KVM: x86 emulator: implement 'movnti mem, reg'

patch a012e65a in mainline.

Implement emulation of instruction:
    movnti m32/m64, r32/r64
    opcode: 0x0f 0xc3

Needed to support Linux 2.6.16 as guest (used for mmio).
Signed-off-by: Sheng Yang <sheng.yang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/kvm/x86_emulate.c

@@ -198,7 +198,8 @@ static u16 twobyte_table[256] = {
 	0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
 	    DstReg | SrcMem16 | ModRM | Mov,
 	/* 0xC0 - 0xCF */
-	0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, ImplicitOps | ModRM,
+	0, 0, 0, 0, 0, 0, 0, 0,
 	/* 0xD0 - 0xDF */
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	/* 0xE0 - 0xEF */
@@ -1324,6 +1325,10 @@ twobyte_insn:
 		dst.bytes = op_bytes;
 		dst.val = (d & ByteOp) ? (s8) src.val : (s16) src.val;
 		break;
+	case 0xc3:		/* movnti */
+		dst.bytes = op_bytes;
+		dst.val = (op_bytes == 4) ? (u32) src.val : (u64) src.val;
+		break;
 	}
 	goto writeback;