[v4] Documentation: i40e: Update kernel documentation

Message ID 20180514160932.26373-1-jeffrey.t.kirsher@intel.com
State Under Review
Delegated to: Jeff Kirsher
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  • [v4] Documentation: i40e: Update kernel documentation
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Commit Message

Jeff Kirsher May 14, 2018, 4:09 p.m.
Updated the i40e.txt kernel documentation with the latest information.

Looking to convert this kernel documentation to *.rst format in a
follow-on patch.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
v2: fixed up documentation based on community feedback and internal
    review
v3: found and fixed additional typos, acronyms not capitalized
v4: clean up out-of-tree driver reference, which does not belong to the
    kernel driver documentation.  Also cleaned up incorrect use of 's, as
    well as make command line examples consistent

 Documentation/networking/i40e.txt | 876 +++++++++++++++++++++++++-----
 1 file changed, 746 insertions(+), 130 deletions(-)

Patch

diff --git a/Documentation/networking/i40e.txt b/Documentation/networking/i40e.txt
index c2d6e1824b29..2f30984aed48 100644
--- a/Documentation/networking/i40e.txt
+++ b/Documentation/networking/i40e.txt
@@ -1,190 +1,806 @@ 
-Linux Base Driver for the Intel(R) Ethernet Controller XL710 Family
-===================================================================
 
-Intel i40e Linux driver.
-Copyright(c) 2013 Intel Corporation.
+i40e Linux* Base Driver for the Intel(R) Ethernet Controller 700 Series
+===============================================================================
+
+February 26, 2018
+Copyright(c) 1999-2018 Intel Corporation.
 
 Contents
 ========
 
+- Overview
 - Identifying Your Adapter
-- Additional Configurations
-- Performance Tuning
-- Known Issues
-- Support
+- Intel(R) Ethernet Flow Director
+- Additional Features & Configurations
 
 
 Identifying Your Adapter
-========================
+------------------------
+The driver in this kernel is compatible with devices based on the following:
+  * Intel(R) Ethernet Controller X710
+  * Intel(R) Ethernet Controller XL710
+  * Intel(R) Ethernet Network Connection X722
+  * Intel(R) Ethernet Controller XXV710
+
+For the best performance, make sure the latest NVM/FW is installed on your
+device.
+
+For information on how to identify your adapter, and for the latest NVM/FW
+images and Intel network drivers, refer to the Intel Support website:
+http://www.intel.com/support
+
+Driver information can be obtained using ethtool, lspci, and ifconfig.
+Instructions on updating ethtool can be found in the section Additional
+Configurations later in this document.
+
+For questions related to hardware requirements, refer to the documentation
+supplied with your Intel adapter. All hardware requirements listed apply to use
+with Linux.
+
+NOTE: 1 Gb devices based on the Intel(R) Ethernet Network Connection X722 do
+not support the following features:
+  * Data Center Bridging (DCB)
+  * QOS
+  * VMQ
+  * SR-IOV
+  * Task Encapsulation offload (VXLAN, NVGRE)
+  * Energy Efficient Ethernet (EEE)
+  * Auto-media detect
+
+
+SFP+ and QSFP+ Devices:
+-----------------------
+For information about supported media, refer to this document:
+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.
+
+NOTE: For connections based on Intel(R) Ethernet Controller 700 Series, support
+is dependent on your system board. Please see your vendor for details.
+
+NOTE: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.
+
+NOTE: In systems that do not have adequate airflow to cool the adapter and
+optical modules, you must use high temperature optical modules.
+
+
+TC0 must be enabled when setting up DCB on a switch
+---------------------------------------------------
+The kernel assumes that TC0 is available, and will disable Priority Flow
+Control (PFC) on the device if TC0 is not available. To fix this, ensure TC0 is
+enabled when setting up DCB on your switch.
+
+
+Virtual Functions (VFs)
+-----------------------
+Use sysfs to enable VFs. For example:
+#echo $num_vf_enabled > /sys/class/net/$dev/device/sriov_numvfs	#enable
+VFs
+#echo 0 > /sys/class/net/$dev/device/sriov_numvfs	#disable VFs
+
+NOTE: Neither the device nor the driver control how VFs are mapped into config
+space. Bus layout will vary by operating system. On operating systems that
+support it, you can check sysfs to find the mapping. Some hardware
+configurations support fewer SR-IOV instances, as the whole XL710 controller
+(all functions) is limited to 128 SR-IOV interfaces in total.
+NOTE: When SR-IOV mode is enabled, hardware VLAN filtering and VLAN tag
+stripping/insertion will remain enabled. Please remove the old VLAN filter
+before the new VLAN filter is added. For example,
+ip link set eth0 vf 0 vlan 100	#set vlan 100 for VF 0
+ip link set eth0 vf 0 vlan 0	#Delete vlan 100
+ip link set eth0 vf 0 vlan 200	#set a new vlan 200 for VF 0
+
+
+Configuring SR-IOV for improved network security
+------------------------------------------------
+In a virtualized environment, on Intel(R) Ethernet Server Adapters that support
+SR-IOV, the virtual function (VF) may be subject to malicious behavior.
+Software-generated layer two frames, like IEEE 802.3x (link flow control), IEEE
+802.1Qbb (priority based flow-control), and others of this type, are not
+expected and can throttle traffic between the host and the virtual switch,
+reducing performance. To resolve this issue, configure all SR-IOV enabled ports
+for VLAN tagging. This configuration allows unexpected, and potentially
+malicious, frames to be dropped.
+
+
+Configuring VLAN tagging on SR-IOV enabled adapter ports
+--------------------------------------------------------
+To configure VLAN tagging for the ports on an SR-IOV enabled adapter, use the
+following command. The VLAN configuration should be done before the VF driver
+is loaded or the VM is booted.
+
+$ ip link set dev <PF netdev id> vf <id> vlan <vlan id>
+
+For example, the following instructions will configure PF eth0 and the first VF
+on VLAN 10.
+$ ip link set dev eth0 vf 0 vlan 10
+
+
+VLAN Tag Packet Steering
+------------------------
+Allows you to send all packets with a specific VLAN tag to a particular SR-IOV
+virtual function (VF). Further, this feature allows you to designate a
+particular VF as trusted, and allows that trusted VF to request selective
+promiscuous mode on the Physical Function (PF).
+
+To set a VF as trusted or untrusted, enter the following command in the
+Hypervisor:
+  # ip link set dev eth0 vf 1 trust [on|off]
+
+Once the VF is designated as trusted, use the following commands in the VM to
+set the VF to promiscuous mode.
+  For promiscuous all:
+  # ip link set eth2 promisc on
+    Where eth2 is a VF interface in the VM
+  For promiscuous Multicast:
+  # ip link set eth2 allmulticast on
+    Where eth2 is a VF interface in the VM
+
+NOTE: By default, the ethtool priv-flag vf-true-promisc-support is set to
+"off",meaning that promiscuous mode for the VF will be limited. To set the
+promiscuous mode for the VF to true promiscuous and allow the VF to see all
+ingress traffic, use the following command.
+  # ethtool -set-priv-flags p261p1 vf-true-promisc-support on
+The vf-true-promisc-support priv-flag does not enable promiscuous mode; rather,
+it designates which type of promiscuous mode (limited or true) you will get
+when you enable promiscuous mode using the ip link commands above. Note that
+this is a global setting that affects the entire device. However,the
+vf-true-promisc-support priv-flag is only exposed to the first PF of the
+device. The PF remains in limited promiscuous mode (unless it is in MFP mode)
+regardless of the vf-true-promisc-support setting.
+
+Now add a VLAN interface on the VF interface.
+  # ip link add link eth2 name eth2.100 type vlan id 100
+
+Note that the order in which you set the VF to promiscuous mode and add the
+VLAN interface does not matter (you can do either first). The end result in
+this example is that the VF will get all traffic that is tagged with VLAN 100.
+
+
+Enabling a VF link if the port is disconnected
+----------------------------------------------
+If the physical function (PF) link is down, you can force link up (from the
+host PF) on any virtual functions (VF) bound to the PF. Note that this requires
+kernel support (Redhat kernel 3.10.0-327 or newer, upstream kernel 3.11.0 or
+newer, and associated iproute2 user space support). If the following command
+does not work, it may not be supported by your system. The following command
+forces link up on VF 0 bound to PF eth0:
+  ip link set eth0 vf 0 state enable
+
+
+Do not unload port driver if VF with active VM is bound to it
+-------------------------------------------------------------
+Do not unload a port's driver if a Virtual Function (VF) with an active Virtual
+Machine (VM) is bound to it. Doing so will cause the port to appear to hang.
+Once the VM shuts down, or otherwise releases the VF, the command will complete.
+
+
+Intel(R) Ethernet Flow Director
+-------------------------------
+The Intel Ethernet Flow Director performs the following tasks:
+
+- Directs receive packets according to their flows to different queues.
+- Enables tight control on routing a flow in the platform.
+- Matches flows and CPU cores for flow affinity.
+- Supports multiple parameters for flexible flow classification and load
+  balancing (in SFP mode only).
+
+NOTE: An included script (set_irq_affinity) automates setting the IRQ to CPU
+affinity.
+
+NOTE: The Linux i40e driver supports the following flow types: IPv4, TCPv4, and
+UDPv4. For a given flow type, it supports valid combinations of IP addresses
+(source or destination) and UDP/TCP ports (source and destination). For
+example, you can supply only a source IP address, a source IP address and a
+destination port, or any combination of one or more of these four parameters.
+
+NOTE: The Linux i40e driver allows you to filter traffic based on a
+user-defined flexible two-byte pattern and offset by using the ethtool user-def
+and mask fields. Only L3 and L4 flow types are supported for user-defined
+flexible filters. For a given flow type, you must clear all Intel Ethernet Flow
+Director filters before changing the input set (for that flow type).
+
+ethtool commands:
+
+To enable or disable the Intel Ethernet Flow Director:
+
+  # ethtool -K ethX ntuple <on|off>
+
+When disabling ntuple filters, all the user programmed filters are flushed from
+the driver cache and hardware. All needed filters must be re-added when ntuple
+is re-enabled.
+
+To add a filter that directs packet to queue 2, use -U or -N switch:
+
+  # ethtool -N ethX flow-type tcp4 src-ip 192.168.10.1 dst-ip \
+  192.168.10.2 src-port 2000 dst-port 2001 action 2 [loc 1]
+
+To set a filter using only the source and destination IP address:
+
+  # ethtool -N ethX flow-type tcp4 src-ip 192.168.10.1 dst-ip \
+  192.168.10.2 action 2 [loc 1]
+
+To set a filter based on a user defined pattern and offset:
+
+  # ethtool -N ethX flow-type tcp4 src-ip 192.168.10.1 dst-ip \
+  192.168.10.2 user-def 0xffffffff00000001 m 0x40 action 2 [loc 1]
+
+  where the value of the user-def field (0xffffffff00000001) is the
+  pattern and m 0x40 is the offset.
+
+Note that in this case the mask (m 0x40) parameter is used with the user-def
+field, whereas for cloud filter support the mask parameter is not used.
+
+To see the list of filters currently present:
+  # ethtool <-u|-n> ethX
+
+
+Application Targeted Routing (ATR) Perfect Filters
+--------------------------------------------------
+ATR is enabled by default when the kernel is in multiple transmit queue mode.
+An ATR Intel Ethernet Flow Director filter rule is added when a TCP-IP flow
+starts and is deleted when the flow ends. When a TCP-IP Intel Ethernet Flow
+Director rule is added from ethtool (Sideband filter), ATR is turned off by the
+driver. To re-enable ATR, the sideband can be disabled with the ethtool -K
+option. For example:
+ethtool –K [adapter] ntuple [off|on]
+
+If sideband is re-enabled after ATR is re-enabled, ATR remains enabled until a
+TCP-IP flow is added. When all TCP-IP sideband rules are deleted, ATR is
+automatically re-enabled.
+
+Packets that match the ATR rules are counted in fdir_atr_match stats in
+ethtool, which also can be used to verify whether ATR rules still exist.
+
+
+Sideband Perfect Filters
+------------------------
+Sideband Perfect Filters are used to direct traffic that matches specified
+characteristics. They are enabled through ethtool's ntuple interface. To add a
+new filter use the following command:
+  ethtool -U <device> flow-type <type> src-ip <ip> dst-ip <ip> src-port <port>
+dst-port <port> action <queue>
+Where:
+  <device> - the ethernet device to program
+  <type> - can be ip4, tcp4, udp4, or sctp4
+  <ip> - the ip address to match on
+  <port> - the port number to match on
+  <queue> - the queue to direct traffic towards (-1 discards the matched
+traffic)
+Use the following command to display all of the active filters:
+  ethtool -u <device>
+Use the following command to delete a filter:
+  ethtool -U <device> delete <N>
+Where <N> is the filter id displayed when printing all the active filters, and
+may also have been specified using "loc <N>" when adding the filter.
 
-The driver in this release is compatible with the Intel Ethernet
-Controller XL710 Family.
+The following example matches TCP traffic sent from 192.168.0.1, port 5300,
+directed to 192.168.0.5, port 80, and sends it to queue 7:
+  ethtool -U enp130s0 flow-type tcp4 src-ip 192.168.0.1 dst-ip 192.168.0.5
+  src-port 5300 dst-port 80 action 7
+
+For each flow-type, the programmed filters must all have the same matching
+input set. For example, issuing the following two commands is acceptable:
+  ethtool -U enp130s0 flow-type ip4 src-ip 192.168.0.1 src-port 5300 action 7
+  ethtool -U enp130s0 flow-type ip4 src-ip 192.168.0.5 src-port 55 action 10
+Issuing the next two commands, however, is not acceptable, since the first
+specifies src-ip and the second specifies dst-ip:
+  ethtool -U enp130s0 flow-type ip4 src-ip 192.168.0.1 src-port 5300 action 7
+  ethtool -U enp130s0 flow-type ip4 dst-ip 192.168.0.5 src-port 55 action 10
+The second command will fail with an error. You may program multiple filters
+with the same fields, using different values, but, on one device, you may not
+program two tcp4 filters with different matching fields.
+
+Matching on a sub-portion of a field is not supported by the i40e driver, thus
+partial mask fields are not supported.
 
-For more information on how to identify your adapter, go to the Adapter &
-Driver ID Guide at:
+The driver also supports matching user-defined data within the packet payload.
+This flexible data is specified using the "user-def" field of the ethtool
+command in the following way:
++----------------------------+--------------------------+
+| 31    28    24    20    16 | 15    12    8    4    0  |
++----------------------------+--------------------------+
+| offset into packet payload | 2 bytes of flexible data |
++----------------------------+--------------------------+
+
+For example,
+  ... user-def 0x4FFFF ...
+
+tells the filter to look 4 bytes into the payload and match that value against
+0xFFFF. The offset is based on the beginning of the payload, and not the
+beginning of the packet. Thus
+
+  flow-type tcp4 ... user-def 0x8BEAF ...
+
+would match TCP/IPv4 packets which have the value 0xBEAF 8 bytes into the
+TCP/IPv4 payload.
+
+Note that ICMP headers are parsed as 4 bytes of header and 4 bytes of payload.
+Thus to match the first byte of the payload, you must actually add 4 bytes to
+the offset. Also note that IPv4 filters match both ICMP frames as well as raw
+(unknown) IPv4 frames, where the payload will be the L3 payload of the IPv4
+frame.
+
+The maximum offset is 64. The hardware will only read up to 64 bytes of data
+from the payload. The offset must be even because the flexible data is 2 bytes
+long and must be aligned to byte 0 of the packet payload.
+
+The user-defined flexible offset is also considered part of the input set and
+cannot be programmed separately for multiple filters of the same type. However,
+the flexible data is not part of the input set and multiple filters may use the
+same offset but match against different data.
+
+To create filters that direct traffic to a specific Virtual Function, use the
+"action" parameter. Specify the action as a 64 bit value, where the lower 32
+bits represents the queue number, while the next 8 bits represent which VF.
+Note that 0 is the PF, so the VF identifier is offset by 1. For example:
+
+  ... action 0x800000002 ...
+
+specifies to direct traffic to Virtual Function 7 (8 minus 1) into queue 2 of
+that VF.
+
+Note that these filters will not break internal routing rules, and will not
+route traffic that otherwise would not have been sent to the specified Virtual
+Function.
+
+
+Additional Features and Configurations
+-------------------------------------------
+
+Setting the link-down-on-close Private Flag
+-------------------------------------------
+When the link-down-on-close private flag is set to "on", the port's link will
+go down when the interface is brought down using the ifconfig ethX down command.
+
+Use ethtool to view and set link-down-on-close, as follows:
+  ethtool --show-priv-flags ethX
+  ethtool --set-priv-flags ethX link-down-on-close [on|off]
+
+
+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 ifconfig command to increase the MTU size. For example, enter the
+following where <x> is the interface number:
+
+   ifconfig eth<x> mtu 9000 up
+Alternatively, you can use the ip command as follows:
+   ip link set mtu 9000 dev eth<x>
+   ip link set up dev eth<x>
 
-    http://support.intel.com/support/network/sb/CS-012904.htm
+This setting is not saved across reboots. The setting change can be made
+permanent by adding 'MTU=9000' to the file:
+/etc/sysconfig/network-scripts/ifcfg-eth<x> for RHEL or to the file
+/etc/sysconfig/network/<config_file> for SLES.
 
+NOTE: The maximum MTU setting for Jumbo Frames is 9702. This value coincides
+with the maximum Jumbo Frames size of 9728 bytes.
 
-Enabling the driver
-===================
+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.
 
-The driver is enabled via the standard kernel configuration system,
-using the make command:
 
-     make config/oldconfig/menuconfig/etc.
+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. Download it at:
+http://ftp.kernel.org/pub/software/network/ethtool/
 
-The driver is located in the menu structure at:
+Supported ethtool Commands and Options for Filtering
+----------------------------------------------------
+-n --show-nfc
+  Retrieves the receive network flow classification configurations.
 
-	-> Device Drivers
-	  -> Network device support (NETDEVICES [=y])
-	    -> Ethernet driver support
-	      -> Intel devices
-	        -> Intel(R) Ethernet Controller XL710 Family
+rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6
+  Retrieves the hash options for the specified network traffic type.
 
-Additional Configurations
-=========================
+-N --config-nfc
+  Configures the receive network flow classification.
 
-  Generic Receive Offload (GRO)
-  -----------------------------
-  The driver supports the in-kernel software implementation of GRO.  GRO has
-  shown that by coalescing Rx traffic into larger chunks of data, CPU
-  utilization can be significantly reduced when under large Rx load.  GRO is
-  an evolution of the previously-used LRO interface.  GRO is able to coalesce
-  other protocols besides TCP.  It's also safe to use with configurations that
-  are problematic for LRO, namely bridging and iSCSI.
+rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6
+m|v|t|s|d|f|n|r...
+  Configures the hash options for the specified network traffic type.
 
-  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.
+  udp4 UDP over IPv4
+  udp6 UDP over IPv6
 
-  The latest release of ethtool can be found from
-  https://www.kernel.org/pub/software/network/ethtool
+  f Hash on bytes 0 and 1 of the Layer 4 header of the Rx packet.
+  n Hash on bytes 2 and 3 of the Layer 4 header of the Rx packet.
 
 
-  Flow Director n-ntuple traffic filters (FDir)
-  ---------------------------------------------
-  The driver utilizes the ethtool interface for configuring ntuple filters,
-  via "ethtool -N <device> <filter>".
+Speed and Duplex Configuration
+------------------------------
+In addressing speed and duplex configuration issues, you need to distinguish
+between copper-based adapters and fiber-based adapters.
 
-  The sctp4, ip4, udp4, and tcp4 flow types are supported with the standard
-  fields including src-ip, dst-ip, src-port and dst-port. The driver only
-  supports fully enabling or fully masking the fields, so use of the mask
-  fields for partial matches is not supported.
+In the default mode, an Intel(R) Ethernet Network Adapter using copper
+connections will attempt to auto-negotiate with its link partner to determine
+the best setting. If the adapter cannot establish link with the link partner
+using auto-negotiation, you may need to manually configure the adapter and link
+partner to identical settings to establish link and pass packets. This should
+only be needed when attempting to link with an older switch that does not
+support auto-negotiation or one that has been forced to a specific speed or
+duplex mode. Your link partner must match the setting you choose. 1 Gbps speeds
+and higher cannot be forced. Use the autonegotiation advertising setting to
+manually set devices for 1 Gbps and higher.
 
-  Additionally, the driver supports using the action to specify filters for a
-  Virtual Function. You can specify the action as a 64bit value, where the
-  lower 32 bits represents the queue number, while the next 8 bits represent
-  which VF. Note that 0 is the PF, so the VF identifier is offset by 1. For
-  example:
+NOTE: You cannot set the speed for devices based on the Intel(R) Ethernet
+Network Adapter XXV710 based devices.
 
-    ... action 0x800000002 ...
+Speed, duplex, and autonegotiation advertising are configured through the
+ethtool* utility. ethtool is included with all versions of Red Hat after Red
+Hat 7.2. For the latest version, download and install ethtool from the
+following website:
 
-  Would indicate to direct traffic for Virtual Function 7 (8 minus 1) on queue
-  2 of that VF.
+   http://ftp.kernel.org/pub/software/network/ethtool/
 
-  The driver also supports using the user-defined field to specify 2 bytes of
-  arbitrary data to match within the packet payload in addition to the regular
-  fields. The data is specified in the lower 32bits of the user-def field in
-  the following way:
+Caution: Only experienced network administrators should force speed and duplex
+or change autonegotiation advertising manually. The settings at the switch must
+always match the adapter settings. Adapter performance may suffer or your
+adapter may not operate if you configure the adapter differently from your
+switch.
 
-  +----------------------------+---------------------------+
-  | 31    28    24    20    16 | 15    12     8     4     0|
-  +----------------------------+---------------------------+
-  | offset into packet payload |  2 bytes of flexible data |
-  +----------------------------+---------------------------+
+An Intel(R) Ethernet Network Adapter using fiber-based connections, however,
+will not attempt to auto-negotiate with its link partner since those adapters
+operate only in full duplex and only at their native speed.
 
-  As an example,
 
-    ... user-def 0x4FFFF ....
+NAPI
+----
+NAPI (Rx polling mode) is supported in the i40e driver.
+For more information on NAPI, see
+https://www.linuxfoundation.org/collaborate/workgroups/networking/napi
 
-  means to match the value 0xFFFF 4 bytes into the packet payload. Note that
-  the offset is based on the beginning of the payload, and not the beginning
-  of the packet. Thus
 
-    flow-type tcp4 ... user-def 0x8BEAF ....
+Flow Control
+------------
+Ethernet Flow Control (IEEE 802.3x) can be configured with ethtool to enable
+receiving and transmitting pause frames for i40e. When transmit is enabled,
+pause frames are generated when the receive packet buffer crosses a predefined
+threshold. When receive is enabled, the transmit unit will halt for the time
+delay specified when a pause frame is received.
 
-  would match TCP/IPv4 packets which have the value 0xBEAF 8bytes into the
-  TCP/IPv4 payload.
+NOTE: You must have a flow control capable link partner.
 
-  For ICMP, the hardware parses the ICMP header as 4 bytes of header and 4
-  bytes of payload, so if you want to match an ICMP frames payload you may need
-  to add 4 to the offset in order to match the data.
+Flow Control is  by default.
 
-  Furthermore, the offset can only be up to a value of 64, as the hardware
-  will only read up to 64 bytes of data from the payload. It must also be even
-  as the flexible data is 2 bytes long and must be aligned to byte 0 of the
-  packet payload.
+Use ethtool to change the flow control settings.
 
-  When programming filters, the hardware is limited to using a single input
-  set for each flow type. This means that it is an error to program two
-  different filters with the same type that don't match on the same fields.
-  Thus the second of the following two commands will fail:
+To enable or disable Rx or Tx Flow Control:
+ethtool -A eth? rx <on|off> tx <on|off>
+Note: This command only enables or disables Flow Control if auto-negotiation is
+disabled. If auto-negotiation is enabled, this command changes the parameters
+used for auto-negotiation with the link partner.
 
-    ethtool -N <device> flow-type tcp4 src-ip 192.168.0.7 action 5
-    ethtool -N <device> flow-type tcp4 dst-ip 192.168.15.18 action 1
+To enable or disable auto-negotiation:
+ethtool -s eth? autoneg <on|off>
+Note: Flow Control auto-negotiation is part of link auto-negotiation. Depending
+on your device, you may not be able to change the auto-negotiation setting.
 
-  This is because the first filter will be accepted and reprogram the input
-  set for TCPv4 filters, but the second filter will be unable to reprogram the
-  input set until all the conflicting TCPv4 filters are first removed.
 
-  Note that the user-defined flexible offset is also considered part of the
-  input set and cannot be programmed separately for multiple filters of the
-  same type. However, the flexible data is not part of the input set and
-  multiple filters may use the same offset but match against different data.
+RSS Hash Flow
+-------------
 
-  Data Center Bridging (DCB)
-  --------------------------
-  DCB configuration is not currently supported.
+Allows you to set the hash bytes per flow type and any combination of one or
+more options for Receive Side Scaling (RSS) hash byte configuration.
 
-  FCoE
-  ----
-  The driver supports Fiber Channel over Ethernet (FCoE) and Data Center
-  Bridging (DCB) functionality. Configuring DCB and FCoE is outside the scope
-  of this driver doc. Refer to http://www.open-fcoe.org/ for FCoE project
-  information and http://www.open-lldp.org/ or email list
-  e1000-eedc@lists.sourceforge.net for DCB information.
+#ethtool -N <dev> rx-flow-hash <type> <option>
 
-  MAC and VLAN anti-spoofing feature
-  ----------------------------------
-  When a malicious driver attempts to send a spoofed packet, it is dropped by
-  the hardware and not transmitted.  An interrupt is sent to the PF driver
-  notifying it of the spoof attempt.
+Where <type> is:
+  tcp4	signifying TCP over IPv4
+  udp4	signifying UDP over IPv4
+  tcp6	signifying TCP over IPv6
+  udp6	signifying UDP over IPv6
+And <option> is one or more of:
+  s	Hash on the IP source address of the Rx packet.
+  d	Hash on the IP destination address of the Rx packet.
+  f	Hash on bytes 0 and 1 of the Layer 4 header of the Rx packet.
+  n	Hash on bytes 2 and 3 of the Layer 4 header of the Rx packet.
 
-  When a spoofed packet is detected the PF driver will send the following
-  message to the system log (displayed by  the "dmesg" command):
 
-  Spoof event(s) detected on VF (n)
+MAC and VLAN anti-spoofing feature
+----------------------------------
+When a malicious driver attempts to send a spoofed packet, it is dropped by the
+hardware and not transmitted.
+NOTE: This feature can be disabled for a specific Virtual Function (VF):
+ip link set <pf dev> vf <vf id> spoofchk {off|on}
 
-  Where n=the VF that attempted to do the spoofing.
 
+IEEE 1588 Precision Time Protocol (PTP) Hardware Clock (PHC)
+------------------------------------------------------------
+Precision Time Protocol (PTP) is used to synchronize clocks in a computer
+network. PTP support varies among Intel devices that support this driver. Use
+"ethtool -T <netdev name>" to get a definitive list of PTP capabilities
+supported by the device.
 
-Performance Tuning
-==================
 
-An excellent article on performance tuning can be found at:
+IEEE 802.1ad (QinQ) Support
+---------------------------
 
-http://www.redhat.com/promo/summit/2008/downloads/pdf/Thursday/Mark_Wagner.pdf
+The IEEE 802.1ad standard, informally known as QinQ, allows for multiple VLAN
+IDs within a single Ethernet frame. VLAN IDs are sometimes referred to as
+"tags," and multiple VLAN IDs are thus referred to as a "tag stack." Tag stacks
+allow L2 tunneling and the ability to segregate traffic within a particular
+VLAN ID, among other uses.
 
+The following are examples of how to configure 802.1ad (QinQ):
+  ip link add link eth0 eth0.24 type vlan proto 802.1ad id 24
+  ip link add link eth0.24 eth0.24.371 type vlan proto 802.1Q id 371
+Where "24" and "371" are example VLAN IDs.
 
-Known Issues
-============
+NOTES:
+- 802.1ad (QinQ)is supported in 3.19 and later kernels.
+- Receive checksum offloads, cloud filters, and VLAN acceleration are not
+supported for 802.1ad (QinQ) packets.
 
 
-Support
-=======
+VXLAN and GENEVE Overlay HW Offloading
+--------------------------------------
 
-For general information, go to the Intel support website at:
+Virtual Extensible LAN (VXLAN) allows you to extend an L2 network over an L3
+network, which may be useful in a virtualized or cloud environment. Some
+Intel(R) Ethernet Network devices perform VXLAN processing, offloading it from
+the operating system. This reduces CPU utilization.
 
-    http://support.intel.com
+VXLAN offloading is controlled by the Tx and Rx checksum offload options
+provided by ethtool. That is, if Tx checksum offload is enabled, and the
+adapter has the capability, VXLAN offloading is also enabled.
 
-or the Intel Wired Networking project hosted by Sourceforge at:
+Support for VXLAN and GENEVE HW offloading is dependent on kernel support of
+the HW offloading features.
+
+
+Multiple Functions per Port
+---------------------------
+
+Some adapters based on the Intel Ethernet Controller X710/XL710 support
+multiple functions on a single physical port. Configure these functions through
+the System Setup/BIOS.
+
+Minimum TX Bandwidth is the guaranteed minimum data transmission bandwidth, as
+a percentage of the full physical port link speed, that the partition will
+receive. The bandwidth the partition is awarded will never fall below the level
+you specify.
+
+The range for the minimum bandwidth values is:
+1 to ((100 minus # of partitions on the physical port) plus 1)
+For example, if a physical port has 4 partitions, the range would be:
+1 to ((100 - 4) + 1 = 97)
+
+The Maximum Bandwidth percentage represents the maximum transmit bandwidth
+allocated to the partition as a percentage of the full physical port link
+speed. The accepted range of values is 1-100. The value is used as a limiter,
+should you chose that any one particular function not be able to consume 100%
+of a port's bandwidth (should it be available). The sum of all the values for
+Maximum Bandwidth is not restricted, because no more than 100% of a port's
+bandwidth can ever be used.
+
+NOTE: X710/XXV710 devices fail to enable Max VFs (64) when Multiple Functions
+per Port (MFP) and SR-IOV are enabled. An error from i40e is logged that says
+"add vsi failed for VF N, aq_err 16". To workaround the issue, enable less than
+64 virtual functions (VFs).
+
+
+Data Center Bridging (DCB)
+--------------------------
+NOTE:
+The kernel assumes that TC0 is available, and will disable Priority Flow
+Control (PFC) on the device if TC0 is not available. To fix this, ensure TC0 is
+enabled when setting up DCB on your switch.
+
+
+DCB is a configuration Quality of Service implementation in hardware. It uses
+the VLAN priority tag (802.1p) to filter traffic. That means that there are 8
+different priorities that traffic can be filtered into. It also enables
+priority flow control (802.1Qbb) which can limit or eliminate the number of
+dropped packets during network stress. Bandwidth can be allocated to each of
+these priorities, which is enforced at the hardware level (802.1Qaz).
+
+Adapter firmware implements LLDP and DCBX protocol agents as per 802.1AB and
+802.1Qaz respectively. The firmware based DCBX agent runs in willing mode only
+and can accept settings from a DCBX capable peer. Software configuration of
+DCBX parameters via dcbtool/lldptool are not supported.
+
+NOTE: Firmware LLDP can be disabled by setting the private flag disable-fw-lldp.
+
+The i40e driver implements the DCB netlink interface layer to allow user-space
+to communicate with the driver and query DCB configuration for the port.
+
+
+Interrupt Rate Limiting
+-----------------------
+
+The Intel(R) Ethernet Controller XL710 family supports an interrupt rate
+limiting mechanism. The user can control, via ethtool, the number of
+microseconds between interrupts.
+
+Syntax:
+# ethtool -C ethX rx-usecs-high N
+
+Valid Range: 0-235 (0=no limit)
+
+The range of 0-235 microseconds provides an effective range of 4,310 to 250,000
+interrupts per second. The value of rx-usecs-high can be set independently of
+rx-usecs and tx-usecs in the same ethtool command, and is also independent of
+the adaptive interrupt moderation algorithm. The underlying hardware supports
+granularity in 4-microsecond intervals, so adjacent values may result in the
+same interrupt rate.
+
+One possible use case is the following:
+# ethtool -C ethX adaptive-rx off adaptive-tx off rx-usecs-high 20 rx-usecs 5
+tx-usecs 5
+
+The above command would disable adaptive interrupt moderation, and allow a
+maximum of 5 microseconds before indicating a receive or transmit was complete.
+However, instead of resulting in as many as 200,000 interrupts per second, it
+limits total interrupts per second to 50,000 via the rx-usecs-high parameter.
+
+
+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.
+
+NOTE: For better performance when processing small (64B) frame sizes, try
+enabling Hyper threading in the BIOS in order to increase the number of logical
+cores in the system and subsequently increase the number of queues available to
+the adapter.
+
+Virtualized Environments:
+
+1. Disable XPS on both ends by using the included virt_perf_default script
+  or by running the following command as root:
+  for file in `ls /sys/class/net/<ethX>/queues/tx-*/xps_cpus`;
+  do echo 0 > $file; done
+
+2. 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.
 
-    http://e1000.sourceforge.net
+3. Configure as many Rx/Tx queues in the VM as available. Do not rely on
+  the default setting of 1.
+
+
+Non-virtualized Environments
+
+Pin the adapter's IRQs to specific cores by disabling the irqbalance service
+and using the included set_irq_affinity script. Please see the script's help
+text for further options.
+
+  - The following settings will distribute the IRQs across all the cores
+    evenly:
+
+    # scripts/set_irq_affinity -x all <interface1> , [ <interface2>, ... ]
+
+  - The following settings will distribute the IRQs across all the cores that
+    are local to the adapter (same NUMA node):
+
+    # scripts/set_irq_affinity -x local <interface1> ,[ <interface2>, ... ]
+
+For very CPU intensive workloads, we recommend pinning the IRQs to all cores.
+
+For IP Forwarding: Disable Adaptive ITR and lower Rx and Tx interrupts per
+queue using ethtool.
+
+  - Setting rx-usecs and tx-usecs to 125 will limit interrupts to about 8000
+    interrupts per second per queue.
+
+    # ethtool -C <interface> adaptive-rx off adaptive-tx off rx-usecs 125
+    tx-usecs 125
+
+For lower CPU utilization: Disable Adaptive ITR and lower Rx and Tx interrupts
+per queue using ethtool.
+
+  - Setting rx-usecs and tx-usecs to 250 will limit interrupts to about 4000
+    interrupts per second per queue.
+
+    # ethtool -C <interface> adaptive-rx off adaptive-tx off rx-usecs 250
+    tx-usecs 250
+
+For lower latency: Disable Adaptive ITR and ITR by setting Rx and Tx to 0 using
+ethtool.
+
+    # ethtool -C <interface> adaptive-rx off adaptive-tx off rx-usecs 0
+    tx-usecs 0
+
+
+Application Device Queues (ADq)
+-------------------------------
+
+Application Device Queues (ADq) allows you to dedicate one or more queues to a
+specific application. This can reduce latency for the specified application,
+and allow Tx traffic to be rate limited per application. Follow the steps below
+to set ADq.
+
+NOTE: Run all tc commands from the iproute2 <pathtoiproute2>/tc/ directory.
+  1. Create traffic classes (TCs). Maximum of 8 TCs can be created per
+  interface. The shaper bw_rlimit parameter is optional.
+  Example:
+  Sets up two tcs, tc0 and tc1, with 16 queues each and max tx rate set
+  to 1Gbit for tc0 and 3Gbit for tc1.
+  # tc qdisc add dev <interface> root mqprio num_tc 2 map 0 0 0 0 1 1 1 1
+  queues 16@0 16@16 hw 1 mode channel shaper bw_rlimit min_rate 1Gbit 2Gbit
+  max_rate 1Gbit 3Gbit
+
+  map: priority mapping for up to 16 priorities to tcs
+  (e.g. map 0 0 0 0 1 1 1 1 sets priorities 0-3 to use tc0 and 4-7 to
+  use tc1)
+
+  queues: for each tc, <num queues>@<offset> (e.g. queues 16@0 16@16 assigns
+  16 queues to tc0 at offset 0 and 16 queues to tc1 at offset 16. Max total
+  number of queues for all tcs is 64 or number of cores, whichever is
+  lower.)
+
+  hw 1 mode channel: ‘channel’ with ‘hw’ set to 1 is a new new hardware
+  offload mode in mqprio that makes full use of the mqprio options, the
+  TCs, the queue configurations, and the QoS parameters.
+
+  shaper bw_rlimit: for each tc, sets minimum and maximum bandwidth rates.
+  Totals must be equal or less than port speed.
+  For example: min_rate 1Gbit 3Gbit:
+  Verify bandwidth limit using network monitoring tools such as ifstat
+  or sar –n DEV [interval] [number of samples]
+
+NOTE: Setting up channels via ethtool (ethtool -L) is not supported when the
+TCs are configured using mqprio.
+
+  2. Enable HW TC offload on interface:
+  # ethtool -K <interface> hw-tc-offload on
+  3. Apply TCs to ingress (RX) flow of interface:
+  # tc qdisc add dev <interface> ingress
+NOTES:
+- You must have kernel version 4.15 or later and the sch_mqprio, act_mirred
+  and cls_flower modules loaded to set ADq
+- You must have iproute2 latest version
+- NVM version 6.01 or later is required.
+- ADq cannot be enabled when any the following features are enabled: Data
+  Center Bridging (DCB), Multiple Functions per Port (MFP), or Sideband
+  Filters.
+- If another driver (for example, DPDK) has set cloud filters, you cannot
+  enable ADq.
+- Tunnel filters are not supported in ADq. If encapsulated packets do
+  arrive in non-tunnel mode, filtering will be done on the inner headers.
+  For example, for VXLAN traffic in non-tunnel mode, PCTYPE is identified
+  as a VXLAN encapsulated packet, outer headers are ignored. Therefore,
+  inner headers are matched.
+- If a TC filter on a PF matches traffic over a VF (on the PF), that
+  traffic will be routed to the appropriate queue of the PF, and will
+  not be passed on the VF. Such traffic will end up getting dropped higher
+  up in the TCP/IP stack as it does not match PF address data.
+- If traffic matches multiple TC filters that point to different TCs,
+  that traffic will be duplicated and sent to all matching TC queues.
+  The hardware switch mirrors the packet to a VSI list when multiple
+  filters are matched.
+
+
+Support
+-------
+For general information, go to the Intel support website at:
+http://www.intel.com/support/
+
+or the Intel Wired Networking project hosted by Sourceforge at:
+http://sourceforge.net/projects/e1000
 
-If an issue is identified with the released source code on the supported
-kernel with a supported adapter, email the specific information related
-to the issue to e1000-devel@lists.sourceforge.net and copy
-netdev@vger.kernel.org.
+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 e1000-devel@lists.sf.net.