devbind.rst revision 6b3e017e
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29
30
31dpdk-devbind Application
32========================
33
34The ``dpdk-devbind`` tool is a Data Plane Development Kit (DPDK) utility
35that helps binding and unbinding devices from specific drivers.
36As well as checking their status in that regard.
37
38
39Running the Application
40-----------------------
41
42The tool has a number of command line options:
43
44.. code-block:: console
45
46   dpdk-devbind [options] DEVICE1 DEVICE2 ....
47
48OPTIONS
49-------
50
51* ``--help, --usage``
52
53        Display usage information and quit
54
55* ``-s, --status``
56
57        Print the current status of all known network interfaces.
58        For each device, it displays the PCI domain, bus, slot and function,
59        along with a text description of the device. Depending upon whether the
60        device is being used by a kernel driver, the ``igb_uio`` driver, or no
61        driver, other relevant information will be displayed:
62        - the Linux interface name e.g. ``if=eth0``
63        - the driver being used e.g. ``drv=igb_uio``
64        - any suitable drivers not currently using that device e.g. ``unused=igb_uio``
65        NOTE: if this flag is passed along with a bind/unbind option, the
66        status display will always occur after the other operations have taken
67        place.
68
69* ``-b driver, --bind=driver``
70
71        Select the driver to use or "none" to unbind the device
72
73* ``-u, --unbind``
74
75        Unbind a device (Equivalent to ``-b none``)
76
77* ``--force``
78
79        By default, devices which are used by Linux - as indicated by having
80        routes in the routing table - cannot be modified. Using the ``--force``
81        flag overrides this behavior, allowing active links to be forcibly
82        unbound.
83        WARNING: This can lead to loss of network connection and should be used
84        with caution.
85
86
87.. warning::
88
89    Due to the way VFIO works, there are certain limitations to which devices can be used with VFIO.
90    Mainly it comes down to how IOMMU groups work.
91    Any Virtual Function device can be used with VFIO on its own, but physical devices will require either all ports bound to VFIO,
92    or some of them bound to VFIO while others not being bound to anything at all.
93
94    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.
95    Therefore, the bridge driver should also be unbound from the bridge PCI device for VFIO to work with devices behind the bridge.
96
97.. warning::
98
99    While any user can run the ``dpdk-devbind.py`` script to view the status of the network ports,
100    binding or unbinding network ports requires root privileges.
101
102
103Examples
104--------
105
106To display current device status::
107
108   dpdk-devbind --status
109
110To bind eth1 from the current driver and move to use igb_uio::
111
112   dpdk-devbind --bind=igb_uio eth1
113
114To unbind 0000:01:00.0 from using any driver::
115
116   dpdk-devbind -u 0000:01:00.0
117
118To bind 0000:02:00.0 and 0000:02:00.1 to the ixgbe kernel driver::
119
120   dpdk-devbind -b ixgbe 02:00.0 02:00.1
121
122To check status of all network ports, assign one to the igb_uio driver and check status again::
123
124   # Check the status of the available devices.
125   dpdk-devbind --status
126   Network devices using DPDK-compatible driver
127   ============================================
128   <none>
129
130   Network devices using kernel driver
131   ===================================
132   0000:0a:00.0 '82599ES 10-Gigabit' if=eth2 drv=ixgbe unused=
133
134
135   # Bind the device to igb_uio.
136   sudo dpdk-devbind -b igb_uio 0000:0a:00.0
137
138
139   # Recheck the status of the devices.
140   dpdk-devbind --status
141   Network devices using DPDK-compatible driver
142   ============================================
143   0000:0a:00.0 '82599ES 10-Gigabit' drv=igb_uio unused=
144