev_vf.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)
  

On 09/09, lunyuan.cui wrote:
>This patch enables VF to support multi-queue Rx interrupt.
>
>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 everytime.
>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.
>
>Signed-off-by: Lunyuan Cui <lunyuanx.cui@intel.com>
>---
> drivers/net/i40e/i40e_ethdev_vf.c | 28 ++++++++++++++++++----------
> 1 file changed, 18 insertions(+), 10 deletions(-)
>
>diff --git a/drivers/net/i40e/i40e_ethdev_vf.c b/drivers/net/i40e/i40e_ethdev_vf.c
>index 308fb9835..ecfec46f8 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 +667,24 @@ 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 = 0;
>+		map_info->vecmap[i].rxq_map |= 1 << i;

Above 2 lines can combined into

		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
>