"Who do the crowds say that I am?"
"But you, who do you say that I am?"
After solitary prayer, Jesus returns to his disciples and asks these questions. He must have already heard rumors as to who the crowd thought he was. He also had a pretty good idea as to his true identity.
He received the answers he expected from "the crowd, the others." He joyfully accepted Peter's response about being "the Christ of God," albeit with a warning of coming events involving suffering, rejection, and death.