Run noVNC for virt-manager:

$ websockify 6080 127.0.0.1:5900
$ sudo iptables -I INPUT -m state --state NEW -s YOUR_IP_ADDRESS -m tcp -p tcp --dport 6080 -j ACCEPT

Open in browser URL: http://kanaka.github.com/noVNC/noVNC/vnc.html. Input SERVER_IP_ADDRESS and PORT_NOVNC (6080)