From dde7e6d12a9ef9f727d05ce824f4fe75ca2a5b3a Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Thu, 29 Jul 2010 15:11:52 +0300
Subject: [PATCH] KVM: x86 emulator: move x86_decode_insn() downwards

No code changes.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
 arch/x86/kvm/emulate.c | 744 ++++++++++++++++++++---------------------
 1 file changed, 372 insertions(+), 372 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 799e895fb08e..c6f435917538 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -945,378 +945,6 @@ static int decode_abs(struct x86_emulate_ctxt *ctxt,
 	return rc;
 }
 
-int
-x86_decode_insn(struct x86_emulate_ctxt *ctxt)
-{
-	struct x86_emulate_ops *ops = ctxt->ops;
-	struct decode_cache *c = &ctxt->decode;
-	int rc = X86EMUL_CONTINUE;
-	int mode = ctxt->mode;
-	int def_op_bytes, def_ad_bytes, dual, goffset;
-	struct opcode opcode, *g_mod012, *g_mod3;
-
-	/* we cannot decode insn before we complete previous rep insn */
-	WARN_ON(ctxt->restart);
-
-	c->eip = ctxt->eip;
-	c->fetch.start = c->fetch.end = c->eip;
-	ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS);
-
-	switch (mode) {
-	case X86EMUL_MODE_REAL:
-	case X86EMUL_MODE_VM86:
-	case X86EMUL_MODE_PROT16:
-		def_op_bytes = def_ad_bytes = 2;
-		break;
-	case X86EMUL_MODE_PROT32:
-		def_op_bytes = def_ad_bytes = 4;
-		break;
-#ifdef CONFIG_X86_64
-	case X86EMUL_MODE_PROT64:
-		def_op_bytes = 4;
-		def_ad_bytes = 8;
-		break;
-#endif
-	default:
-		return -1;
-	}
-
-	c->op_bytes = def_op_bytes;
-	c->ad_bytes = def_ad_bytes;
-
-	/* Legacy prefixes. */
-	for (;;) {
-		switch (c->b = insn_fetch(u8, 1, c->eip)) {
-		case 0x66:	/* operand-size override */
-			/* switch between 2/4 bytes */
-			c->op_bytes = def_op_bytes ^ 6;
-			break;
-		case 0x67:	/* address-size override */
-			if (mode == X86EMUL_MODE_PROT64)
-				/* switch between 4/8 bytes */
-				c->ad_bytes = def_ad_bytes ^ 12;
-			else
-				/* switch between 2/4 bytes */
-				c->ad_bytes = def_ad_bytes ^ 6;
-			break;
-		case 0x26:	/* ES override */
-		case 0x2e:	/* CS override */
-		case 0x36:	/* SS override */
-		case 0x3e:	/* DS override */
-			set_seg_override(c, (c->b >> 3) & 3);
-			break;
-		case 0x64:	/* FS override */
-		case 0x65:	/* GS override */
-			set_seg_override(c, c->b & 7);
-			break;
-		case 0x40 ... 0x4f: /* REX */
-			if (mode != X86EMUL_MODE_PROT64)
-				goto done_prefixes;
-			c->rex_prefix = c->b;
-			continue;
-		case 0xf0:	/* LOCK */
-			c->lock_prefix = 1;
-			break;
-		case 0xf2:	/* REPNE/REPNZ */
-			c->rep_prefix = REPNE_PREFIX;
-			break;
-		case 0xf3:	/* REP/REPE/REPZ */
-			c->rep_prefix = REPE_PREFIX;
-			break;
-		default:
-			goto done_prefixes;
-		}
-
-		/* Any legacy prefix after a REX prefix nullifies its effect. */
-
-		c->rex_prefix = 0;
-	}
-
-done_prefixes:
-
-	/* REX prefix. */
-	if (c->rex_prefix)
-		if (c->rex_prefix & 8)
-			c->op_bytes = 8;	/* REX.W */
-
-	/* Opcode byte(s). */
-	opcode = opcode_table[c->b];
-	if (opcode.flags == 0) {
-		/* Two-byte opcode? */
-		if (c->b == 0x0f) {
-			c->twobyte = 1;
-			c->b = insn_fetch(u8, 1, c->eip);
-			opcode = twobyte_table[c->b];
-		}
-	}
-	c->d = opcode.flags;
-
-	if (c->d & Group) {
-		dual = c->d & GroupDual;
-		c->modrm = insn_fetch(u8, 1, c->eip);
-		--c->eip;
-
-		if (c->d & GroupDual) {
-			g_mod012 = opcode.u.gdual->mod012;
-			g_mod3 = opcode.u.gdual->mod3;
-		} else
-			g_mod012 = g_mod3 = opcode.u.group;
-
-		c->d &= ~(Group | GroupDual);
-
-		goffset = (c->modrm >> 3) & 7;
-
-		if ((c->modrm >> 6) == 3)
-			opcode = g_mod3[goffset];
-		else
-			opcode = g_mod012[goffset];
-		c->d |= opcode.flags;
-	}
-
-	c->execute = opcode.u.execute;
-
-	/* Unrecognised? */
-	if (c->d == 0 || (c->d & Undefined)) {
-		DPRINTF("Cannot emulate %02x\n", c->b);
-		return -1;
-	}
-
-	if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack))
-		c->op_bytes = 8;
-
-	/* ModRM and SIB bytes. */
-	if (c->d & ModRM)
-		rc = decode_modrm(ctxt, ops);
-	else if (c->d & MemAbs)
-		rc = decode_abs(ctxt, ops);
-	if (rc != X86EMUL_CONTINUE)
-		goto done;
-
-	if (!c->has_seg_override)
-		set_seg_override(c, VCPU_SREG_DS);
-
-	if (!(!c->twobyte && c->b == 0x8d))
-		c->modrm_ea += seg_override_base(ctxt, ops, c);
-
-	if (c->ad_bytes != 8)
-		c->modrm_ea = (u32)c->modrm_ea;
-
-	if (c->rip_relative)
-		c->modrm_ea += c->eip;
-
-	/*
-	 * Decode and fetch the source operand: register, memory
-	 * or immediate.
-	 */
-	switch (c->d & SrcMask) {
-	case SrcNone:
-		break;
-	case SrcReg:
-		decode_register_operand(&c->src, c, 0);
-		break;
-	case SrcMem16:
-		c->src.bytes = 2;
-		goto srcmem_common;
-	case SrcMem32:
-		c->src.bytes = 4;
-		goto srcmem_common;
-	case SrcMem:
-		c->src.bytes = (c->d & ByteOp) ? 1 :
-							   c->op_bytes;
-		/* Don't fetch the address for invlpg: it could be unmapped. */
-		if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7)
-			break;
-	srcmem_common:
-		/*
-		 * For instructions with a ModR/M byte, switch to register
-		 * access if Mod = 3.
-		 */
-		if ((c->d & ModRM) && c->modrm_mod == 3) {
-			c->src.type = OP_REG;
-			c->src.val = c->modrm_val;
-			c->src.ptr = c->modrm_ptr;
-			break;
-		}
-		c->src.type = OP_MEM;
-		c->src.ptr = (unsigned long *)c->modrm_ea;
-		c->src.val = 0;
-		break;
-	case SrcImm:
-	case SrcImmU:
-		c->src.type = OP_IMM;
-		c->src.ptr = (unsigned long *)c->eip;
-		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		if (c->src.bytes == 8)
-			c->src.bytes = 4;
-		/* NB. Immediates are sign-extended as necessary. */
-		switch (c->src.bytes) {
-		case 1:
-			c->src.val = insn_fetch(s8, 1, c->eip);
-			break;
-		case 2:
-			c->src.val = insn_fetch(s16, 2, c->eip);
-			break;
-		case 4:
-			c->src.val = insn_fetch(s32, 4, c->eip);
-			break;
-		}
-		if ((c->d & SrcMask) == SrcImmU) {
-			switch (c->src.bytes) {
-			case 1:
-				c->src.val &= 0xff;
-				break;
-			case 2:
-				c->src.val &= 0xffff;
-				break;
-			case 4:
-				c->src.val &= 0xffffffff;
-				break;
-			}
-		}
-		break;
-	case SrcImmByte:
-	case SrcImmUByte:
-		c->src.type = OP_IMM;
-		c->src.ptr = (unsigned long *)c->eip;
-		c->src.bytes = 1;
-		if ((c->d & SrcMask) == SrcImmByte)
-			c->src.val = insn_fetch(s8, 1, c->eip);
-		else
-			c->src.val = insn_fetch(u8, 1, c->eip);
-		break;
-	case SrcAcc:
-		c->src.type = OP_REG;
-		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		c->src.ptr = &c->regs[VCPU_REGS_RAX];
-		switch (c->src.bytes) {
-			case 1:
-				c->src.val = *(u8 *)c->src.ptr;
-				break;
-			case 2:
-				c->src.val = *(u16 *)c->src.ptr;
-				break;
-			case 4:
-				c->src.val = *(u32 *)c->src.ptr;
-				break;
-			case 8:
-				c->src.val = *(u64 *)c->src.ptr;
-				break;
-		}
-		break;
-	case SrcOne:
-		c->src.bytes = 1;
-		c->src.val = 1;
-		break;
-	case SrcSI:
-		c->src.type = OP_MEM;
-		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		c->src.ptr = (unsigned long *)
-			register_address(c,  seg_override_base(ctxt, ops, c),
-					 c->regs[VCPU_REGS_RSI]);
-		c->src.val = 0;
-		break;
-	case SrcImmFAddr:
-		c->src.type = OP_IMM;
-		c->src.ptr = (unsigned long *)c->eip;
-		c->src.bytes = c->op_bytes + 2;
-		insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip);
-		break;
-	case SrcMemFAddr:
-		c->src.type = OP_MEM;
-		c->src.ptr = (unsigned long *)c->modrm_ea;
-		c->src.bytes = c->op_bytes + 2;
-		break;
-	}
-
-	/*
-	 * Decode and fetch the second source operand: register, memory
-	 * or immediate.
-	 */
-	switch (c->d & Src2Mask) {
-	case Src2None:
-		break;
-	case Src2CL:
-		c->src2.bytes = 1;
-		c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8;
-		break;
-	case Src2ImmByte:
-		c->src2.type = OP_IMM;
-		c->src2.ptr = (unsigned long *)c->eip;
-		c->src2.bytes = 1;
-		c->src2.val = insn_fetch(u8, 1, c->eip);
-		break;
-	case Src2One:
-		c->src2.bytes = 1;
-		c->src2.val = 1;
-		break;
-	}
-
-	/* Decode and fetch the destination operand: register or memory. */
-	switch (c->d & DstMask) {
-	case ImplicitOps:
-		/* Special instructions do their own operand decoding. */
-		return 0;
-	case DstReg:
-		decode_register_operand(&c->dst, c,
-			 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
-		break;
-	case DstMem:
-	case DstMem64:
-		if ((c->d & ModRM) && c->modrm_mod == 3) {
-			c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-			c->dst.type = OP_REG;
-			c->dst.val = c->dst.orig_val = c->modrm_val;
-			c->dst.ptr = c->modrm_ptr;
-			break;
-		}
-		c->dst.type = OP_MEM;
-		c->dst.ptr = (unsigned long *)c->modrm_ea;
-		if ((c->d & DstMask) == DstMem64)
-			c->dst.bytes = 8;
-		else
-			c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		c->dst.val = 0;
-		if (c->d & BitOp) {
-			unsigned long mask = ~(c->dst.bytes * 8 - 1);
-
-			c->dst.ptr = (void *)c->dst.ptr +
-						   (c->src.val & mask) / 8;
-		}
-		break;
-	case DstAcc:
-		c->dst.type = OP_REG;
-		c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		c->dst.ptr = &c->regs[VCPU_REGS_RAX];
-		switch (c->dst.bytes) {
-			case 1:
-				c->dst.val = *(u8 *)c->dst.ptr;
-				break;
-			case 2:
-				c->dst.val = *(u16 *)c->dst.ptr;
-				break;
-			case 4:
-				c->dst.val = *(u32 *)c->dst.ptr;
-				break;
-			case 8:
-				c->dst.val = *(u64 *)c->dst.ptr;
-				break;
-		}
-		c->dst.orig_val = c->dst.val;
-		break;
-	case DstDI:
-		c->dst.type = OP_MEM;
-		c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
-		c->dst.ptr = (unsigned long *)
-			register_address(c, es_base(ctxt, ops),
-					 c->regs[VCPU_REGS_RDI]);
-		c->dst.val = 0;
-		break;
-	}
-
-done:
-	return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
-}
-
 static int read_emulated(struct x86_emulate_ctxt *ctxt,
 			 struct x86_emulate_ops *ops,
 			 unsigned long addr, void *dest, unsigned size)
@@ -2624,6 +2252,378 @@ static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base,
 	op->ptr = (unsigned long *)register_address(c,  base, c->regs[reg]);
 }
 
+int
+x86_decode_insn(struct x86_emulate_ctxt *ctxt)
+{
+	struct x86_emulate_ops *ops = ctxt->ops;
+	struct decode_cache *c = &ctxt->decode;
+	int rc = X86EMUL_CONTINUE;
+	int mode = ctxt->mode;
+	int def_op_bytes, def_ad_bytes, dual, goffset;
+	struct opcode opcode, *g_mod012, *g_mod3;
+
+	/* we cannot decode insn before we complete previous rep insn */
+	WARN_ON(ctxt->restart);
+
+	c->eip = ctxt->eip;
+	c->fetch.start = c->fetch.end = c->eip;
+	ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS);
+
+	switch (mode) {
+	case X86EMUL_MODE_REAL:
+	case X86EMUL_MODE_VM86:
+	case X86EMUL_MODE_PROT16:
+		def_op_bytes = def_ad_bytes = 2;
+		break;
+	case X86EMUL_MODE_PROT32:
+		def_op_bytes = def_ad_bytes = 4;
+		break;
+#ifdef CONFIG_X86_64
+	case X86EMUL_MODE_PROT64:
+		def_op_bytes = 4;
+		def_ad_bytes = 8;
+		break;
+#endif
+	default:
+		return -1;
+	}
+
+	c->op_bytes = def_op_bytes;
+	c->ad_bytes = def_ad_bytes;
+
+	/* Legacy prefixes. */
+	for (;;) {
+		switch (c->b = insn_fetch(u8, 1, c->eip)) {
+		case 0x66:	/* operand-size override */
+			/* switch between 2/4 bytes */
+			c->op_bytes = def_op_bytes ^ 6;
+			break;
+		case 0x67:	/* address-size override */
+			if (mode == X86EMUL_MODE_PROT64)
+				/* switch between 4/8 bytes */
+				c->ad_bytes = def_ad_bytes ^ 12;
+			else
+				/* switch between 2/4 bytes */
+				c->ad_bytes = def_ad_bytes ^ 6;
+			break;
+		case 0x26:	/* ES override */
+		case 0x2e:	/* CS override */
+		case 0x36:	/* SS override */
+		case 0x3e:	/* DS override */
+			set_seg_override(c, (c->b >> 3) & 3);
+			break;
+		case 0x64:	/* FS override */
+		case 0x65:	/* GS override */
+			set_seg_override(c, c->b & 7);
+			break;
+		case 0x40 ... 0x4f: /* REX */
+			if (mode != X86EMUL_MODE_PROT64)
+				goto done_prefixes;
+			c->rex_prefix = c->b;
+			continue;
+		case 0xf0:	/* LOCK */
+			c->lock_prefix = 1;
+			break;
+		case 0xf2:	/* REPNE/REPNZ */
+			c->rep_prefix = REPNE_PREFIX;
+			break;
+		case 0xf3:	/* REP/REPE/REPZ */
+			c->rep_prefix = REPE_PREFIX;
+			break;
+		default:
+			goto done_prefixes;
+		}
+
+		/* Any legacy prefix after a REX prefix nullifies its effect. */
+
+		c->rex_prefix = 0;
+	}
+
+done_prefixes:
+
+	/* REX prefix. */
+	if (c->rex_prefix)
+		if (c->rex_prefix & 8)
+			c->op_bytes = 8;	/* REX.W */
+
+	/* Opcode byte(s). */
+	opcode = opcode_table[c->b];
+	if (opcode.flags == 0) {
+		/* Two-byte opcode? */
+		if (c->b == 0x0f) {
+			c->twobyte = 1;
+			c->b = insn_fetch(u8, 1, c->eip);
+			opcode = twobyte_table[c->b];
+		}
+	}
+	c->d = opcode.flags;
+
+	if (c->d & Group) {
+		dual = c->d & GroupDual;
+		c->modrm = insn_fetch(u8, 1, c->eip);
+		--c->eip;
+
+		if (c->d & GroupDual) {
+			g_mod012 = opcode.u.gdual->mod012;
+			g_mod3 = opcode.u.gdual->mod3;
+		} else
+			g_mod012 = g_mod3 = opcode.u.group;
+
+		c->d &= ~(Group | GroupDual);
+
+		goffset = (c->modrm >> 3) & 7;
+
+		if ((c->modrm >> 6) == 3)
+			opcode = g_mod3[goffset];
+		else
+			opcode = g_mod012[goffset];
+		c->d |= opcode.flags;
+	}
+
+	c->execute = opcode.u.execute;
+
+	/* Unrecognised? */
+	if (c->d == 0 || (c->d & Undefined)) {
+		DPRINTF("Cannot emulate %02x\n", c->b);
+		return -1;
+	}
+
+	if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack))
+		c->op_bytes = 8;
+
+	/* ModRM and SIB bytes. */
+	if (c->d & ModRM)
+		rc = decode_modrm(ctxt, ops);
+	else if (c->d & MemAbs)
+		rc = decode_abs(ctxt, ops);
+	if (rc != X86EMUL_CONTINUE)
+		goto done;
+
+	if (!c->has_seg_override)
+		set_seg_override(c, VCPU_SREG_DS);
+
+	if (!(!c->twobyte && c->b == 0x8d))
+		c->modrm_ea += seg_override_base(ctxt, ops, c);
+
+	if (c->ad_bytes != 8)
+		c->modrm_ea = (u32)c->modrm_ea;
+
+	if (c->rip_relative)
+		c->modrm_ea += c->eip;
+
+	/*
+	 * Decode and fetch the source operand: register, memory
+	 * or immediate.
+	 */
+	switch (c->d & SrcMask) {
+	case SrcNone:
+		break;
+	case SrcReg:
+		decode_register_operand(&c->src, c, 0);
+		break;
+	case SrcMem16:
+		c->src.bytes = 2;
+		goto srcmem_common;
+	case SrcMem32:
+		c->src.bytes = 4;
+		goto srcmem_common;
+	case SrcMem:
+		c->src.bytes = (c->d & ByteOp) ? 1 :
+							   c->op_bytes;
+		/* Don't fetch the address for invlpg: it could be unmapped. */
+		if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7)
+			break;
+	srcmem_common:
+		/*
+		 * For instructions with a ModR/M byte, switch to register
+		 * access if Mod = 3.
+		 */
+		if ((c->d & ModRM) && c->modrm_mod == 3) {
+			c->src.type = OP_REG;
+			c->src.val = c->modrm_val;
+			c->src.ptr = c->modrm_ptr;
+			break;
+		}
+		c->src.type = OP_MEM;
+		c->src.ptr = (unsigned long *)c->modrm_ea;
+		c->src.val = 0;
+		break;
+	case SrcImm:
+	case SrcImmU:
+		c->src.type = OP_IMM;
+		c->src.ptr = (unsigned long *)c->eip;
+		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		if (c->src.bytes == 8)
+			c->src.bytes = 4;
+		/* NB. Immediates are sign-extended as necessary. */
+		switch (c->src.bytes) {
+		case 1:
+			c->src.val = insn_fetch(s8, 1, c->eip);
+			break;
+		case 2:
+			c->src.val = insn_fetch(s16, 2, c->eip);
+			break;
+		case 4:
+			c->src.val = insn_fetch(s32, 4, c->eip);
+			break;
+		}
+		if ((c->d & SrcMask) == SrcImmU) {
+			switch (c->src.bytes) {
+			case 1:
+				c->src.val &= 0xff;
+				break;
+			case 2:
+				c->src.val &= 0xffff;
+				break;
+			case 4:
+				c->src.val &= 0xffffffff;
+				break;
+			}
+		}
+		break;
+	case SrcImmByte:
+	case SrcImmUByte:
+		c->src.type = OP_IMM;
+		c->src.ptr = (unsigned long *)c->eip;
+		c->src.bytes = 1;
+		if ((c->d & SrcMask) == SrcImmByte)
+			c->src.val = insn_fetch(s8, 1, c->eip);
+		else
+			c->src.val = insn_fetch(u8, 1, c->eip);
+		break;
+	case SrcAcc:
+		c->src.type = OP_REG;
+		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		c->src.ptr = &c->regs[VCPU_REGS_RAX];
+		switch (c->src.bytes) {
+			case 1:
+				c->src.val = *(u8 *)c->src.ptr;
+				break;
+			case 2:
+				c->src.val = *(u16 *)c->src.ptr;
+				break;
+			case 4:
+				c->src.val = *(u32 *)c->src.ptr;
+				break;
+			case 8:
+				c->src.val = *(u64 *)c->src.ptr;
+				break;
+		}
+		break;
+	case SrcOne:
+		c->src.bytes = 1;
+		c->src.val = 1;
+		break;
+	case SrcSI:
+		c->src.type = OP_MEM;
+		c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		c->src.ptr = (unsigned long *)
+			register_address(c,  seg_override_base(ctxt, ops, c),
+					 c->regs[VCPU_REGS_RSI]);
+		c->src.val = 0;
+		break;
+	case SrcImmFAddr:
+		c->src.type = OP_IMM;
+		c->src.ptr = (unsigned long *)c->eip;
+		c->src.bytes = c->op_bytes + 2;
+		insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip);
+		break;
+	case SrcMemFAddr:
+		c->src.type = OP_MEM;
+		c->src.ptr = (unsigned long *)c->modrm_ea;
+		c->src.bytes = c->op_bytes + 2;
+		break;
+	}
+
+	/*
+	 * Decode and fetch the second source operand: register, memory
+	 * or immediate.
+	 */
+	switch (c->d & Src2Mask) {
+	case Src2None:
+		break;
+	case Src2CL:
+		c->src2.bytes = 1;
+		c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8;
+		break;
+	case Src2ImmByte:
+		c->src2.type = OP_IMM;
+		c->src2.ptr = (unsigned long *)c->eip;
+		c->src2.bytes = 1;
+		c->src2.val = insn_fetch(u8, 1, c->eip);
+		break;
+	case Src2One:
+		c->src2.bytes = 1;
+		c->src2.val = 1;
+		break;
+	}
+
+	/* Decode and fetch the destination operand: register or memory. */
+	switch (c->d & DstMask) {
+	case ImplicitOps:
+		/* Special instructions do their own operand decoding. */
+		return 0;
+	case DstReg:
+		decode_register_operand(&c->dst, c,
+			 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
+		break;
+	case DstMem:
+	case DstMem64:
+		if ((c->d & ModRM) && c->modrm_mod == 3) {
+			c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+			c->dst.type = OP_REG;
+			c->dst.val = c->dst.orig_val = c->modrm_val;
+			c->dst.ptr = c->modrm_ptr;
+			break;
+		}
+		c->dst.type = OP_MEM;
+		c->dst.ptr = (unsigned long *)c->modrm_ea;
+		if ((c->d & DstMask) == DstMem64)
+			c->dst.bytes = 8;
+		else
+			c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		c->dst.val = 0;
+		if (c->d & BitOp) {
+			unsigned long mask = ~(c->dst.bytes * 8 - 1);
+
+			c->dst.ptr = (void *)c->dst.ptr +
+						   (c->src.val & mask) / 8;
+		}
+		break;
+	case DstAcc:
+		c->dst.type = OP_REG;
+		c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		c->dst.ptr = &c->regs[VCPU_REGS_RAX];
+		switch (c->dst.bytes) {
+			case 1:
+				c->dst.val = *(u8 *)c->dst.ptr;
+				break;
+			case 2:
+				c->dst.val = *(u16 *)c->dst.ptr;
+				break;
+			case 4:
+				c->dst.val = *(u32 *)c->dst.ptr;
+				break;
+			case 8:
+				c->dst.val = *(u64 *)c->dst.ptr;
+				break;
+		}
+		c->dst.orig_val = c->dst.val;
+		break;
+	case DstDI:
+		c->dst.type = OP_MEM;
+		c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+		c->dst.ptr = (unsigned long *)
+			register_address(c, es_base(ctxt, ops),
+					 c->regs[VCPU_REGS_RDI]);
+		c->dst.val = 0;
+		break;
+	}
+
+done:
+	return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
+}
+
 int
 x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 {