XENBUS(4) (xen)

XENBUS(4) | Device Drivers Manual (xen) | XENBUS(4)

# NAME

`xenbus` —
Xen bus abstraction for paravirtualized drivers

# SYNOPSIS

`xenbus* at hypervisor?`

# DESCRIPTION

The `xenbus` interface offers an abstraction layer used for communications between domains. `xenbus` is mainly used by split paravirtualized drivers, so backend and frontend devices can exchange configuration information, properties, and statistics.

`xenbus` is not used for data transfer (network frames, blocks, PCI commands, ...). This functionality is implemented by each paravirtualized driver independently, typically via shared memory pages and an event channel that serves as a virtual interrupt, for signaling.

The `xenbus` abstraction offers guests the possibility to read and write information directly from and to XenStore, a centralized database accessible to all domains. For this reason, it also has an event channel associated to it, so that domains can post messages to the XenStore facility.

# DIAGNOSTICS

xenbus0: using event channel %d
  The event channel associated to the `xenbus` interface, for communication with the XenStore database.

# SEE ALSO

pciback(4), xbd(4), xbdback(4), xennet(4), xpci(4), xvif(4)

# HISTORY

The `xenbus` driver first appeared in NetBSD 3.0.

# AUTHORS

The `xenbus` driver was written by Manuel Bouyer <bouyer@NetBSD.org>.

January 8, 2011 | NetBSD 9.4