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freebsd-skq/share/man/man4/if_ntb.4

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Replace NTB man page with more detailed and up to date. Sponsored by: iXsystems, Inc.
2016-07-10 10:17:38 +00:00
.\"
.\" Copyright (c) 2016 Alexander Motin <mav@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
Some NTB man pages polishing. MFC after: 12 days
2017-09-02 11:57:08 +00:00
.Dd September 2, 2017
Replace NTB man page with more detailed and up to date. Sponsored by: iXsystems, Inc.
2016-07-10 10:17:38 +00:00
.Dt IF_NTB 4
.Os
.Sh NAME
.Nm if_ntb
.Nd Virtual Ethernet interface for Non-Transparent Bridges
.Sh SYNOPSIS
To compile this driver into your kernel,
place the following lines in your kernel configuration file:
.Bd -ragged -offset indent
Add NTB driver for PLX/Avago/Broadcom PCIe switches. This driver supports both NTB-to-NTB and NTB-to-Root Port modes (though the second with predictable complications on hot-plug and reboot events). I tested it with PEX 8717 and PEX 8733 chips, but expect it should work with many other compatible ones too. It supports up to two NT bridges per chip, each of which can have up to 2 64-bit or 4 32-bit memory windows, 6 or 12 scratchpad registers and 16 doorbells. There are also 4 DMA engines in those chips, but they are not yet supported. While there, rename Intel NTB driver from generic ntb_hw(4) to more specific ntb_hw_intel(4), so now it is on par with this new ntb_hw_plx(4) driver and alike to Linux naming. MFC after: 2 weeks Sponsored by: iXsystems, Inc.
2017-08-30 21:16:32 +00:00
.Cd "device ntb"
.Cd "device ntb_transport"
Replace NTB man page with more detailed and up to date. Sponsored by: iXsystems, Inc.
2016-07-10 10:17:38 +00:00
.Cd "device if_ntb"
.Ed
.Pp
Or, to load the driver as a module at boot, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_ntb_load="YES"
.Ed
.Pp
The following tunables are settable from the
.Xr loader 8 :
.Bl -ohang
.It Va hw.if_ntb.num_queues
Some NTB man pages polishing. MFC after: 12 days
2017-09-02 11:57:08 +00:00
Limits maximal number of queues per interface.
Once more refactor KPI between ntb_transport(4) and if_ntb(4).. New design allows to attach multiple consumers to ntb_transport(4) instance. Previous design obtained from Linux theoretically allowed that, but was not practically usable (Linux also has only one consumer driver now).
2016-07-29 17:15:41 +00:00
Default is unlimited.
Replace NTB man page with more detailed and up to date. Sponsored by: iXsystems, Inc.
2016-07-10 10:17:38 +00:00
.El
.Sh DESCRIPTION
The
.Nm
driver attaches on top of the
.Xr ntb_transport 4
Some NTB man pages polishing. MFC after: 12 days
2017-09-02 11:57:08 +00:00
driver to utilize one or more of its packet queues to create virtual
Ethernet network interface between the systems.
Typical MTU for the interface is about 64KB to reduce overhead.
Default MAC address for the interface is randomly generated.
Replace NTB man page with more detailed and up to date. Sponsored by: iXsystems, Inc.
2016-07-10 10:17:38 +00:00
.Pp
The
.Nm
driver does not implement any real hardware offload, but since PCIe link is
protected by CRC32, in some situations it may be possible to save some CPU
cycles by enabling fake checksum offload on both link sides via setting
.Cm rxcsum
and
.Cm txcsum
interface options.
.Sh SEE ALSO
.Xr ntb_transport 4
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was developed by Intel and originally written by
.An Carl Delsey Aq Mt carl@FreeBSD.org .
Later improvements were done by
.An Conrad E. Meyer Aq Mt cem@FreeBSD.org
and
.An Alexander Motin Aq Mt mav@FreeBSD.org .
Once more refactor KPI between ntb_transport(4) and if_ntb(4).. New design allows to attach multiple consumers to ntb_transport(4) instance. Previous design obtained from Linux theoretically allowed that, but was not practically usable (Linux also has only one consumer driver now).
2016-07-29 17:15:41 +00:00
.Sh BUGS
Linux supports only one queue per interface, so manual configuration
may be required for compatibility.
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