NAME

SYNOPSIS

DESCRIPTION

Parameters such as the number of virtual CPUs, amount of guest memory, and I/O connectivity can be specified with command-line parameters.

If not using a boot ROM, the guest operating system must be loaded with bhyveload(8) or a similar boot loader before running bhyve, otherwise, it is enough to run bhyve with a boot ROM of choice.

bhyve runs until the guest operating system reboots or an unhandled hypervisor exit is detected.

OPTIONS

-A

Generate ACPI tables. Required for FreeBSD/amd64 guests.

-a

The guest's local APIC is configured in xAPIC mode. The xAPIC mode is the default setting so this option is redundant. It will be deprecated in a future version.

-C

Include guest memory in core file.

-c [setting ...]

Number of guest virtual CPUs and/or the CPU topology. The default value for each of numcpus, sockets, cores, and threads is 1. The current maximum number of guest virtual CPUs is 16. If numcpus is not specified then it will be calculated from the other arguments. The topology must be consistent in that the numcpus must equal the product of sockets, cores, and threads. If a setting is specified more than once the last one has precedence.

-D

Destroy the VM on guest initiated power-off.

-e

Force bhyve to exit when a guest issues an access to an I/O port that is not emulated. This is intended for debug purposes.

-G port

Start a debug server that uses the GDB protocol to export guest state to a debugger. An IPv4 TCP socket will be bound to the supplied port to listen for debugger connections. Only a single debugger may be attached to the debug server at a time. If port begins with ‘w’, bhyve will pause execution at the first instruction waiting for a debugger to attach.

-H

Yield the virtual CPU thread when a HLT instruction is detected. If this option is not specified, virtual CPUs will use 100% of a host CPU.

-h

Print help message and exit.

-k config_file

Set configuration variables from a simple, key-value config file. Each line of the config file is expected to consist of a config variable name, an equals sign (‘=’), and a value. No spaces are permitted between the variable name, equals sign, or value. Blank lines and lines starting with ‘#’ are ignored. See bhyve_config(5) for more details.

-l help

Print a list of supported LPC devices.

-l lpcdev[,conf]

Allow devices behind the LPC PCI-ISA bridge to be configured. The only supported devices are the TTY-class devices com1, com2, com3, and com4, the boot ROM device bootrom, and the debug/test device pc-testdev.

The possible values for the conf argument are listed in the -s flag description.

-m memsize[K|k|M|m|G|g|T|t]

Set the guest physical memory size This must be the same size that was given to bhyveload(8).

The size argument may be suffixed with one of K, M, G or T (either upper or lower case) to indicate a multiple of kilobytes, megabytes, gigabytes, or terabytes. If no suffix is given, the value is assumed to be in megabytes.

The default is 256M.

-o var=value

Set the configuration variable var to value.

-P

Force the guest virtual CPU to exit when a PAUSE instruction is detected.

-p vcpu:hostcpu

Pin guest's virtual CPU vcpu to hostcpu.

-r file

Resume a guest from a snapshot. The guest memory contents are restored from file, and the guest device and vCPU state are restored from the file “file.kern”.

Note that the current snapshot file format requires that the configuration of devices in the new VM match the VM from which the snapshot was taken by specifying the same -s and -l options. The count of vCPUs and memory configuration are read from the snapshot.

-S

Wire guest memory.

-s help

Print a list of supported PCI devices.

-s slot,emulation[,conf]

Configure a virtual PCI slot and function.

bhyve provides PCI bus emulation and virtual devices that can be attached to slots on the bus. There are 32 available slots, with the option of providing up to 8 functions per slot.

The slot can be specified in one of the following formats:

• pcislot
• pcislot:function
• bus:pcislot:function

The pcislot value is 0 to 31. The optional function value is 0 to 7. The optional bus value is 0 to 255. If not specified, the function value defaults to 0. If not specified, the bus value defaults to 0.

The emulation argument can be one of the following:

hostbridge

A simple host bridge. This is usually configured at slot 0, and is required by most guest operating systems.

amd_hostbridge

Emulation identical to hostbridge using a PCI vendor ID of AMD.

passthru

PCI pass-through device.

virtio-net

Virtio network interface.

virtio-blk

Virtio block storage interface.

virtio-scsi

Virtio SCSI interface.

virtio-9p

Virtio 9p (VirtFS) interface.

virtio-rnd

Virtio RNG interface.

virtio-console

Virtio console interface, which exposes multiple ports to the guest in the form of simple char devices for simple IO between the guest and host userspaces.

ahci

AHCI controller attached to arbitrary devices.

ahci-cd

AHCI controller attached to an ATAPI CD/DVD.

ahci-hd

AHCI controller attached to a SATA hard drive.

e1000

Intel e82545 network interface.

uart

PCI 16550 serial device.

lpc

LPC PCI-ISA bridge with COM1, COM2, COM3, and COM4 16550 serial ports, a boot ROM, and, optionally, the debug/test device. The LPC bridge emulation can only be configured on bus 0.

fbuf

Raw framebuffer device attached to VNC server.

xhci

eXtensible Host Controller Interface (xHCI) USB controller.

nvme

NVM Express (NVMe) controller.

hda

High Definition Audio Controller.

The optional parameter conf describes the backend for device emulations. If conf is not specified, the device emulation has no backend and can be considered unconnected.

Network device backends:

• tapN[,mac=xx:xx:xx:xx:xx:xx][,mtu=N]
• vmnetN[,mac=xx:xx:xx:xx:xx:xx][,mtu=N]
• netgraph,path=ADDRESS,peerhook=HOOK[,socket=NAME][,hook=HOOK][,mac=xx:xx:xx:xx:xx:xx][,mtu=N]

If mac is not specified, the MAC address is derived from a fixed OUI and the remaining bytes from an MD5 hash of the slot and function numbers and the device name.

The MAC address is an ASCII string in ethers(5) format.

With virtio-net devices, the mtu parameter can be specified to inform the guest about the largest MTU that should be allowed, expressed in bytes.

With netgraph backend, the path and peerhook parameters must be specified to set the destination node and corresponding hook. The optional parameters socket and hook may be used to set the ng_socket(4) node name and source hook. The ADDRESS, HOOK, and NAME must comply with netgraph(4) addressing rules.

Block storage device backends:

• /filename[,block-device-options]
• /dev/xxx[,block-device-options]

The block-device-options are:

nocache

Open the file with O_DIRECT.

direct

Open the file using O_SYNC.

ro

Force the file to be opened read-only.

sectorsize=logical[/physical]

Specify the logical and physical sector sizes of the emulated disk. The physical sector size is optional and is equal to the logical sector size if not explicitly specified.

nodelete

Disable emulation of guest trim requests via DIOCGDELETE requests.

SCSI device backends:

• /dev/cam/ctl[pp.vp][,scsi-device-options]

The scsi-device-options are:

iid=IID

Initiator ID to use when sending requests to specified CTL port. The default value is 0.

9P device backends:

• sharename=/path/to/share[,9p-device-options]

The 9p-device-options are:

ro

Expose the share in read-only mode.

TTY device backends:

stdio

Connect the serial port to the standard input and output of the bhyve process.

/dev/xxx

Use the host TTY device for serial port I/O.

Boot ROM device backends:

romfile

Map romfile in the guest address space reserved for boot firmware.

Pass-through device backends:

slot/bus/function

Connect to a PCI device on the host at the selector described by slot, bus, and function numbers.

Guest memory must be wired using the -S option when a pass-through device is configured.

The host device must have been reserved at boot-time using the pptdevs loader variable as described in vmm(4).

Virtio console device backends:

• port1=/path/to/port1.sock[,portN=/path/to/port2.sock ...]

A maximum of 16 ports per device can be created. Every port is named and corresponds to a Unix domain socket created by bhyve. bhyve accepts at most one connection per port at a time.

Limitations:

• Due to lack of destructors in bhyve, sockets on the filesystem must be cleaned up manually after bhyve exits.
• There is no way to use the “console port” feature, nor the console port resize at present.
• Emergency write is advertised, but no-op at present.

Framebuffer devices backends:

• [rfb=ip-and-port][,w=width][,h=height][,vga=vgaconf][,wait][,password=password]

Configuration options are defined as follows:

rfb=ip-and-port (or tcp=ip-and-port)

An IP address and a port VNC should listen on. There are two formats:

• [IPv4:]port
• [IPv6%zone]:port

The default is to listen on localhost IPv4 address and default VNC port 5900. An IPv6 address must be enclosed in square brackets and may contain an optional zone identifier.

w=width and h=height

A display resolution, width and height, respectively. If not specified, a default resolution of 1024x768 pixels will be used. Minimal supported resolution is 640x480 pixels, and maximum is 1920x1200 pixels.

vga=vgaconf

Possible values for this option are io (default), on , and off. PCI graphics cards have a dual personality in that they are standard PCI devices with BAR addressing, but may also implicitly decode legacy VGA I/O space (0x3c0-3df) and memory space (64KB at 0xA0000). The default io option should be used for guests that attempt to issue BIOS calls which result in I/O port queries, and fail to boot if I/O decode is disabled.

The on option should be used along with the CSM BIOS capability in UEFI to boot traditional BIOS guests that require the legacy VGA I/O and memory regions to be available.

The off option should be used for the UEFI guests that assume that VGA adapter is present if they detect the I/O ports. An example of such a guest is OpenBSD in UEFI mode.

Please refer to the bhyve FreeBSD wiki page (https://wiki.freebsd.org/bhyve) for configuration notes of particular guests.

wait

Instruct bhyve to only boot upon the initiation of a VNC connection, simplifying the installation of operating systems that require immediate keyboard input. This can be removed for post-installation use.

password=password

This type of authentication is known to be cryptographically weak and is not intended for use on untrusted networks. Many implementations will want to use stronger security, such as running the session over an encrypted channel provided by IPsec or SSH.

xHCI USB device backends:

tablet

A USB tablet device which provides precise cursor synchronization when using VNC.

NVMe device backends:

• devpath[,maxq=#][,qsz=#][,ioslots=#][,sectsz=#][,ser=#][,eui64=#][,dsm=opt]

Configuration options are defined as follows:

devpath

Accepted device paths are: /dev/blockdev or /path/to/image or ram=size_in_MiB.

maxq

Max number of queues.

qsz

Max elements in each queue.

ioslots

Max number of concurrent I/O requests.

sectsz

Sector size (defaults to blockif sector size).

ser

Serial number with maximum 20 characters.

eui64

IEEE Extended Unique Identifier (8 byte value).

dsm

DataSet Management support. Supported values are: auto, enable, and disable.

AHCI device backends:

• [[hd:|cd:]path][,nmrr=nmrr][,ser=#][,rev=#][,model=#]

Configuration options are defined as follows:

nmrr

Nominal Media Rotation Rate, known as RPM. Value 1 will indicate device as Solid State Disk. Default value is 0, not report.

ser

Serial Number with maximum 20 characters.

rev

Revision Number with maximum 8 characters.

model

Model Number with maximum 40 characters.

HD Audio device backends:

• [play=playback][,rec=recording]

Configuration options are defined as follows:

play

Playback device, typically /dev/dsp0.

rec

Recording device, typically /dev/dsp0.

-U uuid

Set the universally unique identifier (UUID) in the guest's System Management BIOS System Information structure. By default a UUID is generated from the host's hostname and vmname.

-u

RTC keeps UTC time.

-W

Force virtio PCI device emulations to use MSI interrupts instead of MSI-X interrupts.

-w

Ignore accesses to unimplemented Model Specific Registers (MSRs). This is intended for debug purposes.

-x

The guest's local APIC is configured in x2APIC mode.

-Y

Disable MPtable generation.

vmname

Alphanumeric name of the guest. This should be the same as that created by bhyveload(8).

CONFIGURATION VARIABLES

Once all of the command line options have been processed, the configuration values are frozen. bhyve then uses the value of configuration values to initialize device models and global settings.

More details on configuration variables can be found in bhyve_config(5).

DEBUG SERVER

SIGNAL HANDLING

SIGTERM

Trigger ACPI poweroff for a VM

EXIT STATUS

0

rebooted

1

powered off

2

halted

3

triple fault

4

exited due to an error

EXAMPLES

To run a virtual machine with 1GB of memory, two virtual CPUs, a virtio block device backed by the /my/image filesystem image, and a serial port for the console:

bhyve -c 2 -s 0,hostbridge -s 1,lpc -s 2,virtio-blk,/my/image \
  -l com1,stdio -A -H -P -m 1G vm1

Run a 24GB single-CPU virtual machine with three network ports, one of which has a MAC address specified:

bhyve -s 0,hostbridge -s 1,lpc -s 2:0,virtio-net,tap0 \
  -s 2:1,virtio-net,tap1 \
  -s 2:2,virtio-net,tap2,mac=00:be:fa:76:45:00 \
  -s 3,virtio-blk,/my/image -l com1,stdio \
  -A -H -P -m 24G bigvm

Run an 8GB quad-CPU virtual machine with 8 AHCI SATA disks, an AHCI ATAPI CD-ROM, a single virtio network port, an AMD hostbridge, and the console port connected to an nmdm(4) null-modem device.

bhyve -c 4 \
  -s 0,amd_hostbridge -s 1,lpc \
  -s 1:0,ahci,hd:/images/disk.1,hd:/images/disk.2,\
hd:/images/disk.3,hd:/images/disk.4,\
hd:/images/disk.5,hd:/images/disk.6,\
hd:/images/disk.7,hd:/images/disk.8,\
cd:/images/install.iso \
  -s 3,virtio-net,tap0 \
  -l com1,/dev/nmdm0A \
  -A -H -P -m 8G

Run a UEFI virtual machine with a display resolution of 800 by 600 pixels that can be accessed via VNC at: 0.0.0.0:5900.

bhyve -c 2 -m 4G -w -H \
  -s 0,hostbridge \
  -s 3,ahci-cd,/path/to/uefi-OS-install.iso \
  -s 4,ahci-hd,disk.img \
  -s 5,virtio-net,tap0 \
  -s 29,fbuf,tcp=0.0.0.0:5900,w=800,h=600,wait \
  -s 30,xhci,tablet \
  -s 31,lpc -l com1,stdio \
  -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
   uefivm

Run a UEFI virtual machine with a VNC display that is bound to all IPv6 addresses on port 5900.

bhyve -c 2 -m 4G -w -H \
  -s 0,hostbridge \
  -s 4,ahci-hd,disk.img \
  -s 5,virtio-net,tap0 \
  -s 29,fbuf,tcp=[::]:5900,w=800,h=600 \
  -s 30,xhci,tablet \
  -s 31,lpc -l com1,stdio \
  -l bootrom,/usr/local/share/uefi-firmware/BHYVE_UEFI.fd \
   uefivm

SEE ALSO

Intel, 64 and IA-32 Architectures Software Developer’s Manual, Volume 3.

HISTORY

AUTHORS