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diff --git a/Documentation/networking/i40e.rst b/Documentation/networking/i40e.rst new file mode 100644 index 0000000000000..0cc16c525d102 --- /dev/null +++ b/Documentation/networking/i40e.rst @@ -0,0 +1,770 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Linux* Base Driver for the Intel(R) Ethernet Controller 700 Series +================================================================== + +Intel 40 Gigabit Linux driver. +Copyright(c) 1999-2018 Intel Corporation. + +Contents +======== + +- Overview +- Identifying Your Adapter +- Intel(R) Ethernet Flow Director +- Additional Configurations +- Known Issues +- 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. + + +Identifying Your Adapter +======================== +The driver 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: +https://www.intel.com/support + +SFP+ and QSFP+ Devices +---------------------- +For information about supported media, refer to this document: +https://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. 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: 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 systems that do not have adequate airflow to cool the adapter and +optical modules, you must use high temperature optical modules. + +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 + +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. + +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: 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). + +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 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 matching 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 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. + +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 ip4 filters match both ICMP frames as well as raw +(unknown) ip4 frames, where the payload will be the L3 payload of the IP4 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. + +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> + +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 + /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. + +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. + +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: +https://www.kernel.org/pub/software/network/ethtool/ + +Supported ethtool Commands and Options for Filtering +---------------------------------------------------- +-n --show-nfc + Retrieves the receive network flow classification configurations. + +rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 + Retrieves the hash options for the specified network traffic type. + +-N --config-nfc + Configures the receive network flow classification. + +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. + +udp4 UDP over IPv4 +udp6 UDP over IPv6 + +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. + +Speed and Duplex Configuration +------------------------------ +In addressing speed and duplex configuration issues, you need to distinguish +between copper-based adapters and fiber-based adapters. + +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. + +NOTE: You cannot set the speed for devices based on the Intel(R) Ethernet +Network Adapter XXV710 based devices. + +Speed, duplex, and autonegotiation advertising are configured through the +ethtool* utility. + +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. + +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. + +NAPI +---- +NAPI (Rx polling mode) is supported in the i40e driver. +For more information on NAPI, see +https://wiki.linuxfoundation.org/networking/napi + +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. + +NOTE: You must have a flow control capable link partner. + +Flow Control is on by default. + +Use ethtool to change the flow control settings. + +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. + +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. + +RSS Hash Flow +------------- +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. + +:: + + # ethtool -N <dev> rx-flow-hash <type> <option> + +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. + +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} + +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. + +IEEE 802.1ad (QinQ) Support +--------------------------- +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. + +NOTES: + Receive checksum offloads, cloud filters, and VLAN acceleration are not + supported for 802.1ad (QinQ) packets. + +VXLAN and GENEVE Overlay HW Offloading +-------------------------------------- +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. + +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. + +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) +-------------------------- +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. + +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. + +Interrupt Rate Limiting +----------------------- +:Valid Range: 0-235 (0=no limit) + +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 + +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 cpu's to +individual lcpu's, making sure to use a set of cpu's included in the +device's local_cpulist: /sys/class/net/<ethX>/device/local_cpulist. + +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. + +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] + +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: + - Run all tc commands from the iproute2 <pathtoiproute2>/tc/ directory. + - ADq is not compatible with cloud filters. + - Setting up channels via ethtool (ethtool -L) is not supported when the + TCs are configured using mqprio. + - 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. + + +Known Issues/Troubleshooting +============================ + +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 + +Unexpected Issues when the device driver and DPDK share a device +---------------------------------------------------------------- +Unexpected issues may result when an i40e device is in multi driver mode and +the kernel driver and DPDK driver are sharing the device. This is because +access to the global NIC resources is not synchronized between multiple +drivers. Any change to the global NIC configuration (writing to a global +register, setting global configuration by AQ, or changing switch modes) will +affect all ports and drivers on the device. Loading DPDK with the +"multi-driver" module parameter may mitigate some of the issues. + +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. + + +Support +======= +For general information, go to the Intel support website at: + +https://www.intel.com/support/ + +or the Intel Wired Networking project hosted by Sourceforge at: + +https://sourceforge.net/projects/e1000 + +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. |