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133 lines
4.1 KiB
Groff
133 lines
4.1 KiB
Groff
.\" Copyright (c) 2012 Luigi Rizzo, Universita` di Pisa
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" This document is derived in part from the enet man page (enet.4)
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.\" distributed with 4.3BSD Unix.
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.\"
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.\" $FreeBSD$
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.\" $Id: $
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.\"
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.Dd July 27, 2012
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.Dt VALE 4
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.Os
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.Sh NAME
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.Nm vale
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.Nd a very fast Virtual Local Ethernet using the netmap API
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.Sh SYNOPSIS
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.Cd device netmap
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.Sh DESCRIPTION
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.Nm
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is a feature of the
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.Xr netmap 4
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module that implements multiple Virtual switches that can
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be used to interconnect netmap clients, including traffic
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sources and sinks, packet forwarders, userspace firewalls,
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and so on.
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.Pp
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.Nm
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is implemented completely in software, and is extremely fast.
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On a modern machine it can move almost 20 Million packets per
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second (Mpps) per core with small frames, and about 70 Gbit/s
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with 1500 byte frames.
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.Sh OPERATION
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.Nm
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dynamically creates switches and ports as clients connect
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to it using the
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.Xr netmap 4
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API.
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.Pp
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.Nm
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ports are named
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.Pa vale[bdg:][port]
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where
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.Pa vale
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is the prefix indicating a VALE switch rather than a standard interface,
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.Pa bdg
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indicates a specific switch (the colon is a separator),
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and
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.Pa port
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indicates a port within the switch.
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Bridge and port names are arbitrary strings, the only
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constraint being that the full name must fit within 16
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characters.
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.Pp
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See
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.Xr netmap 4
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for details on the API.
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.Ss LIMITS
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.Nm
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currently supports up to 4 switches, 16 ports per switch, with
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1024 buffers per port.
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These hard limits will be
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changed to sysctl variables in future releases.
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.Sh SYSCTL VARIABLES
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.Nm
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uses the following sysctl variables to control operation:
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.Bl -tag -width dev.netmap.verbose
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.It dev.netmap.bridge
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The maximum number of packets processed internally
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in each iteration.
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Defaults to 1024, use lower values to trade latency
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with throughput.
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.Pp
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.It dev.netmap.verbose
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Set to non-zero values to enable in-kernel diagnostics.
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.El
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.Sh EXAMPLES
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Create one switch, with a traffic generator connected to one
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port, and a netmap-enabled tcpdump instance on another port:
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.Bd -literal -offset indent
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tcpdump -ni vale-a:1 &
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pkt-gen -i vale-a:0 -f tx &
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.Ed
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.Pp
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Create two switches,
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each connected to two qemu machines on different ports.
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.Bd -literal -offset indent
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qemu -net nic -net netmap,ifname=vale-1:a ... &
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qemu -net nic -net netmap,ifname=vale-1:b ... &
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qemu -net nic -net netmap,ifname=vale-2:c ... &
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qemu -net nic -net netmap,ifname=vale-2:d ... &
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.Ed
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.Sh SEE ALSO
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.Xr netmap 4
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.Pp
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.Xr http://info.iet.unipi.it/~luigi/vale/
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.Pp
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Luigi Rizzo, Giuseppe Lettieri: VALE, a switched ethernet for virtual machines,
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June 2012, http://info.iet.unipi.it/~luigi/vale/
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.Sh AUTHORS
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.An -nosplit
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The
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.Nm
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switch was designed and implemented in 2012 by
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.An Luigi Rizzo
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and
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.An Giuseppe Lettieri
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at the Universita` di Pisa.
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.Pp
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.Nm
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was funded by the European Commission within FP7 Projects
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CHANGE (257422) and OPENLAB (287581).
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