docs: improve documantion of xl's viridian option

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <ian.jackson.citrix.com>
Acked-by: Ian Jackson <ian.jackson.citrix.com>

diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index 33a3256c2208b85db235de0b299fbfe39ac823b4..9d90290cc104477cde9822993663834c86e16aca 100644 (file)
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -555,7 +555,13 @@ Windows L<http://wiki.xen.org/wiki/XenWindowsGplPv>.
 
 Turns on or off the exposure of MicroSoft Hyper-V (AKA viridian)
 compatible enlightenments to the guest.  These can improve performance
-of Microsoft Windows guests (XXX which versions of Windows benefit?)
+of Microsoft Windows guests from Windows Vista and Windows 2008
+onwards and setting this option for such guests is strongly
+recommended. This option should be harmless for other versions of
+Windows (although it won't give any benefit) and the majority of other
+non-Windows OSes. However it is known to be incompatible with some
+other Operating Systems and in some circumstance can prevent Xen's own
+paravirtualisation interfaces for HVM guests from being used.
 
 =back