.. BSD LICENSE
- Copyright(c) 2015 Intel Corporation. All rights reserved.
+ Copyright(c) 2015-2016 Intel Corporation. All rights reserved.
All rights reserved.
Redistribution and use in source and binary forms, with or without
The FM10K poll mode driver library provides support for the Intel FM10000
(FM10K) family of 40GbE/100GbE adapters.
+FTAG Based Forwarding of FM10K
+------------------------------
+
+FTAG Based Forwarding is a unique feature of FM10K. The FM10K family of NICs
+support the addition of a Fabric Tag (FTAG) to carry special information.
+The FTAG is placed at the beginning of the frame, it contains information
+such as where the packet comes from and goes, and the vlan tag. In FTAG based
+forwarding mode, the switch logic forwards packets according to glort (global
+resource tag) information, rather than the mac and vlan table. Currently this
+feature works only on PF.
+
+To enable this feature, the user should pass a devargs parameter to the eal
+like "-w 84:00.0,enable_ftag=1", and the application should make sure an
+appropriate FTAG is inserted for every frame on TX side.
+
+Vector PMD for FM10K
+--------------------
+
+Vector PMD (vPMD) 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)''.
+The wider register gives space to hold multiple packet buffers so as to save
+on the number of instructions when bulk processing packets.
+
+There is no change to the PMD API. The RX/TX handlers are the only two entries for
+vPMD packet I/O. They are transparently registered at runtime RX/TX execution
+if all required conditions are met.
+
+1. To date, only an SSE version of FM10K vPMD is available.
+ To ensure that vPMD is in the binary code, set
+ ``CONFIG_RTE_LIBRTE_FM10K_INC_VECTOR=y`` 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
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+For Vector RX it is assumed that the number of descriptor rings will be a power
+of 2. With this pre-condition, the ring pointer can easily scroll back to the
+head after hitting the tail without a conditional check. In addition Vector RX
+can use this assumption to do a bit mask using ``ring_size - 1``.
+
+
+Features not Supported by Vector RX PMD
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Some features are not supported when trying to increase the throughput in
+vPMD. They are:
+
+* IEEE1588
+
+* Flow director
+
+* Header split
+
+* RX checksum offload
+
+Other features are supported using optional MACRO configuration. They include:
+
+* HW VLAN strip
+
+* L3/L4 packet type
+
+To enable via ``RX_OLFLAGS`` use ``RTE_LIBRTE_FM10K_RX_OLFLAGS_ENABLE=y``.
+
+To guarantee the constraint, the following configuration flags in ``dev_conf.rxmode``
+will be checked:
+
+* ``hw_vlan_extend``
+
+* ``hw_ip_checksum``
+
+* ``header_split``
+
+* ``fdir_conf->mode``
+
+
+RX Burst Size
+^^^^^^^^^^^^^
+
+As vPMD is focused on high throughput, it processes 4 packets at a time. So it assumes
+that the RX burst should be greater than 4 packets per burst. It returns zero if using
+``nb_pkt`` < 4 in the receive handler. If ``nb_pkt`` is not a multiple of 4, a
+floor alignment will be applied.
+
+
+TX Constraint
+~~~~~~~~~~~~~
+
+Features not Supported by TX Vector PMD
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+TX vPMD only works when ``txq_flags`` is set to ``FM10K_SIMPLE_TX_FLAG``.
+This means that it does not support TX multi-segment, VLAN offload or TX csum
+offload. The following MACROs are used for these three features:
+
+* ``ETH_TXQ_FLAGS_NOMULTSEGS``
+
+* ``ETH_TXQ_FLAGS_NOVLANOFFL``
+
+* ``ETH_TXQ_FLAGS_NOXSUMSCTP``
+
+* ``ETH_TXQ_FLAGS_NOXSUMUDP``
+
+* ``ETH_TXQ_FLAGS_NOXSUMTCP``
Limitations
-----------
The Intel FM10000 family of NICs integrate a hardware switch and multiple host
interfaces. The FM10000 PMD driver only manages host interfaces. For the
switch component another switch driver has to be loaded prior to to the
-FM10000 PMD driver. The switch driver can be acquired for Intel support or
-from the `Match Interface <https://github.com/match-interface>`_ project.
+FM10000 PMD driver. The switch driver can be acquired from Intel support.
Only Testpoint is validated with DPDK, the latest version that has been
-validated with DPDK2.2 is 4.1.6.
+validated with DPDK is 4.1.6.
CRC striping
~~~~~~~~~~~~
for in the statistics, it is necessary to read statistic regularly. It is
suggested to read stats every 20 seconds, which will ensure the statistics
are accurate.
+
+
+Interrupt mode
+~~~~~~~~~~~~~~
+
+The FM10000 family of NICS need one separate interrupt for mailbox. So only
+drivers which support multiple interrupt vectors e.g. vfio-pci can work
+for fm10k interrupt mode.
git.droids-corp.org / dpdk.git / blobdiff