1.\" Copyright (c) 2011 Bryan Venteicher 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.Dd January 22, 2012 26.Dt VIRTIO_BALLOON 4 27.Os 28.Sh NAME 29.Nm virtio_balloon 30.Nd VirtIO Memory Balloon driver 31.Sh SYNOPSIS 32To compile this driver into the kernel, 33place the following lines in your 34kernel configuration file: 35.Bd -ragged -offset indent 36.Cd "device virtio_balloon" 37.Ed 38.Pp 39Alternatively, to load the driver as a 40module at boot time, place the following line in 41.Xr loader.conf 5 : 42.Bd -literal -offset indent 43virtio_balloon_load="YES" 44.Ed 45.Sh DESCRIPTION 46The 47.Nm 48device driver provides support for VirtIO memory balloon devices. 49.Pp 50The memory balloon allows the guest to, at the request of the 51hypervisor, return memory allocated to the hypervisor so it can 52be made available to other guests. 53The hypervisor can later signal the balloon to return the memory. 54.Sh SEE ALSO 55.Xr virtio 4 56.Sh HISTORY 57The 58.Nm 59driver was written by 60.An Bryan Venteicher Aq Mt bryanv@FreeBSD.org . 61It first appeared in 62.Fx 9.0 . 63