idTGV seats,, Upper Deck?

Hi, I have seats booked Paris to Nice on the idTGV, we have dual ( facing) seats in a zen car,, I have the option to change my seats, and keep hearing about sitting on the top deck of the train, but wondering, when I go to my seat selection it doesn't appear to have an option to select deck one or two, so should I assume my train does not have an upper deck? Thanks