i40iw Linux* Driver for Intel(R) Ethernet Connection X722
===============================================================================

July 24, 2018

===============================================================================

Contents
--------

- Prerequisites
- Building and Installation
- Testing
- Interoperability
- RDMA Statistics
- Known Issues


================================================================================


Prerequisites
-------------

- Choose from the following supported OS/kernel configurations and then
  follow corresponding building/installation instructions in the next
  section.
    1) Linux distribution supported by OFED 4.8-2(recommended).
    2) Upstream kernel v4.8-v4.16 with inbox Infiniband* support installed
       or RHEL 7.4, RHEL 7.5, SLES 12 SP3, or SLES 15 with inbox
       Infiniband* support installed.
    3) Linux distribution supported by OFED 3.18-3.
- NOTE: The i40e driver must be built from source on the system prior to
  i40iw install.


Building and Installation
-------------------------

Option 1 (recommended): OFED 4.8-2
(check OFED release notes for supported OS/kernel versions)
---------------------------------------
1. Download OFED 4.8-2 from http://downloads.openfabrics.org/OFED/
   ofed-4.8-2/OFED-4.8-2.tgz
2. Untar OFED-4.8-2.tgz and install using './install -all'
3. Untar i40iw-<version>.tar.gz.
4. Install the i40iw PF driver as follows:
  cd i40iw-<version> directory
  ./build.sh <absolute path to i40e driver directory> 4
  For example: ./build.sh /opt/i40e-2.3.3 4
5. OFED 4.8-2 comes with an older version of rdma_core user-space package
   Please download the latest from https://github.com/linux-rdma/rdma-core/
   releases and follow its installation procedure.
Note: There might be errors resulting from conflicting packages when upgrading
rdma core to the latest content. If so, use the following procedure:
   Remove the existing packages using:
    rpm -e <package.rpm>
   Install the newer version of the package:
    rpm -ivh <package.rpm>

Option 2: Inbox RDMA kernel components
(Linux Kernel v4.8-v4.16/RHEL 7.4/RHEL 7.5/SLES 12 SP3/SLES 15)
-------------------------------------------------------------
1. Untar i40iw-<version>.tar.gz.
2. Install the i40iw PF driver as follows:
   cd i40iw-<version> directory
   ./build.sh <absolute path to i40e driver directory> k
   For example: ./build.sh /opt/i40e-2.3.3 k
3. Please download the latest rdma_core user-space package from
   https://github.com/linux-rdma/rdma-core/releases and follow its
   installation procedure.
Note: There might be errors resulting from conflicting packages when upgrading
rdma core to the latest content. If so, use the following procedure:
   Remove the existing packages using:
    rpm -e <package.rpm>
   Install the newer version of the package:
    rpm -ivh <package.rpm>

Option 3: OFED 3.18-3
(check OFED release notes for supported OS/kernel versions)
----------------------------------------
1. Download OFED 3.18-3 from http://www.openfabrics.org/downloads/OFED/
   ofed-3.18-3/OFED-3.18-3.tgz
2. Untar OFED-3.18-3.tgz and install using './install -all'
3. Untar i40iw-<version>.tar.gz and libi40iw-<version>.tar.gz.
4. Install the i40iw PF driver as follows:
   cd i40iw-<version> directory
   ./build.sh <absolute path to i40e driver source directory> 3
   For example: ./build.sh /opt/i40e-2.3.3
5. Install user-space library as follows:
   cd libi40iw-<version>
   ./build.sh


Verify RDMA traffic
-------------------

The following rping test can be run to confirm RDMA functionality:
   Server side: rping -s -a <server_ip> -vVd
   Client side: rping -c -a <server_ip> -vVd
Execute the server side before the client side. Rping will run endlessly
printing the data on the console. First run rping server and client both
on machine A. After confirming machine A is operating correctly,
run rping server and client both on machine B. After confirming machine B
is operating correctly, run rping from machine A to machine B.


Adapter and Switch Flow Control Setting
---------------------------------------
We recommend enabling link-level flow control (both TX and RX)
on X722 and connected switch.

For better performance, enable flow control on all the nodes and on the
switch they are connected to.

To enable flow control on X722 use ethtool -A command. For
example:
  ethtool -A p4p1 rx on tx on
Confirm the setting with ethtool -a command. For example:
  ethtool -a p4p1
You should see this output:
  Pause parameters for p4p1:
  Autonegotiate: off
  RX: on
  TX: on

To enable link-level flow control on the switch, please consult your switch
vendor's documentation. Look for flow-control and make sure both TX and RX are
set. Here is an example for a generic switch to enable both TX and RX flow
control on port 45:

  enable flow-control tx-pause ports 45
  enable flow-control rx-pause ports 45


================================================================================


Interoperability
----------------

To interoperate with Chelsio iWARP devices with OFED 4.8 or Linux
kernel v4.8-v4.16:

Load Chelsio T4/T5 RDMA driver (iw_cxgb4) with parameter
dack_mode set to 0.

modprobe iw_cxgb4 dack_mode=0

If iw_cxgb4 is loaded on system boot, create /etc/modprobe.d/iw_cxgb4.conf
file with the following entry:

options iw_cxgb4 dack_mode=0

Reload iw_cxgb4 for the new parameters to take effect.


RDMA Statistics
---------------

Use the following command to read RDMA Protocol statistics:
  cd /sys/class/infiniband/i40iw0/proto_stats; for f in *; do echo -n
  "$f: "; cat "$f"; done; cd

The following counters will increment when RDMA applications are
transferring data over the network:
  - ipInReceives
  - tcpInSegs
  - tcpOutSegs


Memory Requirements:
--------------------

Default i40iw load requires a minimum of 6GB of memory for initialization.

For applications where the amount of memory is constrained, you can
decrease the required memory by lowering the available resources to
the i40iw driver. To do this, load the driver with the following profile
setting.

Note: This can have performance and scaling impacts as the number of
queue pairs and other RDMA resources are decreased in order to lower
memory usage to approximately 1.2 GB.

  modprobe i40iw resource_profile=2


Scaling Limits
--------------

Intel(R) Ethernet Connection X722 has limited RDMA resources, including
the number of Queue Pairs (QPs), Completion Queues (CQs) and Memory
Regions (MRs). In highly scaled environments or highly interconnected
HPC-style applications such as all-to-all, users may experience QP failure
errors once they reach the RDMA resource limits.

Below are the per-physical port limits for 4-port devices for the three
resources associated with the default i40iw driver load:
  QPs: 16384
  CQs: 32768
  MRs: 2453503

Other resource profiles allocate resources differently. If the i40iw is
loaded with resource_profile 2, then resources will be more limited.

The example below shows the resource limit per-physical port when you
use modprobe i40iw resource_profile 2. (Note that this may increase if you
load fewer than 32 VFs using the max_rdma_vfs module parameter.)
  QPs: 2048
  CQs:3584
  MRs: 6143


================================================================================


Known Issues/Troubleshooting
----------------------------

Intel(R) Ethernet Connection X722 iWARP RDMA VF driver discontinued
-------------------------------------------------------------------
Support for the Intel(R) Ethernet Connection X722 iWARP RDMA VF driver
(i40iwvf) has been discontinued. There is no change to the Linux iWARP RDMA PF
driver (i40iw).


OFED 3.18-3
-----------

You may experience a kernel crash using OFED 3.18-3 under heavy load.
It is fixed in upstream kernel with commit dafb558717.


Incompatible Drivers in initramfs
---------------------------------

There may be incompatible drivers in the initramfs image. You can either
update the image or remove the drivers from initramfs.

Specifically look for i40e, ib_addr, ib_cm, ib_core, ib_mad, ib_sa, ib_ucm,
ib_uverbs, iw_cm, rdma_cm, rdma_ucm in the output of the following command:
  lsinitrd |less
If you see any of those modules, rebuild initramfs with the following
command and include the name of the module in the "" list. Below is an
example:
  dracut --force --omit-drivers "i40e ib_addr ib_cm ib_core ib_mad ib_sa
  ib_ucm ib_uverbs iw_cm rdma_cm rdma_ucm"


================================================================================


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 a supported kernel
with a supported adapter, email the specific information related to the issue
to e1000-rdma@lists.sourceforge.net


================================================================================


License
-------

This software is available to you under a choice of one of two
licenses. You may choose to be licensed under the terms of the GNU
General Public License (GPL) Version 2, available from the file
COPYING in the main directory of this source tree, or the
OpenFabrics.org BSD license below:

  Redistribution and use in source and binary forms, with or
  without modification, are permitted provided that the following
  conditions are met:

  - Redistributions of source code must retain the above
    copyright notice, this list of conditions and the following
    disclaimer.

  - Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following
    disclaimer in the documentation and/or other materials
    provided with the distribution.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.


================================================================================


Trademarks
----------
Intel and Itanium are trademarks or registered trademarks 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.


