King's Indian Defense: Four Pawns Attack

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 O-O 6.Nf3 c5 7.dxc5 Qa5 8.Bd3 Qxc5 9.Qe2 Nc6