Xen users - Jul 2013 - XEN 4.2.2: How to enable vnc-tls to make vnc sessions secure?

I am using XEN 4.2.2 source compile. Does XEN''s configure enable by
default  QEMU''s --enable-vnc-tls? After I start a guest, I
don''t see on
QEMU''s command line that it has started tls vnc ...

In /etc/xen/xend-config.sxp we can find the option:

(vnc-tls 1)

After reading, I figured out that you must create /etc/xen/vnc and put
certificates there? I also restarted xend but it never enabled tls nor I
did not got any error.

I could not find any help to this issue via google ...