abd6790ce8
Contains projects/virtio commits:
r245738:
virtio: Minor man page tweaks
r246060:
virtio: Cleanup feature description printing
r246306:
virtio: Remove old debugging flag
r247238:
virtio: Remove PRIx64 macros from format strings
r247239:
virtio: Constify some fields
r247240:
virtio: Minor code simplifications
r249962:
virtio: Update to my freebsd.org email address
MFC after: 1 month
98 lines
3.2 KiB
Groff
98 lines
3.2 KiB
Groff
.\" Copyright (c) 2011 Bryan Venteicher
|
|
.\" 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 AUTHOR 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 AUTHOR 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 January 22, 2012
|
|
.Dt VIRTIO 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm virtio
|
|
.Nd VirtIO Device Support
|
|
.Sh SYNOPSIS
|
|
To compile VirtIO device support into the kernel, place the following lines
|
|
in your kernel configuration file:
|
|
.Bd -ragged -offset indent
|
|
.Cd "device virtio"
|
|
.Cd "device virtio_pci"
|
|
.Ed
|
|
.Pp
|
|
Alternatively, to load VirtIO support as modules at boot time, place the
|
|
following lines in
|
|
.Xr loader.conf 5 :
|
|
.Bd -literal -offset indent
|
|
virtio_load="YES"
|
|
virtio_pci_load="YES"
|
|
.Ed
|
|
.Sh DESCRIPTION
|
|
VirtIO is a specification for para-virtualized I/O in a virtual machine (VM).
|
|
Traditionally, the hypervisor emulated real devices such as an Ethernet
|
|
interface or disk controller to provide the VM with I/O.
|
|
This emulation is often inefficient.
|
|
.Pp
|
|
VirtIO defines an interface for efficient I/O between the hypervisor and VM.
|
|
The
|
|
.Nm
|
|
module provides a shared memory transport called a virtqueue.
|
|
The
|
|
.Xr virtio_pci
|
|
device driver represents an emulated PCI device that the hypervisor makes
|
|
available to the VM.
|
|
This device provides the probing, configuration, and
|
|
interrupt notifications needed to interact with the hypervisor.
|
|
.Fx
|
|
supports the following VirtIO devices:
|
|
.Bl -hang -offset indent -width xxxxxxxx
|
|
.It Nm Ethernet
|
|
An emulated Ethernet device is provided by the
|
|
.Xr vtnet 4
|
|
device driver.
|
|
.It Nm Block
|
|
An emulated disk controller is provided by the
|
|
.Xr virtio_blk 4
|
|
device driver.
|
|
.It Nm SCSI
|
|
An emulated SCSI HBA is provided by the
|
|
.Xr virtio_scsi 4
|
|
device driver.
|
|
.It Nm Balloon
|
|
A pseudo-device to allow the VM to release memory back to the hypervisor is
|
|
provided by the
|
|
.Xr virtio_balloon 4
|
|
device driver.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr virtio_balloon 4 ,
|
|
.Xr virtio_blk 4 ,
|
|
.Xr virtio_scsi 4 ,
|
|
.Xr vtnet 4
|
|
.Sh HISTORY
|
|
Support for VirtIO first appeared in
|
|
.Fx 9.0 .
|
|
.Sh AUTHORS
|
|
.An -nosplit
|
|
.Fx
|
|
support for VirtIO was first added by
|
|
.An Bryan Venteicher Aq bryanv@FreeBSD.org .
|