path: root/usr.sbin/vmctl/vmctl.8

.\"	$OpenBSD: vmctl.8,v 1.78 2024/05/04 07:51:21 jmc Exp $
.\"
.\" Copyright (c) 2015-2024 Mike Larkin <mlarkin@openbsd.org>
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.Dd $Mdocdate: May 4 2024 $
.Dt VMCTL 8
.Os
.Sh NAME
.Nm vmctl
.Nd control the virtual machine daemon
.Sh SYNOPSIS
.Nm
.Op Fl v
.Ar command
.Op Ar arg ...
.Sh DESCRIPTION
The
.Nm
utility is used to control the virtual machine monitor (VMM) subsystem.
A VMM manages virtual machines (VMs) on a host.
The VMM subsystem is responsible for creating, destroying, and executing
VMs.
.Pp
The
.Fl v
option enables verbose mode.
Within the commands,
the
.Ar size
argument can be specified with a human-readable scale,
using the format described in
.Xr scan_scaled 3 .
The
.Ar id
argument can be either a numeric, non-zero identifier or alternatively
the name of a virtual machine.
.Pp
The
.Ar name
argument can only consist of alphanumeric characters, as well as '.', '-',
and '_',
and must start with a letter.
.Pp
The
.Ar disk
argument is used by commands that take a path to a disk image file.
It may be prefixed with a format prefix
.Pf ( raw : Ns Ar disk
or
.Pf qcow2 : Ns Ar disk )
.Sm on
in order to specify the disk image format.
If left unspecified, the format defaults to
.Sq raw
if it cannot be derived automatically.
.Pp
The commands are as follows:
.Bl -tag -width Ds
.It Cm console Ar id
Using
.Xr cu 1
connect to the console of the VM with the specified
.Ar id .
.It Cm create Oo Fl b Ar base | Fl i Ar disk Oc Oo Fl s Ar size Oc Ar disk
Create a VM disk image file with the specified
.Ar disk
path.
.Bl -tag -width "-i input"
.It Fl b Ar base
For
.Sq qcow2 ,
a
.Ar base
image may be specified.
The base image is not modified and the derived image contains only the
changes written by the VM.
.It Fl i Ar disk
Copy and convert the input
.Ar disk
to the newly created disk.
This option conflicts with
.Fl b Ar base .
.It Fl s Ar size
Specify the
.Ar size
of the new disk image, rounded to megabytes.
If the
.Fl b
option is specified, the size must match the size of the
.Ar base
image.
For the
.Fl i
option, the size cannot be smaller than the input disk size.
The size can be omitted with the
.Fl b
and
.Fl i
options and will be obtained from the base or input image respectively.
.El
.It Cm load Ar filename
Load additional configuration from the specified file.
.It Cm log brief | verbose
Disable or enable verbose debug logging.
.It Cm pause Ar id
Pause a VM with the specified
.Ar id .
.It Cm receive Ar name
Receive a VM from standard input and start it with the specified
.Ar name .
.It Cm reload
Remove all stopped VMs and reload the configuration from the default
configuration file.
VMs that are currently running will not have their configuration reloaded.
To reload configurations for currently running VMs, stop those VMs before
issuing the reload command.
.It Cm reset Op Cm all | switches | vms
Reset the running state,
reset
.Cm switches ,
or reset and terminate all
.Cm vms .
.It Cm send Ar id
Send a VM with the specified
.Ar id
to standard output and terminate it.
The VM is paused during send processing.
Data sent to standard output contains the VM parameters and its memory,
not the disk image.
.Pp
In order to move a VM from one host to another, disk files must be
synced between the send and the receive processes and must be located
under the same path.
.It Cm show Oo Fl r Oc Op Ar id
An alias for the
.Cm status
command.
.It Xo Cm start
.Op Fl cL
.Bk -words
.Op Fl B Ar device
.Op Fl b Ar path
.Op Fl d Ar disk
.Op Fl i Ar count
.Op Fl m Ar size
.Op Fl n Ar switch
.Op Fl r Ar path
.Op Fl t Ar name
.Ar id | name
.Ek
.Xc
Start a new VM
.Ar name
with the specified parameters.
An existing VM may be started by referencing its
.Ar id .
.Bl -tag -width "-I parent"
.It Fl B Ar device
Force system to boot from the specified device for this boot.
.Ar device
can be set to:
.Pp
.Bl -tag -width "cdrom" -compact
.It Ar cdrom
Boot the CD-ROM image.
.It Ar disk
Boot from disk.
.It Ar net
Perform a PXE boot using the first network interface.
.El
.Pp
Currently
.Ar net
is only supported when booting a kernel using the
.Fl b
flag while
.Ar disk
and
.Ar cdrom
only work with VMs booted using BIOS.
.It Fl b Ar path
Boot the VM with the specified
.Ox
kernel or custom BIOS image.
If not specified, the default is to boot using the BIOS image in
.Pa /etc/firmware/vmm-bios .
If the VM is an existing VM, use the provided image for only the next boot.
.It Fl c
Automatically connect to the VM console.
.It Fl d Ar disk
Use a disk image at the specified
.Ar disk
path (may be specified multiple times to add multiple disk images).
.It Fl i Ar count
Number of network interfaces to add to the VM.
.It Fl L
Add a local network interface.
.Xr vmd 8
will auto-generate an IPv4 subnet for the interface,
configure a gateway address on the VM host side,
and run a simple DHCP/BOOTP server for the VM.
See
.Sx LOCAL INTERFACES
below for more information on how addresses are calculated and assigned when
using the
.Fl L
option.
.It Fl m Ar size
Memory
.Ar size
of the VM, rounded to megabytes.
The default is 512M.
The maximum amount of memory assignable to a VM is governed by the datasize
parameter for the vmd user in
.Pa /etc/login.conf .
.It Fl n Ar switch
Add a network interface that is attached to the specified virtual
.Ar switch .
See the SWITCH CONFIGURATION section in
.Xr vm.conf 5
for more information.
.It Fl r Ar path
ISO image file for virtual CD-ROM.
This image file will be available in the
selected VM as a SCSI CD-ROM device attached to a virtio SCSI adapter
(e.g.\&
.Xr vioscsi 4 ) .
.It Fl t Ar name
Use an existing VM with the specified
.Ar name
as a template to create a new VM instance.
The instance will inherit settings from the parent VM,
except for exclusive options such as disk, interface lladdr, and
interface names.
.El
.It Cm status Oo Fl r Oc Op Ar id
List VMs running on the host, optionally listing just the selected VM
.Ar id .
If the
.Fl r
flag is present, the output will only contain running VMs.
.It Cm stop Oo Fl fw Oc Oo Fl a | Ar id Oc
Stop (terminate) a VM defined by the specified VM
.Ar id
or all running VMs
.Pq Fl a .
By default,
a graceful shutdown will be attempted if the VM supports the
.Xr vmmci 4
device.
.Pp
The following options can be specified when stopping a VM:
.Bl -tag -width "-w"
.It Fl f
Forcefully stop the VM without attempting a graceful shutdown.
.It Fl w
Wait until the VM has been terminated.
.El
.It Cm unpause Ar id
Unpause (resume from a paused state) a VM with the specified
.Ar id .
.It Cm wait Ar id
Wait until the specified VM has stopped.
.El
.Pp
If the
.Fl i ,
.Fl L ,
or
.Fl n
options are specified during VM startup, a corresponding number
of host-side
.Xr tap 4
interfaces will be allocated and mapped to the
.Xr vio 4
interfaces inside the guest VM.
This tap/vio interface mapping
allows guest network traffic to be manipulated by the host.
Any valid host-side interface configuration may be performed on these
tap interfaces, such as bridging (via
.Xr veb 4 ) ,
or using
.Xr pf 4
nat-to rules to create private or host-side NATed networks, as desired.
For each
.Xr tap 4
network interface on the host,
.Xr vmd 8
will set the interface's description to allow easy identification of
the corresponding VM by ID, interface number, and name:
.Bd -literal -offset indent
# ifconfig tap0
tap0: flags=8842<BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	lladdr fe:e1:ba:d8:50:d1
	description: vm1-if0-myvm
	index 15 priority 0 llprio 3
	groups: tap
	status: active
.Ed
.Sh LOCAL INTERFACES
Local interfaces can be used to easily configure VM networking without
needing to manually assign network addresses.
A local interface is added
to a VM using the -L option to the 'vmctl start' command and results in the
addition of a
.Xr vio 4
interface inside the VM and a corresponding
.Xr tap 4
interface on the host.
When using local interfaces,
.Xr vmd 8
will provide DHCP services to the guest VM and offer addresses selected
from the 100.64.0.0/10 IPv4 range.
From within the 100.64.0.0/10
range,
.Xr vmd 8
allocates a pair of addresses for the guest-side
.Xr vio 4
and host-side
.Xr tap 4
interfaces as follows:
.Pp
For the first local interface:
.Bl -bullet -compact
.It
The host (tapX) address is assigned 100.64.n.2,
where 'n' is the numeric VM ID visible in the 'vmctl status' command
.It
The guest (vio0) address is assigned 100.64.n.3
.El
.Pp
For the second and subsequent local interface(s):
.Bl -bullet -compact
.It
The second local interface uses 100.64.n.4 and 100.64.n.5 for the
host (tapX) and guest (vio1) interfaces, respectively.
.It
Subsequent local interfaces are numbered similarly, continuing with 100.64.n.6
and 100.64.n.7, etc
.El
.Pp
Multiple -L options can be provided to the 'vmctl start' command, if more than
one interface is desired.
Local interfaces are assigned to the VM before
any other interfaces specified with the -i option (thus, local interfaces,
if requested, are numbered starting at vio0 inside the guest VM).
.Pp
If NAT is desired, the
.Va net.inet.ip.forwarding
.Xr sysctl 8
must also be set to 1.
.Pp
When using local interfaces, the DHCP configuration offered to the guest VM
specifies the address of the corresponding host
.Xr tap 4
interface as both the default route and the (sole) nameserver.
Guest VM traffic can optionally be NATed through the host
with an entry in the host machine's
.Pa /etc/pf.conf
similar to the following:
.Bd -literal -offset indent
pass out on egress from 100.64.0.0/10 to any nat-to (egress)
.Ed
.Pp
If desired, DNS queries originating from guest VMs can be redirected to a
different DNS server with an entry in the host machine's
.Pa /etc/pf.conf
similar to the following:
.Bd -literal -offset indent
pass in proto { udp tcp } from 100.64.0.0/10 to any port domain \e
      rdr-to $dns_server port domain
.Ed
.Sh FILES
.Bl -tag -width "/etc/var/run/vmd.sockXX" -compact
.It Pa /etc/vm.conf
Default configuration file.
.It Pa /var/run/vmd.sock
.Ux Ns -domain
socket used for communication with
.Xr vmd 8 .
.El
.Sh EXIT STATUS
.Ex -std vmctl
.Nm
may fail due to one of the following reasons:
.Pp
.Bl -bullet -compact
.It
The VMM subsystem could not be enabled or disabled as requested.
.It
A requested VM-based operation could not be completed.
.El
.Sh EXAMPLES
Create a 4.5 Gigabyte disk image, disk.img:
.Bd -literal -offset indent
$ vmctl create -s 4.5G disk.img
.Ed
.Pp
Convert a disk image from the
.Sq raw
format to
.Sq qcow2 :
.Bd -literal -offset indent
$ vmctl create -i disk.img disk.qcow2
.Ed
.Pp
Create a new VM with 1GB memory, one network interface, one disk image
('disk.img') and boot from kernel '/bsd':
.Bd -literal -offset indent
# vmctl start -m 1G -i 1 -b /bsd -d disk.img "myvm"
.Ed
.Pp
Start a new VM instance with the name 'myvm' from a pre-configured
VM 'openbsd.4G':
.Bd -literal -offset indent
# vmctl start -t "openbsd.4G" -d mydisk.img "myvm"
.Ed
.Pp
Terminate VM number 1:
.Bd -literal -offset indent
# vmctl stop 1
.Ed
.Sh SEE ALSO
.Xr pf 4 ,
.Xr tap 4 ,
.Xr veb 4 ,
.Xr vio 4 ,
.Xr vmm 4 ,
.Xr vm.conf 5 ,
.Xr rc.conf 8 ,
.Xr sysctl 8 ,
.Xr vmd 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 .