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diff --git a/src/spdk/dpdk/doc/guides/nics/ixgbe.rst b/src/spdk/dpdk/doc/guides/nics/ixgbe.rst new file mode 100644 index 00000000..16d63902 --- /dev/null +++ b/src/spdk/dpdk/doc/guides/nics/ixgbe.rst @@ -0,0 +1,263 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright(c) 2010-2016 Intel Corporation. + +IXGBE Driver +============ + +Vector PMD for IXGBE +-------------------- + +Vector PMD uses Intel® SIMD instructions to optimize packet I/O. +It improves load/store bandwidth efficiency of L1 data cache by using a wider SSE/AVX register 1 (1). +The wider register gives space to hold multiple packet buffers so as to save instruction number when processing bulk of packets. + +There is no change to PMD API. The RX/TX handler are the only two entries for vPMD packet I/O. +They are transparently registered at runtime RX/TX execution if all condition checks pass. + +1. To date, only an SSE version of IX GBE vPMD is available. + To ensure that vPMD is in the binary code, ensure that the option CONFIG_RTE_IXGBE_INC_VECTOR=y is in the configure file. + +Some constraints apply as pre-conditions for specific optimizations on bulk packet transfers. +The following sections explain RX and TX constraints in the vPMD. + +RX Constraints +~~~~~~~~~~~~~~ + +Prerequisites and Pre-conditions +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The following prerequisites apply: + +* To enable vPMD to work for RX, bulk allocation for Rx must be allowed. + +Ensure that the following pre-conditions are satisfied: + +* rxq->rx_free_thresh >= RTE_PMD_IXGBE_RX_MAX_BURST + +* rxq->rx_free_thresh < rxq->nb_rx_desc + +* (rxq->nb_rx_desc % rxq->rx_free_thresh) == 0 + +* rxq->nb_rx_desc < (IXGBE_MAX_RING_DESC - RTE_PMD_IXGBE_RX_MAX_BURST) + +These conditions are checked in the code. + +Scattered packets are not supported in this mode. +If an incoming packet is greater than the maximum acceptable length of one "mbuf" data size (by default, the size is 2 KB), +vPMD for RX would be disabled. + +By default, IXGBE_MAX_RING_DESC is set to 4096 and RTE_PMD_IXGBE_RX_MAX_BURST is set to 32. + +Feature not Supported by RX Vector PMD +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Some features are not supported when trying to increase the throughput in vPMD. +They are: + +* IEEE1588 + +* FDIR + +* Header split + +* RX checksum off load + +Other features are supported using optional MACRO configuration. They include: + +* HW VLAN strip + +* HW extend dual VLAN + +To guarantee the constraint, capabilities in dev_conf.rxmode.offloads will be checked: + +* DEV_RX_OFFLOAD_VLAN_STRIP + +* DEV_RX_OFFLOAD_VLAN_EXTEND + +* DEV_RX_OFFLOAD_CHECKSUM + +* DEV_RX_OFFLOAD_HEADER_SPLIT + +* dev_conf + +fdir_conf->mode will also be checked. + +RX Burst Size +^^^^^^^^^^^^^ + +As vPMD is focused on high throughput, it assumes that the RX burst size is equal to or greater than 32 per burst. +It returns zero if using nb_pkt < 32 as the expected packet number in the receive handler. + +TX Constraint +~~~~~~~~~~~~~ + +Prerequisite +^^^^^^^^^^^^ + +The only prerequisite is related to tx_rs_thresh. +The tx_rs_thresh value must be greater than or equal to RTE_PMD_IXGBE_TX_MAX_BURST, +but less or equal to RTE_IXGBE_TX_MAX_FREE_BUF_SZ. +Consequently, by default the tx_rs_thresh value is in the range 32 to 64. + +Feature not Supported by TX Vector PMD +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +TX vPMD only works when offloads is set to 0 + +This means that it does not support any TX offload. + +Application Programming Interface +--------------------------------- + +In DPDK release v16.11 an API for ixgbe specific functions has been added to the ixgbe PMD. +The declarations for the API functions are in the header ``rte_pmd_ixgbe.h``. + +Sample Application Notes +------------------------ + +l3fwd +~~~~~ + +When running l3fwd with vPMD, there is one thing to note. +In the configuration, ensure that DEV_RX_OFFLOAD_CHECKSUM in port_conf.rxmode.offloads is NOT set. +Otherwise, by default, RX vPMD is disabled. + +load_balancer +~~~~~~~~~~~~~ + +As in the case of l3fwd, to enable vPMD, do NOT set DEV_RX_OFFLOAD_CHECKSUM in port_conf.rxmode.offloads. +In addition, for improved performance, use -bsz "(32,32),(64,64),(32,32)" in load_balancer to avoid using the default burst size of 144. + + +Limitations or Known issues +--------------------------- + +Malicious Driver Detection not Supported +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The Intel x550 series NICs support a feature called MDD (Malicious +Driver Detection) which checks the behavior of the VF driver. +If this feature is enabled, the VF must use the advanced context descriptor +correctly and set the CC (Check Context) bit. +DPDK PF doesn't support MDD, but kernel PF does. We may hit problem in this +scenario kernel PF + DPDK VF. If user enables MDD in kernel PF, DPDK VF will +not work. Because kernel PF thinks the VF is malicious. But actually it's not. +The only reason is the VF doesn't act as MDD required. +There's significant performance impact to support MDD. DPDK should check if +the advanced context descriptor should be set and set it. And DPDK has to ask +the info about the header length from the upper layer, because parsing the +packet itself is not acceptable. So, it's too expensive to support MDD. +When using kernel PF + DPDK VF on x550, please make sure to use a kernel +PF driver that disables MDD or can disable MDD. + +Some kernel drivers already disable MDD by default while some kernels can use +the command ``insmod ixgbe.ko MDD=0,0`` to disable MDD. Each "0" in the +command refers to a port. For example, if there are 6 ixgbe ports, the command +should be changed to ``insmod ixgbe.ko MDD=0,0,0,0,0,0``. + + +Statistics +~~~~~~~~~~ + +The statistics of ixgbe hardware must be polled regularly in order for it to +remain consistent. Running a DPDK application without polling the statistics will +cause registers on hardware to count to the maximum value, and "stick" at +that value. + +In order to avoid statistic registers every reaching the maximum value, +read the statistics from the hardware using ``rte_eth_stats_get()`` or +``rte_eth_xstats_get()``. + +The maximum time between statistics polls that ensures consistent results can +be calculated as follows: + +.. code-block:: c + + max_read_interval = UINT_MAX / max_packets_per_second + max_read_interval = 4294967295 / 14880952 + max_read_interval = 288.6218096127183 (seconds) + max_read_interval = ~4 mins 48 sec. + +In order to ensure valid results, it is recommended to poll every 4 minutes. + +MTU setting +~~~~~~~~~~~ + +Although the user can set the MTU separately on PF and VF ports, the ixgbe NIC +only supports one global MTU per physical port. +So when the user sets different MTUs on PF and VF ports in one physical port, +the real MTU for all these PF and VF ports is the largest value set. +This behavior is based on the kernel driver behavior. + +VF MAC address setting +~~~~~~~~~~~~~~~~~~~~~~ + +On ixgbe, the concept of "pool" can be used for different things depending on +the mode. In VMDq mode, "pool" means a VMDq pool. In IOV mode, "pool" means a +VF. + +There is no RTE API to add a VF's MAC address from the PF. On ixgbe, the +``rte_eth_dev_mac_addr_add()`` function can be used to add a VF's MAC address, +as a workaround. + + +Inline crypto processing support +-------------------------------- + +Inline IPsec processing is supported for ``RTE_SECURITY_ACTION_TYPE_INLINE_CRYPTO`` +mode for ESP packets only: + +- ESP authentication only: AES-128-GMAC (128-bit key) +- ESP encryption and authentication: AES-128-GCM (128-bit key) + +IPsec Security Gateway Sample Application supports inline IPsec processing for +ixgbe PMD. + +For more details see the IPsec Security Gateway Sample Application and Security +library documentation. + + +Virtual Function Port Representors +---------------------------------- +The IXGBE PF PMD supports the creation of VF port representors for the control +and monitoring of IXGBE virtual function devices. Each port representor +corresponds to a single virtual function of that device. Using the ``devargs`` +option ``representor`` the user can specify which virtual functions to create +port representors for on initialization of the PF PMD by passing the VF IDs of +the VFs which are required.:: + + -w DBDF,representor=[0,1,4] + +Currently hot-plugging of representor ports is not supported so all required +representors must be specified on the creation of the PF. + +Supported Chipsets and NICs +--------------------------- + +- Intel 82599EB 10 Gigabit Ethernet Controller +- Intel 82598EB 10 Gigabit Ethernet Controller +- Intel 82599ES 10 Gigabit Ethernet Controller +- Intel 82599EN 10 Gigabit Ethernet Controller +- Intel Ethernet Controller X540-AT2 +- Intel Ethernet Controller X550-BT2 +- Intel Ethernet Controller X550-AT2 +- Intel Ethernet Controller X550-AT +- Intel Ethernet Converged Network Adapter X520-SR1 +- Intel Ethernet Converged Network Adapter X520-SR2 +- Intel Ethernet Converged Network Adapter X520-LR1 +- Intel Ethernet Converged Network Adapter X520-DA1 +- Intel Ethernet Converged Network Adapter X520-DA2 +- Intel Ethernet Converged Network Adapter X520-DA4 +- Intel Ethernet Converged Network Adapter X520-QDA1 +- Intel Ethernet Converged Network Adapter X520-T2 +- Intel 10 Gigabit AF DA Dual Port Server Adapter +- Intel 10 Gigabit AT Server Adapter +- Intel 10 Gigabit AT2 Server Adapter +- Intel 10 Gigabit CX4 Dual Port Server Adapter +- Intel 10 Gigabit XF LR Server Adapter +- Intel 10 Gigabit XF SR Dual Port Server Adapter +- Intel 10 Gigabit XF SR Server Adapter +- Intel Ethernet Converged Network Adapter X540-T1 +- Intel Ethernet Converged Network Adapter X540-T2 +- Intel Ethernet Converged Network Adapter X550-T1 +- Intel Ethernet Converged Network Adapter X550-T2 |