-.. BSD LICENSE
- Copyright(c) 2016 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.
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright(c) 2016 Intel Corporation.
I40E Poll Mode Driver
======================
-The I40E PMD (librte_pmd_i40e) provides poll mode driver support
-for the Intel X710/XL710/X722 10/40 Gbps family of adapters.
+The i40e PMD (librte_pmd_i40e) provides poll mode driver support for
+10/25/40 Gbps Intel® Ethernet 700 Series Network Adapters based on
+the Intel Ethernet Controller X710/XL710/XXV710 and Intel Ethernet
+Connection X722 (only support part of features).
Features
--------
-Features of the I40E PMD are:
+Features of the i40e PMD are:
- Multiple queues for TX and RX
- Receiver Side Scaling (RSS)
- SR-IOV VF
- Hot plug
- IEEE1588/802.1AS timestamping
-
+- VF Daemon (VFD) - EXPERIMENTAL
+- Dynamic Device Personalization (DDP)
+- Queue region configuration
+- Virtual Function Port Representors
+- Malicious Device Drive event catch and notify
+- Generic flow API
Prerequisites
-------------
- To get better performance on Intel platforms, please follow the "How to get best performance with NICs on Intel platforms"
section of the :ref:`Getting Started Guide for Linux <linux_gsg>`.
+- Upgrade the NVM/FW version following the `Intel® Ethernet NVM Update Tool Quick Usage Guide for Linux
+ <https://www-ssl.intel.com/content/www/us/en/embedded/products/networking/nvm-update-tool-quick-linux-usage-guide.html>`_ and `Intel® Ethernet NVM Update Tool: Quick Usage Guide for EFI <https://www.intel.com/content/www/us/en/embedded/products/networking/nvm-update-tool-quick-efi-usage-guide.html>`_ if needed.
+
+- For information about supported media, please refer to this document: `Intel® Ethernet Controller X710/XXV710/XL710 Feature Support Matrix
+ <http://www.intel.com/content/dam/www/public/us/en/documents/release-notes/xl710-ethernet-controller-feature-matrix.pdf>`_.
+
+ .. Note::
+
+ * Some adapters based on the Intel(R) Ethernet Controller 700 Series only
+ support Intel Ethernet Optics modules. On these adapters, other modules are not
+ supported and will not function.
+
+ * For connections based on Intel(R) Ethernet Controller 700 Series,
+ support is dependent on your system board. Please see your vendor for details.
+
+ * In all cases Intel recommends using Intel Ethernet Optics; other modules
+ may function but are not validated by Intel. Contact Intel for supported media types.
+
+Recommended Matching List
+-------------------------
+
+It is highly recommended to upgrade the i40e kernel driver and firmware to
+avoid the compatibility issues with i40e PMD. Here is the suggested matching
+list which has been tested and verified. The detailed information can refer
+to chapter Tested Platforms/Tested NICs in release notes.
+
+For X710/XL710/XXV710,
+
+ +--------------+-----------------------+------------------+
+ | DPDK version | Kernel driver version | Firmware version |
+ +==============+=======================+==================+
+ | 20.05 | 2.11.27 | 7.30 |
+ +--------------+-----------------------+------------------+
+ | 20.02 | 2.10.19 | 7.20 |
+ +--------------+-----------------------+------------------+
+ | 19.11 | 2.9.21 | 7.00 |
+ +--------------+-----------------------+------------------+
+ | 19.08 | 2.8.43 | 7.00 |
+ +--------------+-----------------------+------------------+
+ | 19.05 | 2.7.29 | 6.80 |
+ +--------------+-----------------------+------------------+
+ | 19.02 | 2.7.26 | 6.80 |
+ +--------------+-----------------------+------------------+
+ | 18.11 | 2.4.6 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 18.08 | 2.4.6 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 18.05 | 2.4.6 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 18.02 | 2.4.3 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 17.11 | 2.1.26 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 17.08 | 2.0.19 | 6.01 |
+ +--------------+-----------------------+------------------+
+ | 17.05 | 1.5.23 | 5.05 |
+ +--------------+-----------------------+------------------+
+ | 17.02 | 1.5.23 | 5.05 |
+ +--------------+-----------------------+------------------+
+ | 16.11 | 1.5.23 | 5.05 |
+ +--------------+-----------------------+------------------+
+ | 16.07 | 1.4.25 | 5.04 |
+ +--------------+-----------------------+------------------+
+ | 16.04 | 1.4.25 | 5.02 |
+ +--------------+-----------------------+------------------+
+
+
+For X722,
+
+ +--------------+-----------------------+------------------+
+ | DPDK version | Kernel driver version | Firmware version |
+ +==============+=======================+==================+
+ | 20.05 | 2.11.27 | 4.11 |
+ +--------------+-----------------------+------------------+
+ | 20.02 | 2.10.19 | 4.11 |
+ +--------------+-----------------------+------------------+
+ | 19.11 | 2.9.21 | 4.10 |
+ +--------------+-----------------------+------------------+
+ | 19.08 | 2.9.21 | 4.10 |
+ +--------------+-----------------------+------------------+
+ | 19.05 | 2.7.29 | 3.33 |
+ +--------------+-----------------------+------------------+
+ | 19.02 | 2.7.26 | 3.33 |
+ +--------------+-----------------------+------------------+
+ | 18.11 | 2.4.6 | 3.33 |
+ +--------------+-----------------------+------------------+
+
Pre-Installation Configuration
------------------------------
Toggle the use of Vector PMD instead of normal RX/TX path.
To enable vPMD for RX, bulk allocation for Rx must be allowed.
-- ``CONFIG_RTE_LIBRTE_I40E_RX_OLFLAGS_ENABLE`` (default ``y``)
-
- Toggle to enable RX ``olflags``.
- This is only meaningful when Vector PMD is used.
-
- ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC`` (default ``n``)
Toggle to use a 16-byte RX descriptor, by default the RX descriptor is 32 byte.
Number of queues reserved for PF.
-- ``CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF`` (default ``4``)
-
- Number of queues reserved for each SR-IOV VF.
-
- ``CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM`` (default ``4``)
Number of queues reserved for each VMDQ Pool.
-- ``CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL`` (default ``-1``)
-
- Interrupt Throttling interval.
-
-
-Driver Compilation
-~~~~~~~~~~~~~~~~~~
-
-To compile the I40E PMD see :ref:`Getting Started Guide for Linux <linux_gsg>` or
-:ref:`Getting Started Guide for FreeBSD <freebsd_gsg>` depending on your platform.
-
-
-Linux
------
+Runtime Config Options
+~~~~~~~~~~~~~~~~~~~~~~
+- ``Reserved number of Queues per VF`` (default ``4``)
-Running testpmd
-~~~~~~~~~~~~~~~
+ The number of reserved queue per VF is determined by its host PF. If the
+ PCI address of an i40e PF is aaaa:bb.cc, the number of reserved queues per
+ VF can be configured with EAL parameter like -w aaaa:bb.cc,queue-num-per-vf=n.
+ The value n can be 1, 2, 4, 8 or 16. If no such parameter is configured, the
+ number of reserved queues per VF is 4 by default. If VF request more than
+ reserved queues per VF, PF will able to allocate max to 16 queues after a VF
+ reset.
-This section demonstrates how to launch ``testpmd`` with Intel XL710/X710
-devices managed by ``librte_pmd_i40e`` in the Linux operating system.
-#. Load ``igb_uio`` or ``vfio-pci`` driver:
+- ``Support multiple driver`` (default ``disable``)
- .. code-block:: console
-
- modprobe uio
- insmod ./x86_64-native-linuxapp-gcc/kmod/igb_uio.ko
-
- or
+ There was a multiple driver support issue during use of 700 series Ethernet
+ Adapter with both Linux kernel and DPDK PMD. To fix this issue, ``devargs``
+ parameter ``support-multi-driver`` is introduced, for example::
- .. code-block:: console
+ -w 84:00.0,support-multi-driver=1
- modprobe vfio-pci
+ With the above configuration, DPDK PMD will not change global registers, and
+ will switch PF interrupt from IntN to Int0 to avoid interrupt conflict between
+ DPDK and Linux Kernel.
-#. Bind the XL710/X710 adapters to ``igb_uio`` or ``vfio-pci`` loaded in the previous step:
+- ``Support VF Port Representor`` (default ``not enabled``)
- .. code-block:: console
+ The i40e PF PMD supports the creation of VF port representors for the control
+ and monitoring of i40e virtual function devices. Each port representor
+ corresponds to a single virtual function of that device. Using the ``devargs``
+ option ``representor`` the user can specify which virtual functions to create
+ port representors for on initialization of the PF PMD by passing the VF IDs of
+ the VFs which are required.::
- ./tools/dpdk_nic_bind.py --bind igb_uio 0000:83:00.0
+ -w DBDF,representor=[0,1,4]
- Or setup VFIO permissions for regular users and then bind to ``vfio-pci``:
+ Currently hot-plugging of representor ports is not supported so all required
+ representors must be specified on the creation of the PF.
- .. code-block:: console
+- ``Use latest supported vector`` (default ``disable``)
- ./tools/dpdk_nic_bind.py --bind vfio-pci 0000:83:00.0
+ Latest supported vector path may not always get the best perf so vector path was
+ recommended to use only on later platform. But users may want the latest vector path
+ since it can get better perf in some real work loading cases. So ``devargs`` param
+ ``use-latest-supported-vec`` is introduced, for example::
-#. Start ``testpmd`` with basic parameters:
+ -w 84:00.0,use-latest-supported-vec=1
- .. code-block:: console
+- ``Enable validation for VF message`` (default ``not enabled``)
- ./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4 -w 83:00.0 -- -i
+ The PF counts messages from each VF. If in any period of seconds the message
+ statistic from a VF exceeds maximal limitation, the PF will ignore any new message
+ from that VF for some seconds.
+ Format -- "maximal-message@period-seconds:ignore-seconds"
+ For example::
- Example output:
+ -w 84:00.0,vf_msg_cfg=80@120:180
- .. code-block:: console
+Vector RX Pre-conditions
+~~~~~~~~~~~~~~~~~~~~~~~~
+For Vector RX it is assumed that the number of descriptor rings will be a power
+of 2. With this pre-condition, the ring pointer can easily scroll back to the
+head after hitting the tail without a conditional check. In addition Vector RX
+can use this assumption to do a bit mask using ``ring_size - 1``.
- ...
- EAL: PCI device 0000:83:00.0 on NUMA socket 1
- EAL: probe driver: 8086:1572 rte_i40e_pmd
- EAL: PCI memory mapped at 0x7f7f80000000
- EAL: PCI memory mapped at 0x7f7f80800000
- PMD: eth_i40e_dev_init(): FW 5.0 API 1.5 NVM 05.00.02 eetrack 8000208a
- Interactive-mode selected
- Configuring Port 0 (socket 0)
- ...
-
- PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are
- satisfied.Rx Burst Bulk Alloc function will be used on port=0, queue=0.
-
- ...
- Port 0: 68:05:CA:26:85:84
- Checking link statuses...
- Port 0 Link Up - speed 10000 Mbps - full-duplex
- Done
+Driver compilation and testing
+------------------------------
- testpmd>
+Refer to the document :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>`
+for details.
SR-IOV: Prerequisites and sample Application Notes
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+--------------------------------------------------
#. Load the kernel module:
ip link set ens802f0 vf 0 mac a0:b0:c0:d0:e0:f0
#. Assign VF to VM, and bring up the VM.
- Please see the documenation for the*I40E/IXGBE/IGB Virtual Function Driver*.
+ Please see the documentation for the *I40E/IXGBE/IGB Virtual Function Driver*.
+
+#. Running testpmd:
+
+ Follow instructions available in the document
+ :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>`
+ to run testpmd.
+
+ Example output:
+
+ .. code-block:: console
+
+ ...
+ EAL: PCI device 0000:83:00.0 on NUMA socket 1
+ EAL: probe driver: 8086:1572 rte_i40e_pmd
+ EAL: PCI memory mapped at 0x7f7f80000000
+ EAL: PCI memory mapped at 0x7f7f80800000
+ PMD: eth_i40e_dev_init(): FW 5.0 API 1.5 NVM 05.00.02 eetrack 8000208a
+ Interactive-mode selected
+ Configuring Port 0 (socket 0)
+ ...
+
+ PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are
+ satisfied.Rx Burst Bulk Alloc function will be used on port=0, queue=0.
+
+ ...
+ Port 0: 68:05:CA:26:85:84
+ Checking link statuses...
+ Port 0 Link Up - speed 10000 Mbps - full-duplex
+ Done
+
+ testpmd>
Sample Application Notes
.. code-block:: console
- ./app/testpmd -c ffff -n 4 -- -i --forward-mode=mac
+ ./app/testpmd -l 0-15 -n 4 -- -i --forward-mode=mac
...
testpmd> set promisc 0 off
.. code-block:: console
- ./app/testpmd -c ffff -n 4 -- -i --disable-rss --pkt-filter-mode=perfect \
+ ./app/testpmd -l 0-15 -n 4 -- -i --disable-rss --pkt-filter-mode=perfect \
--rxq=8 --txq=8 --nb-cores=8 --nb-ports=1
Add a rule to direct ``ipv4-udp`` packet whose ``dst_ip=2.2.2.5, src_ip=2.2.2.3, src_port=32, dst_port=32`` to queue 1:
testpmd> flush_flow_director 0
+Floating VEB
+~~~~~~~~~~~~~
+
+The Intel® Ethernet 700 Series support a feature called
+"Floating VEB".
+
+A Virtual Ethernet Bridge (VEB) is an IEEE Edge Virtual Bridging (EVB) term
+for functionality that allows local switching between virtual endpoints within
+a physical endpoint and also with an external bridge/network.
+
+A "Floating" VEB doesn't have an uplink connection to the outside world so all
+switching is done internally and remains within the host. As such, this
+feature provides security benefits.
+
+In addition, a Floating VEB overcomes a limitation of normal VEBs where they
+cannot forward packets when the physical link is down. Floating VEBs don't need
+to connect to the NIC port so they can still forward traffic from VF to VF
+even when the physical link is down.
+
+Therefore, with this feature enabled VFs can be limited to communicating with
+each other but not an outside network, and they can do so even when there is
+no physical uplink on the associated NIC port.
+
+To enable this feature, the user should pass a ``devargs`` parameter to the
+EAL, for example::
+
+ -w 84:00.0,enable_floating_veb=1
+
+In this configuration the PMD will use the floating VEB feature for all the
+VFs created by this PF device.
+
+Alternatively, the user can specify which VFs need to connect to this floating
+VEB using the ``floating_veb_list`` argument::
+
+ -w 84:00.0,enable_floating_veb=1,floating_veb_list=1;3-4
+
+In this example ``VF1``, ``VF3`` and ``VF4`` connect to the floating VEB,
+while other VFs connect to the normal VEB.
+
+The current implementation only supports one floating VEB and one regular
+VEB. VFs can connect to a floating VEB or a regular VEB according to the
+configuration passed on the EAL command line.
+
+The floating VEB functionality requires a NIC firmware version of 5.0
+or greater.
+
+Dynamic Device Personalization (DDP)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The Intel® Ethernet 700 Series except for the Intel Ethernet Connection
+X722 support a feature called "Dynamic Device Personalization (DDP)",
+which is used to configure hardware by downloading a profile to support
+protocols/filters which are not supported by default. The DDP
+functionality requires a NIC firmware version of 6.0 or greater.
+
+Current implementation supports GTP-C/GTP-U/PPPoE/PPPoL2TP/ESP,
+steering can be used with rte_flow API.
+
+GTPv1 package is released, and it can be downloaded from
+https://downloadcenter.intel.com/download/27587.
+
+PPPoE package is released, and it can be downloaded from
+https://downloadcenter.intel.com/download/28040.
+
+ESP-AH package is released, and it can be downloaded from
+https://downloadcenter.intel.com/download/29446.
+
+Load a profile which supports GTP and store backup profile:
+
+.. code-block:: console
+
+ testpmd> ddp add 0 ./gtp.pkgo,./backup.pkgo
+
+Delete a GTP profile and restore backup profile:
+
+.. code-block:: console
+
+ testpmd> ddp del 0 ./backup.pkgo
+
+Get loaded DDP package info list:
+
+.. code-block:: console
+
+ testpmd> ddp get list 0
+
+Display information about a GTP profile:
+
+.. code-block:: console
+
+ testpmd> ddp get info ./gtp.pkgo
+
+Input set configuration
+~~~~~~~~~~~~~~~~~~~~~~~
+Input set for any PCTYPE can be configured with user defined configuration,
+For example, to use only 48bit prefix for IPv6 src address for IPv6 TCP RSS:
+
+.. code-block:: console
+
+ testpmd> port config 0 pctype 43 hash_inset clear all
+ testpmd> port config 0 pctype 43 hash_inset set field 13
+ testpmd> port config 0 pctype 43 hash_inset set field 14
+ testpmd> port config 0 pctype 43 hash_inset set field 15
+
+Queue region configuration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The Intel® Ethernet 700 Series supports a feature of queue regions
+configuration for RSS in the PF, so that different traffic classes or
+different packet classification types can be separated to different
+queues in different queue regions. There is an API for configuration
+of queue regions in RSS with a command line. It can parse the parameters
+of the region index, queue number, queue start index, user priority, traffic
+classes and so on. Depending on commands from the command line, it will call
+i40e private APIs and start the process of setting or flushing the queue
+region configuration. As this feature is specific for i40e only private
+APIs are used. These new ``test_pmd`` commands are as shown below. For
+details please refer to :doc:`../testpmd_app_ug/index`.
+
+.. code-block:: console
+
+ testpmd> set port (port_id) queue-region region_id (value) \
+ queue_start_index (value) queue_num (value)
+ testpmd> set port (port_id) queue-region region_id (value) flowtype (value)
+ testpmd> set port (port_id) queue-region UP (value) region_id (value)
+ testpmd> set port (port_id) queue-region flush (on|off)
+ testpmd> show port (port_id) queue-region
+
+Generic flow API
+~~~~~~~~~~~~~~~~~~~
+
+- ``RSS Flow``
+
+ RSS Flow supports to set hash input set, hash function, enable hash
+ and configure queue region.
+ For example:
+ Configure queue region as queue 0, 1, 2, 3.
+
+ .. code-block:: console
+
+ testpmd> flow create 0 ingress pattern end actions rss types end \
+ queues 0 1 2 3 end / end
+
+ Enable hash and set input set for ipv4-tcp.
+
+ .. code-block:: console
+
+ testpmd> flow create 0 ingress pattern eth / ipv4 / tcp / end \
+ actions rss types ipv4-tcp l3-src-only end queues end / end
+
+ Set symmetric hash enable for flow type ipv4-tcp.
+
+ .. code-block:: console
+
+ testpmd> flow create 0 ingress pattern eth / ipv4 / tcp / end \
+ actions rss types ipv4-tcp end queues end func symmetric_toeplitz / end
+
+ Set hash function as simple xor.
+
+ .. code-block:: console
+
+ testpmd> flow create 0 ingress pattern end actions rss types end \
+ queues end func simple_xor / end
+
+Limitations or Known issues
+---------------------------
+
+MPLS packet classification
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For firmware versions prior to 5.0, MPLS packets are not recognized by the NIC.
+The L2 Payload flow type in flow director can be used to classify MPLS packet
+by using a command in testpmd like:
+
+ testpmd> flow_director_filter 0 mode IP add flow l2_payload ether \
+ 0x8847 flexbytes () fwd pf queue <N> fd_id <M>
+
+With the NIC firmware version 5.0 or greater, some limited MPLS support
+is added: Native MPLS (MPLS in Ethernet) skip is implemented, while no
+new packet type, no classification or offload are possible. With this change,
+L2 Payload flow type in flow director cannot be used to classify MPLS packet
+as with previous firmware versions. Meanwhile, the Ethertype filter can be
+used to classify MPLS packet by using a command in testpmd like:
+
+ testpmd> ethertype_filter 0 add mac_ignr 00:00:00:00:00:00 ethertype \
+ 0x8847 fwd queue <M>
+
+16 Byte RX Descriptor setting on DPDK VF
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Currently the VF's RX descriptor mode is decided by PF. There's no PF-VF
+interface for VF to request the RX descriptor mode, also no interface to notify
+VF its own RX descriptor mode.
+For all available versions of the i40e driver, these drivers don't support 16
+byte RX descriptor. If the Linux i40e kernel driver is used as host driver,
+while DPDK i40e PMD is used as the VF driver, DPDK cannot choose 16 byte receive
+descriptor. The reason is that the RX descriptor is already set to 32 byte by
+the i40e kernel driver. That is to say, user should keep
+``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n`` in config file.
+In the future, if the Linux i40e driver supports 16 byte RX descriptor, user
+should make sure the DPDK VF uses the same RX descriptor mode, 16 byte or 32
+byte, as the PF driver.
+
+The same rule for DPDK PF + DPDK VF. The PF and VF should use the same RX
+descriptor mode. Or the VF RX will not work.
+
+Receive packets with Ethertype 0x88A8
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Due to the FW limitation, PF can receive packets with Ethertype 0x88A8
+only when floating VEB is disabled.
+
+Incorrect Rx statistics when packet is oversize
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+When a packet is over maximum frame size, the packet is dropped.
+However, the Rx statistics, when calling `rte_eth_stats_get` incorrectly
+shows it as received.
+
+VF & TC max bandwidth setting
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The per VF max bandwidth and per TC max bandwidth cannot be enabled in parallel.
+The behavior is different when handling per VF and per TC max bandwidth setting.
+When enabling per VF max bandwidth, SW will check if per TC max bandwidth is
+enabled. If so, return failure.
+When enabling per TC max bandwidth, SW will check if per VF max bandwidth
+is enabled. If so, disable per VF max bandwidth and continue with per TC max
+bandwidth setting.
+
+TC TX scheduling mode setting
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+There are 2 TX scheduling modes for TCs, round robin and strict priority mode.
+If a TC is set to strict priority mode, it can consume unlimited bandwidth.
+It means if APP has set the max bandwidth for that TC, it comes to no
+effect.
+It's suggested to set the strict priority mode for a TC that is latency
+sensitive but no consuming much bandwidth.
+
+VF performance is impacted by PCI extended tag setting
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To reach maximum NIC performance in the VF the PCI extended tag must be
+enabled. The DPDK i40e PF driver will set this feature during initialization,
+but the kernel PF driver does not. So when running traffic on a VF which is
+managed by the kernel PF driver, a significant NIC performance downgrade has
+been observed (for 64 byte packets, there is about 25% line-rate downgrade for
+a 25GbE device and about 35% for a 40GbE device).
+
+For kernel version >= 4.11, the kernel's PCI driver will enable the extended
+tag if it detects that the device supports it. So by default, this is not an
+issue. For kernels <= 4.11 or when the PCI extended tag is disabled it can be
+enabled using the steps below.
+
+#. Get the current value of the PCI configure register::
+
+ setpci -s <XX:XX.X> a8.w
+
+#. Set bit 8::
+
+ value = value | 0x100
+
+#. Set the PCI configure register with new value::
+
+ setpci -s <XX:XX.X> a8.w=<value>
+
+Vlan strip of VF
+~~~~~~~~~~~~~~~~
+
+The VF vlan strip function is only supported in the i40e kernel driver >= 2.1.26.
+
+DCB function
+~~~~~~~~~~~~
+
+DCB works only when RSS is enabled.
+
+Global configuration warning
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+I40E PMD will set some global registers to enable some function or set some
+configure. Then when using different ports of the same NIC with Linux kernel
+and DPDK, the port with Linux kernel will be impacted by the port with DPDK.
+For example, register I40E_GL_SWT_L2TAGCTRL is used to control L2 tag, i40e
+PMD uses I40E_GL_SWT_L2TAGCTRL to set vlan TPID. If setting TPID in port A
+with DPDK, then the configuration will also impact port B in the NIC with
+kernel driver, which don't want to use the TPID.
+So PMD reports warning to clarify what is changed by writing global register.
+
+High Performance of Small Packets on 40GbE NIC
+----------------------------------------------
+
+As there might be firmware fixes for performance enhancement in latest version
+of firmware image, the firmware update might be needed for getting high performance.
+Check the Intel support website for the latest firmware updates.
+Users should consult the release notes specific to a DPDK release to identify
+the validated firmware version for a NIC using the i40e driver.
+
+Use 16 Bytes RX Descriptor Size
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+As i40e PMD supports both 16 and 32 bytes RX descriptor sizes, and 16 bytes size can provide helps to high performance of small packets.
+Configuration of ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC`` in config files can be changed to use 16 bytes size RX descriptors.
+
+Input set requirement of each pctype for FDIR
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Each PCTYPE can only have one specific FDIR input set at one time.
+For example, if creating 2 rte_flow rules with different input set for one PCTYPE,
+it will fail and return the info "Conflict with the first rule's input set",
+which means the current rule's input set conflicts with the first rule's.
+Remove the first rule if want to change the input set of the PCTYPE.
+
+Example of getting best performance with l3fwd example
+------------------------------------------------------
+
+The following is an example of running the DPDK ``l3fwd`` sample application to get high performance with a
+server with Intel Xeon processors and Intel Ethernet CNA XL710.
+
+The example scenario is to get best performance with two Intel Ethernet CNA XL710 40GbE ports.
+See :numref:`figure_intel_perf_test_setup` for the performance test setup.
+
+.. _figure_intel_perf_test_setup:
+
+.. figure:: img/intel_perf_test_setup.*
+
+ Performance Test Setup
+
+
+1. Add two Intel Ethernet CNA XL710 to the platform, and use one port per card to get best performance.
+ The reason for using two NICs is to overcome a PCIe v3.0 limitation since it cannot provide 80GbE bandwidth
+ for two 40GbE ports, but two different PCIe v3.0 x8 slot can.
+ Refer to the sample NICs output above, then we can select ``82:00.0`` and ``85:00.0`` as test ports::
+
+ 82:00.0 Ethernet [0200]: Intel XL710 for 40GbE QSFP+ [8086:1583]
+ 85:00.0 Ethernet [0200]: Intel XL710 for 40GbE QSFP+ [8086:1583]
+
+2. Connect the ports to the traffic generator. For high speed testing, it's best to use a hardware traffic generator.
+
+3. Check the PCI devices numa node (socket id) and get the cores number on the exact socket id.
+ In this case, ``82:00.0`` and ``85:00.0`` are both in socket 1, and the cores on socket 1 in the referenced platform
+ are 18-35 and 54-71.
+ Note: Don't use 2 logical cores on the same core (e.g core18 has 2 logical cores, core18 and core54), instead, use 2 logical
+ cores from different cores (e.g core18 and core19).
+
+4. Bind these two ports to igb_uio.
+
+5. As to Intel Ethernet CNA XL710 40GbE port, we need at least two queue pairs to achieve best performance, then two queues per port
+ will be required, and each queue pair will need a dedicated CPU core for receiving/transmitting packets.
+
+6. The DPDK sample application ``l3fwd`` will be used for performance testing, with using two ports for bi-directional forwarding.
+ Compile the ``l3fwd sample`` with the default lpm mode.
+
+7. The command line of running l3fwd would be something like the following::
+
+ ./l3fwd -l 18-21 -n 4 -w 82:00.0 -w 85:00.0 \
+ -- -p 0x3 --config '(0,0,18),(0,1,19),(1,0,20),(1,1,21)'
+
+ This means that the application uses core 18 for port 0, queue pair 0 forwarding, core 19 for port 0, queue pair 1 forwarding,
+ core 20 for port 1, queue pair 0 forwarding, and core 21 for port 1, queue pair 1 forwarding.
+
+8. Configure the traffic at a traffic generator.
+
+ * Start creating a stream on packet generator.
+
+ * Set the Ethernet II type to 0x0800.
+
+Tx bytes affected by the link status change
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+For firmware versions prior to 6.01 for X710 series and 3.33 for X722 series, the tx_bytes statistics data is affected by
+the link down event. Each time the link status changes to down, the tx_bytes decreases 110 bytes.