76. IEEE1588 Precise Time Protocol Tests¶

The functional test of the IEEE1588 Precise Time Protocol offload support in Poll Mode Drivers is done with a specific ieee1588` forwarding mode of the testpmd application.

In this mode, packets are received one by one and are expected to be PTP V2 L2 Ethernet frames with the specific Ethernet type 0x88F7, containing PTP SYNC messages (version 2 at offset 1, and message ID 0 at offset 0).

When started, the test enables the IEEE1588 PTP offload support of each controller. It makes them automatically filter and timestamp the receipt of incoming PTP SYNC messages contained in PTP V2 Ethernet frames. Conversely, when stopped, the test disables the IEEE1588 PTP offload support of each controller,

While running, the test checks that each received packet is a valid IEEE1588 PTP V2 Ethernet frame with a message of type PTP_SYNC_MESSAGE, and that the packet has been identified and timestamped by the hardware. For this purpose, it checks that the corresponding PKT_RX_IEEE1588_PTP and PKT_RX_IEEE1588_TMST flags have been set in the mbufs returned by the PMD receive function.

Then, the test checks that the two NIC registers holding the timestamp of a received PTP packet are effectively valid, and that they contain a value greater than their previous value.

If everything is OK, the test sends the received packet as-is on the same port, requesting for its transmission to be timestamped by the hardware. For this purpose, it set the PKT_TX_IEEE1588_TMST flag of the mbuf before sending it. The test finally checks that the two NIC registers holding the timestamp of a transmitted PTP packet are effectively valid, and that they contain a value greater than their previous value.

76.1. 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 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

The support of the IEEE1588 Precise Time Protocol in Poll Mode Drivers must be configured at compile-time with the DRTE_LIBRTE_IEEE1588 option:

CC=gcc meson -Denable_kmods=True -Dlibdir=lib -Dc_args=-DRTE_LIBRTE_IEEE1588 --default-library=static x86_64-native-linuxapp-gcc

Configure the packet format for the traffic generator to be IEEE1588 PTP Ethernet type 0x88F7 and containing PTP SYNC (version 2 at offset 1, and message ID 0 at offset 0).

Start the testpmd application with the following parameters:

-cffffff -n 3 -- -i --tx-offloads=0x00008000

The -n command is used to select the number of memory channels. It should match the number of memory channels on that setup. –tx-offloads: for IEEE1588, the full-feature tx path needs to be enabled. Enabling any tx offload will force DPDK utilize full tx path. Enabling multiple segment offload is more reasonable for user cases.

If test on ICE, start testpmd with the following parameters:

-cffffff -n 3 -- -i --tx-offloads=0x00008000 --enable-rx-timestamp

76.2. Test Case: Enable IEEE1588 PTP packet reception and generation¶

Select the ieee1588 test forwarding mode and start the test:

testpmd> set fwd ieee1588
Set ieee1588 packet forwarding mode
testpmd> start
  ieee1588 packet forwarding - CRC stripping disabled - packets/burst=16
  nb forwarding cores=1 - nb forwarding ports=2
  RX queues=1 - RX desc=128 - RX free threshold=0
  RX threshold registers: pthresh=0 hthresh=0 wthresh=0
  TX queues=1 - TX desc=512 - TX free threshold=0
  TX threshold registers: pthresh=39 hthresh=0 wthresh=0
testpmd>

On the traffic generator side send one IEEE1588 PTP packet.

Verify that the testpmd application outputs something like this, with a timestamp different than 0:

testpmd> Port 8 IEEE1588 PTP V2 SYNC Message filtered by hardware
Port 8 RX timestamp value 0x78742550448000000
Port 8 TX timestamp value 0x78742561472000000 validated after 2 micro-seconds
Port 8 IEEE1588 PTP V2 SYNC Message filtered by hardware
Port 8 RX timestamp value 0x79165536192000000
Port 8 TX timestamp value 0x79165545648000000 validated after 2 micro-seconds

Verify that the TX timestamp is bigger than the RX timestamp. Verify that the second RX timestamp is bigger than the first RX timestamp. Verify that the TX IEEE1588 PTP packet is received by the traffic generator.

76.3. Test Case: Disable IEEE1588 PTP packet reception and generation¶

Stop the IEEE1588 fwd:

testpmd> stop
...
testpmd>

Send one IEEE1588 PTP packet

Verify that the packet is not filtered by the HW (IEEE1588 PTP V2 SYNC Message is not displayed). (??? Is it correct? Should we set fwd rxonly ?)