Shouldn't we point out the limit is for the host (dom0/Hypervisor) side as the
guest/domU kernel has (currently) other limitations (x86/2GB and x86_64/4GB) ?

release notes contains the following under "Virtualization":

<quote>
At present, the Virtualization feature has the following limitations:

<snip>    

* (x86) Hardware-virtualized guests cannot have more than 2GB of RAM.
* (x86_64) Hardware-virtualized guests cannot have more than 4GB of RAM.

</quote>

as per BZ 218820.

thanks!

Yes, but the 16G limit in this release note request is nothing to do with guest
limits --- it's a physical hardware support issue.  The i686 kernel-xen *HOST*
kernel cannot support more than 16GB of physical memory.

I suggest modifying 

* (x86) Hardware-virtualized guests cannot have more than 2GB of RAM.
* (x86_64) Hardware-virtualized guests cannot have more than 4GB of RAM.

to replace "RAM" with "virtual memory" or just "memory" to make this distinction
even clearer (a guest does not use physical RAM when it is saved to disk, for
example.)

Confirmed with 20070125.0.

Verified in the latest trees.