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usr.sbin/bhyve/bhyve_config.5

This file was added.

.Dd December 3, 2020

.Dt BHYVE_CONFIG 5

.Os

.Sh NAME

.Nm bhyve_config

.Nd "bhyve configuration variables"

.Sh DESCRIPTION

.Xr bhyve 8

uses a hierarchical tree of configuration variables to describe global and

per-device settings.

Internal nodes in this tree do not have a value,

only leaf nodes have values.

This manual describes the configuration variables understood by

.Xr bhyve 8 .

If additional variables are defined,

rewUnsubmitted

Done

This manual describes the configuration variables understood by

- .Xr bhyve 8.

+ .Xr bhyve 8 .

If additional variables are defined,

missed a space

rew: missed a space

.Xr bhyve 8

will ignore them and will not emit errors for unknown variables.

However, these additional variables can be referenced by other

variables as described below.

.Sh VARIABLE VALUES

Configuration variable values are stored as strings.

A configuration variable value may refer to one or more other

configuration values by name.

Instances of the pattern

.Sq % Ns Pq Ar var

are replaced by the value of the configuration variable

.Va var .

To avoid unwanted expansion,

.Sq %

characters can be escaped by a leading

.Sq % .

For example,

if a configuration variable

.Va disk

uses the value

.Pa /dev/zvol/bhyve/%(name) ,

then the final value of the

.Va disk

variable will be set to the path of a ZFS volume whose name matches

the name of the virtual machine on the pool

.Pa bhyve .

.Pp

Some configuration variables may be interpreted as a boolean value.

For those variables the following case-insensitive values may be used to

indicate true:

.Pp

.Bl -bullet -offset indent -compact

.It

true

.It

yes

.It

.El

.Pp

The following values may be used to indicate false:

.Pp

.Bl -bullet -offset indent -compact

.It

false

.It

off

.It

.El

.Pp

Some configuration variables may be interperted as an integer.

For those variables,

any syntax supported by

.Xr strtol 3

may be used.

.Sh GLOBAL SETTINGS

.Ss Architecture Neutral Settings

.Bl -column "memory.guest_in_core" "integer" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va name Ta string Ta Ta

The name of the VM.

.It Va cpus Ta integer Ta 1 Ta

The total number of virtual CPUs.

.It Va cores Ta integer Ta 1 Ta

The number of virtual cores in each virtual socket.

.It Va threads Ta integer Ta 1 Ta

The number of virtual CPUs in each virtual core.

.It Va sockets Ta integer Ta 1 Ta

The number of virtual sockets.

.It Va memory.guest_in_core Ta bool Ta false Ta

Include guest memory in core file.

.It Va memory.size Ta string Ta 256M Ta

Guest physical memory size in bytes.

The value must be formatted as described in

.Xr expand_number 3 .

.It Va memory.wired Ta bool Ta false Ta

Wire guest memory.

.It Va acpi_tables Ta bool Ta false Ta

Generate ACPI tables.

.It Va destroy_on_poweroff Ta bool Ta false Ta

Destroy the VM on guest-initiated power-off.

.It Va gdb.port Ta integer Ta 0 Ta

TCP port number for the debug server.

If this is set to a non-zero value, a debug server

will listen for connections on this port.

.It Va gdb.wait Ta bool Ta false Ta

If the debug server is enabled, wait for a debugger to connect

before starting the guest.

.It Va rtc.use_localtime Ta bool Ta true Ta

The real time clock uses the local time of the host.

If this is set to false, the real time clock uses UTC.

.It Va uuid Ta string Ta Ta

The universally unique identifier (UUID) to use in the guest's

System Management BIOS System Information structure.

If an explicit value is not set, a valid UUID is generated from

the host's hostname and the VM name.

.It Va virtio_msix Ta bool Ta true Ta

Use MSI-X interrupts for PCI VirtIO devices.

If set to false, MSI interrupts are used instead.

.It Va config.dump Ta bool Ta false Ta

If this value is set to true,

then

.Xr bhyve 8

will write all of its configuration variables to stdout and exit

after it has finished parsing command line options.

.El

.Ss x86-Specific Settings

.Bl -column "x86.vmexit_on_pause" "integer" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va x86.mptable Ta bool Ta true Ta

Generate an MPTable.

.It Va x86.x2apic Ta bool Ta false Ta

Configure guest's local APICs in x2APIC mode.

.It Va x86.strictio Ta bool Ta false Ta

Exit if a guest accesses an I/O port that is not emulated.

By default, writes are ignored and reads return all bits set.

.It Va x86.strictmsr Ta bool Ta true Ta

Inject a general protection fault if a guest accesses a Model Specific

If this is false, writes are ignored and reads return zero.

.It Va x86.vmexit_on_hlt Ta bool Ta false Ta

Force a VM exit when a guest CPU executes the

.Dv HLT

instruction.

This allows idle guest CPUs to yield the host CPU.

.It Va x86.vmexit_on_pause Ta bool Ta false Ta

Force a VM exit when a guest CPU executes the

.Dv PAUSE

instruction.

.El

.Sh DEVICE SETTINGS

Device settings are stored under a device node.

The device node's name is set by the parent bus of the device.

.Ss PCI Device Settings

PCI devices are described by a device node named

.Dq pci Ns Ar bus . Ns Ar slot . Ns Ar function

where each of

.Ar bus ,

.Ar slot ,

and

.Ar function

are formatted as decimal values with no padding.

All PCI device nodes must contain a configuration variable named

.Dq device

which specifies the device model to use.

The following PCI device models are supported:

.Bl -tag -indent

.It Li hostbridge

Provide a simple PCI-Host bridge device.

This is usually configured at pci0:0:0 and is required by most guest

operating systems.

.It Li ahci

AHCI storage controller.

.It Li e1000

Intel e82545 network interface.

.It Li fbuf

VGA framebuffer device attached to VNC server.

.It Li lpc

LPC PCI-ISA bridge with COM1-COM4 16550 serial ports,

a boot ROM,

and an optional debug/test device.

This device must be configured on bus 0.

.It Li hda

High Definition audio controller.

.It Li nvme

NVM Express (NVMe) controller.

.It Li passthru

PCI pass-through device.

.It Li uart

PCI 16550 serial device.

.It Li virtio-9p

VirtIO 9p (VirtFS) interface.

.It Li virtio-blk

VirtIO block storage interface.

.It Li virtio-console

VirtIO console interface.

.It Li virtio-net

VirtIO network interface.

.It Li virtio-rnd

VirtIO RNG interface.

.It Li virtio-scsi

VirtIO SCSI interface.

.It Li xhci

Extensible Host Controller Interface (XHCI) USB controller.

.El

.Ss USB Device Settings

USB controller devices contain zero or more child USB devices

attached to slots.

Each USB device stores its settings in a node named

.Dq slot. Ns Va N

under the controller's device node.

.Va N

is the number of the slot to which the USB device is attached.

Note that USB slot numbers begin at 1.

All USB device nodes must contain a configuration variable named

.Dq device

which specifies the device model to use.

The following USB device models are supported:

.Bl -tag -indent

.It Li tablet

A USB tablet device which provides precise cursor synchronization

when using VNC.

.El

.Ss Block Device Settings

Block devices use the following settings to configure their backing store.

These settings are stored in the configuration node of the respective device.

.Bl -column "sectorsize" "logical[/physical]" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It path Ta string Ta Ta

The path of the file or disk device to use as the backing store.

.It nocache Ta bool Ta false Ta

Disable caching on the backing file by opening the backing file with

.Dv O_DIRECT .

.It nodelete Ta bool Ta false Ta

Disable emulation of guest trim requests via

.Dv DIOCGDELETE

requests.

.It sync Ta bool Ta false Ta

Write changes to the backing file with synchronous writes.

.It direct Ta bool Ta false Ta

An alias for

.Va sync .

.It ro Ta bool Ta false Ta

Disable writes to the backing file.

.It sectorsize Ta Va logical Ns Op / Ns Va physical Ta Ta

Specify the logical and physical sector size of the emulated disk.

If the physical size is not specified,

it is equal to the logical size.

.El

.Ss Network Backend Settings

Network devices use the following settings to configure their backend.

The backend is responsible for passing packets between the device model

and a desired destination.

Configuring a backend requires setting the

.Va backend

variable to one of the following values:

.Bl -tag

.It tap Ns Va N

Use the named

.Xr tap 4

interface as the backend.

.It vmnet Ns Va N

Use the named

.Xr vmnet 4

interface as the backend.

.It netgraph

Use a

.Xr netgraph 4

socket hook as the backend.

This backend uses the following additional variables:

.Bl -column "peerhook" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va path Ta string Ta Ta

The name of the

.Xr netgraph 4

destination node.

.It Va peerhook Ta string Ta Ta

The name of the destination hook.

.It Va socket Ta string Ta Ta

The name of the created

.Xr ng_socket 4

node.

.It Va hook Ta string Ta vmlink Ta

The name of the source hook on the created

.Xr ng_socket 4

node.

.El

.It netmap: Ns Va interface

Use

.Xr netmap 4

on a network interface as the backend.

.It vale Ns Va bridge : Ns Va port

Use a port on a

.Xr vale 4

bridge as the backend.

.El

.Ss UART Device Settings

.Bl -column "Name" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va path Ta path Ta Ta

Backend device for the serial port.

Either the pathname of a character device or

.Dq stdio

to use standard input and output of the

.Xr bhyve 8

process.

.El

.Ss Host Bridge Settings

.Bl -column "vendor" "integer" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va vendor Ta integer Ta 0x1275 Ta

PCI vendor ID.

.It Va device Ta integer Ta 0x1275 Ta

PCI device ID.

.El

.Ss AHCI Controller Settings

AHCI controller devices contain zero or more ports each of which

provides a storage device.

Each port stores its settings in a node named

.Dq port. Ns Va N

under the controller's device node.

The

.Va N

values are formatted as successive decimal values starting with 0.

In addition to the block device settings described above, each

port supports the following settings:

.Bl -column "model" "integer" "generated"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va type Ta string Ta Ta

The type of storage device to emulate.

Must be set to either

.Dq cd

.Dq hd .

.It Va nmrr Ta integer Ta 0 Ta

Nominal Media Rotation Rate, also known as RPM.

A value 1 of indicates a device with no rate such as a Solid State Disk.

.It Va ser Ta string Ta generated Ta

Serial number of up to twenty characters.

A default serial number is generated using a hash of the backing

store's pathname.

.It Va rev Ta string Ta 001 Ta

Revision number of up to eight characters.

.It Va model Ta string Ta Ta

Model number of up to forty characters.

Separate default model strings are used for

.Dq cd

and

.Dq hd

device types.

.El

.Ss e1000 Settings

In addition to the network backend settings,

Intel e82545 network interfaces support the following variables:

.Bl -column "Name" "MAC address" "generated"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va mac Ta MAC address Ta generated Ta

MAC address.

If an explicit address is not provided,

a MAC address is generated from a hash of the device's PCI address.

.El

.Ss Frame Buffer Settings

.Bl -column "password" "[IP:]port" "127.0.0.1:5900"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va wait Ta bool Ta false Ta

Wait for a remote connection before starting the VM.

.It Va rfb Ta Oo Ar IP Ns : Oc Ns Ar port Ta 127.0.0.1:5900 Ta

TCP address to listen on for remote connections.

The IP address must be given as a numeric address.

IPv6 addresses must be enclosed in square brackets and

support scoped identifiers as described in

.Xr getaddrinfo 3 .

A bare port number may be given in which case the IPv4

localhost address is used.

.It Va vga Ta string Ta io Ta

VGA configuration.

More details are provided in

.Xr bhyve 8 .

.It Va w Ta integer Ta 1024 Ta

Frame buffer width in pixels.

.It Va h Ta integer Ta 768 Ta

Frame buffer height in pixels.

.It Va password Ta string Ta Ta

Password to use for VNC authentication.

This type of authentication is known to be cryptographically weak and is not

intended for use on untrusted networks.

.El

.Ss High Definition Audio Settings

.Bl -column "Name" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va play Ta path Ta Ta

Host playback device,

typically

.Pa /dev/dsp0 .

.It Va rec Ta path Ta Ta

Host recording device,

typically

.Pa /dev/dsp0 .

.El

.Ss LPC Device Settings

The LPC bridge stores its configuration under a top-level

.Va lpc

node rather than under the PCI LPC device's node.

The following nodes are available under

.Va lpc :

.Bl -column "pc-testdev" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va bootrom Ta path Ta Ta

Path to a boot ROM.

The contents of this file are copied into the guest's

memory ending just before the 4GB physical address.

If a boot ROM is present, a firmware interface device is

also enabled for use by the boot ROM.

.It Va com1 Ta node Ta Ta

Settings for the COM1 serial port device.

.It Va com2 Ta node Ta Ta

Settings for the COM2 serial port device.

.It Va com3 Ta node Ta Ta

Settings for the COM3 serial port device.

.It Va com4 Ta node Ta Ta

Settings for the COM4 serial port device.

.It Va pc-testdev Ta bool Ta false Ta

Enable the PC debug/test device.

.El

.Ss NVMe Controller Settings

Each NVMe controller supports a single storage device.

The device can be backed either by a memory disk described by the

.Va ram

variable, or a block device using the the block device settings described above.

In addition, each controller supports the following settings:

.Bl -column "ioslots" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va maxq Ta integer Ta 16 Ta

Maximum number of I/O submission and completion queue pairs.

.It Va qsz Ta integer Ta 2058 Ta

Number of elements in each I/O queue.

.It Va ioslots Ta integer Ta 8 Ta

Maximum number of concurrent I/O requests.

.It Va sectsz Ta integer Ta Ta

Sector size.

Can be one of 512, 4096, or 8192.

Devices backed by a memory disk use 4096 as the default.

Devices backed by a block device use the block device's sector size

as the default.

.It Va ser Ta string Ta Ta

Serial number of up to twenty characters.

A default serial number is generated using a hash of the device's PCI address.

.It Va eui64 Ta integer Ta Ta

IEEE Extended Unique Identifier.

If an EUI is not provided, a default is generated using a checksum of the

device's PCI address.

.It Va dsm Ta string Ta auto Ta

Whether or not to advertise DataSet Management support.

One of

.Dq auto ,

.Dq enable ,

.Dq disable .

The

.Dq auto

setting only advertises support if the backing store supports

resource freeing, for example via TRIM.

.It Va ram Ta integer Ta Ta

If set, allocate a memory disk as the backing store.

The value of this variable is the size of the memory disk in megabytes.

.El

.Ss PCI Passthrough Settings

.Bl -column "Name" "integer" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va bus Ta integer Ta Ta

Host PCI bus address of device to pass through.

.It Va slot Ta integer Ta Ta

Host PCI slot address of device to pass through.

.It Va func Ta integer Ta Ta

Host PCI function address of device to pass through.

.El

.Ss VirtIO 9p Settings

Each VirtIO 9p device exposes a single filesystem from a host path.

.Bl -column "sharename" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va sharename Ta string Ta Ta

The share name exposed to the guest.

.It Va path Ta path Ta Ta

The path of a directory on the host to export to the guest.

.It Va ro Ta bool Ta false Ta

If true, the guest filesystem is read-only.

.El

.Ss VirtIO Console Device Settings

Each VirtIO Console device contains one or more console ports.

Each port stores its settings in a node named

.Dq port. Ns Va N

under the controller's device node.

jhbAuthorUnsubmitted

Done

Upon further reflection, I think I should probably change this to be more like AHCI, so that you have:

port.0.name=console
port.0.path=/some/socket
port.1.name=foo
port.1.path=/other/socket
...

Rather than the current:

ports.console=/some/socket
ports.foo=/other/socket

In addition, a second bug is that I don't see why these devices have to only work with UNIX domain sockets. It should be reasonable to hook these up to a /dev/ndmX device, or to use "stdio" like we do for UART devices? However, that seems orthogonal.

jhb: Upon further reflection, I think I should probably change this to be more like AHCI, so that…

grehanUnsubmitted

Not Done

The initial use of this was as an out-of-bound messaging path for guest tools, not so much as a serial port.

virtio-console can't operate in polled-mode so isn't of much use as an actual guest console.

grehan: The initial use of this was as an out-of-bound messaging path for guest tools, not so much as a…

jhbAuthorUnsubmitted

Done

Huh, ok. I might still clean up the config to be more like AHCI.

jhb: Huh, ok. I might still clean up the config to be more like AHCI.

The

.Va N

values are formatted as successive decimal values starting with 0.

Each port supports the following settings:

.Bl -column "Name" "Format" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va name Ta string Ta Ta

The name of the port exposed to the guest.

.It Va path Ta path Ta Ta

The path of a UNIX domain socket providing the host connection for the port.

.El

.Ss VirtIO Network Interface Settings

In addition to the network backend settings,

VirtIO network interfaces support the following variables:

.Bl -column "Name" "MAC address" "generated"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va mac Ta MAC address Ta generated Ta

MAC address.

If an explicit address is not provided,

a MAC address is generated from a hash of the device's PCI address.

.It Va mtu Ta integer Ta 1500 Ta

The largest supported MTU advertised to the guest.

.El

.Ss VirtIO SCSI Settings

.Bl -column "Name" "integer" "Default"

.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description

.It Va dev Ta path Ta Ta

The path of a CAM target layer (CTL) device to export:

.Pa /dev/cam/ctl Ns Oo Ar pp . Ns Ar vp Oc .

.It Va iid Ta integer Ta 0 Ta

Initiator ID to use when sending requests to the CTL port.

.El

.Sh SEE ALSO

.Xr expand_number 3 ,

rewUnsubmitted

Done

.Xr getaddrinfo 3 ,

.Xr strtol 3 ,

- .Xr netgraph ,

+ .Xr netgraph 4 ,

.Xr netmap 4 ,

missed a number, netgraph(4).

rew: missed a number, netgraph(4).

.Xr getaddrinfo 3 ,

.Xr strtol 3 ,

.Xr netgraph 4 ,

.Xr netmap 4 ,

.Xr ng_socket 4 ,

.Xr tap 4 ,

.Xr vale 4 ,

.Xr vmnet 4 ,

.Xr bhyve 8