enable-rx-checksum
TX side, the insertion of a L3/L4 checksum by hardware can be enabled with the
following command of the testpmd application and running in a dedicated
tx checksum mode:
set fwd csum
tx_checksum set mask port_id
The transmission of packet is done with the start command of the testpmd
application that will receive packets and then transmit the packet out on all
configured ports. mask is used to indicated what hardware checksum
offload is required on the port_id. Please check the NIC datasheet for the
corresponding Hardware limits:
bit 0 - insert ip checksum offload if set
bit 1 - insert udp checksum offload if set
bit 2 - insert tcp checksum offload if set
bit 3 - insert sctp checksum offload if set
2.1. Prerequisites
If using vfio the kernel must be >= 3.6+ and VT-d must be enabled in bios.When
using vfio, use the following commands to to load the vfio driver and bind it
to the device under test:
modprobe vfio
modprobe vfio-pci
usertools/dpdk-devbind.py --bind=vfio-pci device_bus_id
Assuming that ports 0 and 2 are connected to a traffic generator,
launch the testpmd with the following arguments:
./build/app/testpmd -cffffff -n 1 -- -i --burst=1 --txpt=32 \
--txht=8 --txwt=0 --txfreet=0 --rxfreet=64 --mbcache=250 --portmask=0x5
enable-rx-checksum
Set the verbose level to 1 to display information for each received packet:
testpmd> set verbose 1
2.2. Test Case: Validate checksum on the receive packet
Setup the csum forwarding mode:
testpmd> set fwd csum
Set csum packet forwarding mode
Start the packet forwarding:
testpmd> start
csum packet forwarding - CRC stripping disabled - packets/burst=32
nb forwarding cores=1 - nb forwarding ports=10
RX queues=1 - RX desc=128 - RX free threshold=64
RX threshold registers: pthresh=8 hthresh=8 wthresh=4
TX queues=1 - TX desc=512 - TX free threshold=0
TX threshold registers: pthresh=32 hthresh=8 wthresh=8
Configure the traffic generator to send the multiple packets with the following
combination: good/bad ip checksum + good/bad udp/tcp checksum.
Except that SCTP header + payload length must be a multiple of 4 bytes.
IPv4 + UDP/TCP packet length can range from the minimum length to 1518 bytes.
Then verify that how many packets found with Bad-ipcsum or Bad-l4csum:
testpmd> stop
---------------------- Forward statistics for port 0 ----------------------
RX-packets: 0 RX-dropped: 0 RX-total: 0
Bad-ipcsum: 0 Bad-l4csum: 0
TX-packets: 0 TX-dropped: 0 TX-total: 0
----------------------------------------------------------------------------
2.3. Test Case: Insert IPv4/IPv6 UDP/TCP/SCTP checksum on the transmit packet
Setup the csum forwarding mode:
testpmd> set fwd csum
Set csum packet forwarding mode
Enable the IPv4/UDP/TCP/SCTP checksum offload on port 0:
testpmd> tx_checksum set 0xf 0
testpmd> start
csum packet forwarding - CRC stripping disabled - packets/burst=32
nb forwarding cores=1 - nb forwarding ports=10
RX queues=1 - RX desc=128 - RX free threshold=64
RX threshold registers: pthresh=8 hthresh=8 wthresh=4
TX queues=1 - TX desc=512 - TX free threshold=0
TX threshold registers: pthresh=32 hthresh=8 wthresh=8
Configure the traffic generator to send the multiple packets for the following
combination: IPv4/UDP, IPv4/TCP, IPv4/SCTP, IPv6/UDP, IPv6/TCP.
Except that SCTP header + payload length must be a multiple of 4 bytes.
IPv4 + UDP/TCP packet length can range from the minimum length to 1518 bytes.
Then verify that the same number of packet are correctly received on the traffic
generator side. And IPv4 checksum, TCP checksum, UDP checksum, SCTP CRC32c need
be validated as pass by the IXIA.
The IPv4 source address will not be changed by testpmd.
2.4. Test Case: Do not insert IPv4/IPv6 UDP/TCP checksum on the transmit packet
Setup the csum forwarding mode:
testpmd> set fwd csum
Set csum packet forwarding mode
Disable the IPv4/UDP/TCP/SCTP checksum offload on port 0:
testpmd> tx_checksum set 0x0 0
testpmd> start
csum packet forwarding - CRC stripping disabled - packets/burst=32
nb forwarding cores=1 - nb forwarding ports=10
RX queues=1 - RX desc=128 - RX free threshold=64
RX threshold registers: pthresh=8 hthresh=8 wthresh=4
TX queues=1 - TX desc=512 - TX free threshold=0
TX threshold registers: pthresh=32 hthresh=8 wthresh=8
Configure the traffic generator to send the multiple packets for the following
combination: IPv4/UDP, IPv4/TCP, IPv6/UDP, IPv6/TCP.
IPv4 + UDP/TCP packet length can range from the minimum length to 1518 bytes.
Then verify that the same number of packet are correctly received on the traffic
generator side. And IPv4 checksum, TCP checksum, UDP checksum need
be validated as pass by the IXIA.
The first byte of source IPv4 address will be increment by testpmd. The checksum
is indeed recalculated by software algorithms.
2.5. Test Case: Validate RX checksum valid flags on the receive packet
Setup the csum forwarding mode:
testpmd> set fwd csum
Set csum packet forwarding mode
Start the packet forwarding:
testpmd> start
csum packet forwarding - CRC stripping disabled - packets/burst=32
nb forwarding cores=1 - nb forwarding ports=10
RX queues=1 - RX desc=128 - RX free threshold=64
RX threshold registers: pthresh=8 hthresh=8 wthresh=4
TX queues=1 - TX desc=512 - TX free threshold=0
TX threshold registers: pthresh=32 hthresh=8 wthresh=8
Configure the traffic generator to send the multiple packets with the following
combination: good/bad ip checksum + good/bad udp/tcp checksum.
Check the Rx checksum flags consistent with expected flags.
