BHYVELOAD(8) FreeBSD System Manager's Manual BHYVELOAD(8)
NAME
bhyveload - load a FreeBSD guest inside a bhyve virtual machine
SYNOPSIS
bhyveload [-C] [-S] [-c cons-dev] [-d disk-path] [-e name=value]
[-h host-path] [-l os-loader] [-m memsize[K|k|M|m|G|g|T|t]]
vmname
DESCRIPTION
bhyveload is used to load a FreeBSD guest inside a bhyve(4) virtual
machine.
bhyveload is based on loader(8) and will present an interface identical
to the FreeBSD loader on the user's terminal. This behavior can be
changed by specifying a different OS loader.
The virtual machine is identified as vmname and will be created if it
does not already exist.
OPTIONS
The following options are available:
-c cons-dev
cons-dev is a tty(4) device to use for bhyveload terminal I/O.
The text string "stdio" is also accepted and selects the use of
unbuffered standard I/O. This is the default value.
-d disk-path
The disk-path is the pathname of the guest's boot disk image.
-e name=value
Set the FreeBSD loader environment variable name to value.
The option may be used more than once to set more than one
environment variable.
-h host-path
The host-path is the directory at the top of the guest's boot
filesystem.
-l os-loader
Specify a different OS loader. By default bhyveload will use
/boot/userboot.so, which presents a standard FreeBSD loader.
-m memsize[K|k|M|m|G|g|T|t]
memsize is the amount of memory allocated to the guest.
The memsize 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 respectively.
memsize defaults to 256M.
-C Include guest memory in the core file when bhyveload dumps core.
This is intended for debugging an OS loader as it allows
inspection of the guest memory.
-S Wire guest memory.
EXAMPLES
To create a virtual machine named freebsd-vm that boots off the ISO image
/freebsd/release.iso and has 1GB memory allocated to it:
bhyveload -m 1G -d /freebsd/release.iso freebsd-vm
To create a virtual machine named test-vm with 256MB of memory allocated,
the guest root filesystem under the host directory /user/images/test and
terminal I/O sent to the nmdm(4) device /dev/nmdm1B
bhyveload -m 256MB -h /usr/images/test -c /dev/nmdm1B test-vm
SEE ALSO
bhyve(4), nmdm(4), vmm(4), bhyve(8), loader(8)
HISTORY
bhyveload first appeared in FreeBSD 10.0, and was developed at NetApp
Inc.
AUTHORS
bhyveload was developed by Neel Natu <
[email protected]> at NetApp Inc
with a lot of help from Doug Rabson <
[email protected]>.
BUGS
bhyveload can only load FreeBSD as a guest.
SECURITY CONSIDERATIONS
Note that in some configurations, bhyveload will execute guest loader
scripts in the context of the host machine. Note, however, that
bhyveload will enter a capsicum(4) sandbox before it loads the os-loader
or executes any loader scripts. On the host filesystem, the sandbox will
only have access to the path specified by the -h flag, the contents of
the /boot directory if -l was not specified, and the chosen console
device.
Note that the guest loader scripts are already subject to some
limitations that are not relaxed simply because we are running in
userland. For instance, any I/O on the loader's "host" device that can
be done in loader scripts is limited to the interface that bhyveload
provides, which itself will restrict paths that can be touched to those
within a specified -h directory, if any. Access to files within /boot
inside the sandbox would require arbitrary code execution in userboot,
and userboot is usually provided by the host machine rather than anything
that is a part of the guest image. All access to the -h directory as
well as /boot is strictly read-only in the sandbox.
FreeBSD 14.1-RELEASE-p8 January 12, 2024 FreeBSD 14.1-RELEASE-p8