bionic (4) virtio.4freebsd.gz

NAME

     virtio — VirtIO Device Support

SYNOPSIS

     To compile VirtIO device support into the kernel, place the following lines in your kernel configuration
     file:

           device virtio
           device virtio_pci

     Alternatively, to load VirtIO support as modules at boot time, place the following lines in loader.conf(5):

           virtio_load="YES"
           virtio_pci_load="YES"

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.

     VirtIO defines an interface for efficient I/O between the hypervisor and VM.  The virtio module provides a
     shared memory transport called a virtqueue.  The virtio_pci device driver represents an emulated PCI device
     that the hypervisor makes available to the VM.  This device provides the probing, configuration, and
     interrupt notifications needed to interact with the hypervisor.  FreeBSD supports the following VirtIO
     devices:

           Ethernet  An emulated Ethernet device is provided by the vtnet(4) device driver.

           Block     An emulated disk controller is provided by the virtio_blk(4) device driver.

           SCSI      An emulated SCSI HBA is provided by the virtio_scsi(4) device driver.

           Balloon   A pseudo-device to allow the VM to release memory back to the hypervisor is provided by the
                     virtio_balloon(4) device driver.

SEE ALSO

     virtio_balloon(4), virtio_blk(4), virtio_console(4), virtio_scsi(4), vtnet(4)

HISTORY

     Support for VirtIO first appeared in FreeBSD 9.0.

AUTHORS

     FreeBSD support for VirtIO was first added by Bryan Venteicher <bryanv@FreeBSD.org>.