.\"	$OpenBSD: vmd.8,v 1.12 2024/09/24 20:02:39 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
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.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: September 24 2024 $
.Dt VMD 8
.Os
.Sh NAME
.Nm vmd
.Nd virtual machine daemon
.Sh SYNOPSIS
.Nm vmd
.Op Fl dnv
.Op Fl D Ar macro Ns = Ns Ar value
.Op Fl f Ar file
.Sh DESCRIPTION
.Nm
is a daemon responsible for the execution of virtual machines (VMs) on a
host.
.Nm
is typically started at boot time and is controlled via
.Xr vmctl 8 .
.Pp
To have
.Nm
enabled at boot time, use
.Dq rcctl enable vmd ,
which sets
.Pp
.Dl vmd_flags=\(dq\(dq
.Pp
in
.Xr rc.conf.local 8 .
.Pp
.Nm
interfaces with the virtual machine monitor (VMM) built into the kernel.
One instance of
.Nm
will be spawned for each VM running on the host, plus extra instances
for control operations.
Each child
.Nm
will in turn create one or more VCPU (virtual CPU) threads responsible for
driving the VM's operations using
.Xr vmm 4 .
.Pp
.Nm
is also responsible for proxying various other commands/requests from
.Xr vmctl 8 ,
such as stopping VMs, and retrieving information from
.Xr vmm 4
about running VMs.
.Pp
When the host machine is shut down,
.Nm
sends each running VM a shutdown request via the
.Xr vmmci 4
device.
If the VMs are vmmci-aware,
this provides each VM the chance to shut down cleanly in anticipation
of host shutdown.
During shutdown,
.Nm
waits 30 seconds for the VMs to terminate cleanly before forcibly
stopping them.
This 30 second default can be changed by
.Dq rcctl set vmd timeout n ,
where 'n' is the desired timeout in seconds.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl D Ar macro Ns = Ns Ar value
Define
.Ar macro
to be set to
.Ar value
on the command line.
Overrides the definition of
.Ar macro
in the configuration file.
.It Fl d
Do not daemonize and log to
.Em stderr .
.It Fl f Ar file
Specify an alternative configuration file.
The default is
.Pa /etc/vm.conf .
.It Fl n
Configtest mode.
Only check the configuration file for validity.
.It Fl v
Verbose mode.
Multiple
.Fl v
options increase the verbosity.
.El
.Sh FILES
.Bl -tag -width "/etc/firmware/vmm-biosXX" -compact
.It Pa /etc/firmware/vmm-bios
Default BIOS boot image.
The BIOS is an external firmware file that is distributed separately
due to an incompatible license.
A prepackaged version of the firmware can be installed using
.Xr fw_update 8 .
.It Pa /etc/vm.conf
Default configuration file.
This is optional.
.It Pa /var/run/vmd.sock
.Ux Ns -domain
socket used for communication with
.Xr vmctl 8 .
.El
.Sh SEE ALSO
.Xr vmm 4 ,
.Xr vmmci 4 ,
.Xr vm.conf 5 ,
.Xr rc.conf 8 ,
.Xr vmctl 8
.Sh HISTORY
The
.Nm
command first appeared in
.Ox 5.9 .
.Sh AUTHORS
.An -nosplit
.An Mike Larkin Aq Mt mlarkin@openbsd.org
and
.An Reyk Floeter Aq Mt reyk@openbsd.org .