1.\" SPDX-License-Identifier: BSD-2-Clause 2.\" 3.\" Copyright (c) 2021 John H. Baldwin <jhb@FreeBSD.org> 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd June 30, 2022 27.Dt BHYVE_CONFIG 5 28.Os 29.Sh NAME 30.Nm bhyve_config 31.Nd "bhyve configuration variables" 32.Sh DESCRIPTION 33.Xr bhyve 8 34uses a hierarchical tree of configuration variables to describe global and 35per-device settings. 36Internal nodes in this tree do not have a value, 37only leaf nodes have values. 38This manual describes the configuration variables understood by 39.Xr bhyve 8 . 40If additional variables are defined, 41.Xr bhyve 8 42will ignore them and will not emit errors for unknown variables. 43However, these additional variables can be referenced by other 44variables as described below. 45.Sh VARIABLE VALUES 46Configuration variable values are stored as strings. 47A configuration variable value may refer to one or more other 48configuration values by name. 49Instances of the pattern 50.Sq % Ns Pq Ar var 51are replaced by the value of the configuration variable 52.Va var . 53To avoid unwanted expansion, 54.Sq % 55characters can be escaped by a leading 56.Sq % . 57For example, 58if a configuration variable 59.Va disk 60uses the value 61.Pa /dev/zvol/bhyve/%(name) , 62then the final value of the 63.Va disk 64variable will be set to the path of a ZFS volume whose name matches 65the name of the virtual machine on the pool 66.Pa bhyve . 67.Pp 68Some configuration variables may be interpreted as a boolean value. 69For those variables the following case-insensitive values may be used to 70indicate true: 71.Pp 72.Bl -bullet -offset indent -compact 73.It 74true 75.It 76on 77.It 78yes 79.It 801 81.El 82.Pp 83The following values may be used to indicate false: 84.Pp 85.Bl -bullet -offset indent -compact 86.It 87false 88.It 89off 90.It 91no 92.It 930 94.El 95.Pp 96Some configuration variables may be interperted as an integer. 97For those variables, 98any syntax supported by 99.Xr strtol 3 100may be used. 101.Sh GLOBAL SETTINGS 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 106The name of the VM. 107.It Va cpus Ta integer Ta 1 Ta 108The total number of virtual CPUs. 109.It Va cores Ta integer Ta 1 Ta 110The number of virtual cores in each virtual socket. 111.It Va threads Ta integer Ta 1 Ta 112The number of virtual CPUs in each virtual core. 113.It Va sockets Ta integer Ta 1 Ta 114The number of virtual sockets. 115.It Va memory.guest_in_core Ta bool Ta false Ta 116Include guest memory in core file. 117.It Va memory.size Ta string Ta 256M Ta 118Guest physical memory size in bytes. 119The value must be formatted as described in 120.Xr expand_number 3 . 121.It Va memory.wired Ta bool Ta false Ta 122Wire guest memory. 123.It Va acpi_tables Ta bool Ta false Ta 124Generate ACPI tables. 125.It Va destroy_on_poweroff Ta bool Ta false Ta 126Destroy the VM on guest-initiated power-off. 127.It Va gdb.address Ta string Ta localhost Ta 128Hostname, IP address, or IPv6 address for the debug server. 129.It Va gdb.port Ta integer Ta 0 Ta 130TCP port number for the debug server. 131If this is set to a non-zero value, a debug server 132will listen for connections on this port. 133.It Va gdb.wait Ta bool Ta false Ta 134If the debug server is enabled, wait for a debugger to connect 135before starting the guest. 136.It Va keyboard.layout Ta string Ta Ta 137Specify the keyboard layout name with the file name in 138.Ar /usr/share/bhyve/kbdlayout . 139This value only works when loaded with UEFI mode for VNC, and 140used a VNC client that don't support QEMU Extended Key Event 141Message (e.g. TightVNC). 142.It Va rtc.use_localtime Ta bool Ta true Ta 143The real time clock uses the local time of the host. 144If this is set to false, the real time clock uses UTC. 145.It Va uuid Ta string Ta Ta 146The universally unique identifier (UUID) to use in the guest's 147System Management BIOS System Information structure. 148If an explicit value is not set, a valid UUID is generated from 149the host's hostname and the VM name. 150.It Va virtio_msix Ta bool Ta true Ta 151Use MSI-X interrupts for PCI VirtIO devices. 152If set to false, MSI interrupts are used instead. 153.It Va config.dump Ta bool Ta false Ta 154If this value is set to true after 155.Xr bhyve 8 156has finished parsing command line options, 157then 158.Xr bhyve 8 159will write all of its configuration variables to stdout and exit. 160No VM will be started. 161.It Va bios.vendor Ta string Ta BHYVE Ta 162This value is used for the guest's System Management BIOS System Information structure. 163.It Va bios.version Ta string Ta 14.0 Ta 164This value is used for the guest's System Management BIOS System Information structure. 165.It Va bios.release_date Ta string Ta 10/17/2021 Ta 166This value is used for the guest's System Management BIOS System Information structure. 167.It Va system.family_name Ta string Ta Virtual Machine Ta 168Family the computer belongs to. 169This value is used for the guest's System Management BIOS System Information structure. 170.It Va system.manufacturer Ta string Ta FreeBSD Ta 171This value is used for the guest's System Management BIOS System Information structure. 172.It Va system.product_name Ta string Ta BHYVE Ta 173This value is used for the guest's System Management BIOS System Information structure. 174.It Va system.serial_number Ta string Ta None Ta 175This value is used for the guest's System Management BIOS System Information structure. 176.It Va system.sku Ta string Ta None Ta 177Stock keeping unit of the computer. 178It's also called product ID or purchase order number. 179This value is used for the guest's System Management BIOS System Information structure. 180.It Va system.version Ta string Ta 1.0 Ta 181This value is used for the guest's System Management BIOS System Information structure. 182.It Va board.manufacturer Ta string Ta FreeBSD Ta 183This value is used for the guest's System Management BIOS System Information structure. 184.It Va board.product_name Ta string Ta BHYVE Ta 185This value is used for the guest's System Management BIOS System Information structure. 186.It Va board.version Ta string Ta 1.0 Ta 187This value is used for the guest's System Management BIOS System Information structure. 188.It Va board.serial_number Ta string Ta None Ta 189This value is used for the guest's System Management BIOS System Information structure. 190.It Va board.asset_tag Ta string Ta None Ta 191This value is used for the guest's System Management BIOS System Information structure. 192.It Va board.location Ta string Ta None Ta 193Describes the board's location within the chassis. 194This value is used for the guest's System Management BIOS System Information structure. 195.It Va chassis.manufacturer Ta string Ta FreeBSD Ta 196This value is used for the guest's System Management BIOS System Information structure. 197.It Va chassis.version Ta string Ta 1.0 Ta 198This value is used for the guest's System Management BIOS System Information structure. 199.It Va chassis.serial_number Ta string Ta None Ta 200This value is used for the guest's System Management BIOS System Information structure. 201.It Va chassis.asset_tag Ta string Ta None Ta 202This value is used for the guest's System Management BIOS System Information structure. 203.It Va chassis.sku Ta string Ta None Ta 204Stock keeping unit of the chassis. 205It's also called product ID or purchase order number. 206This value is used for the guest's System Management BIOS System Information structure. 207.El 208.Ss x86-Specific Settings 209.Bl -column "x86.vmexit_on_pause" "integer" "Default" 210.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 211.It Va x86.mptable Ta bool Ta true Ta 212Generate an MPTable. 213.It Va x86.x2apic Ta bool Ta false Ta 214Configure guest's local APICs in x2APIC mode. 215.It Va x86.strictio Ta bool Ta false Ta 216Exit if a guest accesses an I/O port that is not emulated. 217By default, writes are ignored and reads return all bits set. 218.It Va x86.strictmsr Ta bool Ta true Ta 219Inject a general protection fault if a guest accesses a Model Specific 220Register (MSR) that is not emulated. 221If this is false, writes are ignored and reads return zero. 222.It Va x86.vmexit_on_hlt Ta bool Ta false Ta 223Force a VM exit when a guest CPU executes the 224.Dv HLT 225instruction. 226This allows idle guest CPUs to yield the host CPU. 227.It Va x86.vmexit_on_pause Ta bool Ta false Ta 228Force a VM exit when a guest CPU executes the 229.Dv PAUSE 230instruction. 231.El 232.Sh DEVICE SETTINGS 233Device settings are stored under a device node. 234The device node's name is set by the parent bus of the device. 235.Ss PCI Device Settings 236PCI devices are described by a device node named 237.Dq pci . Ns Ar bus . Ns Ar slot . Ns Ar function 238where each of 239.Ar bus , 240.Ar slot , 241and 242.Ar function 243are formatted as decimal values with no padding. 244All PCI device nodes must contain a configuration variable named 245.Dq device 246which specifies the device model to use. 247The following PCI device models are supported: 248.Bl -tag -indent 249.It Li hostbridge 250Provide a simple PCI-Host bridge device. 251This is usually configured at pci0:0:0 and is required by most guest 252operating systems. 253.It Li ahci 254AHCI storage controller. 255.It Li e1000 256Intel e82545 network interface. 257.It Li fbuf 258VGA framebuffer device attached to VNC server. 259.It Li lpc 260LPC PCI-ISA bridge with COM1-COM4 16550 serial ports, 261a boot ROM, 262and an optional debug/test device. 263This device must be configured on bus 0. 264.It Li hda 265High Definition audio controller. 266.It Li nvme 267NVM Express (NVMe) controller. 268.It Li passthru 269PCI pass-through device. 270.It Li uart 271PCI 16550 serial device. 272.It Li virtio-9p 273VirtIO 9p (VirtFS) interface. 274.It Li virtio-blk 275VirtIO block storage interface. 276.It Li virtio-console 277VirtIO console interface. 278.It Li virtio-input 279VirtIO input interface. 280.It Li virtio-net 281VirtIO network interface. 282.It Li virtio-rnd 283VirtIO RNG interface. 284.It Li virtio-scsi 285VirtIO SCSI interface. 286.It Li xhci 287Extensible Host Controller Interface (XHCI) USB controller. 288.El 289.Ss USB Device Settings 290USB controller devices contain zero or more child USB devices 291attached to slots. 292Each USB device stores its settings in a node named 293.Dq slot. Ns Va N 294under the controller's device node. 295.Va N 296is the number of the slot to which the USB device is attached. 297Note that USB slot numbers begin at 1. 298All USB device nodes must contain a configuration variable named 299.Dq device 300which specifies the device model to use. 301The following USB device models are supported: 302.Bl -tag -indent 303.It Li tablet 304A USB tablet device which provides precise cursor synchronization 305when using VNC. 306.El 307.Ss Block Device Settings 308Block devices use the following settings to configure their backing store. 309These settings are stored in the configuration node of the respective device. 310.Bl -column "sectorsize" "logical[/physical]" "Default" 311.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 312.It path Ta string Ta Ta 313The path of the file or disk device to use as the backing store. 314.It nocache Ta bool Ta false Ta 315Disable caching on the backing file by opening the backing file with 316.Dv O_DIRECT . 317.It nodelete Ta bool Ta false Ta 318Disable emulation of guest trim requests via 319.Dv DIOCGDELETE 320requests. 321.It sync Ta bool Ta false Ta 322Write changes to the backing file with synchronous writes. 323.It direct Ta bool Ta false Ta 324An alias for 325.Va sync . 326.It ro Ta bool Ta false Ta 327Disable writes to the backing file. 328.It sectorsize Ta Va logical Ns Op / Ns Va physical Ta Ta 329Specify the logical and physical sector size of the emulated disk. 330If the physical size is not specified, 331it is equal to the logical size. 332.El 333.Ss Network Backend Settings 334Network devices use the following settings to configure their backend. 335The backend is responsible for passing packets between the device model 336and a desired destination. 337Configuring a backend requires setting the 338.Va backend 339variable. 340The type of a backend can either be set explicitly via the 341.Va type 342variable 343or it can be inferred from the value of 344.Va backend . 345.Pp 346The following types of backends are supported: 347.Bl -tag -width "netgraph" 348.It tap 349Use the 350.Xr tap 4 351interface named in 352.Va backend 353as the backend. 354.It netgraph 355Use a 356.Xr netgraph 4 357socket hook as the backend. 358This backend uses the following additional variables: 359.Bl -column "peerhook" "Format" "Default" 360.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 361.It Va path Ta string Ta Ta 362The name of the 363.Xr netgraph 4 364destination node. 365.It Va peerhook Ta string Ta Ta 366The name of the destination hook. 367.It Va socket Ta string Ta Ta 368The name of the created 369.Xr ng_socket 4 370node. 371.It Va hook Ta string Ta vmlink Ta 372The name of the source hook on the created 373.Xr ng_socket 4 374node. 375.El 376.It netmap 377Use 378.Xr netmap 4 379either on a network interface or a port on a 380.Xr vale 4 381bridge as the backend. 382The value of 383.Va backend 384is passed to 385.Xr nm_open 386to connect to a netmap port. 387.El 388.Pp 389If 390.Va type 391is not specified explicitly, then it is inferred from 392.Va backend 393based on the following patterns: 394.Bl -column -offset indent "valuebridge:port" 395.It Sy Pattern Ta Sy Type 396.It tap Ns Va N Ta tap 397.It vmnet Ns Va N Ta tap 398.It netgraph Ta netgraph 399.It netmap: Ns Va interface Ta netmap 400.It vale Ns Va bridge : Ns Va port Ta netmap 401.El 402.Ss UART Device Settings 403.Bl -column "Name" "Format" "Default" 404.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 405.It Va path Ta path Ta Ta 406Backend device for the serial port. 407Either the pathname of a character device or 408.Dq stdio 409to use standard input and output of the 410.Xr bhyve 8 411process. 412.El 413.Ss Host Bridge Settings 414.Bl -column "vendor" "integer" "Default" 415.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 416.It Va vendor Ta integer Ta 0x1275 Ta 417PCI vendor ID. 418.It Va devid Ta integer Ta 0x1275 Ta 419PCI device ID. 420.El 421.Ss AHCI Controller Settings 422AHCI controller devices contain zero or more ports each of which 423provides a storage device. 424Each port stores its settings in a node named 425.Dq port. Ns Va N 426under the controller's device node. 427The 428.Va N 429values are formatted as successive decimal values starting with 0. 430In addition to the block device settings described above, each 431port supports the following settings: 432.Bl -column "model" "integer" "generated" 433.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 434.It Va type Ta string Ta Ta 435The type of storage device to emulate. 436Must be set to either 437.Dq cd 438or 439.Dq hd . 440.It Va nmrr Ta integer Ta 0 Ta 441Nominal Media Rotation Rate, also known as RPM. 442A value 1 of indicates a device with no rate such as a Solid State Disk. 443.It Va ser Ta string Ta generated Ta 444Serial number of up to twenty characters. 445A default serial number is generated using a hash of the backing 446store's pathname. 447.It Va rev Ta string Ta 001 Ta 448Revision number of up to eight characters. 449.It Va model Ta string Ta Ta 450Model number of up to forty characters. 451Separate default model strings are used for 452.Dq cd 453and 454.Dq hd 455device types. 456.El 457.Ss e1000 Settings 458In addition to the network backend settings, 459Intel e82545 network interfaces support the following variables: 460.Bl -column "Name" "MAC address" "generated" 461.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 462.It Va mac Ta MAC address Ta generated Ta 463MAC address. 464If an explicit address is not provided, 465a MAC address is generated from a hash of the device's PCI address. 466.El 467.Ss Frame Buffer Settings 468.Bl -column "password" "[IP:]port" "127.0.0.1:5900" 469.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 470.It Va wait Ta bool Ta false Ta 471Wait for a remote connection before starting the VM. 472.It Va rfb Ta Oo Ar IP Ns : Oc Ns Ar port Ta 127.0.0.1:5900 Ta 473TCP address to listen on for remote connections. 474The IP address must be given as a numeric address. 475IPv6 addresses must be enclosed in square brackets and 476support scoped identifiers as described in 477.Xr getaddrinfo 3 . 478A bare port number may be given in which case the IPv4 479localhost address is used. 480.It Va vga Ta string Ta io Ta 481VGA configuration. 482More details are provided in 483.Xr bhyve 8 . 484.It Va w Ta integer Ta 1024 Ta 485Frame buffer width in pixels. 486.It Va h Ta integer Ta 768 Ta 487Frame buffer height in pixels. 488.It Va password Ta string Ta Ta 489Password to use for VNC authentication. 490This type of authentication is known to be cryptographically weak and is not 491intended for use on untrusted networks. 492.El 493.Ss High Definition Audio Settings 494.Bl -column "Name" "Format" "Default" 495.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 496.It Va play Ta path Ta Ta 497Host playback device, 498typically 499.Pa /dev/dsp0 . 500.It Va rec Ta path Ta Ta 501Host recording device, 502typically 503.Pa /dev/dsp0 . 504.El 505.Ss LPC Device Settings 506The LPC bridge stores its configuration under a top-level 507.Va lpc 508node rather than under the PCI LPC device's node. 509The following nodes are available under 510.Va lpc : 511.Bl -column "pc-testdev" "Format" "Default" 512.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 513.It Va bootrom Ta path Ta Ta 514Path to a boot ROM. 515The contents of this file are copied into the guest's 516memory ending just before the 4GB physical address. 517If a boot ROM is present, a firmware interface device is 518also enabled for use by the boot ROM. 519.It Va bootvars Ta path Ta Ta 520Path to boot VARS. 521The contents of this file are copied beneath the boot ROM. 522Firmware can write to it to save variables. 523All variables will be persistent even on reboots of the guest. 524.It Va com1 Ta node Ta Ta 525Settings for the COM1 serial port device. 526.It Va com2 Ta node Ta Ta 527Settings for the COM2 serial port device. 528.It Va com3 Ta node Ta Ta 529Settings for the COM3 serial port device. 530.It Va com4 Ta node Ta Ta 531Settings for the COM4 serial port device. 532.It Va pc-testdev Ta bool Ta false Ta 533Enable the PC debug/test device. 534.El 535.Ss NVMe Controller Settings 536Each NVMe controller supports a single storage device. 537The device can be backed either by a memory disk described by the 538.Va ram 539variable, or a block device using the block device settings described above. 540In addition, each controller supports the following settings: 541.Bl -column "ioslots" "Format" "Default" 542.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 543.It Va maxq Ta integer Ta 16 Ta 544Maximum number of I/O submission and completion queue pairs. 545.It Va qsz Ta integer Ta 2058 Ta 546Number of elements in each I/O queue. 547.It Va ioslots Ta integer Ta 8 Ta 548Maximum number of concurrent I/O requests. 549.It Va sectsz Ta integer Ta Ta 550Sector size. 551Can be one of 512, 4096, or 8192. 552Devices backed by a memory disk use 4096 as the default. 553Devices backed by a block device use the block device's sector size 554as the default. 555.It Va ser Ta string Ta Ta 556Serial number of up to twenty characters. 557A default serial number is generated using a hash of the device's PCI address. 558.It Va eui64 Ta integer Ta Ta 559IEEE Extended Unique Identifier. 560If an EUI is not provided, a default is generated using a checksum of the 561device's PCI address. 562.It Va dsm Ta string Ta auto Ta 563Whether or not to advertise DataSet Management support. 564One of 565.Dq auto , 566.Dq enable , 567or 568.Dq disable . 569The 570.Dq auto 571setting only advertises support if the backing store supports 572resource freeing, for example via TRIM. 573.It Va ram Ta integer Ta Ta 574If set, allocate a memory disk as the backing store. 575The value of this variable is the size of the memory disk in megabytes. 576.El 577.Ss PCI Passthrough Settings 578.Bl -column "Name" "integer" "Default" 579.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 580.It Va bus Ta integer Ta Ta 581Host PCI bus address of device to pass through. 582.It Va slot Ta integer Ta Ta 583Host PCI slot address of device to pass through. 584.It Va func Ta integer Ta Ta 585Host PCI function address of device to pass through. 586.It Va rom Ta path Ta Ta 587ROM file of the device which will be executed by OVMF to init the device. 588.El 589.Ss VirtIO 9p Settings 590Each VirtIO 9p device exposes a single filesystem from a host path. 591.Bl -column "sharename" "Format" "Default" 592.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 593.It Va sharename Ta string Ta Ta 594The share name exposed to the guest. 595.It Va path Ta path Ta Ta 596The path of a directory on the host to export to the guest. 597.It Va ro Ta bool Ta false Ta 598If true, the guest filesystem is read-only. 599.El 600.Ss VirtIO Block Device Settings 601In addition to the block device settings described above, each 602VirtIO block device supports the following settings: 603.Bl -column "model" "integer" "generated" 604.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 605.It Va ser Ta string Ta generated Ta 606Serial number of up to twenty characters. 607A default serial number is generated using a hash of the backing 608store's pathname. 609.El 610.Ss VirtIO Console Device Settings 611Each VirtIO Console device contains one or more console ports. 612Each port stores its settings in a node named 613.Dq port. Ns Va N 614under the controller's device node. 615The 616.Va N 617values are formatted as successive decimal values starting with 0. 618Each port supports the following settings: 619.Bl -column "Name" "Format" "Default" 620.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 621.It Va name Ta string Ta Ta 622The name of the port exposed to the guest. 623.It Va path Ta path Ta Ta 624The path of a UNIX domain socket providing the host connection for the port. 625.El 626.Ss VirtIO Input Interface Settings 627Each VirtIO Input device contains one input event device. 628All input events of the input event device are send to the guest by VirtIO Input interface. 629VirtIO Input Interfaces support the following variables: 630.Bl -column "Name" "Format" "Default" 631.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 632.It Va path Ta path Ta Ta 633The path of the input event device exposed to the guest 634.El 635.Ss VirtIO Network Interface Settings 636In addition to the network backend settings, 637VirtIO network interfaces support the following variables: 638.Bl -column "Name" "MAC address" "generated" 639.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 640.It Va mac Ta MAC address Ta generated Ta 641MAC address. 642If an explicit address is not provided, 643a MAC address is generated from a hash of the device's PCI address. 644.It Va mtu Ta integer Ta 1500 Ta 645The largest supported MTU advertised to the guest. 646.El 647.Ss VirtIO SCSI Settings 648.Bl -column "Name" "integer" "Default" 649.It Sy Name Ta Sy Format Ta Sy Default Ta Sy Description 650.It Va dev Ta path Ta Ta 651The path of a CAM target layer (CTL) device to export: 652.Pa /dev/cam/ctl Ns Oo Ar pp . Ns Ar vp Oc . 653.It Va iid Ta integer Ta 0 Ta 654Initiator ID to use when sending requests to the CTL port. 655.El 656.Sh SEE ALSO 657.Xr expand_number 3 , 658.Xr getaddrinfo 3 , 659.Xr strtol 3 , 660.Xr netgraph 4 , 661.Xr netmap 4 , 662.Xr ng_socket 4 , 663.Xr tap 4 , 664.Xr vale 4 , 665.Xr vmnet 4 , 666.Xr bhyve 8 667