[PATCH] KVM: x86 emulator: add LDS/LES/LFS/LGS/LSS instruction emulation

[Wei Yongjun <yjwei@cn.fujitsu.com>]

Add LDS/LES/LFS/LGS/LSS instruction emulation.
(opcode 0xc4, 0xc5, 0x0f 0xb2, 0x0f 0xb4~0xb5)
Used by FreeDOS livecd.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/emulate.c |   51 ++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 1d36c38..7c2ae18 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1503,6 +1503,23 @@ static int emulate_ret_far(struct x86_emulate_ctxt *ctxt,
 	return rc;
 }
 
+static int emulate_load_segment(struct x86_emulate_ctxt *ctxt,
+			   struct x86_emulate_ops *ops, int seg)
+{
+	struct decode_cache *c = &ctxt->decode;
+	unsigned short sel;
+	int rc;
+
+	memcpy(&sel, c->src.valptr + c->op_bytes, 2);
+
+	rc = load_segment_descriptor(ctxt, ops, sel, seg);
+	if (rc != X86EMUL_CONTINUE)
+		return rc;
+
+	c->dst.val = c->src.val;
+	return rc;
+}
+
 static inline void
 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
 			struct x86_emulate_ops *ops, struct desc_struct *cs,
@@ -2308,7 +2325,8 @@ static struct opcode opcode_table[256] = {
 	X8(D(DstReg | SrcImm | Mov)),
 	/* 0xC0 - 0xC7 */
 	D(ByteOp | DstMem | SrcImm | ModRM), D(DstMem | SrcImmByte | ModRM),
-	N, D(ImplicitOps | Stack), N, N,
+	N, D(ImplicitOps | Stack),
+	D(DstReg | SrcMemFAddr | ModRM), D(DstReg | SrcMemFAddr | ModRM),
 	D(ByteOp | DstMem | SrcImm | ModRM | Mov), D(DstMem | SrcImm | ModRM | Mov),
 	/* 0xC8 - 0xCF */
 	N, N, N, D(ImplicitOps | Stack),
@@ -2378,9 +2396,9 @@ static struct opcode twobyte_table[256] = {
 	D(ModRM), N,
 	/* 0xB0 - 0xB7 */
 	D(ByteOp | DstMem | SrcReg | ModRM | Lock), D(DstMem | SrcReg | ModRM | Lock),
-	N, D(DstMem | SrcReg | ModRM | BitOp | Lock),
-	N, N, D(ByteOp | DstReg | SrcMem | ModRM | Mov),
-	    D(DstReg | SrcMem16 | ModRM | Mov),
+	D(DstReg | SrcMemFAddr | ModRM), D(DstMem | SrcReg | ModRM | BitOp | Lock),
+	D(DstReg | SrcMemFAddr | ModRM), D(DstReg | SrcMemFAddr | ModRM),
+	D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
 	/* 0xB8 - 0xBF */
 	N, N,
 	G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock),
@@ -3055,6 +3073,16 @@ special_insn:
 		c->dst.addr.reg = &c->eip;
 		c->dst.bytes = c->op_bytes;
 		goto pop_instruction;
+	case 0xc4:		/* les */
+		rc = emulate_load_segment(ctxt, ops, VCPU_SREG_ES);
+		if (rc != X86EMUL_CONTINUE)
+			goto done;
+		break;
+	case 0xc5:		/* lds */
+		rc = emulate_load_segment(ctxt, ops, VCPU_SREG_DS);
+		if (rc != X86EMUL_CONTINUE)
+			goto done;
+		break;
 	case 0xc6 ... 0xc7:	/* mov (sole member of Grp11) */
 	mov:
 		c->dst.val = c->src.val;
@@ -3483,10 +3511,25 @@ twobyte_insn:
 			c->dst.addr.reg = (unsigned long *)&c->regs[VCPU_REGS_RAX];
 		}
 		break;
+	case 0xb2:		/* lss */
+		rc = emulate_load_segment(ctxt, ops, VCPU_SREG_SS);
+		if (rc != X86EMUL_CONTINUE)
+			goto done;
+		break;
 	case 0xb3:
 	      btr:		/* btr */
 		emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags);
 		break;
+	case 0xb4:		/* lfs */
+		rc = emulate_load_segment(ctxt, ops, VCPU_SREG_FS);
+		if (rc != X86EMUL_CONTINUE)
+			goto done;
+		break;
+	case 0xb5:		/* lgs */
+		rc = emulate_load_segment(ctxt, ops, VCPU_SREG_GS);
+		if (rc != X86EMUL_CONTINUE)
+			goto done;
+		break;
 	case 0xb6 ... 0xb7:	/* movzx */
 		c->dst.bytes = c->op_bytes;
 		c->dst.val = (c->d & ByteOp) ? (u8) c->src.val
-- 
1.7.0.4