.\"	$OpenBSD: vmm.4,v 1.5 2015/12/06 19:06:17 jmc Exp $
.\"
.\"Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
.\"
.\"Permission to use, copy, modify, and distribute this software for any
.\"purpose with or without fee is hereby granted, provided that the above
.\"copyright notice and this permission notice appear in all copies.
.\"
.\"THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\"WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\"MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\"ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\"WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\"ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\"OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: December 6 2015 $
.Dt VMM 4 amd64
.Os
.Sh NAME
.Nm vmm
.Nd virtual machine monitor
.Sh SYNOPSIS
.Cd "vmm0    at mainbus0"
.Sh DESCRIPTION
The
.Nm
driver implements a virtual machine monitor (VMM) suitable for executing
.Em virtual machines
(VMs).
A VMM runs on the
.Em host
operating system and provides facilities to execute one or more
VMs, each of which is provided with a suitable complement of
virtual hardware.
.Pp
These VMs run independently of the host, but may interact with
it as any other machine would (e.g. via network communications or
other means).
.Pp
VMs are allocated hardware resources by the VMM during creation,
including:
.Pp
.Bl -bullet -offset indent -compact
.It
Virtual CPUs
.It
Virtual network interfaces
.It
Virtual disk images
.It
Virtual serial ports
.El
.Pp
Although VMs execute independently of each other and the host, they
do consume host resources and, as such, the number of VMs (and their
configurations) should be taken into consideration when planning
host capacity.
.Pp
The
.Nm
driver requires suitable host CPU capabilities in order to provide
VM services.
The
.Nm
driver requires at least one CPU with hardware-assisted virtualization
capabilities and nested or extended paging capabilities to be
present on the host.
For more information, consult the CPU vendor's documentation.
.Sh SEE ALSO
.Xr cpu 4 ,
.Xr intro 4 ,
.Xr virtio 4 ,
.Xr vmctl 8 ,
.Xr vmd 8
.Sh HISTORY
The
.Nm
driver
appeared in
.Ox 5.9 .
.Sh AUTHORS
.An Mike Larkin Aq Mt mlarkin@openbsd.org