1 .\" Copyright (c) 2011 Bryan Venteicher
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25 .\" $FreeBSD: src/share/man/man4/virtio.4,v 1.5 2012/11/17 01:50:49 svnexp Exp $
32 .Nd VirtIO Device Support
34 To compile VirtIO device support into the kernel, place the following lines
35 in your kernel configuration file:
36 .Bd -ragged -offset indent
38 .Cd "device virtio_pci"
41 Alternatively, to load VirtIO support as modules at boot time, place the
44 .Bd -literal -offset indent
49 VirtIO is a specification for para-virtualized I/O in a virtual machine (VM).
50 Traditionally, the hypervisor emulated real devices such as an Ethernet
51 interface or disk controller to provide the VM with I/O.
52 This emulation is often inefficient.
54 VirtIO defines an interface for efficient I/O between the hypervisor and VM.
57 module provides a shared memory transport called a virtqueue.
60 device driver represents an emulated PCI device that the hypervisor makes
62 This device provides the probing, configuration, and
63 interrupt notifications needed to interact with the hypervisor.
65 supports the following VirtIO device(s):
66 .Bl -hang -offset indent -width xxxxxxxx
68 .\"An emulated Ethernet device is provided by the
72 An emulated disk controller is provided by the
76 .\"An emulated SCSI HBA is provided by the
80 .\"A pseudo-device to allow the VM to release memory back to the hypervisor is
82 .\".Xr virtio_balloon 4
86 .\".Xr virtio_balloon 4 ,
88 .\".Xr virtio_scsi 4 ,
91 Support for VirtIO first appeared in
96 support for VirtIO was first added by
97 .An Bryan Venteicher Aq Mt bryanv@daemoninthecloset.org .