DPDK runs in userspace and PMDs uses the Linux kernel UIO interface to
allow access to physical devices from userspace. The NFP PMD requires
-a separate UIO driver, **nfp_uio**, to perform correct
-initialization. This driver is part of Netronome´s BSP and it is
-equivalent to Intel's igb_uio driver.
+the **igb_uio** UIO driver, available with DPDK, to perform correct
+initialization.
Building the software
---------------------
Netronome's PMD code is provided in the **drivers/net/nfp** directory.
-Because Netronome´s BSP dependencies the driver is disabled by default
-in DPDK build using **common_linuxapp configuration** file. Enabling the
-driver or if you use another configuration file and want to have NFP
-support, this variable is needed:
+Although NFP PMD has Netronome´s BSP dependencies, it is possible to
+compile it along with other DPDK PMDs even if no BSP was installed before.
+Of course, a DPDK app will require such a BSP installed for using the
+NFP PMD.
+
+Default PMD configuration is at **common_linuxapp configuration** file:
- **CONFIG_RTE_LIBRTE_NFP_PMD=y**
the NFP PMD.
-System configuration
---------------------
-
-Using the NFP PMD is not different to using other PMDs. Usual steps are:
-
-#. **Configure hugepages:** All major Linux distributions have the hugepages
- functionality enabled by default. By default this allows the system uses for
- working with transparent hugepages. But in this case some hugepages need to
- be created/reserved for use with the DPDK through the hugetlbfs file system.
- First the virtual file system need to be mounted:
-
- .. code-block:: console
-
- mount -t hugetlbfs none /mnt/hugetlbfs
-
- The command uses the common mount point for this file system and it needs to
- be created if necessary.
-
- Configuring hugepages is performed via sysfs:
-
- .. code-block:: console
-
- /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
-
- This sysfs file is used to specify the number of hugepages to reserve.
- For example:
-
- .. code-block:: console
-
- echo 1024 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
-
- This will reserve 2GB of memory using 1024 2MB hugepages. The file may be
- read to see if the operation was performed correctly:
+Driver compilation and testing
+------------------------------
- .. code-block:: console
-
- cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
-
- The number of unused hugepages may also be inspected.
-
- Before executing the DPDK app it should match the value of nr_hugepages.
-
- .. code-block:: console
-
- cat /sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages
-
- The hugepages reservation should be performed at system initialisation and
- it is usual to use a kernel parameter for configuration. If the reservation
- is attempted on a busy system it will likely fail. Reserving memory for
- hugepages may be done adding the following to the grub kernel command line:
-
- .. code-block:: console
-
- default_hugepagesz=1M hugepagesz=2M hugepages=1024
-
- This will reserve 2GBytes of memory using 2Mbytes huge pages.
+Refer to the document :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>`
+for details.
- Finally, for a NUMA system the allocation needs to be made on the correct
- NUMA node. In a DPDK app there is a master core which will (usually) perform
- memory allocation. It is important that some of the hugepages are reserved
- on the NUMA memory node where the network device is attached. This is because
- of a restriction in DPDK by which TX and RX descriptors rings must be created
- on the master code.
- Per-node allocation of hugepages may be inspected and controlled using sysfs.
- For example:
-
- .. code-block:: console
-
- cat /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages
-
- For a NUMA system there will be a specific hugepage directory per node
- allowing control of hugepage reservation. A common problem may occur when
- hugepages reservation is performed after the system has been working for
- some time. Configuration using the global sysfs hugepage interface will
- succeed but the per-node allocations may be unsatisfactory.
-
- The number of hugepages that need to be reserved depends on how the app uses
- TX and RX descriptors, and packets mbufs.
+System configuration
+--------------------
#. **Enable SR-IOV on the NFP-6xxx device:** The current NFP PMD works with
Virtual Functions (VFs) on a NFP device. Make sure that one of the Physical
-k option shows the device driver, if any, that devices are bound to.
Depending on the modules loaded at this point the new PCI devices may be
bound to nfp_netvf driver.
-
-#. **To install the uio kernel module (manually):** All major Linux
- distributions have support for this kernel module so it is straightforward
- to install it:
-
- .. code-block:: console
-
- modprobe uio
-
- The module should now be listed by the lsmod command.
-
-#. **To install the nfp_uio kernel module (manually):** This module supports
- NFP-6xxx devices through the UIO interface.
-
- This module is part of Netronome´s BSP and it should be available when the
- BSP is installed.
-
- .. code-block:: console
-
- modprobe nfp_uio.ko
-
- The module should now be listed by the lsmod command.
-
- Depending on which NFP modules are loaded, nfp_uio may be automatically
- bound to the NFP PCI devices by the system. Otherwise the binding needs
- to be done explicitly. This is the case when nfp_netvf, the Linux kernel
- driver for NFP VFs, was loaded when VFs were created. As described later
- in this document this configuration may also be performed using scripts
- provided by the Netronome´s BSP.
-
- First the device needs to be unbound, for example from the nfp_netvf
- driver:
-
- .. code-block:: console
-
- echo 0000:03:08.0 > /sys/bus/pci/devices/0000:03:08.0/driver/unbind
-
- lspci -d19ee: -k
-
- The output of lspci should now show that 0000:03:08.0 is not bound to
- any driver.
-
- The next step is to add the NFP PCI ID to the NFP UIO driver:
-
- .. code-block:: console
-
- echo 19ee 6003 > /sys/bus/pci/drivers/nfp_uio/new_id
-
- And then to bind the device to the nfp_uio driver:
-
- .. code-block:: console
-
- echo 0000:03:08.0 > /sys/bus/pci/drivers/nfp_uio/bind
-
- lspci -d19ee: -k
-
- lspci should show that device bound to nfp_uio driver.
-
-#. **Using tools from Netronome´s BSP to install and bind modules:** DPDK provides
- scripts which are useful for installing the UIO modules and for binding the
- right device to those modules avoiding doing so manually. However, these scripts
- have not support for Netronome´s UIO driver. Along with drivers, the BSP installs
- those DPDK scripts slightly modified with support for Netronome´s UIO driver.
-
- Those specific scripts can be found in Netronome´s BSP installation directory.
- Refer to BSP documentation for more information.
-
- * **setup.sh**
- * **dpdk_nic_bind.py**
-
- Configuration may be performed by running setup.sh which invokes
- dpdk_nic_bind.py as needed. Executing setup.sh will display a menu of
- configuration options.
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