BHYVE(8) System Manager's Manual BHYVE(8) NAME bhyve -- run a guest operating system inside a virtual machine SYNOPSIS bhyve [-AaCDeHhPSuWwxY] [-c [[cpus=]numcpus][,sockets=n][,cores=n][,threads=n]] [-G port] [-l help|lpcdev[,conf]] [-m memsize[K|k|M|m|G|g|T|t]] [-p vcpu:hostcpu] [-r file] [-s help|slot,emulation[,conf]] [-U uuid] vmname DESCRIPTION bhyve is a hypervisor that runs guest operating systems inside a virtual machine. 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 hyper- visor exit is detected. OPTIONS -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. -A Generate ACPI tables. Required for FreeBSD/amd64 guests. -c [setting ...] Number of guest virtual CPUs and/or the CPU topology. The de- fault 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. -C Include guest memory in core file. -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 pur- poses. -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 sin- gle 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 Print help message and exit. -H Yield the virtual CPU thread when a HLT instruction is de- tected. If this option is not specified, virtual CPUs will use 100% of a host CPU. -l [help|lpcdev[,conf]] Allow devices behind the LPC PCI-ISA bridge to be configured. The only supported devices are the TTY-class devices com1 through com4, the boot ROM device bootrom, and the debug/test device pc-testdev. help print a list of supported LPC devices. -m memsize[K|k|M|m|G|g|T|t] Guest physical memory size in bytes. 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 (ei- ther 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. memsize defaults to 256M. -p vcpu:hostcpu Pin guest's virtual CPU vcpu to hostcpu. -P Force the guest virtual CPU to exit when a PAUSE instruction is detected. -r file Resume a guest from a snapshot. The guest memory contents are restored from file, and the guest device and vCPU state are re- stored 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] op- tions. The count of vCPUs and memory configuration are read from the snapshot. -s [help|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. help print a list of supported PCI devices. slot 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 de- faults to 0. emulation hostbridge | amd_hostbridge Provide a simple host bridge. This is usually configured at slot 0, and is required by most guest operating sys- tems. The amd_hostbridge emulation is identical but uses 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 and COM2 16550 serial ports, a boot ROM, and, optionally, the debug/test device. The LPC bridge emulation can only be con- figured 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. [conf] This optional parameter describes the backend for device emulations. If conf is not specified, the device emulation has no backend and can be consid- ered unconnected. Network 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 ad- dress 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 para- meter 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 corre- sponding 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 devices: /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 devices: /dev/cam/ctl[pp.vp][,scsi-device-options] The scsi-device-options are: iid=IID Initiator ID to use when sending re- quests to specified CTL port. The de- fault value is 0. 9P devices: sharename=/path/to/share[,9p-device-options] The 9p-device-options are: ro Expose the share in read-only mode. TTY devices: 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: romfile Map romfile in the guest address space reserved for boot firmware. Pass-through devices: 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 devices: port1=/path/to/port1.sock,anotherport=... A maximum of 16 ports per device can be created. Every port is named and cor- responds to a Unix domain socket cre- ated 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 "con- sole port" feature, nor the con- sole port resize at present. * Emergency write is advertised, but no-op at present. Framebuffer devices: [rfb=[IP:]port][,w=width][,h=height][,vga=vgaconf][,wait][,password=password] IPv4:port or [IPv6%zone]:port An IP address and a port VNC should listen on. The de- fault is to listen on local- host IPv4 address and default VNC port 5900. An IPv6 ad- dress must be enclosed in square brackets and may con- tain an optional zone identi- fier. width and height A display resolution, width and height, respectively. If not specified, a default res- olution of 1024x768 pixels will be used. Minimal sup- ported resolution is 640x480 pixels, and maximum is 1920x1200 pixels. vgaconf Possible values for this op- tion 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 de- code legacy VGA I/O space (0x3c0-3df) and memory space (64KB at 0xA0000). The de- fault "io" option should be used for guests that attempt to issue BIOS calls which re- sult 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 immedi- ate keyboard input. This can be removed for post-installa- tion use. password This type of authentication is known to be cryptographi- cally weak and is not in- tended for use on untrusted networks. Many implementa- tions will want to use stronger security, such as running the session over an encrypted channel provided by IPsec or SSH. xHCI USB devices: tablet A USB tablet device which provides pre- cise cursor synchronization when using VNC. NVMe devices: 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 charac- ters. AHCI devices: 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 charac- ters. rev Revision Number with maximum 8 charac- ters. model Model Number with maximum 40 charac- ters. HD Audio devices: play Playback device, typically /dev/dsp0. rec Recording device, typically /dev/dsp0. -S Wire guest memory. -u RTC keeps UTC time. -U uuid Set the universally unique identifier (UUID) in the guest's System Management BIOS System Information structure. By de- fault a UUID is generated from the host's hostname and vmname. -w Ignore accesses to unimplemented Model Specific Registers (MSRs). This is intended for debug purposes. -W Force virtio PCI device emulations to use MSI interrupts in- stead of MSI-X interrupts. -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). DEBUG SERVER The current debug server provides limited support for debuggers. Registers Each virtual CPU is exposed to the debugger as a thread. General purpose registers can be queried for each virtual CPU, but other registers such as floating-point and system registers cannot be queried. Memory Memory (including memory mapped I/O regions) can be read and written by the debugger. Memory operations use virtual addresses that are resolved to physical addresses via the current virtual CPU's active address transla- tion. Control The running guest can be interrupted by the debugger at any time (for example, by pressing Ctrl-C in the debugger). Single stepping is only supported on Intel CPUs supporting the MTRAP VM exit. Breakpoints are supported on Intel CPUs that support single stepping. Note that continuing from a breakpoint while interrupts are enabled in the guest may not work as expected due to timer interrupts firing while single step- ping over the breakpoint. SIGNAL HANDLING bhyve deals with the following signals: SIGTERM Trigger ACPI poweroff for a VM EXIT STATUS Exit status indicates how the VM was terminated: 0 rebooted 1 powered off 2 halted 3 triple fault 4 exited due to an error EXAMPLES If not using a boot ROM, the guest operating system must have been loaded with bhyveload(8) or a similar boot loader before bhyve(4) can be run. Otherwise, the boot loader is not needed. 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 ad- dresses 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 bhyve(4), netgraph(4), ng_socket(4), nmdm(4), vmm(4), ethers(5), bhyvectl(8), bhyveload(8) Intel, 64 and IA-32 Architectures Software Developer^as Manual, Volume 3. HISTORY bhyve first appeared in FreeBSD 10.0. AUTHORS Neel Natu <neel@freebsd.org> Peter Grehan <grehan@freebsd.org> FreeBSD 13.0 January 18, 2021 BHYVE(8)
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | DEBUG SERVER | SIGNAL HANDLING | EXIT STATUS | EXAMPLES | SEE ALSO | HISTORY | AUTHORS
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