CG: add note about virtualization+hardware.

diff --git a/Documentation/contributor/introduction.itexi b/Documentation/contributor/introduction.itexi
index ffcc80f29dcfb7d897e707ade90e5b920f1d90d3..c36b316141e360593427158a859129bfdab4fa20 100644 (file)
--- a/Documentation/contributor/introduction.itexi
+++ b/Documentation/contributor/introduction.itexi
@@ -200,6 +200,15 @@ the client.
 Follow instructions for Linux when reading instructions about
 @ref{Working with source code}, or @ref{Compiling}.
 
+@quotation
+Advanced note: not all hardware is supported in all virtualization
+tools.  In particular, contributors have reported problems with
+USB devices.  If you would like to investigate further, then look
+for help for your virtualization tool using your normal OS as the
+@qq{host} and Ubuntu as the @qq{client}.
+
+@end quotation
+
 
 @node Mentors
 @section Mentors