Compiling P4 Programs for ES2K

This document explains how to install and use the Intel® IPU E2100 P4Tools Container to compile a P4 program to build artifacts, including the .pkg file, that can be deployed on ES2K.

The supported host OSes are listed in the “Supported Operating Systems” section of the IPU Software User Guide (RDC Doc#778226), henceforth referred to as the “IPU SWG”.

Build and run the P4Tools container

The tools required to compile and build a custom p4 package can be installed by building the P4 Tools Container.

See “Getting Started Guide with P4 on P4 Tools Container” in the IPU SWG for instructions on building and launching the P4 Tools container.

Once <your_p4_tools_container> is sucessfully built, proceed to the next step.

Launch the P4Tools container

# Launch the P4Tools container on the host.
[user@host P4Tools] sudo docker exec -it <your_p4_tools_container> /bin/bash

# Inside the container, verify the p4 compiler version.
[root@a54d354e447e /] p4c --version
p4c 1.2.3.7 (SHA:  BUILD: release)

The p4c compiler should now be ready for use.

In previous versions of the SDK, cpt had to be invoked separately. It is no longer necessary to do so. cpt will be invoked automatically by specifying cpt flags to p4c.

Build reference P4 programs

The p4-programs directory in the SDK folder contains a number of sample P4 programs. The SDK is contained in a tar file named intel-ipu-sdk-source-code-<$VERSION>.tgz.

Extract the p4-programs from the tarball.

[root@host ~] ls -l $INTEL-IPU-SDK-<VERSION>/tools/pipeline/p4-programs
total 1100
-rw-r--r--.  1 user user     79 Dec 13 15:54 CONTENTS
drwxr-xr-x. 10 user user   4096 Dec 13 15:54 fxp-cxp-features
drwxr-xr-x. 10 user user   4096 Dec 13 15:54 fxp-net-scenarios
drwxr-xr-x.  7 user user    106 Dec 13 15:54 layer-2-forwarding
drwxr-xr-x.  8 user user    116 Dec 13 15:54 layer-3-forwarding
-rw-r--r--.  1 user user  81529 Dec 23 03:09 Makefile
-rw-r--r--.  1 user user   1494 Dec 13 15:54 mev_sample.conf
drwxr-xr-x.  2 user user    131 Dec 13 15:54 testsuite

Each P4 program has its own directory and an accompanying README file that provides instructions on how to configure the IPU pipeline.

Compiling a P4 Program

Use the p4c compiler driver to compile and build packages. We will be using one of the reference programs mentioned above as an example: p4-programs/layer-3-forwarding/l3-fwd_p2p.

The Makefile contains the exact commands to build the artifacts for all the reference programs.

1. Copy the entire p4-programs directory from the host to the P4Tools container.

   sudo docker cp p4-programs/ <p4Tools container id>:/opt/
   

2. Set environment variables in the container prior to building.

   [root@a54d354e447e p4-programs] which p4c
   /opt/p4-tools/p4c/bin/p4c
   [root@a54d354e447e p4-programs] export P4C_PATH=/opt/p4-tools/p4c/bin
   export CPT_PATH=/opt/p4-tools/cpt/bin
   export PATH=$P4C_PATH:$CPT_PATH:$PATH
   export LD_LIBRARY_PATH=$P4C_PATH/../lib:/usr/local/lib:$LD_LIBRARY_PATH
   export PREV_ARTIFACT_DIR=
   

3. Compile l3-fwd_p2p. All artifacts will be generated in the artifacts directory.

   [root@a54d354e447e ~] cd /opt/p4-programs
   
   # Compiling /opt/p4-programs/layer-3-forwarding/l3-fwd_p2p/l3-fwd_p2p.p4
   # and generating the runtime files and assembly...
   [root@a54d354e447e p4-programs] make l3-fwd_p2p
   /opt/p4-tools/p4c/bin/p4c --target idpf --arch pna
       -I/opt/p4-tools/p4c/bin/../lib -I/opt/p4-tools/p4c/bin/../share/p4c/p4include
       -I/opt/p4-tools/p4c/bin/../share/p4c/idpf-lib --package-by-domain
       --p4runtime-files ./artifacts/l3-fwd_p2p/p4Info.txt --save-temps 
       -Xp4c "--Wdisable --no-pedantic --context ./artifacts/l3-fwd_p2p/context.json
       --bfrt ./artifacts/l3-fwd_p2p/bf-rt.json"
       --save-temps --npic --format csr --pkg-version 1.2 --pkg-name "FXP Package"
       -Xassembler ".cpt_ver.s" /opt/p4-programs/layer-3-forwarding/l3-fwd_p2p/l3-fwd_p2p.p4
       -o artifacts/l3-fwd_p2p
   

4. All output files, including the .pkg file, will be in the artifacts directory.

   [root@a54d354e447e p4-programs] ls -lrt artifacts/l3-fwd_p2p/
   total 2884
   -rw-r--r--. 1 root root 950608 Dec 22 23:57 l3-fwd_p2p_0b32dac62c9b4c18b3213e04a6bb8c5b.pkgo
   -rw-r--r--. 1 root root   3045 Dec 23 00:18 p4Info.txt
   -rw-r--r--. 1 root root   8866 Dec 23 00:18 bf-rt.json
   -rw-r--r--. 1 root root  30390 Dec 23 00:18 context.json
   -rw-r--r--. 1 root root  37269 Dec 23 00:18 l3-fwd_p2p.s
   -rw-r--r--. 1 root root 950608 Dec 23 00:18 l3-fwd_p2p_b222a542c1474685bd70a36994d16101.pkgo
   -rw-r--r--. 1 root root 950608 Dec 23 00:18 l3-fwd_p2p.pkg 
   

   These files are called P4 artifacts.

Deploying P4 programs

Please see Deploying P4 Programs for details about deployment.