Cruising from Singapore to Shanghai

Canadian citizen going on a cruise from Singapore to Shanghai. Going back home to Vancouver the day the cruise ends. This is the itinerary: Singapore, Singapore - At Sea - Ho Chi Minh City, Vietnam - Nha Trang, Vietnam - At Sea - Hong Kong, Hong Kong - Hong Kong, Hong Kong - At Sea - Okinawa, Japan - At Sea - Shanghai, China

These are the flights:

1 Cathay Pacific Cathay Pacific 889 Vancouver Mar 27, 2017 at 02:00 Hong Kong Mar 28, 2017 at 06:15
2 Cathay Pacific Cathay Pacific 759 Hong Kong Mar 28, 2017 at 08:45 Singapore Mar 28, 2017 at 12:35
3 Cathay Pacific Dragon Air 5835 Shanghai Apr 09, 2017 at 19:15 Hong Kong Apr 09, 2017 at 21:55
4 Cathay Pacific Cathay Pacific 888 Hong Kong Apr 10, 2017 at 00:30 Vancouver Apr 09, 2017 at 21:20

Is a Visa required? Is that layover in Hong Kong a problem? Thanks