2 files changed, 161 insertions, 0 deletions
diff --git a/Documentation/networking/device_drivers/ethernet/index.rst b/Documentation/networking/device_drivers/ethernet/index.rst
index 9827e816084b..43de285b8a92 100644
--- a/Documentation/networking/device_drivers/ethernet/index.rst
+++ b/Documentation/networking/device_drivers/ethernet/index.rst
@@ -32,6 +32,7 @@ Contents:
    intel/e1000
    intel/e1000e
    intel/fm10k
+   intel/idpf
    intel/igb
    intel/igbvf
    intel/ixgbe
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.