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:

vio(4) VirtIO network device vioblk(4) VirtIO disk viocon(4) VirtIO console device viomb(4) VirtIO memory ballooning driver viornd(4) VirtIO random number device vioscsi(4) VirtIO SCSI adapter vmmci(4) 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.