--- wikisrc/ports/xen/howto.mdwn	2014/12/24 01:06:43	1.20
+++ wikisrc/ports/xen/howto.mdwn	2014/12/24 01:12:49	1.21
@@ -246,6 +246,22 @@ As with non-Xen systems, you should have
 kernel that works without Xen) and fallback versions of the non-Xen
 kernel, Xen, and the dom0 kernel.
 
+Configuring Xen
+---------------
+
+Now, you have a system that will boot Xen and the dom0 kernel, and
+just run the dom0 kernel.  There will be no domUs, and none can be
+started because you still have to configure the dom0 tools.
+
+For 3.3 (and probably 3.1), add to rc.conf (but note that you should
+have installed 4.2):
+  xend=YES
+  xenbackendd=YES
+
+For 4.1 and 4.2, add to rc.conf:
+  xend=YES
+  xencommons=YES
+
 Updating NetBSD in a dom0
 -------------------------
 
@@ -260,7 +276,14 @@ rescue purposes and the DOM0 kernel used
 Updating Xen versions
 ---------------------
 
-TODO: write
+Updating Xen is conceptually not difficult, but can run into all the
+issues found when installing Xen.  Assuming migration from 4.1 to 4.2,
+remove the xenkernel41 and xentools41 packages and install the
+xenkernel42 and xentools42 packages.  Copy the 4.2 xen.gz to /.
+
+Ensure that the contents of /etc/rc.d/xen* are correct.  Enable the
+correct set of daemons.  Ensure that the domU config files are valid
+for the new version.
 
 Creating unprivileged domains (domU)
 ====================================
@@ -411,7 +434,7 @@ working vif-bridge is also provided with
 
     #!/bin/sh
     #============================================================================
-    # $NetBSD: howto.mdwn,v 1.19 2014/12/24 00:41:04 gdt Exp $
+    # $NetBSD: howto.mdwn,v 1.20 2014/12/24 01:06:43 gdt Exp $
     #
     # /usr/pkg/etc/xen/vif-bridge
     #