An Air France Boeing 777-300, registration F-GSQH performing flight AF-347 from Montreal,QC (Canada) to Paris Charles de Gaulle (France) with 100 people on board, was enroute at FL380 about 280nm northeast of Goose Bay when the crew received a forward cargo smoke indication, declared Mayday Mayday and decided to divert to Goose Bay receiving a direct vector to the approach fix for RNAV approach to runway 26, the crew decided not to dump fuel. Upon inquiry by ATC the crew reported they did not smell any unusual odour and did not have any smoke, just the smoke indication, the crew requested emergency services on arrival and requested that first all passengers and crew would disembark before the cargo door was opened. The aircraft landed safely in Goose Bay about 53 minutes after turning around and leaving FL380. The aircraft vacated the runway and stopped on the parallel taxiway for an inspection by emergency services. The passengers disembarked via mobile stairs. Emergency services did not find any trace of fire, smoke or heat, the indication was identified false.