xref: /freebsd/share/man/man4/virtio_balloon.4 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)
110b59a9bSPeter Grehan.\" Copyright (c) 2011 Bryan Venteicher
210b59a9bSPeter Grehan.\" All rights reserved.
310b59a9bSPeter Grehan.\"
410b59a9bSPeter Grehan.\" Redistribution and use in source and binary forms, with or without
510b59a9bSPeter Grehan.\" modification, are permitted provided that the following conditions
610b59a9bSPeter Grehan.\" are met:
710b59a9bSPeter Grehan.\" 1. Redistributions of source code must retain the above copyright
810b59a9bSPeter Grehan.\"    notice, this list of conditions and the following disclaimer.
910b59a9bSPeter Grehan.\" 2. Redistributions in binary form must reproduce the above copyright
1010b59a9bSPeter Grehan.\"    notice, this list of conditions and the following disclaimer in the
1110b59a9bSPeter Grehan.\"    documentation and/or other materials provided with the distribution.
1210b59a9bSPeter Grehan.\"
1310b59a9bSPeter Grehan.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1410b59a9bSPeter Grehan.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1510b59a9bSPeter Grehan.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1610b59a9bSPeter Grehan.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1710b59a9bSPeter Grehan.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1810b59a9bSPeter Grehan.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
1910b59a9bSPeter Grehan.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2010b59a9bSPeter Grehan.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2110b59a9bSPeter Grehan.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2210b59a9bSPeter Grehan.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2310b59a9bSPeter Grehan.\" SUCH DAMAGE.
2410b59a9bSPeter Grehan.\"
2528083eaaSChristian Brueffer.Dd January 22, 2012
2610b59a9bSPeter Grehan.Dt VIRTIO_BALLOON 4
2710b59a9bSPeter Grehan.Os
2810b59a9bSPeter Grehan.Sh NAME
2910b59a9bSPeter Grehan.Nm virtio_balloon
3010b59a9bSPeter Grehan.Nd VirtIO Memory Balloon driver
3110b59a9bSPeter Grehan.Sh SYNOPSIS
3210b59a9bSPeter GrehanTo compile this driver into the kernel,
3310b59a9bSPeter Grehanplace the following lines in your
3410b59a9bSPeter Grehankernel configuration file:
3510b59a9bSPeter Grehan.Bd -ragged -offset indent
3610b59a9bSPeter Grehan.Cd "device virtio_balloon"
3710b59a9bSPeter Grehan.Ed
3810b59a9bSPeter Grehan.Pp
3910b59a9bSPeter GrehanAlternatively, to load the driver as a
4010b59a9bSPeter Grehanmodule at boot time, place the following line in
4110b59a9bSPeter Grehan.Xr loader.conf 5 :
4210b59a9bSPeter Grehan.Bd -literal -offset indent
4310b59a9bSPeter Grehanvirtio_balloon_load="YES"
4410b59a9bSPeter Grehan.Ed
4510b59a9bSPeter Grehan.Sh DESCRIPTION
4610b59a9bSPeter GrehanThe
4710b59a9bSPeter Grehan.Nm
4810b59a9bSPeter Grehandevice driver provides support for VirtIO memory balloon devices.
4910b59a9bSPeter Grehan.Pp
5010b59a9bSPeter GrehanThe memory balloon allows the guest to, at the request of the
5110b59a9bSPeter Grehanhypervisor, return memory allocated to the hypervisor so it can
5228083eaaSChristian Bruefferbe made available to other guests.
5328083eaaSChristian BruefferThe hypervisor can later signal the balloon to return the memory.
5410b59a9bSPeter Grehan.Sh SEE ALSO
5510b59a9bSPeter Grehan.Xr virtio 4
5610b59a9bSPeter Grehan.Sh HISTORY
5710b59a9bSPeter GrehanThe
5810b59a9bSPeter Grehan.Nm
5910b59a9bSPeter Grehandriver was written by
60*6c899950SBaptiste Daroussin.An Bryan Venteicher Aq Mt bryanv@FreeBSD.org .
6110b59a9bSPeter GrehanIt first appeared in
6210b59a9bSPeter Grehan.Fx 9.0 .
63