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diff --git a/Documentation/networking/device_drivers/ethernet/intel/idpf.rst b/Documentation/networking/device_drivers/ethernet/intel/idpf.rst new file mode 100644 index 000000000000..adb16e2abd21 --- /dev/null +++ b/Documentation/networking/device_drivers/ethernet/intel/idpf.rst @@ -0,0 +1,160 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +========================================================================== +idpf Linux* Base Driver for the Intel(R) Infrastructure Data Path Function +========================================================================== + +Intel idpf Linux driver. +Copyright(C) 2023 Intel Corporation. + +.. contents:: + +The idpf driver serves as both the Physical Function (PF) and Virtual Function +(VF) driver for the Intel(R) Infrastructure Data Path Function. + +Driver information can be obtained using ethtool, lspci, and ip. + +For questions related to hardware requirements, refer to the documentation +supplied with your Intel adapter. All hardware requirements listed apply to use +with Linux. + + +Identifying Your Adapter +======================== +For information on how to identify your adapter, and for the latest Intel +network drivers, refer to the Intel Support website: +http://www.intel.com/support + + +Additional Features and Configurations +====================================== + +ethtool +------- +The driver utilizes the ethtool interface for driver configuration and +diagnostics, as well as displaying statistical information. The latest ethtool +version is required for this functionality. If you don't have one yet, you can +obtain it at: +https://kernel.org/pub/software/network/ethtool/ + + +Viewing Link Messages +--------------------- +Link messages will not be displayed to the console if the distribution is +restricting system messages. In order to see network driver link messages on +your console, set dmesg to eight by entering the following:: + + # dmesg -n 8 + +.. note:: + This setting is not saved across reboots. + + +Jumbo Frames +------------ +Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU) +to a value larger than the default value of 1500. + +Use the ip command to increase the MTU size. For example, enter the following +where <ethX> is the interface number:: + + # ip link set mtu 9000 dev <ethX> + # ip link set up dev <ethX> + +.. note:: + The maximum MTU setting for jumbo frames is 9706. This corresponds to the + maximum jumbo frame size of 9728 bytes. + +.. note:: + This driver will attempt to use multiple page sized buffers to receive + each jumbo packet. This should help to avoid buffer starvation issues when + allocating receive packets. + +.. note:: + Packet loss may have a greater impact on throughput when you use jumbo + frames. If you observe a drop in performance after enabling jumbo frames, + enabling flow control may mitigate the issue. + + +Performance Optimization +======================== +Driver defaults are meant to fit a wide variety of workloads, but if further +optimization is required, we recommend experimenting with the following +settings. + + +Interrupt Rate Limiting +----------------------- +This driver supports an adaptive interrupt throttle rate (ITR) mechanism that +is tuned for general workloads. The user can customize the interrupt rate +control for specific workloads, via ethtool, adjusting the number of +microseconds between interrupts. + +To set the interrupt rate manually, you must disable adaptive mode:: + + # ethtool -C <ethX> adaptive-rx off adaptive-tx off + +For lower CPU utilization: + - Disable adaptive ITR and lower Rx and Tx interrupts. The examples below + affect every queue of the specified interface. + + - Setting rx-usecs and tx-usecs to 80 will limit interrupts to about + 12,500 interrupts per second per queue:: + + # ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 80 + tx-usecs 80 + +For reduced latency: + - Disable adaptive ITR and ITR by setting rx-usecs and tx-usecs to 0 + using ethtool:: + + # ethtool -C <ethX> adaptive-rx off adaptive-tx off rx-usecs 0 + tx-usecs 0 + +Per-queue interrupt rate settings: + - The following examples are for queues 1 and 3, but you can adjust other + queues. + + - To disable Rx adaptive ITR and set static Rx ITR to 10 microseconds or + about 100,000 interrupts/second, for queues 1 and 3:: + + # ethtool --per-queue <ethX> queue_mask 0xa --coalesce adaptive-rx off + rx-usecs 10 + + - To show the current coalesce settings for queues 1 and 3:: + + # ethtool --per-queue <ethX> queue_mask 0xa --show-coalesce + + + +Virtualized Environments +------------------------ +In addition to the other suggestions in this section, the following may be +helpful to optimize performance in VMs. + + - Using the appropriate mechanism (vcpupin) in the VM, pin the CPUs to + individual LCPUs, making sure to use a set of CPUs included in the + device's local_cpulist: /sys/class/net/<ethX>/device/local_cpulist. + + - Configure as many Rx/Tx queues in the VM as available. (See the idpf driver + documentation for the number of queues supported.) For example:: + + # ethtool -L <virt_interface> rx <max> tx <max> + + +Support +======= +For general information, go to the Intel support website at: +http://www.intel.com/support/ + +If an issue is identified with the released source code on a supported kernel +with a supported adapter, email the specific information related to the issue +to intel-wired-lan@lists.osuosl.org. + + +Trademarks +========== +Intel is a trademark or registered trademark of Intel Corporation or its +subsidiaries in the United States and/or other countries. + +* Other names and brands may be claimed as the property of others. |