1 .. SPDX-License-Identifier: BSD-3-Clause
2 Copyright(c) 2016 Intel Corporation.
7 The i40e PMD (librte_pmd_i40e) provides poll mode driver support for
8 10/25/40 Gbps Intel® Ethernet 700 Series Network Adapters based on
9 the Intel Ethernet Controller X710/XL710/XXV710 and Intel Ethernet
10 Connection X722 (only support part of features).
16 Features of the i40e PMD are:
18 - Multiple queues for TX and RX
19 - Receiver Side Scaling (RSS)
21 - Packet type information
25 - VLAN/QinQ stripping and inserting
29 - Port hardware statistics
31 - Link state information
33 - Mirror on port, VLAN and VSI
34 - Interrupt mode for RX
35 - Scattered and gather for TX and RX
36 - Vector Poll mode driver
41 - IEEE1588/802.1AS timestamping
42 - VF Daemon (VFD) - EXPERIMENTAL
43 - Dynamic Device Personalization (DDP)
44 - Queue region configuration
45 - Virtual Function Port Representors
50 - Identifying your adapter using `Intel Support
51 <http://www.intel.com/support>`_ and get the latest NVM/FW images.
53 - Follow the DPDK :ref:`Getting Started Guide for Linux <linux_gsg>` to setup the basic DPDK environment.
55 - To get better performance on Intel platforms, please follow the "How to get best performance with NICs on Intel platforms"
56 section of the :ref:`Getting Started Guide for Linux <linux_gsg>`.
58 - Upgrade the NVM/FW version following the `Intel® Ethernet NVM Update Tool Quick Usage Guide for Linux
59 <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.
61 Recommended Matching List
62 -------------------------
64 It is highly recommended to upgrade the i40e kernel driver and firmware to
65 avoid the compatibility issues with i40e PMD. Here is the suggested matching
66 list which has been tested and verified. The detailed information can refer
67 to chapter Tested Platforms/Tested NICs in release notes.
69 +--------------+-----------------------+------------------+
70 | DPDK version | Kernel driver version | Firmware version |
71 +==============+=======================+==================+
72 | 19.08 | 2.9.21 | 7.00 |
73 +--------------+-----------------------+------------------+
74 | 19.05 | 2.7.29 | 6.80 |
75 +--------------+-----------------------+------------------+
76 | 19.02 | 2.7.26 | 6.80 |
77 +--------------+-----------------------+------------------+
78 | 18.11 | 2.4.6 | 6.01 |
79 +--------------+-----------------------+------------------+
80 | 18.08 | 2.4.6 | 6.01 |
81 +--------------+-----------------------+------------------+
82 | 18.05 | 2.4.6 | 6.01 |
83 +--------------+-----------------------+------------------+
84 | 18.02 | 2.4.3 | 6.01 |
85 +--------------+-----------------------+------------------+
86 | 17.11 | 2.1.26 | 6.01 |
87 +--------------+-----------------------+------------------+
88 | 17.08 | 2.0.19 | 6.01 |
89 +--------------+-----------------------+------------------+
90 | 17.05 | 1.5.23 | 5.05 |
91 +--------------+-----------------------+------------------+
92 | 17.02 | 1.5.23 | 5.05 |
93 +--------------+-----------------------+------------------+
94 | 16.11 | 1.5.23 | 5.05 |
95 +--------------+-----------------------+------------------+
96 | 16.07 | 1.4.25 | 5.04 |
97 +--------------+-----------------------+------------------+
98 | 16.04 | 1.4.25 | 5.02 |
99 +--------------+-----------------------+------------------+
101 Pre-Installation Configuration
102 ------------------------------
107 The following options can be modified in the ``config`` file.
108 Please note that enabling debugging options may affect system performance.
110 - ``CONFIG_RTE_LIBRTE_I40E_PMD`` (default ``y``)
112 Toggle compilation of the ``librte_pmd_i40e`` driver.
114 - ``CONFIG_RTE_LIBRTE_I40E_DEBUG_*`` (default ``n``)
116 Toggle display of generic debugging messages.
118 - ``CONFIG_RTE_LIBRTE_I40E_RX_ALLOW_BULK_ALLOC`` (default ``y``)
120 Toggle bulk allocation for RX.
122 - ``CONFIG_RTE_LIBRTE_I40E_INC_VECTOR`` (default ``n``)
124 Toggle the use of Vector PMD instead of normal RX/TX path.
125 To enable vPMD for RX, bulk allocation for Rx must be allowed.
127 - ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC`` (default ``n``)
129 Toggle to use a 16-byte RX descriptor, by default the RX descriptor is 32 byte.
131 - ``CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_PF`` (default ``64``)
133 Number of queues reserved for PF.
135 - ``CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM`` (default ``4``)
137 Number of queues reserved for each VMDQ Pool.
139 Runtime Config Options
140 ~~~~~~~~~~~~~~~~~~~~~~
142 - ``Reserved number of Queues per VF`` (default ``4``)
144 The number of reserved queue per VF is determined by its host PF. If the
145 PCI address of an i40e PF is aaaa:bb.cc, the number of reserved queues per
146 VF can be configured with EAL parameter like -w aaaa:bb.cc,queue-num-per-vf=n.
147 The value n can be 1, 2, 4, 8 or 16. If no such parameter is configured, the
148 number of reserved queues per VF is 4 by default. If VF request more than
149 reserved queues per VF, PF will able to allocate max to 16 queues after a VF
153 - ``Support multiple driver`` (default ``disable``)
155 There was a multiple driver support issue during use of 700 series Ethernet
156 Adapter with both Linux kernel and DPDK PMD. To fix this issue, ``devargs``
157 parameter ``support-multi-driver`` is introduced, for example::
159 -w 84:00.0,support-multi-driver=1
161 With the above configuration, DPDK PMD will not change global registers, and
162 will switch PF interrupt from IntN to Int0 to avoid interrupt conflict between
163 DPDK and Linux Kernel.
165 - ``Support VF Port Representor`` (default ``not enabled``)
167 The i40e PF PMD supports the creation of VF port representors for the control
168 and monitoring of i40e virtual function devices. Each port representor
169 corresponds to a single virtual function of that device. Using the ``devargs``
170 option ``representor`` the user can specify which virtual functions to create
171 port representors for on initialization of the PF PMD by passing the VF IDs of
172 the VFs which are required.::
174 -w DBDF,representor=[0,1,4]
176 Currently hot-plugging of representor ports is not supported so all required
177 representors must be specified on the creation of the PF.
179 - ``Use latest supported vector`` (default ``disable``)
181 Latest supported vector path may not always get the best perf so vector path was
182 recommended to use only on later platform. But users may want the latest vector path
183 since it can get better perf in some real work loading cases. So ``devargs`` param
184 ``use-latest-supported-vec`` is introduced, for example::
186 -w 84:00.0,use-latest-supported-vec=1
188 Vector RX Pre-conditions
189 ~~~~~~~~~~~~~~~~~~~~~~~~
190 For Vector RX it is assumed that the number of descriptor rings will be a power
191 of 2. With this pre-condition, the ring pointer can easily scroll back to the
192 head after hitting the tail without a conditional check. In addition Vector RX
193 can use this assumption to do a bit mask using ``ring_size - 1``.
195 Driver compilation and testing
196 ------------------------------
198 Refer to the document :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>`
202 SR-IOV: Prerequisites and sample Application Notes
203 --------------------------------------------------
205 #. Load the kernel module:
207 .. code-block:: console
211 Check the output in dmesg:
213 .. code-block:: console
215 i40e 0000:83:00.1 ens802f0: renamed from eth0
217 #. Bring up the PF ports:
219 .. code-block:: console
223 #. Create VF device(s):
225 Echo the number of VFs to be created into the ``sriov_numvfs`` sysfs entry
230 .. code-block:: console
232 echo 2 > /sys/devices/pci0000:00/0000:00:03.0/0000:81:00.0/sriov_numvfs
235 #. Assign VF MAC address:
237 Assign MAC address to the VF using iproute2 utility. The syntax is:
239 .. code-block:: console
241 ip link set <PF netdev id> vf <VF id> mac <macaddr>
245 .. code-block:: console
247 ip link set ens802f0 vf 0 mac a0:b0:c0:d0:e0:f0
249 #. Assign VF to VM, and bring up the VM.
250 Please see the documentation for the *I40E/IXGBE/IGB Virtual Function Driver*.
254 Follow instructions available in the document
255 :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>`
260 .. code-block:: console
263 EAL: PCI device 0000:83:00.0 on NUMA socket 1
264 EAL: probe driver: 8086:1572 rte_i40e_pmd
265 EAL: PCI memory mapped at 0x7f7f80000000
266 EAL: PCI memory mapped at 0x7f7f80800000
267 PMD: eth_i40e_dev_init(): FW 5.0 API 1.5 NVM 05.00.02 eetrack 8000208a
268 Interactive-mode selected
269 Configuring Port 0 (socket 0)
272 PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are
273 satisfied.Rx Burst Bulk Alloc function will be used on port=0, queue=0.
276 Port 0: 68:05:CA:26:85:84
277 Checking link statuses...
278 Port 0 Link Up - speed 10000 Mbps - full-duplex
284 Sample Application Notes
285 ------------------------
290 Vlan filter only works when Promiscuous mode is off.
292 To start ``testpmd``, and add vlan 10 to port 0:
294 .. code-block:: console
296 ./app/testpmd -l 0-15 -n 4 -- -i --forward-mode=mac
299 testpmd> set promisc 0 off
300 testpmd> rx_vlan add 10 0
306 The Flow Director works in receive mode to identify specific flows or sets of flows and route them to specific queues.
307 The Flow Director filters can match the different fields for different type of packet: flow type, specific input set per flow type and the flexible payload.
309 The default input set of each flow type is::
311 ipv4-other : src_ip_address, dst_ip_address
312 ipv4-frag : src_ip_address, dst_ip_address
313 ipv4-tcp : src_ip_address, dst_ip_address, src_port, dst_port
314 ipv4-udp : src_ip_address, dst_ip_address, src_port, dst_port
315 ipv4-sctp : src_ip_address, dst_ip_address, src_port, dst_port,
317 ipv6-other : src_ip_address, dst_ip_address
318 ipv6-frag : src_ip_address, dst_ip_address
319 ipv6-tcp : src_ip_address, dst_ip_address, src_port, dst_port
320 ipv6-udp : src_ip_address, dst_ip_address, src_port, dst_port
321 ipv6-sctp : src_ip_address, dst_ip_address, src_port, dst_port,
323 l2_payload : ether_type
325 The flex payload is selected from offset 0 to 15 of packet's payload by default, while it is masked out from matching.
327 Start ``testpmd`` with ``--disable-rss`` and ``--pkt-filter-mode=perfect``:
329 .. code-block:: console
331 ./app/testpmd -l 0-15 -n 4 -- -i --disable-rss --pkt-filter-mode=perfect \
332 --rxq=8 --txq=8 --nb-cores=8 --nb-ports=1
334 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:
336 .. code-block:: console
338 testpmd> flow_director_filter 0 mode IP add flow ipv4-udp \
339 src 2.2.2.3 32 dst 2.2.2.5 32 vlan 0 flexbytes () \
340 fwd pf queue 1 fd_id 1
342 Check the flow director status:
344 .. code-block:: console
346 testpmd> show port fdir 0
348 ######################## FDIR infos for port 0 ####################
350 SUPPORTED FLOW TYPE: ipv4-frag ipv4-tcp ipv4-udp ipv4-sctp ipv4-other
351 ipv6-frag ipv6-tcp ipv6-udp ipv6-sctp ipv6-other
354 max_len: 16 payload_limit: 480
355 payload_unit: 2 payload_seg: 3
356 bitmask_unit: 2 bitmask_num: 2
359 src_ipv4: 0x00000000,
360 dst_ipv4: 0x00000000,
363 src_ipv6: 0x00000000,0x00000000,0x00000000,0x00000000,
364 dst_ipv6: 0x00000000,0x00000000,0x00000000,0x00000000
365 FLEX PAYLOAD SRC OFFSET:
366 L2_PAYLOAD: 0 1 2 3 4 5 6 ...
367 L3_PAYLOAD: 0 1 2 3 4 5 6 ...
368 L4_PAYLOAD: 0 1 2 3 4 5 6 ...
370 ipv4-udp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
371 ipv4-tcp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
372 ipv4-sctp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
373 ipv4-other: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
374 ipv4-frag: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
375 ipv6-udp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
376 ipv6-tcp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
377 ipv6-sctp: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
378 ipv6-other: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
379 ipv6-frag: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
380 l2_payload: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
381 guarant_count: 1 best_count: 0
382 guarant_space: 512 best_space: 7168
389 Delete all flow director rules on a port:
391 .. code-block:: console
393 testpmd> flush_flow_director 0
398 The Intel® Ethernet 700 Series support a feature called
401 A Virtual Ethernet Bridge (VEB) is an IEEE Edge Virtual Bridging (EVB) term
402 for functionality that allows local switching between virtual endpoints within
403 a physical endpoint and also with an external bridge/network.
405 A "Floating" VEB doesn't have an uplink connection to the outside world so all
406 switching is done internally and remains within the host. As such, this
407 feature provides security benefits.
409 In addition, a Floating VEB overcomes a limitation of normal VEBs where they
410 cannot forward packets when the physical link is down. Floating VEBs don't need
411 to connect to the NIC port so they can still forward traffic from VF to VF
412 even when the physical link is down.
414 Therefore, with this feature enabled VFs can be limited to communicating with
415 each other but not an outside network, and they can do so even when there is
416 no physical uplink on the associated NIC port.
418 To enable this feature, the user should pass a ``devargs`` parameter to the
421 -w 84:00.0,enable_floating_veb=1
423 In this configuration the PMD will use the floating VEB feature for all the
424 VFs created by this PF device.
426 Alternatively, the user can specify which VFs need to connect to this floating
427 VEB using the ``floating_veb_list`` argument::
429 -w 84:00.0,enable_floating_veb=1,floating_veb_list=1;3-4
431 In this example ``VF1``, ``VF3`` and ``VF4`` connect to the floating VEB,
432 while other VFs connect to the normal VEB.
434 The current implementation only supports one floating VEB and one regular
435 VEB. VFs can connect to a floating VEB or a regular VEB according to the
436 configuration passed on the EAL command line.
438 The floating VEB functionality requires a NIC firmware version of 5.0
441 Dynamic Device Personalization (DDP)
442 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
444 The Intel® Ethernet 700 Series except for the Intel Ethernet Connection
445 X722 support a feature called "Dynamic Device Personalization (DDP)",
446 which is used to configure hardware by downloading a profile to support
447 protocols/filters which are not supported by default. The DDP
448 functionality requires a NIC firmware version of 6.0 or greater.
450 Current implementation supports GTP-C/GTP-U/PPPoE/PPPoL2TP,
451 steering can be used with rte_flow API.
453 GTPv1 package is released, and it can be downloaded from
454 https://downloadcenter.intel.com/download/27587.
456 PPPoE package is released, and it can be downloaded from
457 https://downloadcenter.intel.com/download/28040.
459 Load a profile which supports GTP and store backup profile:
461 .. code-block:: console
463 testpmd> ddp add 0 ./gtp.pkgo,./backup.pkgo
465 Delete a GTP profile and restore backup profile:
467 .. code-block:: console
469 testpmd> ddp del 0 ./backup.pkgo
471 Get loaded DDP package info list:
473 .. code-block:: console
475 testpmd> ddp get list 0
477 Display information about a GTP profile:
479 .. code-block:: console
481 testpmd> ddp get info ./gtp.pkgo
483 Input set configuration
484 ~~~~~~~~~~~~~~~~~~~~~~~
485 Input set for any PCTYPE can be configured with user defined configuration,
486 For example, to use only 48bit prefix for IPv6 src address for IPv6 TCP RSS:
488 .. code-block:: console
490 testpmd> port config 0 pctype 43 hash_inset clear all
491 testpmd> port config 0 pctype 43 hash_inset set field 13
492 testpmd> port config 0 pctype 43 hash_inset set field 14
493 testpmd> port config 0 pctype 43 hash_inset set field 15
495 Queue region configuration
496 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
497 The Intel® Ethernet 700 Series supports a feature of queue regions
498 configuration for RSS in the PF, so that different traffic classes or
499 different packet classification types can be separated to different
500 queues in different queue regions. There is an API for configuration
501 of queue regions in RSS with a command line. It can parse the parameters
502 of the region index, queue number, queue start index, user priority, traffic
503 classes and so on. Depending on commands from the command line, it will call
504 i40e private APIs and start the process of setting or flushing the queue
505 region configuration. As this feature is specific for i40e only private
506 APIs are used. These new ``test_pmd`` commands are as shown below. For
507 details please refer to :doc:`../testpmd_app_ug/index`.
509 .. code-block:: console
511 testpmd> set port (port_id) queue-region region_id (value) \
512 queue_start_index (value) queue_num (value)
513 testpmd> set port (port_id) queue-region region_id (value) flowtype (value)
514 testpmd> set port (port_id) queue-region UP (value) region_id (value)
515 testpmd> set port (port_id) queue-region flush (on|off)
516 testpmd> show port (port_id) queue-region
518 Limitations or Known issues
519 ---------------------------
521 MPLS packet classification
522 ~~~~~~~~~~~~~~~~~~~~~~~~~~
524 For firmware versions prior to 5.0, MPLS packets are not recognized by the NIC.
525 The L2 Payload flow type in flow director can be used to classify MPLS packet
526 by using a command in testpmd like:
528 testpmd> flow_director_filter 0 mode IP add flow l2_payload ether \
529 0x8847 flexbytes () fwd pf queue <N> fd_id <M>
531 With the NIC firmware version 5.0 or greater, some limited MPLS support
532 is added: Native MPLS (MPLS in Ethernet) skip is implemented, while no
533 new packet type, no classification or offload are possible. With this change,
534 L2 Payload flow type in flow director cannot be used to classify MPLS packet
535 as with previous firmware versions. Meanwhile, the Ethertype filter can be
536 used to classify MPLS packet by using a command in testpmd like:
538 testpmd> ethertype_filter 0 add mac_ignr 00:00:00:00:00:00 ethertype \
541 16 Byte RX Descriptor setting on DPDK VF
542 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
544 Currently the VF's RX descriptor mode is decided by PF. There's no PF-VF
545 interface for VF to request the RX descriptor mode, also no interface to notify
546 VF its own RX descriptor mode.
547 For all available versions of the i40e driver, these drivers don't support 16
548 byte RX descriptor. If the Linux i40e kernel driver is used as host driver,
549 while DPDK i40e PMD is used as the VF driver, DPDK cannot choose 16 byte receive
550 descriptor. The reason is that the RX descriptor is already set to 32 byte by
551 the i40e kernel driver. That is to say, user should keep
552 ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n`` in config file.
553 In the future, if the Linux i40e driver supports 16 byte RX descriptor, user
554 should make sure the DPDK VF uses the same RX descriptor mode, 16 byte or 32
555 byte, as the PF driver.
557 The same rule for DPDK PF + DPDK VF. The PF and VF should use the same RX
558 descriptor mode. Or the VF RX will not work.
560 Receive packets with Ethertype 0x88A8
561 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
563 Due to the FW limitation, PF can receive packets with Ethertype 0x88A8
564 only when floating VEB is disabled.
566 Incorrect Rx statistics when packet is oversize
567 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
569 When a packet is over maximum frame size, the packet is dropped.
570 However, the Rx statistics, when calling `rte_eth_stats_get` incorrectly
571 shows it as received.
573 VF & TC max bandwidth setting
574 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
576 The per VF max bandwidth and per TC max bandwidth cannot be enabled in parallel.
577 The behavior is different when handling per VF and per TC max bandwidth setting.
578 When enabling per VF max bandwidth, SW will check if per TC max bandwidth is
579 enabled. If so, return failure.
580 When enabling per TC max bandwidth, SW will check if per VF max bandwidth
581 is enabled. If so, disable per VF max bandwidth and continue with per TC max
584 TC TX scheduling mode setting
585 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
587 There are 2 TX scheduling modes for TCs, round robin and strict priority mode.
588 If a TC is set to strict priority mode, it can consume unlimited bandwidth.
589 It means if APP has set the max bandwidth for that TC, it comes to no
591 It's suggested to set the strict priority mode for a TC that is latency
592 sensitive but no consuming much bandwidth.
594 VF performance is impacted by PCI extended tag setting
595 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
597 To reach maximum NIC performance in the VF the PCI extended tag must be
598 enabled. The DPDK i40e PF driver will set this feature during initialization,
599 but the kernel PF driver does not. So when running traffic on a VF which is
600 managed by the kernel PF driver, a significant NIC performance downgrade has
601 been observed (for 64 byte packets, there is about 25% line-rate downgrade for
602 a 25GbE device and about 35% for a 40GbE device).
604 For kernel version >= 4.11, the kernel's PCI driver will enable the extended
605 tag if it detects that the device supports it. So by default, this is not an
606 issue. For kernels <= 4.11 or when the PCI extended tag is disabled it can be
607 enabled using the steps below.
609 #. Get the current value of the PCI configure register::
611 setpci -s <XX:XX.X> a8.w
615 value = value | 0x100
617 #. Set the PCI configure register with new value::
619 setpci -s <XX:XX.X> a8.w=<value>
624 The VF vlan strip function is only supported in the i40e kernel driver >= 2.1.26.
629 DCB works only when RSS is enabled.
631 Global configuration warning
632 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
634 I40E PMD will set some global registers to enable some function or set some
635 configure. Then when using different ports of the same NIC with Linux kernel
636 and DPDK, the port with Linux kernel will be impacted by the port with DPDK.
637 For example, register I40E_GL_SWT_L2TAGCTRL is used to control L2 tag, i40e
638 PMD uses I40E_GL_SWT_L2TAGCTRL to set vlan TPID. If setting TPID in port A
639 with DPDK, then the configuration will also impact port B in the NIC with
640 kernel driver, which don't want to use the TPID.
641 So PMD reports warning to clarify what is changed by writing global register.
643 High Performance of Small Packets on 40GbE NIC
644 ----------------------------------------------
646 As there might be firmware fixes for performance enhancement in latest version
647 of firmware image, the firmware update might be needed for getting high performance.
648 Check the Intel support website for the latest firmware updates.
649 Users should consult the release notes specific to a DPDK release to identify
650 the validated firmware version for a NIC using the i40e driver.
652 Use 16 Bytes RX Descriptor Size
653 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
655 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.
656 Configuration of ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC`` in config files can be changed to use 16 bytes size RX descriptors.
658 Example of getting best performance with l3fwd example
659 ------------------------------------------------------
661 The following is an example of running the DPDK ``l3fwd`` sample application to get high performance with a
662 server with Intel Xeon processors and Intel Ethernet CNA XL710.
664 The example scenario is to get best performance with two Intel Ethernet CNA XL710 40GbE ports.
665 See :numref:`figure_intel_perf_test_setup` for the performance test setup.
667 .. _figure_intel_perf_test_setup:
669 .. figure:: img/intel_perf_test_setup.*
671 Performance Test Setup
674 1. Add two Intel Ethernet CNA XL710 to the platform, and use one port per card to get best performance.
675 The reason for using two NICs is to overcome a PCIe v3.0 limitation since it cannot provide 80GbE bandwidth
676 for two 40GbE ports, but two different PCIe v3.0 x8 slot can.
677 Refer to the sample NICs output above, then we can select ``82:00.0`` and ``85:00.0`` as test ports::
679 82:00.0 Ethernet [0200]: Intel XL710 for 40GbE QSFP+ [8086:1583]
680 85:00.0 Ethernet [0200]: Intel XL710 for 40GbE QSFP+ [8086:1583]
682 2. Connect the ports to the traffic generator. For high speed testing, it's best to use a hardware traffic generator.
684 3. Check the PCI devices numa node (socket id) and get the cores number on the exact socket id.
685 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
687 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
688 cores from different cores (e.g core18 and core19).
690 4. Bind these two ports to igb_uio.
692 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
693 will be required, and each queue pair will need a dedicated CPU core for receiving/transmitting packets.
695 6. The DPDK sample application ``l3fwd`` will be used for performance testing, with using two ports for bi-directional forwarding.
696 Compile the ``l3fwd sample`` with the default lpm mode.
698 7. The command line of running l3fwd would be something like the following::
700 ./l3fwd -l 18-21 -n 4 -w 82:00.0 -w 85:00.0 \
701 -- -p 0x3 --config '(0,0,18),(0,1,19),(1,0,20),(1,1,21)'
703 This means that the application uses core 18 for port 0, queue pair 0 forwarding, core 19 for port 0, queue pair 1 forwarding,
704 core 20 for port 1, queue pair 0 forwarding, and core 21 for port 1, queue pair 1 forwarding.
706 8. Configure the traffic at a traffic generator.
708 * Start creating a stream on packet generator.
710 * Set the Ethernet II type to 0x0800.
712 Tx bytes affected by the link status change
713 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
715 For firmware versions prior to 6.01 for X710 series and 3.33 for X722 series, the tx_bytes statistics data is affected by
716 the link down event. Each time the link status changes to down, the tx_bytes decreases 110 bytes.