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31 .Nd "bhyve configuration variables"
34 uses a hierarchical tree of configuration variables to describe global and
36 Internal nodes in this tree do not have a value,
37 only leaf nodes have values.
38 This manual describes the configuration variables understood by
40 If additional variables are defined,
42 will ignore them and will not emit errors for unknown variables.
43 However, these additional variables can be referenced by other
44 variables as described below.
46 Configuration variable values are stored as strings.
47 A configuration variable value may refer to one or more other
48 configuration values by name.
49 Instances of the pattern
51 are replaced by the value of the configuration variable
53 To avoid unwanted expansion,
55 characters can be escaped by a leading
58 if a configuration variable
61 .Pa /dev/zvol/bhyve/%(name) ,
62 then the final value of the
64 variable will be set to the path of a ZFS volume whose name matches
65 the name of the virtual machine on the pool
68 Some configuration variables may be interpreted as a boolean value.
69 For those variables the following case-insensitive values may be used to
72 .Bl -bullet -offset indent -compact
83 The following values may be used to indicate false:
85 .Bl -bullet -offset indent -compact
96 Some configuration variables may be interperted as an integer.
98 any syntax supported by
102 .Ss Architecture Neutral Settings
103 .Bl -column "memory.guest_in_core" "integer" "Default"
104 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
105 .It Va name Ta string Ta Ta
107 .It Va cpus Ta integer Ta 1 Ta
108 The total number of virtual CPUs.
109 .It Va cores Ta integer Ta 1 Ta
110 The number of virtual cores in each virtual socket.
111 .It Va threads Ta integer Ta 1 Ta
112 The number of virtual CPUs in each virtual core.
113 .It Va sockets Ta integer Ta 1 Ta
114 The number of virtual sockets.
115 .It Va memory.guest_in_core Ta bool Ta false Ta
116 Include guest memory in core file.
117 .It Va memory.size Ta string Ta 256M Ta
118 Guest physical memory size in bytes.
119 The value must be formatted as described in
120 .Xr expand_number 3 .
121 .It Va memory.wired Ta bool Ta false Ta
123 .It Va acpi_tables Ta bool Ta false Ta
124 Generate ACPI tables.
125 .It Va destroy_on_poweroff Ta bool Ta false Ta
126 Destroy the VM on guest-initiated power-off.
127 .It Va gdb.port Ta integer Ta 0 Ta
128 TCP port number for the debug server.
129 If this is set to a non-zero value, a debug server
130 will listen for connections on this port.
131 .It Va gdb.wait Ta bool Ta false Ta
132 If the debug server is enabled, wait for a debugger to connect
133 before starting the guest.
134 .It Va rtc.use_localtime Ta bool Ta true Ta
135 The real time clock uses the local time of the host.
136 If this is set to false, the real time clock uses UTC.
137 .It Va uuid Ta string Ta Ta
138 The universally unique identifier (UUID) to use in the guest's
139 System Management BIOS System Information structure.
140 If an explicit value is not set, a valid UUID is generated from
141 the host's hostname and the VM name.
142 .It Va virtio_msix Ta bool Ta true Ta
143 Use MSI-X interrupts for PCI VirtIO devices.
144 If set to false, MSI interrupts are used instead.
145 .It Va config.dump Ta bool Ta false Ta
146 If this value is set to true,
149 will write all of its configuration variables to stdout and exit
150 after it has finished parsing command line options.
152 .Ss x86-Specific Settings
153 .Bl -column "x86.vmexit_on_pause" "integer" "Default"
154 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
155 .It Va x86.mptable Ta bool Ta true Ta
157 .It Va x86.x2apic Ta bool Ta false Ta
158 Configure guest's local APICs in x2APIC mode.
159 .It Va x86.strictio Ta bool Ta false Ta
160 Exit if a guest accesses an I/O port that is not emulated.
161 By default, writes are ignored and reads return all bits set.
162 .It Va x86.strictmsr Ta bool Ta true Ta
163 Inject a general protection fault if a guest accesses a Model Specific
164 Register (MSR) that is not emulated.
165 If this is false, writes are ignored and reads return zero.
166 .It Va x86.vmexit_on_hlt Ta bool Ta false Ta
167 Force a VM exit when a guest CPU executes the
170 This allows idle guest CPUs to yield the host CPU.
171 .It Va x86.vmexit_on_pause Ta bool Ta false Ta
172 Force a VM exit when a guest CPU executes the
177 Device settings are stored under a device node.
178 The device node's name is set by the parent bus of the device.
179 .Ss PCI Device Settings
180 PCI devices are described by a device node named
181 .Dq pci Ns Ar bus . Ns Ar slot . Ns Ar function
187 are formatted as decimal values with no padding.
188 All PCI device nodes must contain a configuration variable named
190 which specifies the device model to use.
191 The following PCI device models are supported:
194 Provide a simple PCI-Host bridge device.
195 This is usually configured at pci0:0:0 and is required by most guest
198 AHCI storage controller.
200 Intel e82545 network interface.
202 VGA framebuffer device attached to VNC server.
204 LPC PCI-ISA bridge with COM1-COM4 16550 serial ports,
206 and an optional debug/test device.
207 This device must be configured on bus 0.
209 High Definition audio controller.
211 NVM Express (NVMe) controller.
213 PCI pass-through device.
215 PCI 16550 serial device.
217 VirtIO 9p (VirtFS) interface.
219 VirtIO block storage interface.
220 .It Li virtio-console
221 VirtIO console interface.
223 VirtIO network interface.
225 VirtIO RNG interface.
227 VirtIO SCSI interface.
229 Extensible Host Controller Interface (XHCI) USB controller.
231 .Ss USB Device Settings
232 USB controller devices contain zero or more child USB devices
234 Each USB device stores its settings in a node named
236 under the controller's device node.
238 is the number of the slot to which the USB device is attached.
239 Note that USB slot numbers begin at 1.
240 All USB device nodes must contain a configuration variable named
242 which specifies the device model to use.
243 The following USB device models are supported:
246 A USB tablet device which provides precise cursor synchronization
249 .Ss Block Device Settings
250 Block devices use the following settings to configure their backing store.
251 These settings are stored in the configuration node of the respective device.
252 .Bl -column "sectorsize" "logical[/physical]" "Default"
253 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
254 .It path Ta string Ta Ta
255 The path of the file or disk device to use as the backing store.
256 .It nocache Ta bool Ta false Ta
257 Disable caching on the backing file by opening the backing file with
259 .It nodelete Ta bool Ta false Ta
260 Disable emulation of guest trim requests via
263 .It sync Ta bool Ta false Ta
264 Write changes to the backing file with synchronous writes.
265 .It direct Ta bool Ta false Ta
268 .It ro Ta bool Ta false Ta
269 Disable writes to the backing file.
270 .It sectorsize Ta Va logical Ns Op / Ns Va physical Ta Ta
271 Specify the logical and physical sector size of the emulated disk.
272 If the physical size is not specified,
273 it is equal to the logical size.
275 .Ss Network Backend Settings
276 Network devices use the following settings to configure their backend.
277 The backend is responsible for passing packets between the device model
278 and a desired destination.
279 Configuring a backend requires setting the
281 variable to one of the following values:
286 interface as the backend.
290 interface as the backend.
294 socket hook as the backend.
295 This backend uses the following additional variables:
296 .Bl -column "peerhook" "Format" "Default"
297 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
298 .It Va path Ta string Ta Ta
302 .It Va peerhook Ta string Ta Ta
303 The name of the destination hook.
304 .It Va socket Ta string Ta Ta
305 The name of the created
308 .It Va hook Ta string Ta vmlink Ta
309 The name of the source hook on the created
313 .It netmap: Ns Va interface
316 on a network interface as the backend.
317 .It vale Ns Va bridge : Ns Va port
320 bridge as the backend.
322 .Ss UART Device Settings
323 .Bl -column "Name" "Format" "Default"
324 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
325 .It Va path Ta path Ta Ta
326 Backend device for the serial port.
327 Either the pathname of a character device or
329 to use standard input and output of the
333 .Ss Host Bridge Settings
334 .Bl -column "vendor" "integer" "Default"
335 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
336 .It Va vendor Ta integer Ta 0x1275 Ta
338 .It Va devid Ta integer Ta 0x1275 Ta
341 .Ss AHCI Controller Settings
342 AHCI controller devices contain zero or more ports each of which
343 provides a storage device.
344 Each port stores its settings in a node named
346 under the controller's device node.
349 values are formatted as successive decimal values starting with 0.
350 In addition to the block device settings described above, each
351 port supports the following settings:
352 .Bl -column "model" "integer" "generated"
353 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
354 .It Va type Ta string Ta Ta
355 The type of storage device to emulate.
356 Must be set to either
360 .It Va nmrr Ta integer Ta 0 Ta
361 Nominal Media Rotation Rate, also known as RPM.
362 A value 1 of indicates a device with no rate such as a Solid State Disk.
363 .It Va ser Ta string Ta generated Ta
364 Serial number of up to twenty characters.
365 A default serial number is generated using a hash of the backing
367 .It Va rev Ta string Ta 001 Ta
368 Revision number of up to eight characters.
369 .It Va model Ta string Ta Ta
370 Model number of up to forty characters.
371 Separate default model strings are used for
378 In addition to the network backend settings,
379 Intel e82545 network interfaces support the following variables:
380 .Bl -column "Name" "MAC address" "generated"
381 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
382 .It Va mac Ta MAC address Ta generated Ta
384 If an explicit address is not provided,
385 a MAC address is generated from a hash of the device's PCI address.
387 .Ss Frame Buffer Settings
388 .Bl -column "password" "[IP:]port" "127.0.0.1:5900"
389 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
390 .It Va wait Ta bool Ta false Ta
391 Wait for a remote connection before starting the VM.
392 .It Va rfb Ta Oo Ar IP Ns : Oc Ns Ar port Ta 127.0.0.1:5900 Ta
393 TCP address to listen on for remote connections.
394 The IP address must be given as a numeric address.
395 IPv6 addresses must be enclosed in square brackets and
396 support scoped identifiers as described in
398 A bare port number may be given in which case the IPv4
399 localhost address is used.
400 .It Va vga Ta string Ta io Ta
402 More details are provided in
404 .It Va w Ta integer Ta 1024 Ta
405 Frame buffer width in pixels.
406 .It Va h Ta integer Ta 768 Ta
407 Frame buffer height in pixels.
408 .It Va password Ta string Ta Ta
409 Password to use for VNC authentication.
410 This type of authentication is known to be cryptographically weak and is not
411 intended for use on untrusted networks.
413 .Ss High Definition Audio Settings
414 .Bl -column "Name" "Format" "Default"
415 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
416 .It Va play Ta path Ta Ta
417 Host playback device,
420 .It Va rec Ta path Ta Ta
421 Host recording device,
425 .Ss LPC Device Settings
426 The LPC bridge stores its configuration under a top-level
428 node rather than under the PCI LPC device's node.
429 The following nodes are available under
431 .Bl -column "pc-testdev" "Format" "Default"
432 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
433 .It Va bootrom Ta path Ta Ta
435 The contents of this file are copied into the guest's
436 memory ending just before the 4GB physical address.
437 If a boot ROM is present, a firmware interface device is
438 also enabled for use by the boot ROM.
439 .It Va com1 Ta node Ta Ta
440 Settings for the COM1 serial port device.
441 .It Va com2 Ta node Ta Ta
442 Settings for the COM2 serial port device.
443 .It Va com3 Ta node Ta Ta
444 Settings for the COM3 serial port device.
445 .It Va com4 Ta node Ta Ta
446 Settings for the COM4 serial port device.
447 .It Va pc-testdev Ta bool Ta false Ta
448 Enable the PC debug/test device.
450 .Ss NVMe Controller Settings
451 Each NVMe controller supports a single storage device.
452 The device can be backed either by a memory disk described by the
454 variable, or a block device using the the block device settings described above.
455 In addition, each controller supports the following settings:
456 .Bl -column "ioslots" "Format" "Default"
457 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
458 .It Va maxq Ta integer Ta 16 Ta
459 Maximum number of I/O submission and completion queue pairs.
460 .It Va qsz Ta integer Ta 2058 Ta
461 Number of elements in each I/O queue.
462 .It Va ioslots Ta integer Ta 8 Ta
463 Maximum number of concurrent I/O requests.
464 .It Va sectsz Ta integer Ta Ta
466 Can be one of 512, 4096, or 8192.
467 Devices backed by a memory disk use 4096 as the default.
468 Devices backed by a block device use the block device's sector size
470 .It Va ser Ta string Ta Ta
471 Serial number of up to twenty characters.
472 A default serial number is generated using a hash of the device's PCI address.
473 .It Va eui64 Ta integer Ta Ta
474 IEEE Extended Unique Identifier.
475 If an EUI is not provided, a default is generated using a checksum of the
476 device's PCI address.
477 .It Va dsm Ta string Ta auto Ta
478 Whether or not to advertise DataSet Management support.
486 setting only advertises support if the backing store supports
487 resource freeing, for example via TRIM.
488 .It Va ram Ta integer Ta Ta
489 If set, allocate a memory disk as the backing store.
490 The value of this variable is the size of the memory disk in megabytes.
492 .Ss PCI Passthrough Settings
493 .Bl -column "Name" "integer" "Default"
494 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
495 .It Va bus Ta integer Ta Ta
496 Host PCI bus address of device to pass through.
497 .It Va slot Ta integer Ta Ta
498 Host PCI slot address of device to pass through.
499 .It Va func Ta integer Ta Ta
500 Host PCI function address of device to pass through.
502 .Ss VirtIO 9p Settings
503 Each VirtIO 9p device exposes a single filesystem from a host path.
504 .Bl -column "sharename" "Format" "Default"
505 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
506 .It Va sharename Ta string Ta Ta
507 The share name exposed to the guest.
508 .It Va path Ta path Ta Ta
509 The path of a directory on the host to export to the guest.
510 .It Va ro Ta bool Ta false Ta
511 If true, the guest filesystem is read-only.
513 .Ss VirtIO Console Device Settings
514 Each VirtIO Console device contains one or more console ports.
515 Each port stores its settings in a node named
517 under the controller's device node.
520 values are formatted as successive decimal values starting with 0.
521 Each port supports the following settings:
522 .Bl -column "Name" "Format" "Default"
523 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
524 .It Va name Ta string Ta Ta
525 The name of the port exposed to the guest.
526 .It Va path Ta path Ta Ta
527 The path of a UNIX domain socket providing the host connection for the port.
529 .Ss VirtIO Network Interface Settings
530 In addition to the network backend settings,
531 VirtIO network interfaces support the following variables:
532 .Bl -column "Name" "MAC address" "generated"
533 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
534 .It Va mac Ta MAC address Ta generated Ta
536 If an explicit address is not provided,
537 a MAC address is generated from a hash of the device's PCI address.
538 .It Va mtu Ta integer Ta 1500 Ta
539 The largest supported MTU advertised to the guest.
541 .Ss VirtIO SCSI Settings
542 .Bl -column "Name" "integer" "Default"
543 .It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description
544 .It Va dev Ta path Ta Ta
545 The path of a CAM target layer (CTL) device to export:
546 .Pa /dev/cam/ctl Ns Oo Ar pp . Ns Ar vp Oc .
547 .It Va iid Ta integer Ta 0 Ta
548 Initiator ID to use when sending requests to the CTL port.
551 .Xr expand_number 3 ,