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.
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
------
-
-
-Running testpmd
-~~~~~~~~~~~~~~~
-
-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:
-
- .. code-block:: console
-
- modprobe uio
- insmod ./x86_64-native-linuxapp-gcc/kmod/igb_uio.ko
-
- or
-
- .. code-block:: console
-
- modprobe vfio-pci
-
-#. Bind the XL710/X710 adapters to ``igb_uio`` or ``vfio-pci`` loaded in the previous step:
-
- .. code-block:: console
-
- ./usertools/dpdk-devbind.py --bind igb_uio 0000:83:00.0
-
- Or setup VFIO permissions for regular users and then bind to ``vfio-pci``:
-
- .. code-block:: console
-
- ./usertools/dpdk-devbind.py --bind vfio-pci 0000:83:00.0
-
-#. Start ``testpmd`` with basic parameters:
-
- .. code-block:: console
-
- ./x86_64-native-linuxapp-gcc/app/testpmd -l 0-3 -n 4 -w 83:00.0 -- -i
-
- 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
+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:
#. Assign VF to VM, and bring up the VM.
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
------------------------
is to say, user should keep ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n`` in
config file.
-Link down with i40e kernel driver after DPDK application exist
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-After DPDK application quit, and the device is bound back to Linux i40e
-kernel driver, the link cannot be up after ``ifconfig <dev> up``.
-To work around this issue, ``ethtool -s <dev> autoneg on`` should be
-set first and then the link can be brought up through ``ifconfig <dev> up``.
-
-NOTE: requires Linux kernel i40e driver version >= 1.4.X
-
Receive packets with Ethertype 0x88A8
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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're 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% linerate downgrade for
+a 25G device and about 35% for a 40G 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>
+
+High Performance of Small Packets on 40G 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 with the local Intel's Network Division application engineers for 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.
+
+High Performance and per Packet Latency Tradeoff
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Due to the hardware design, the interrupt signal inside NIC is needed for per
+packet descriptor write-back. The minimum interval of interrupts could be set
+at compile time by ``CONFIG_RTE_LIBRTE_I40E_ITR_INTERVAL`` in configuration files.
+Though there is a default configuration, the interval could be tuned by the
+users with that configuration item depends on what the user cares about more,
+performance or per packet latency.
+
+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 an
+Intel server platform and Intel XL710 NICs.
+
+The example scenario is to get best performance with two Intel 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 XL710 NICs to the platform, and use one port per card to get best performance.
+ The reason for using two NICs is to overcome a PCIe Gen3's limitation since it cannot provide 80G bandwidth
+ for two 40G ports, but two different PCIe Gen3 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 XL710 40G 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.
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