Various man pages related to Xen

[Jean-Yves Migeon <jeanyves.migeon%free.fr@localhost>]

Hi lists,

Here's an anthology of man pages associated to Xen. I believe they have
their place directly under man4/, "virtualized" drivers being not really
tied to a specific arch.

Could some of you proof read the HISTORY and AUTHORS sections, so we can
give credit where credit is due? I will commit them afterward.

Thanks!

-- 
Jean-Yves Migeon
jeanyves.migeon%free.fr@localhost

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt PCIBACK 4 xen
.Os
.Sh NAME
.Nm pciback
.Nd Xen backend paravirtualized PCI pass-through driver
.Sh SYNOPSIS
.Cd "pciback* at pci?"
.Sh DESCRIPTION
The
.Nm
driver is the backend part of the PCI pass-through functionality
that can be used by the
.Tn Xen
dom0 to export
.Xr pci 4
devices to a guest domain.
To export a PCI device to a guest domain, the device has to be
attached to
.Nm
in the dom0.
.Pp
When the guest domain is
.Nx ,
the device attached to the
.Nm
driver will attach to a
.Xr xpci 4
bus inside the guest domain.
.Sh EXAMPLES
To attach a device to the
.Nm 
driver,
follow these steps:
.Bl -enum -offset indent -compact
.It
look for the device PCI ID, via
.Xr pcictl 8 .
.It
edit
.Xr boot.conf 5 ,
and add the PCI ID to the list of PCI IDs that you want to
attach to
.Nm ,
in bus:device.function notation.
The list is passed to dom0 module via the
.Ic pciback.hide
parameter: pciback.hide=(bus:dev.fun)(bus:dev.func)(...)
See also
.Xr boot 8 .
.It
reboot dom0.
.It
add the PCI ID to the list of PCI devices in the domain
configuration file: pci = ['bus:dev.fun', '...'] 
.It
start the guest domain.
.El
.Sh SEE ALSO
.Xr pci 4 ,
.Xr xpci 4 ,
.Xr boot 8 ,
.Xr pcictl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 6.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq bouyer%NetBSD.org@localhost .
.Sh CAVEATS
Currently, to attach a device to the
.Nm
backend, this procedure has to be performed at
.Xr boot 8
time.
In the future, it will be possible to do it without requiring
a dom0 reboot.
.Sh SECURITY CONSIDERATIONS
As PCI passthrough offers the possibility for guest domains
to send arbitrary PCI commands to a physical device, this has
direct impact on the overall stability and security of the system.
For example, in case of erroneous or malicious commands, the device
could overwrite physical memory portions, via DMA.

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt XBD 4 xen
.Os
.Sh NAME
.Nm xbd
.Nd Xen frontend paravirtualized block device interface
.Sh SYNOPSIS
.Cd "xbd* at xenbus?"
.Sh DESCRIPTION
The
.Nm
interface forms the frontend part of the paravirtualized drivers
used by
.Tn Xen
guest domains to have a block device interface.
.Pp
From a guest point of view,
.Nm
is similar to a hard disk, and can be treated in the very same way
regarding partitioning, file systems creation and usage, and mounting.
By default, a
.Nx
guest domain will assume that
.Dq xbd0a
serves as the root file system.
.Pp
When the host is
.Nx ,
the
.Nm
interface is backed by a
.Xr xbdback 4
interface.
In the XenStore,
.Nm xbd
and
.Nm xbdback
are identified by
.Dq vbd
(virtual block device)
entries.
.Sh DIAGNOSTICS
.Bl -diag
.It "xbd%d: using event channel %d"
Specifies the event channel used by this
.Nm
interface.
.It "xbd%d: %s MB, %d bytes/sect x %u sectors"
Gives the total size of the
.Nm
block device, its sector's size and total number of sectors.
.It "xbd%d: WARNING: cache flush not supported by backend"
The backend driver associated to this
.Nm
device does not support cache flushing operation.
This can be problematic for file system operations that require
cache sync to avoid data loss or corruption.
.El
.Sh SEE ALSO
.Xr xenbus 4 ,
.Xr xbdback 4 ,
.Xr dkctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 3.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq bouyer%NetBSD.org@localhost .

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt XBDBACK 4 xen
.Os
.Sh NAME
.Nm xbdback
.Nd Xen backend paravirtualized block device interface
.Sh SYNOPSIS
.Cd "pseudo-device xbdback"
.Sh DESCRIPTION
The
.Nm
interface forms the backend part of the paravirtualized drivers
used by
.Tn Xen
domains to offer a block device interface, similar to a hard disk.
.Pp
For
.Nx ,
the guest device name specified in the guest configuration file
does not matter, and can be chosen arbitrarily.
.Nm
interfaces are backed either by a physical device directly, 
or an image file mounted through
.Xr vnd 4 .
.Pp
A
.Nm
interface will appear as a
.Xr xbd 4
block device inside a
.Nx
guest domain.
In the XenStore,
.Nm xbd
and
.Nm xbdback
are identified by
.Dq vbd
(virtual block device)
entries.
.Sh DIAGNOSTICS
.Bl -diag
.It "xbd backend: attach device %s (size %d) for domain %d"
Gives the device used as
.Nm
interface for the given guest domain, and its size, in bytes.
.It "xbd backend 0x%x for domain %d using event channel %d, protocol %s"
Gives the backend identifier, guest domain ID, event channel ID and
protocol used for block level communication.
.It "xbdback %s: can't VOP_OPEN device 0x%x: %d"
When this message appears in the system message buffer with error 16
.Po Er EBUSY Pc ,
the device is likely to be already mounted.
It musts be unmounted first, as the system will refuse to open
it a second time.
.El
.Sh SEE ALSO
.Xr xbd 4 ,
.Xr xenbus 4 ,
.Xr vnd 4
.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 bouyer%NetBSD.org@localhost .

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt XENBUS 4 xen
.Os
.Sh NAME
.Nm xenbus
.Nd Xen bus abstraction for paravirtualized drivers
.Sh SYNOPSIS
.Cd "xenbus* at hypervisor?"
.Sh DESCRIPTION
The
.Nm
interface offers an abstraction layer used for communications
between domains.
.Nm
is mainly used by split paravirtualized drivers, so backend and frontend
devices can exchange configuration information, properties, and
statistics.
.Pp
.Nm
is not used for data transfer (network frames, blocks,
PCI commands, ...). This functionality is implemented by each paravirtualized
driver independently, typically via shared memory pages and an event
channel that serves as a virtual interrupt, for signaling.
.Pp
The
.Nm
abstraction offers guests the possibility to read and write information
directly from and to XenStore, a centralized database accessible to
all domains.
For this reason, it also has an event channel associated to it, so that
domains can post messages to the XenStore facility.
.Sh DIAGNOSTICS
.Bl -diag
.It "xenbus0: using event channel %d"
The event channel associated to the
.Nm
interface, for communication with the XenStore database.
.El
.Sh SEE ALSO
.Xr pciback 4 ,
.Xr xbd 4 ,
.Xr xbdback 4 ,
.Xr xennet 4 ,
.Xr xpci 4 ,
.Xr xvif 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 3.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq bouyer%NetBSD.org@localhost .

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt XENNET 4 xen
.Os
.Sh NAME
.Nm xennet
.Nd Xen frontend paravirtualized network interface
.Sh SYNOPSIS
.Cd "xennet* at xenbus?"
.Sh DESCRIPTION
The
.Nm
interface forms the frontend part of the paravirtualized drivers
used by
.Tn Xen
guest domains to have network connectivity.
.Pp
When the host domain is
.Nx ,
the endpoint of the
.Nm
interface is a
.Xr xvif 4
interface.
In the XenStore,
.Nm xvif
and
.Nm xennet
are identified by
.Dq vif
(virtual interface)
entries.
.Pp
Conceptually, frontends and backends drivers are
similar to two Ethernet cards connected via a crossover cable.
.Sh DIAGNOSTICS
.Bl -diag
.It "xennet%d: can't read mac address, err %d"
The MAC address for this interface could not be read from XenStore.
.It "xennet%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 "xennet%d: using event channel %d"
The
.Tn Xen
event channel (virtual interrupt) ID
associated to this
.Nm .
.It "xennet%d: using RX copy mode"
The
.Nm
and its associated endpoint use copy mode for communication: packets
are copied from one domain's memory to another.
.It "xennet%d: using RX flip mode"
The
.Nm
and its associated endpoint use flip mode for communication: packets
are passed by remapping memory pages between domains.
.El
.Sh SEE ALSO
.Xr ifmedia 4 ,
.Xr xenbus 4 ,
.Xr xvif 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 3.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq bouyer%NetBSD.org@localhost
and
.An Christian Limpach Aq chris%pin.lu@localhost .

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 2011
.Dt XPCI 4 xen
.Os
.Sh NAME
.Nm xpci
.Nd Xen frontend paravirtualized PCI pass-through driver
.Sh SYNOPSIS
.Cd "xpci* at xenbus?"
.Cd "pci* at xpci?"
.Sh DESCRIPTION
The
.Nm
driver is the frontend part of the PCI pass-through functionality
that can be used by
.Tn Xen
guest domains to communicate with PCI devices.
.Pp
From a guest point of view,
.Nm
is similar to a
.Xr pci 4
bus, except that the guest talks with the PCI backend driver
instead of the real physical device directly.
.Pp
When the host domain is
.Nx ,
the
.Nm
driver is backed by a
.Xr pciback 4
driver within the dom0.
.Sh SEE ALSO
.Xr pci 4 ,
.Xr pciback 4 ,
.Xr xenbus 4
.Sh HISTORY
The
.Nm
driver first appeared in
.Nx 6.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Manuel Bouyer Aq bouyer%NetBSD.org@localhost .
.Sh SECURITY CONSIDERATIONS
As PCI passthrough offers the possibility for guest domains
to send arbitrary PCI commands to a physical device, this has
direct impact on the overall stability and security of the system.
For example, in case of erroneous or malicious commands, the device
could overwrite physical memory portions, via DMA.

.\"     $NetBSD$
.\"
.\" Copyright (c) 2011 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to The NetBSD Foundation
.\" by Jean-Yves Migeon <jym%NetBSD.org@localhost>.
.\"
.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
.\"
.Dd January 8, 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 xvifX.Y
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, eg.
.Dq xennetY .
.Pp
For convenience, the MAC address of an
.Nm
interface is chosen depending on the one from its associated
guest interface,
by incrementing the third byte of the
MAC address of the frontend interface.
.Pp
Conceptually, frontends and backends drivers are
similar to two Ethernet cards connected via a crossover cable.
.Sh DIAGNOSTICS
.Bl -diag
.It "xvif%d.%d: can't read %s/mac: %d"
The MAC address for this interface could not be read from XenStore.
.It "xvif%d.%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%d.%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 bouyer%NetBSD.org@localhost .