freebsd-skq/usr.sbin/bhyve/bhyve.8
Neel Natu 9b1aa8d622 Restructure memory allocation in bhyve to support "devmem".
devmem is used to represent MMIO devices like the boot ROM or a VESA framebuffer
where doing a trap-and-emulate for every access is impractical. devmem is a
hybrid of system memory (sysmem) and emulated device models.

devmem is mapped in the guest address space via nested page tables similar
to sysmem. However the address range where devmem is mapped may be changed
by the guest at runtime (e.g. by reprogramming a PCI BAR). Also devmem is
usually mapped RO or RW as compared to RWX mappings for sysmem.

Each devmem segment is named (e.g. "bootrom") and this name is used to
create a device node for the devmem segment (e.g. /dev/vmm/testvm.bootrom).
The device node supports mmap(2) and this decouples the host mapping of
devmem from its mapping in the guest address space (which can change).

Reviewed by:	tychon
Discussed with:	grehan
Differential Revision:	https://reviews.freebsd.org/D2762
MFC after:	4 weeks
2015-06-18 06:00:17 +00:00

342 lines
9.5 KiB
Groff

.\" Copyright (c) 2013 Peter Grehan
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd September 17, 2014
.Dt BHYVE 8
.Os
.Sh NAME
.Nm bhyve
.Nd "run a guest operating system inside a virtual machine"
.Sh SYNOPSIS
.Nm
.Op Fl abehuwxACHPSWY
.Op Fl c Ar numcpus
.Op Fl g Ar gdbport
.Op Fl l Ar lpcdev Ns Op , Ns Ar conf
.Op Fl m Ar size Ns Op Ar K|k|M|m|G|g|T|t
.Op Fl p Ar vcpu:hostcpu
.Op Fl s Ar slot,emulation Ns Op , Ns Ar conf
.Op Fl U Ar uuid
.Ar vmname
.Sh DESCRIPTION
.Nm
is a hypervisor that runs guest operating systems inside a
virtual machine.
.Pp
Parameters such as the number of virtual CPUs, amount of guest memory, and
I/O connectivity can be specified with command-line parameters.
.Pp
The guest operating system must be loaded with
.Xr bhyveload 4
or a similar boot loader before running
.Nm .
.Pp
.Nm
runs until the guest operating system reboots or an unhandled hypervisor
exit is detected.
.Sh OPTIONS
.Bl -tag -width 10n
.It Fl 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.
.It Fl A
Generate ACPI tables.
Required for
.Fx Ns /amd64
guests.
.It Fl b
Enable a low-level console device supported by
.Fx
kernels compiled with
.Cd "device bvmconsole" .
This option will be deprecated in a future version.
.It Fl c Ar numcpus
Number of guest virtual CPUs.
The default is 1 and the maximum is 16.
.It Fl C
Include guest memory in core file.
.It Fl e
Force
.Nm
to exit when a guest issues an access to an I/O port that is not emulated.
This is intended for debug purposes.
.It Fl g Ar gdbport
For
.Fx
kernels compiled with
.Cd "device bvmdebug" ,
allow a remote kernel kgdb to be relayed to the guest kernel gdb stub
via a local IPv4 address and this port.
This option will be deprecated in a future version.
.It Fl h
Print help message and exit.
.It Fl 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.
.It Fl l Ar lpcdev Ns Op , Ns Ar conf
Allow devices behind the LPC PCI-ISA bridge to be configured.
The only supported devices are the TTY-class devices
.Ar com1
and
.Ar com2
and the boot ROM device
.Ar bootrom .
.It Fl m Ar size Ns Op Ar K|k|M|m|G|g|T|t
Guest physical memory size in bytes.
This must be the same size that was given to
.Xr bhyveload 8 .
.Pp
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.
.It Fl p Ar vcpu:hostcpu
Pin guest's virtual CPU
.Em vcpu
to
.Em hostcpu .
.It Fl P
Force the guest virtual CPU to exit when a PAUSE instruction is detected.
.It Fl s Ar slot,emulation Ns Op , Ns Ar conf
Configure a virtual PCI slot and function.
.Pp
.Nm 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.
.Bl -tag -width 10n
.It Ar slot
.Ar pcislot[:function]
.Ar bus:pcislot:function
.Pp
The
.Ar pcislot
value is 0 to 31. The optional function value is 0 to 7. The optional
.Ar bus
value is 0 to 255.
If not specified, the function value defaults to 0.
If not specified, the bus value defaults to 0.
.It Ar emulation
.Bl -tag -width 10n
.It Li hostbridge | Li amd_hostbridge
.Pp
Provide a simple host bridge.
This is usually configured at slot 0, and is required by most guest
operating systems.
The
.Li amd_hostbridge
emulation is identical but uses a PCI vendor ID of
.Li AMD .
.It Li passthru
PCI pass-through device.
.It Li virtio-net
Virtio network interface.
.It Li virtio-blk
Virtio block storage interface.
.It Li virtio-rnd
Virtio RNG interface.
.It Li ahci-cd
AHCI controller attached to an ATAPI CD/DVD.
.It Li ahci-hd
AHCI controller attached to a SATA hard-drive.
.It Li uart
PCI 16550 serial device.
.It Li lpc
LPC PCI-ISA bridge with COM1 and COM2 16550 serial ports and a boot ROM.
The LPC bridge emulation can only be configured on bus 0.
.El
.It Op Ar conf
This optional parameter describes the backend for device emulations.
If
.Ar conf
is not specified, the device emulation has no backend and can be
considered unconnected.
.Pp
Network devices:
.Bl -tag -width 10n
.It Ar tapN Ns Op , Ns Ar mac=xx:xx:xx:xx:xx:xx
.It Ar vmnetN Ns Op , Ns Ar mac=xx:xx:xx:xx:xx:xx
.Pp
If
.Ar 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.
.Pp
The MAC address is an ASCII string in
.Xr ethers 5
format.
.El
.Pp
Block storage devices:
.Bl -tag -width 10n
.It Pa /filename Ns Oo , Ns Ar block-device-options Oc
.It Pa /dev/xxx Ns Oo , Ns Ar block-device-options Oc
.El
.Pp
The
.Ar block-device-options
are:
.Bl -tag -width 8n
.It Li nocache
Open the file with
.Dv O_DIRECT .
.It Li direct
Open the file using
.Dv O_SYNC .
.It Li ro
Force the file to be opened read-only.
.It Li sectorsize= Ns Ar logical Ns Oo / Ns Ar physical Oc
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.
.El
.Pp
TTY devices:
.Bl -tag -width 10n
.It Li stdio
Connect the serial port to the standard input and output of
the bhyve process.
.It Pa /dev/xxx
Use the host TTY device for serial port I/O.
.El
.Pp
Boot ROM device:
.Bl -tag -width 10n
.It Pa romfile
Map
.Ar romfile
in the guest address space reserved for boot firmware.
.El
.Pp
Pass-through devices:
.Bl -tag -width 10n
.It Ns Ar slot Ns / Ns Ar bus Ns / Ns Ar function
Connect to a PCI device on the host at the selector described by
.Ar slot ,
.Ar bus ,
and
.Ar function
numbers.
.El
.Pp
Guest memory must be wired using the
.Fl S
option when a pass-through device is configured.
.Pp
The host device must have been reserved at boot-time using the
.Va pptdev
loader variable as described in
.Xr vmm 4 .
.El
.It Fl S
Wire guest memory.
.It Fl u
RTC keeps UTC time.
.It Fl U Ar uuid
Set the universally unique identifier
.Pq UUID
in the guest's System Management BIOS System Information structure.
By default a UUID is generated from the host's hostname and
.Ar vmname .
.It Fl w
Ignore accesses to unimplemented Model Specific Registers (MSRs). This is intended for debug purposes.
.It Fl W
Force virtio PCI device emulations to use MSI interrupts instead of MSI-X
interrupts.
.It Fl x
The guest's local APIC is configured in x2APIC mode.
.It Fl Y
Disable MPtable generation.
.It Ar vmname
Alphanumeric name of the guest.
This should be the same as that created by
.Xr bhyveload 8 .
.El
.Sh EXAMPLES
The guest operating system must have been loaded with
.Xr bhyveload 4
or a similar boot loader before
.Xr bhyve 4
can be run.
.Pp
To run a virtual machine with 1GB of memory, two virtual CPUs, a virtio
block device backed by the
.Pa /my/image
filesystem image, and a serial port for the console:
.Bd -literal -offset indent
bhyve -c 2 -s 0,hostbridge -s 1,lpc -s 2,virtio-blk,/my/image \\
-l com1,stdio -A -H -P -m 1G vm1
.Ed
.Pp
Run a 24GB single-CPU virtual machine with three network ports, one of which
has a MAC address specified:
.Bd -literal -offset indent
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
.Ed
.Pp
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
.Xr nmdm 4
null-model device.
.Bd -literal -offset indent
bhyve -c 4 \e\
-s 0,amd_hostbridge -s 1,lpc \\
-s 1:0,ahci-hd,/images/disk.1 \\
-s 1:1,ahci-hd,/images/disk.2 \\
-s 1:2,ahci-hd,/images/disk.3 \\
-s 1:3,ahci-hd,/images/disk.4 \\
-s 1:4,ahci-hd,/images/disk.5 \\
-s 1:5,ahci-hd,/images/disk.6 \\
-s 1:6,ahci-hd,/images/disk.7 \\
-s 1:7,ahci-hd,/images/disk.8 \\
-s 2,ahci-cd,/images.install.iso \\
-s 3,virtio-net,tap0 \\
-l com1,/dev/nmdm0A \\
-A -H -P -m 8G
.Ed
.Sh SEE ALSO
.Xr bhyve 4 ,
.Xr nmdm 4 ,
.Xr vmm 4 ,
.Xr ethers 5 ,
.Xr bhyvectl 8 ,
.Xr bhyveload 8
.Sh HISTORY
.Nm
first appeared in
.Fx 10.0 .
.Sh AUTHORS
.An Neel Natu Aq Mt neel@freebsd.org
.An Peter Grehan Aq Mt grehan@freebsd.org