1.. BSD LICENSE 2 Copyright(c) 2010-2015 Intel Corporation. 3 Copyright(c) 2017 Mellanox Corporation. 4 All rights reserved. 5 6 Redistribution and use in source and binary forms, with or without 7 modification, are permitted provided that the following conditions 8 are met: 9 10 * Redistributions of source code must retain the above copyright 11 notice, this list of conditions and the following disclaimer. 12 * Redistributions in binary form must reproduce the above copyright 13 notice, this list of conditions and the following disclaimer in 14 the documentation and/or other materials provided with the 15 distribution. 16 * Neither the name of Intel Corporation nor the names of its 17 contributors may be used to endorse or promote products derived 18 from this software without specific prior written permission. 19 20 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 32.. _linux_gsg_linux_drivers: 33 34Linux Drivers 35============= 36 37Different PMDs may require different kernel drivers in order to work properly. 38Depends on the PMD being used, a corresponding kernel driver should be load 39and bind to the network ports. 40 41UIO 42--- 43 44A small kernel module to set up the device, map device memory to user-space and register interrupts. 45In many cases, the standard ``uio_pci_generic`` module included in the Linux kernel 46can provide the uio capability. This module can be loaded using the command: 47 48.. code-block:: console 49 50 sudo modprobe uio_pci_generic 51 52.. note:: 53 54 ``uio_pci_generic`` module doesn't support the creation of virtual functions. 55 56As an alternative to the ``uio_pci_generic``, the DPDK also includes the igb_uio 57module which can be found in the kmod subdirectory referred to above. It can 58be loaded as shown below: 59 60.. code-block:: console 61 62 sudo modprobe uio 63 sudo insmod kmod/igb_uio.ko 64 65.. note:: 66 67 For some devices which lack support for legacy interrupts, e.g. virtual function 68 (VF) devices, the ``igb_uio`` module may be needed in place of ``uio_pci_generic``. 69 70.. note:: 71 72 If UEFI secure boot is enabled, the Linux kernel may disallow the use of 73 UIO on the system. Therefore, devices for use by DPDK should be bound to the 74 ``vfio-pci`` kernel module rather than ``igb_uio`` or ``uio_pci_generic``. 75 For more details see :ref:`linux_gsg_binding_kernel` below. 76 77Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional 78for platforms that support using VFIO. 79 80VFIO 81---- 82 83A more robust and secure driver in compare to the ``UIO``, relying on IOMMU protection. 84To make use of VFIO, the ``vfio-pci`` module must be loaded: 85 86.. code-block:: console 87 88 sudo modprobe vfio-pci 89 90Note that in order to use VFIO, your kernel must support it. 91VFIO kernel modules have been included in the Linux kernel since version 3.6.0 and are usually present by default, 92however please consult your distributions documentation to make sure that is the case. 93 94Also, to use VFIO, both kernel and BIOS must support and be configured to use IO virtualization (such as Intel® VT-d). 95 96.. note:: 97 98 ``vfio-pci`` module doesn't support the creation of virtual functions. 99 100For proper operation of VFIO when running DPDK applications as a non-privileged user, correct permissions should also be set up. 101This can be done by using the DPDK setup script (called dpdk-setup.sh and located in the usertools directory). 102 103.. note:: 104 105 VFIO can be used without IOMMU. While this is just as unsafe as using UIO, it does make it possible for the user to keep the degree of device access and programming that VFIO has, in situations where IOMMU is not available. 106 107Bifurcated Driver 108----------------- 109 110PMDs which use the bifurcated driver co-exists with the device kernel driver. 111On such model the NIC is controlled by the kernel, while the data 112path is performed by the PMD directly on top of the device. 113 114Such model has the following benefits: 115 116 - It is secure and robust, as the memory management and isolation 117 is done by the kernel. 118 - It enables the user to use legacy linux tools such as ``ethtool`` or 119 ``ifconfig`` while running DPDK application on the same network ports. 120 - It enables the DPDK application to filter only part of the traffic, 121 While the rest will be directed and handled by the kernel driver. 122 123More about the bifurcated driver can be found in 124`Mellanox Bifurcated DPDK PMD 125<https://dpdksummit.com/Archive/pdf/2016Userspace/Day02-Session04-RonyEfraim-Userspace2016.pdf>`__. 126 127.. _linux_gsg_binding_kernel: 128 129Binding and Unbinding Network Ports to/from the Kernel Modules 130-------------------------------------------------------------- 131 132.. note:: 133 134 PMDs Which use the bifurcated driver should not be unbind from their kernel drivers. this section is for PMDs which use the UIO or VFIO drivers. 135 136As of release 1.4, DPDK applications no longer automatically unbind all supported network ports from the kernel driver in use. 137Instead, in case the PMD being used use the UIO or VFIO drivers, all ports that are to be used by an DPDK application must be bound to the 138``uio_pci_generic``, ``igb_uio`` or ``vfio-pci`` module before the application is run. 139For such PMDs, any network ports under Linux* control will be ignored and cannot be used by the application. 140 141To bind ports to the ``uio_pci_generic``, ``igb_uio`` or ``vfio-pci`` module for DPDK use, 142and then subsequently return ports to Linux* control, 143a utility script called dpdk-devbind.py is provided in the usertools subdirectory. 144This utility can be used to provide a view of the current state of the network ports on the system, 145and to bind and unbind those ports from the different kernel modules, including the uio and vfio modules. 146The following are some examples of how the script can be used. 147A full description of the script and its parameters can be obtained by calling the script with the ``--help`` or ``--usage`` options. 148Note that the uio or vfio kernel modules to be used, should be loaded into the kernel before 149running the ``dpdk-devbind.py`` script. 150 151.. warning:: 152 153 Due to the way VFIO works, there are certain limitations to which devices can be used with VFIO. 154 Mainly it comes down to how IOMMU groups work. 155 Any Virtual Function device can be used with VFIO on its own, but physical devices will require either all ports bound to VFIO, 156 or some of them bound to VFIO while others not being bound to anything at all. 157 158 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. 159 Therefore, the bridge driver should also be unbound from the bridge PCI device for VFIO to work with devices behind the bridge. 160 161.. warning:: 162 163 While any user can run the dpdk-devbind.py script to view the status of the network ports, 164 binding or unbinding network ports requires root privileges. 165 166To see the status of all network ports on the system: 167 168.. code-block:: console 169 170 ./usertools/dpdk-devbind.py --status 171 172 Network devices using DPDK-compatible driver 173 ============================================ 174 0000:82:00.0 '82599EB 10-GbE NIC' drv=uio_pci_generic unused=ixgbe 175 0000:82:00.1 '82599EB 10-GbE NIC' drv=uio_pci_generic unused=ixgbe 176 177 Network devices using kernel driver 178 =================================== 179 0000:04:00.0 'I350 1-GbE NIC' if=em0 drv=igb unused=uio_pci_generic *Active* 180 0000:04:00.1 'I350 1-GbE NIC' if=eth1 drv=igb unused=uio_pci_generic 181 0000:04:00.2 'I350 1-GbE NIC' if=eth2 drv=igb unused=uio_pci_generic 182 0000:04:00.3 'I350 1-GbE NIC' if=eth3 drv=igb unused=uio_pci_generic 183 184 Other network devices 185 ===================== 186 <none> 187 188To bind device ``eth1``,``04:00.1``, to the ``uio_pci_generic`` driver: 189 190.. code-block:: console 191 192 ./usertools/dpdk-devbind.py --bind=uio_pci_generic 04:00.1 193 194or, alternatively, 195 196.. code-block:: console 197 198 ./usertools/dpdk-devbind.py --bind=uio_pci_generic eth1 199 200To restore device ``82:00.0`` to its original kernel binding: 201 202.. code-block:: console 203 204 ./usertools/dpdk-devbind.py --bind=ixgbe 82:00.0 205