[dpdk-users] dpdk-i40e could not receive vlan packet whose ip_len was bigger than 1496

[tb.bingel]

Hi all,


I found dpdk-i40e could not receive vlan packet whose ip_len was bigger than 1496, 


and I tested the same test cases with i350(igb)  network card, NO such issue.


Was it a bug in DPDK? Thanks!


Test Environment：
* netcard : Ethernet controller: Intel Corporation Ethernet Controller XL710 for 40GbE QSFP
* CPU : Intel(R) Xeon(R) Silver 4116 CPU @ 2.10GHz
* OS : Ubuntu 16.04 
* DPDK： 19.05


How to reproduce？
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Step 1:  start kni example
$ sudo ./build/kni -l 0-5 -n 4 -- -P -p 0x1 -m --config="(0,1,3)" 
EAL: Detected 48 lcore(s)
EAL: Detected 2 NUMA nodes
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Probing VFIO support...
EAL: PCI device 0000:19:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:19:00.1 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:19:00.2 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:19:00.3 on NUMA socket 0
EAL:   probe driver: 8086:1521 net_e1000_igb
EAL: PCI device 0000:3b:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1583 net_i40e
EAL: PCI device 0000:3b:00.1 on NUMA socket 0
EAL:   probe driver: 8086:1583 net_i40e
APP: Initialising port 0 ...
 
Checking link status
..done
Port0 Link Up - speed 40000Mbps - full-duplex
APP: ========================
APP: KNI Running
APP: kill -SIGUSR1 90114
APP:     Show KNI Statistics.
APP: kill -SIGUSR2 90114
APP:     Zero KNI Statistics.
APP: ========================
APP: Lcore 1 is reading from port 0
APP: Lcore 2 has nothing to do
APP: Lcore 3 is writing to port 0
APP: Lcore 4 has nothing to do
APP: Lcore 0 has nothing to do
APP: Lcore 5 has nothing to do
APP: Configure network interface of 0 up
APP: vEth0 NIC Link is Up 40000 Mbps (AutoNeg) Full Duplex.



Step 2: configure KNI interface WITHOUT VLAN
$ sudo ifconfig vEth0 192.168.99.141/24


Step 3: configure KNI interface WITH VLAN ID

$ sudo vconfig add vEth0 589
Added VLAN with VID == 589 to IF -:vEth0:-
$ sudo ifconfig vEth0 192.168.100.141/24
 

Step 4：ping KNI IP(no VLAN) from antoher PC
$ ping -c 1 -s 1472 -M do 192.168.99.141     
PING 192.168.99.141 (192.168.99.141) 1472(1500) bytes of data.  <<<< It's OK for ip payload 1500
1480 bytes from 192.168.99.141: icmp_seq=1 ttl=64 time=7.53 ms


Step 5: ping KNI VLAN IP from anther PC
$ ping -c 1 -s 1468 -M do 192.168.100.141  
PING 192.168.100.141 (192.168.100.141) 1468(1496) bytes of data.   <<<< It's OK for ip payload 1496
1476 bytes from 192.168.100.141: icmp_seq=1 ttl=64 time=4.66 ms



$ ping -c 1 -s 1469 -M do 192.168.100.141  
PING 192.168.100.141 (192.168.100.141) 1469(1497) bytes of data.   <<< failed for ip payload 1497
^C
--- 192.168.100.141 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms


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