@Andrew I did not see a serial port listed. I'll just get a USB version and plug in to server and see if I can pass thru it. If it works, I can get rid of another Destop server and be fully virtual.
Thanks for your hellp.

@Andrew
I too would like to pass thru a serial port on Dell R460 server host to a vm running linux. I would like to use this to talk to a lighting system with this VM rather than using a stand alone desktop.