---
name: "xen"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["freebsd", "openbsd"]
url: "https://new.carta.tech/xen"
---

# xen(4)

Xen domU nexus device

## NAME

**xen** – Xen domU nexus device

## SYNOPSIS

**xen0 at pvbus?**

## DESCRIPTION

**xen** driver performs HVM domU guest initialization, provides abstraction for virtual Xen interrupts, access to the XenStore configuration storage as well as a device probing facility for paravirtualized devices such as disk and network interfaces.

When running under XenServer, to let the host know that the guest has finished initializing and to allow graceful shutdown, set the following XenStore properties with [hostctl(8)](/hostctl/8.md) in [rc.local(8)](/rc.local/8.md):

```
ostype=$(sysctl -n kern.ostype)
osrelease=$(sysctl -n kern.osrelease)
# XenServer Tools version
hostctl attr/PVAddons/MajorVersion 6
hostctl attr/PVAddons/MinorVersion 2
hostctl attr/PVAddons/MicroVersion 0
hostctl attr/PVAddons/BuildVersion 76888
hostctl attr/PVAddons/Installed 1
# OS version
hostctl data/os_name "$ostype $osrelease"
hostctl data/os_uname $osrelease
hostctl data/os_distro $ostype
# Inform Xen of IPs bound to the VM
hostctl attr/vif/0/ipv4/0 192.0.2.1
hostctl attr/vif/0/ipv6/0 2001:db8::1
# Update XenStore
hostctl data/updated 1
```

## SEE ALSO

[autoconf(4)](/autoconf/4.md), [intro(4)](/intro/4.md), [pvbus(4)](/pvbus/4.md)

## HISTORY

The **xen** driver first appeared in OpenBSD 5.9.

## AUTHORS

The **xen** driver was written by Mike Belopuhov ⟨*mikeb@openbsd.org*⟩ from scratch, inspired by the FreeBSD implementation.