[dpdk-dev] [PATCH v1 5/5] net/i40e: fix max mtu size packets with vlan tag cannot be received by default

[SteveX Yang]

testpmd will initialize default max packet length to 1518 which does't
include vlan tag size in ether overheader. Once, send the max mtu length
packet with vlan tag, the max packet length will exceed 1518 that will
cause packets dropped directly from NIC hw side. But for i40e/i40evf,
they should support dual vlan tags that need more 8 bytes for max packet
size, so, configure the correct max packet size in dev_config ops.

Fixes: ff8282f4bbcd ("net/i40e: consider QinQ when setting MTU")

Signed-off-by: SteveX Yang <stevex.yang at intel.com>
---
 drivers/net/i40e/i40e_ethdev.c    | 10 ++++++++++
 drivers/net/i40e/i40e_ethdev_vf.c | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 841447228..787ff61c0 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -1917,6 +1917,7 @@ i40e_dev_configure(struct rte_eth_dev *dev)
 	struct i40e_hw *hw = I40E_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 	enum rte_eth_rx_mq_mode mq_mode = dev->data->dev_conf.rxmode.mq_mode;
 	int i, ret;
+	struct rte_eth_rxmode *rxmode = &dev->data->dev_conf.rxmode;
 
 	ret = i40e_dev_sync_phy_type(hw);
 	if (ret)
@@ -1930,6 +1931,15 @@ i40e_dev_configure(struct rte_eth_dev *dev)
 	ad->tx_simple_allowed = true;
 	ad->tx_vec_allowed = true;
 
+	/* Considering QinQ packet, max frame size should be MTU and
+	 * corresponding ether overhead.
+	 */
+	if (dev->data->mtu == RTE_ETHER_MTU &&
+		rxmode->max_rx_pkt_len == RTE_ETHER_MAX_LEN) {
+		rxmode->max_rx_pkt_len = RTE_ETHER_MTU + I40E_ETH_OVERHEAD;
+		rxmode->offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+	}
+
 	if (dev->data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG)
 		dev->data->dev_conf.rxmode.offloads |= DEV_RX_OFFLOAD_RSS_HASH;
 
diff --git a/drivers/net/i40e/i40e_ethdev_vf.c b/drivers/net/i40e/i40e_ethdev_vf.c
index b755350cd..7410563db 100644
--- a/drivers/net/i40e/i40e_ethdev_vf.c
+++ b/drivers/net/i40e/i40e_ethdev_vf.c
@@ -1669,6 +1669,7 @@ i40evf_dev_configure(struct rte_eth_dev *dev)
 		I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
 	uint16_t num_queue_pairs = RTE_MAX(dev->data->nb_rx_queues,
 				dev->data->nb_tx_queues);
+	struct rte_eth_rxmode *rxmode = &dev->data->dev_conf.rxmode;
 
 	/* Initialize to TRUE. If any of Rx queues doesn't meet the bulk
 	 * allocation or vector Rx preconditions we will reset it.
@@ -1681,6 +1682,16 @@ i40evf_dev_configure(struct rte_eth_dev *dev)
 	dev->data->dev_conf.intr_conf.lsc =
 		!!(dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC);
 
+
+	/* Considering QinQ packet, max frame size should be MTU and
+	 * corresponding ether overhead.
+	 */
+	if (dev->data->mtu == RTE_ETHER_MTU &&
+		rxmode->max_rx_pkt_len == RTE_ETHER_MAX_LEN) {
+		rxmode->max_rx_pkt_len = RTE_ETHER_MTU + I40E_ETH_OVERHEAD;
+		rxmode->offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+	}
+
 	if (num_queue_pairs > vf->vsi_res->num_queue_pairs) {
 		struct i40e_hw *hw;
 		int ret;
-- 
2.17.1