--- wikisrc/ports/xen/howto.mdwn	2015/03/12 21:21:22	1.98
+++ wikisrc/ports/xen/howto.mdwn	2015/03/12 21:27:36	1.99
@@ -130,20 +130,28 @@ Architecture
 ------------
 
 Xen itself can run on i386 or amd64 machines.  (Practically, almost
-any computer where one would want to run Xen supports amd64.)  If
-using an i386 NetBSD kernel for the dom0, PAE is required (PAE
-versions are built by default).  While i386 dom0 works fine, amd64 is
-recommended as more normal.
+any computer where one would want to run Xen today supports amd64.)
+
+Xen, the dom0 kernel, and each domU kernel can be either i386 or
+amd64.  When building a xenkernel package, one obtains i386 on an i386
+host, and amd64 on an amd64 host.  If the xen kernel is i386, then the
+dom0 kernel and all domU kernels must be i386.  With an amd64 xen
+kernel, an amd64 dom0 kernel is known to work, and an i386 dom0 kernel
+should in theory work.  An amd64 xen/dom0 is known to support both
+i386 and amd64 domUs.
+
+Except for an odd case with Xen 3.1, i386 dom0 and domU kernels must
+be PAE; these are built by default.  (Note that emacs (at least) fails
+if run on i386 with PAE when built without, and vice versa, presumably
+due to bugs in the undump code.)
+
+Because of the above, the standard approach is to use amd64 for the
+dom0.
 
 Xen 4.2 is the last version to support i386 as a host.  TODO: Clarify
 if this is about the CPU having to be amd64, or about the dom0 kernel
 having to be amd64.
 
-One can then run i386 domUs and amd64 domUs, in any combination.  If
-running an i386 NetBSD kernel as a domU, the PAE version is required.
-(Note that emacs (at least) fails if run on i386 with PAE when built
-without, and vice versa, presumably due to bugs in the undump code.)
-
 Stability
 ---------