.\"	$NetBSD: xvif.4,v 1.6 2014/03/18 18:20:39 riastradh Exp $
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.\" by Jean-Yves Migeon <jym@NetBSD.org>.
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.Dd April 7, 2011
.Dt XVIF 4 xen
.Os
.Sh NAME
.Nm xvif
.Nd Xen backend paravirtualized network interface
.Sh SYNOPSIS
.Cd pseudo-device xvif
.Sh DESCRIPTION
The
.Nm
interface forms the backend part of the paravirtualized drivers
used by
.Tn Xen
domains to offer network connectivity.
.Pp
When the guest domain is
.Nx ,
the endpoint of the
.Nm
interface is a
.Xr xennet 4
interface.
In the XenStore,
.Nm xvif
and
.Nm xennet
are identified by
.Dq vif
(virtual interface)
entries.
.Pp
All
.Nm
interfaces follow the
.Dq xvifXiY
naming convention, where
.Sq X
represents the guest domain identifier, and
.Sq Y
an arbitrary identifier; most of the time, it is the
frontend interface identifier, e.g.
.Dq xennetY .
.Pp
For convenience, the MAC address of an
.Nm
interface is chosen by incrementing the third byte of the
MAC address of the frontend device.
.Pp
Conceptually, frontends and backends drivers are
similar to two Ethernet cards connected via a crossover cable.
.Sh DIAGNOSTICS
.Bl -diag
.It "xvif%di%d: can't read %s/mac: %d"
The MAC address for this interface could not be read from XenStore.
.It "xvif%di%d: %s is not a valid mac address"
The MAC address specified in the configuration file of the newly
created guest domain is invalid.
.It "xvif%di%d: Ethernet address %s"
MAC address of the
.Nm
interface.
.El
.Sh SEE ALSO
.Xr ifmedia 4 ,
.Xr xennet 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 4.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq Mt bouyer@NetBSD.org .