VIRTIO(4) | Device Drivers Manual | VIRTIO(4)

# NAME

`virtio` — Para-virtualized I/O in a virtual machine

# SYNOPSIS

## Virtio Over MMIO

`virtio* at acpi?`
`virtio* at fdt?`
`virtio* at pv?`

## Virtio Over PCI Bus

`virtio* at pci? dev ? function ?`

## Virtio devices

`ld* at virtio?`
`vio9p* at virtio?`
`viocon* at virtio?`
`vioif* at virtio?`
`viogpu* at virtio?`
`viomb* at virtio?`
`viornd* at virtio?`
`vioscsi* at virtio?`

# DESCRIPTION

The `virtio` driver implements the VirtIO interface for efficient, standard and extensible I/O between the hypervisor and the virtual machine.

It supports VirtIO devices exposed over pci(4) or over the MMIO transport.

The MMIO transport can be used, for example, in embedded systems and microVMs. Devices may be discovered via acpi(4) or fdt, or specified through kernel command-line parameters using pv(4).

The `virtio` driver provides the core infrastructure to communicate with the hypervisor and supports the following devices:

ld(4)
  A disk device.
vio9p(4)
  A 9P front-end device.
viocon(4)
  A console device.
vioif(4)
  An Ethernet device.
viogpu(4)
  A GPU device.
viomb(4)
  A pseudo-device to release memory back to the hypervisor.
viornd(4)
  An entropy source.
vioscsi(4)
  A SCSI adapter.

# SEE ALSO

acpi(4), ld(4), pci(4), pv(4), vio9p(4), viocon(4), viogpu(4), vioif(4), viomb(4), viornd(4), vioscsi(4)

Rusty Russell, IBM Corporation, Virtio PCI Card Specification, http://ozlabs.org/~rusty/virtio-spec/.

Virtual I/O Device (VIRTIO) Version 1.2, https://docs.oasis-open.org/virtio/virtio/v1.2/virtio-v1.2.html.

# HISTORY

The `virtio` driver first appeared in NetBSD 6.0. Support for attachment via acpi(4) and via fdt was added in NetBSD 9.0. Support for attachment via pv(4) was added in NetBSD 11.0.

August 29, 2026 | NetBSD 11.99