diff options
Diffstat (limited to 'doc/guides/sample_app_ug/l3_forward_virtual.rst')
-rw-r--r-- | doc/guides/sample_app_ug/l3_forward_virtual.rst | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/doc/guides/sample_app_ug/l3_forward_virtual.rst b/doc/guides/sample_app_ug/l3_forward_virtual.rst new file mode 100644 index 00000000..fa04722e --- /dev/null +++ b/doc/guides/sample_app_ug/l3_forward_virtual.rst @@ -0,0 +1,157 @@ +.. BSD LICENSE + Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + * Neither the name of Intel Corporation nor the names of its + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +L3 Forwarding in a Virtualization Environment Sample Application +================================================================ + +The L3 Forwarding in a Virtualization Environment sample application is a simple example of packet processing using the DPDK. +The application performs L3 forwarding that takes advantage of Single Root I/O Virtualization (SR-IOV) features +in a virtualized environment. + +Overview +-------- + +The application demonstrates the use of the hash and LPM libraries in the DPDK to implement packet forwarding. +The initialization and run-time paths are very similar to those of the :doc:`l3_forward`. +The forwarding decision is taken based on information read from the input packet. + +The lookup method is either hash-based or LPM-based and is selected at compile time. +When the selected lookup method is hash-based, a hash object is used to emulate the flow classification stage. +The hash object is used in correlation with the flow table to map each input packet to its flow at runtime. + +The hash lookup key is represented by the DiffServ 5-tuple composed of the following fields read from the input packet: +Source IP Address, Destination IP Address, Protocol, Source Port and Destination Port. +The ID of the output interface for the input packet is read from the identified flow table entry. +The set of flows used by the application is statically configured and loaded into the hash at initialization time. +When the selected lookup method is LPM based, an LPM object is used to emulate the forwarding stage for IPv4 packets. +The LPM object is used as the routing table to identify the next hop for each input packet at runtime. + +The LPM lookup key is represented by the Destination IP Address field read from the input packet. +The ID of the output interface for the input packet is the next hop returned by the LPM lookup. +The set of LPM rules used by the application is statically configured and loaded into the LPM object at the initialization time. + +.. note:: + + Please refer to :ref:`l2_fwd_vf_setup` for virtualized test case setup. + +Compiling the Application +------------------------- + +To compile the application: + +#. Go to the sample application directory: + + .. code-block:: console + + export RTE_SDK=/path/to/rte_sdk + cd ${RTE_SDK}/examples/l3fwd-vf + +#. Set the target (a default target is used if not specified). For example: + + .. code-block:: console + + export RTE_TARGET=x86_64-native-linuxapp-gcc + + See the *DPDK Getting Started Guide* for possible RTE_TARGET values. + +#. Build the application: + + .. code-block:: console + + make + +.. note:: + + The compiled application is written to the build subdirectory. + To have the application written to a different location, + the O=/path/to/build/directory option may be specified in the make command. + +Running the Application +----------------------- + +The application has a number of command line options: + +.. code-block:: console + + ./build/l3fwd-vf [EAL options] -- -p PORTMASK --config(port,queue,lcore)[,(port,queue,lcore)] [--no-numa] + +where, + +* --p PORTMASK: Hexadecimal bitmask of ports to configure + +* --config (port,queue,lcore)[,(port,queue,lcore]: determines which queues from which ports are mapped to which cores + +* --no-numa: optional, disables numa awareness + +For example, consider a dual processor socket platform where cores 0,2,4,6, 8, and 10 appear on socket 0, +while cores 1,3,5,7,9, and 11 appear on socket 1. +Let's say that the programmer wants to use memory from both NUMA nodes, +the platform has only two ports and the programmer wants to use one core from each processor socket to do the packet processing +since only one Rx/Tx queue pair can be used in virtualization mode. + +To enable L3 forwarding between two ports, using one core from each processor, +while also taking advantage of local memory accesses by optimizing around NUMA, +the programmer can pin to the appropriate cores and allocate memory from the appropriate NUMA node. +This is achieved using the following command: + +.. code-block:: console + + ./build/l3fwd-vf -c 0x03 -n 3 -- -p 0x3 --config="(0,0,0),(1,0,1)" + +In this command: + +* The -c option enables cores 0 and 1 + +* The -p option enables ports 0 and 1 + +* The --config option enables one queue on each port and maps each (port,queue) pair to a specific core. + Logic to enable multiple RX queues using RSS and to allocate memory from the correct NUMA nodes + is included in the application and is done transparently. + The following table shows the mapping in this example: + + +----------+-----------+-----------+------------------------------------+ + | **Port** | **Queue** | **lcore** | **Description** | + | | | | | + +==========+===========+===========+====================================+ + | 0 | 0 | 0 | Map queue 0 from port 0 to lcore 0 | + | | | | | + +----------+-----------+-----------+------------------------------------+ + | 1 | 1 | 1 | Map queue 0 from port 1 to lcore 1 | + | | | | | + +----------+-----------+-----------+------------------------------------+ + +Refer to the *DPDK Getting Started Guide* for general information on running applications +and the Environment Abstraction Layer (EAL) options. + +Explanation +----------- + +The operation of this application is similar to that of the basic L3 Forwarding Sample Application. +See :ref:`l3_fwd_explanation` for more information. |