.\" Copyright (c) 2011 Bryan Venteicher
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
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.\" $FreeBSD: head/share/man/man4/virtio_balloon.4 267938 2014-06-26 21:46:14Z bapt $
.\"
.Dd January 22, 2012
.Dt VIRTIO_BALLOON 4
.Os
.Sh NAME
.Nm virtio_balloon
.Nd VirtIO Memory Balloon driver
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following lines in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device virtio_balloon"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
virtio_balloon_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
device driver provides support for VirtIO memory balloon devices.
.Pp
The memory balloon allows the guest to, at the request of the
hypervisor, return memory allocated to the hypervisor so it can
be made available to other guests.
The hypervisor can later signal the balloon to return the memory.
.Sh SEE ALSO
.Xr virtio 4
.Sh HISTORY
The
.Nm
driver was written by
.An Bryan Venteicher Aq Mt bryanv@FreeBSD.org .
It first appeared in
.Fx 9.0 .