Note
Parts of this process can also be done using the setup script described in Chapter 6 of this document.
First, uncompress the archive and move to the uncompressed DPDK source directory:
user@host:~$ unzip DPDK-<version>.zip
user@host:~$ cd DPDK-<version>
user@host:~/DPDK-<version>$ ls
app/ config/ examples/ lib/ LICENSE.GPL LICENSE.LGPL Makefile mk/ scripts/ tools/
The DPDK is composed of several directories:
The format of a DPDK target is:
ARCH-MACHINE-EXECENV-TOOLCHAIN
where:
The targets to be installed depend on the 32-bit and/or 64-bit packages and compilers installed on the host. Available targets can be found in the DPDK/config directory. The defconfig_ prefix should not be used.
Note
Configuration files are provided with the RTE_MACHINE optimization level set. Within the configuration files, the RTE_MACHINE configuration value is set to native, which means that the compiled software is tuned for the platform on which it is built. For more information on this setting, and its possible values, see the DPDK Programmers Guide.
When using the Intel® C++ Compiler (icc), one of the following commands should be invoked for 64-bit or 32-bit use respectively. Notice that the shell scripts update the $PATH variable and therefore should not be performed in the same session. Also, verify the compiler’s installation directory since the path may be different:
source /opt/intel/bin/iccvars.sh intel64
source /opt/intel/bin/iccvars.sh ia32
To install and make targets, use the make install T=<target> command in the top-level DPDK directory.
For example, to compile a 64-bit target using icc, run:
make install T=x86_64-native-linuxapp-icc
To compile a 32-bit build using gcc, the make command should be:
make install T=i686-native-linuxapp-gcc
To compile all 64-bit targets using gcc, use:
make install T=x86_64*gcc
To compile all 64-bit targets using both gcc and icc, use:
make install T=x86_64-*
Note
The wildcard operator (*) can be used to create multiple targets at the same time.
To prepare a target without building it, for example, if the configuration changes need to be made before compilation, use the make config T=<target> command:
make config T=x86_64-native-linuxapp-gcc
Warning
Any kernel modules to be used, e.g. igb_uio, kni, must be compiled with the same kernel as the one running on the target. If the DPDK is not being built on the target machine, the RTE_KERNELDIR environment variable should be used to point the compilation at a copy of the kernel version to be used on the target machine.
Once the target environment is created, the user may move to the target environment directory and continue to make code changes and re-compile. The user may also make modifications to the compile-time DPDK configuration by editing the .config file in the build directory. (This is a build-local copy of the defconfig file from the top- level config directory).
cd x86_64-native-linuxapp-gcc
vi .config
make
In addition, the make clean command can be used to remove any existing compiled files for a subsequent full, clean rebuild of the code.
Once a target is created it contains all libraries and header files for the DPDK environment that are required to build customer applications. In addition, the test and testpmd applications are built under the build/app directory, which may be used for testing. A kmod directory is also present that contains kernel modules which may be loaded if needed:
$ ls x86_64-native-linuxapp-gcc
app build hostapp include kmod lib Makefile
To run any DPDK application, a suitable uio module can be loaded into the running kernel. In many cases, the standard uio_pci_generic module included in the linux kernel can provide the uio capability. This module can be loaded using the command
sudo modprobe uio_pci_generic
As an alternative to the uio_pci_generic, the DPDK also includes the igb_uio module which can be found in the kmod subdirectory referred to above. It can be loaded as shown below:
sudo modprobe uio
sudo insmod kmod/igb_uio.ko
Note
For some devices which lack support for legacy interrupts, e.g. virtual function (VF) devices, the igb_uio module may be needed in place of uio_pci_generic.
Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional for platforms that support using VFIO.
To run an DPDK application and make use of VFIO, the vfio-pci module must be loaded:
sudo modprobe vfio-pci
Note that in order to use VFIO, your kernel must support it. VFIO kernel modules have been included in the Linux kernel since version 3.6.0 and are usually present by default, however please consult your distributions documentation to make sure that is the case.
Also, to use VFIO, both kernel and BIOS must support and be configured to use IO virtualization (such as Intel® VT-d).
For proper operation of VFIO when running DPDK applications as a non-privileged user, correct permissions should also be set up. This can be done by using the DPDK setup script (called setup.sh and located in the tools directory).
As of release 1.4, DPDK applications no longer automatically unbind all supported network ports from the kernel driver in use. Instead, all ports that are to be used by an DPDK application must be bound to the uio_pci_generic, igb_uio or vfio-pci module before the application is run. Any network ports under Linux* control will be ignored by the DPDK poll-mode drivers and cannot be used by the application.
Warning
The DPDK will, by default, no longer automatically unbind network ports from the kernel driver at startup. Any ports to be used by an DPDK application must be unbound from Linux* control and bound to the uio_pci_generic, igb_uio or vfio-pci module before the application is run.
To bind ports to the uio_pci_generic, igb_uio or vfio-pci module for DPDK use, and then subsequently return ports to Linux* control, a utility script called dpdk_nic _bind.py is provided in the tools subdirectory. This utility can be used to provide a view of the current state of the network ports on the system, and to bind and unbind those ports from the different kernel modules, including the uio and vfio modules. The following are some examples of how the script can be used. A full description of the script and its parameters can be obtained by calling the script with the –help or –usage options. Note that the uio or vfio kernel modules to be used, should be loaded into the kernel before running the dpdk_nic_bind.py script.
Warning
Due to the way VFIO works, there are certain limitations to which devices can be used with VFIO. Mainly it comes down to how IOMMU groups work. Any Virtual Function device can be used with VFIO on its own, but physical devices will require either all ports bound to VFIO, or some of them bound to VFIO while others not being bound to anything at all.
If your device is behind a PCI-to-PCI bridge, the bridge will then be part of the IOMMU group in which your device is in. Therefore, the bridge driver should also be unbound from the bridge PCI device for VFIO to work with devices behind the bridge.
Warning
While any user can run the dpdk_nic_bind.py script to view the status of the network ports, binding or unbinding network ports requires root privileges.
To see the status of all network ports on the system:
root@host:DPDK# ./tools/dpdk_nic_bind.py --status
Network devices using DPDK-compatible driver
============================================
0000:82:00.0 '82599EB 10-Gigabit SFI/SFP+ Network Connection' drv=uio_pci_generic unused=ixgbe
0000:82:00.1 '82599EB 10-Gigabit SFI/SFP+ Network Connection' drv=uio_pci_generic unused=ixgbe
Network devices using kernel driver
===================================
0000:04:00.0 'I350 Gigabit Network Connection' if=em0 drv=igb unused=uio_pci_generic *Active*
0000:04:00.1 'I350 Gigabit Network Connection' if=eth1 drv=igb unused=uio_pci_generic
0000:04:00.2 'I350 Gigabit Network Connection' if=eth2 drv=igb unused=uio_pci_generic
0000:04:00.3 'I350 Gigabit Network Connection' if=eth3 drv=igb unused=uio_pci_generic
Other network devices
=====================
<none>
To bind device eth1, 04:00.1, to the uio_pci_generic driver:
root@host:DPDK# ./tools/dpdk_nic_bind.py --bind=uio_pci_generic 04:00.1
or, alternatively,
root@host:DPDK# ./tools/dpdk_nic_bind.py --bind=uio_pci_generic eth1
To restore device 82:00.0 to its original kernel binding:
root@host:DPDK# ./tools/dpdk_nic_bind.py --bind=ixgbe 82:00.0