librte_pmd_rvif: a DPDK poll mode driver for rvif

This is a DPDK poll mode driver (pmd) for a virtual interface, called rvif, which is made for a virtual switch named rvs.

For details of rvs and rvif, please visit https://github.com/yasukata/rvs.

How to use

Compilation

librte_pmd_rvif.so

Please type the following to compile the program.

make

The command above will:

• download the source code of DPDK at ([LOCATION_OF_MAKEFILE]/dpdk/dpdk-$(DPDK_VER).tar.xz)
• compile it in ([LOCATION_OF_MAKEFILE]/dpdk/dpdk-$(DPDK_VER))
• install the compiled binaries at [LOCATION_OF_MAKEFILE]/dpdk/install .
• clone the rvs repository at [LOCATION_OF_MAKEFILE]/deps/rvs .
• compile [LOCATION_OF_MAKEFILE]/main.c

DPDK is installed in [LOCATION_OF_MAKEFILE]/dpdk/install; therefore, you do not need the root permission for the installation, and this does not overwrite the existing DPDK library.

deps/rvs/apps/fwd/a.out

The following command will generate a binary of the forwarder application.

make -C deps/rvs/apps/fwd

Run

We run the testpmd application of DPDK at deps/dpdk/install/bin/dpdk-testpmd for testing.

First, please create two of 32 MB shared memory files by the following commands.

dd if=/dev/zero of=/dev/shm/rvs_shm00 bs=1M count=0 seek=32

dd if=/dev/zero of=/dev/shm/rvs_shm01 bs=1M count=0 seek=32

Terminal/console 1: please execute the following command to launche the forwarder application.

./deps/rvs/apps/fwd/a.out -m /dev/shm/rvs_shm00 -m /dev/shm/rvs_shm01

Terminal/console 2: please open a terminal/console and type the following to start testpmd with the rxonly mode.

sudo LD_LIBRARY_PATH=./deps/dpdk/install/lib/x86_64-linux-gnu LD_PRELOAD=./deps/dpdk/install/lib/x86_64-linux-gnu/dpdk/pmds-23.0/librte_mempool_ring.so.23.0:./librte_pmd_rvif.so ./deps/dpdk/install/bin/dpdk-testpmd -l 0-1 --proc-type=primary --file-prefix=pmd1 --vdev=net_rvif,mac=aa:bb:cc:dd:ee:00,mem=/dev/shm/rvs_shm00 --no-pci -- --nb-cores 1 --forward-mode=rxonly --txq=1 --rxq=1 --txd=512 --rxd=512 --stats-period=1

Terminal/console 3: please open a terminal/console and execute the following to launch testpmd with the txonly mode.

sudo LD_LIBRARY_PATH=./deps/dpdk/install/lib/x86_64-linux-gnu LD_PRELOAD=./deps/dpdk/install/lib/x86_64-linux-gnu/dpdk/pmds-23.0/librte_mempool_ring.so.23.0:./librte_pmd_rvif.so ./deps/dpdk/install/bin/dpdk-testpmd -l 2-3 --proc-type=primary --file-prefix=pmd2 --vdev=net_rvif,mac=aa:bb:cc:dd:ee:01,mem=/dev/shm/rvs_shm01 --no-pci -- --nb-cores 1 --forward-mode=txonly --txq=1 --rxq=1 --txd=512 --rxd=512 --stats-period=1 --txpkts=64

Supposedly, you will see incoming packets in terminal/console 2, which are sent from testpmd in terminal/console 3.

The meaning of the command is as follows.

• LD_LIBRARY_PATH=./deps/dpdk/install/lib/x86_64-linux-gnu: ensure the DPDK library built by us is loaded
• LD_PRELOAD=./deps/dpdk/install/lib/x86_64-linux-gnu/dpdk/pmds-23.0/librte_mempool_ring.so.23.0:./librte_pmd_rvif.so: load librte_pmd_rvif.so at the execution time
• ./deps/dpdk/install/bin/dpdk-testpmd: path to the application
• -l 0-1 --proc-type=primary --file-prefix=pmd1: the arguments passed to DPDK, and this is the default syntax defined by DPDK
• --vdev=net_rvif,mac=aa:bb:cc:dd:ee:00,mem=/dev/shm/rvs_shm00: request DPDK to create an rvif virtual interface, whose mac address is aa:bb:cc:dd:ee:00 and shared memory file is /dev/shm/rvs_shm00; this part is handled by our librte_pmd_rvif.so
• --no-pci: DPDK does not try to look up PCI devices
• --: separator between the arguments passed to DPDK and the testpmd application
• --nb-cores 1 --forward-mode=rxonly --txq=1 --rxq=1 --txd=512 --rxd=512 --stats-period=1: handled by the testpmd application

Some points

For modularity, we build librte_pmd_rvif.so as an independent shared library file, and apply it through LD_PRELOAD.

To use testpmd of DPDK, we specify --default-library=share for the build option of DPDK; otherwise, the DPDK compilation phase statically links the DPDK library and testpmd, and LD_PRELOAD cannot load our librte_pmd_rvif.so for the execution of it.

librte_pmd_rvif/mk/dpdk/1.mk

Line 15 in eab680c

meson --default-library=shared --prefix=$(DPDK_INSTALL_DIR) --libdir=lib/x86_64-linux-gnu $(DPDK_SRC_DIR)/build $(DPDK_SRC_DIR)