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VIRTIO(4) Device Drivers Manual VIRTIO(4)

virtioVirtIO support driver

virtio* at fdt?
virtio* at pci? flags 0x00

The virtio driver provides support service for paravirtualized devices using the VirtIO protocol. Such devices are provided by bhyve, KVM, QEMU, VirtualBox, and vmm(4).

Currently there are drivers for the following virtio devices:

VirtIO network device
VirtIO disk
VirtIO console device
VirtIO GPU device
VirtIO memory ballooning driver
VirtIO random number device
VirtIO SCSI adapter
vmm(4) control interface

The virtio driver conforms to the virtio 0.9.5 specification. The virtio 1.0 standard is only supported for PCI devices.

By default 0.9 is preferred over 1.0. This can be changed by setting the bit 0x4 in the flags. Setting the bit 0x8 in the flags disables 1.0 support completely.


The virtio driver first appeared in OpenBSD 5.3.

The virtio driver was ported to OpenBSD and improved by Stefan Fritsch <>. It is based on the NetBSD driver by Minoura Makoto.

virtio big-endian architectures are not yet supported.

April 26, 2023 OpenBSD-current