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Diffstat (limited to 'Documentation/topics/dpdk/phy.rst')
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diff --git a/Documentation/topics/dpdk/phy.rst b/Documentation/topics/dpdk/phy.rst index ad191dad0..929f394ea 100644 --- a/Documentation/topics/dpdk/phy.rst +++ b/Documentation/topics/dpdk/phy.rst @@ -125,3 +125,89 @@ utilize is a requirement in order to deliver the high-performance possible with DPDK acceleration. It is possible to configure multiple Rx queues for ``dpdk`` ports, thus ensuring this is not a bottleneck for performance. For information on configuring PMD threads, refer to :doc:`pmd`. + +Flow Control +------------ + +Flow control can be enabled only on DPDK physical ports. To enable flow control +support at Tx side while adding a port, run:: + + $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \ + options:dpdk-devargs=0000:01:00.0 options:tx-flow-ctrl=true + +Similarly, to enable Rx flow control, run:: + + $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \ + options:dpdk-devargs=0000:01:00.0 options:rx-flow-ctrl=true + +To enable flow control auto-negotiation, run:: + + $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \ + options:dpdk-devargs=0000:01:00.0 options:flow-ctrl-autoneg=true + +To turn on the Tx flow control at run time for an existing port, run:: + + $ ovs-vsctl set Interface dpdk-p0 options:tx-flow-ctrl=true + +The flow control parameters can be turned off by setting ``false`` to the +respective parameter. To disable the flow control at Tx side, run:: + + $ ovs-vsctl set Interface dpdk-p0 options:tx-flow-ctrl=false + +Rx Checksum Offload +------------------- + +By default, DPDK physical ports are enabled with Rx checksum offload. + +Rx checksum offload can offer performance improvement only for tunneling +traffic in OVS-DPDK because the checksum validation of tunnel packets is +offloaded to the NIC. Also enabling Rx checksum may slightly reduce the +performance of non-tunnel traffic, specifically for smaller size packet. + +.. _port-hotplug: + +Hotplugging +----------- + +OVS supports port hotplugging, allowing the use of physical ports that were not +bound to DPDK when ovs-vswitchd was started. + +.. warning:: + + This feature is not compatible with all NICs. Refer to vendor documentation + for more information. + +.. important:: + + Ports must be bound to DPDK. Refer to :ref:`dpdk-binding-nics` for more + information. + +To *hotplug* a port, simply add it like any other port:: + + $ ovs-vsctl add-port br0 dpdkx -- set Interface dpdkx type=dpdk \ + options:dpdk-devargs=0000:01:00.0 + +Ports can be detached using the ``del-port`` command:: + + $ ovs-vsctl del-port dpdkx + +This should both delete the port and detach the device. If successful, you +should see an ``INFO`` log. For example:: + + INFO|Device '0000:04:00.1' has been detached + +If the log is not seen then the port can be detached like so:: + + $ ovs-appctl netdev-dpdk/detach 0000:01:00.0 + +.. warning:: + + Detaching should not be done if a device is known to be non-detachable, as + this may cause the device to behave improperly when added back with + add-port. The Chelsio Terminator adapters which use the cxgbe driver seem + to be an example of this behavior; check the driver documentation if this + is suspected. + +For more information please refer to the `DPDK Port Hotplug Framework`__. + +__ http://dpdk.org/doc/guides/prog_guide/port_hotplug_framework.html#hotplug |