[PATCH] x86 emulator: Simplify String I/O emulation

[Mohammed Gamal <m.gamal005@gmail.com>]

Simplify ins/insb and outs/outsb instructions

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
---
 arch/x86/kvm/x86_emulate.c |   22 ++++++----------------
 1 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index aef619a..97d60f5 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -1434,24 +1434,14 @@ special_insn:
 		break;
 	case 0x6c:		/* insb */
 	case 0x6d:		/* insw/insd */
-		 if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
-				1,
-				(c->d & ByteOp) ? 1 : c->op_bytes,
-				c->rep_prefix ?
-				address_mask(c, c->regs[VCPU_REGS_RCX]) : 1,
-				(ctxt->eflags & EFLG_DF),
-				register_address(c, es_base(ctxt),
-						 c->regs[VCPU_REGS_RDI]),
-				c->rep_prefix,
-				c->regs[VCPU_REGS_RDX]) == 0) {
-			c->eip = saved_eip;
-			return -1;
-		}
-		return 0;
+		io_direction = 1;
+		goto do_string_io;
 	case 0x6e:		/* outsb */
 	case 0x6f:		/* outsw/outsd */
+		io_direction = 0;
+	do_string_io:
 		if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
-				0,
+				io_direction,
 				(c->d & ByteOp) ? 1 : c->op_bytes,
 				c->rep_prefix ?
 				address_mask(c, c->regs[VCPU_REGS_RCX]) : 1,
@@ -1462,7 +1452,7 @@ special_insn:
 				c->rep_prefix,
 				c->regs[VCPU_REGS_RDX]) == 0) {
 			c->eip = saved_eip;
-			return -1;
+			goto cannot_emulate;
 		}
 		return 0;
 	case 0x70 ... 0x7f: /* jcc (short) */ {
-- 
1.5.4.3