A Vietjet Air Airbus A320-200, registration VN-A656 performing flight VJ-885 from Kaohsiung (Taiwan) to Ho Chi Minh City (Vietnam) with 103 passengers and 7 crew, was enroute at FL340 about 170nm south of Hong Kong (China) when the crew received a cargo smoke indication, declared emergency and diverted to Hong Kong, where the aircraft landed safely on runway 25R about 27 minutes later. Attending emergency services found no trace of fire, heat or smoke. . .