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diff --git a/share/man/man4/virtio.4 b/share/man/man4/virtio.4 new file mode 100644 index 0000000..7787051 --- /dev/null +++ b/share/man/man4/virtio.4 @@ -0,0 +1,91 @@ +.\" 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 July 4, 2011 +.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 +.Xr virtio 4 +module provides a shared memory transport called a virtqueue. +The +.Xr virtio_pci 4 +device driver represents an emulated PCI device that the hypervisor makes +available to the VM. This device provides the probing, configuration, and +interrupt notifications need 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 if_vtnet 4 +device driver. +.It Nm Block +An emulated disk controller is provided by the +.Xr virtio_blk 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 if_vtnet 4 , +.Xr virtio_blk 4 , +.Xr virtio_balloon 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@daemoninthecloset.org . |