[dpdk-dev] [PATCH v1 4/5] net/iavf: 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.

iavf can support dual vlan tags that need more 8 bytes for max packet size,
so, configures the correct max packet size in dev_config ops.

Fixes: 02d212ca3125 ("net/iavf: rename remaining avf strings")

Signed-off-by: SteveX Yang <stevex.yang at intel.com>
---
 drivers/net/iavf/iavf_ethdev.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/iavf/iavf_ethdev.c b/drivers/net/iavf/iavf_ethdev.c
index 8fe81409c..ca4c52a52 100644
--- a/drivers/net/iavf/iavf_ethdev.c
+++ b/drivers/net/iavf/iavf_ethdev.c
@@ -217,7 +217,7 @@ iavf_dev_configure(struct rte_eth_dev *dev)
 	struct iavf_adapter *ad =
 		IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
 	struct iavf_info *vf =  IAVF_DEV_PRIVATE_TO_VF(ad);
-	struct rte_eth_conf *dev_conf = &dev->data->dev_conf;
+	struct rte_eth_rxmode *rxmode = &dev->data->dev_conf.rxmode;
 
 	ad->rx_bulk_alloc_allowed = true;
 	/* Initialize to TRUE. If any of Rx queues doesn't meet the
@@ -229,9 +229,18 @@ iavf_dev_configure(struct rte_eth_dev *dev)
 	if (dev->data->dev_conf.rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG)
 		dev->data->dev_conf.rxmode.offloads |= DEV_RX_OFFLOAD_RSS_HASH;
 
+	/* 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 + IAVF_ETH_OVERHEAD;
+		rxmode->offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+	}
+
 	/* Vlan stripping setting */
 	if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_VLAN) {
-		if (dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_VLAN_STRIP)
+		if (rxmode->offloads & DEV_RX_OFFLOAD_VLAN_STRIP)
 			iavf_enable_vlan_strip(ad);
 		else
 			iavf_disable_vlan_strip(ad);
-- 
2.17.1