xref: /openbmc/linux/arch/x86/kvm/emulate.c (revision 3c6a73cc)
1 /******************************************************************************
2  * emulate.c
3  *
4  * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5  *
6  * Copyright (c) 2005 Keir Fraser
7  *
8  * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9  * privileged instructions:
10  *
11  * Copyright (C) 2006 Qumranet
12  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13  *
14  *   Avi Kivity <avi@qumranet.com>
15  *   Yaniv Kamay <yaniv@qumranet.com>
16  *
17  * This work is licensed under the terms of the GNU GPL, version 2.  See
18  * the COPYING file in the top-level directory.
19  *
20  * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
21  */
22 
23 #include <linux/kvm_host.h>
24 #include "kvm_cache_regs.h"
25 #include <linux/module.h>
26 #include <asm/kvm_emulate.h>
27 #include <linux/stringify.h>
28 
29 #include "x86.h"
30 #include "tss.h"
31 
32 /*
33  * Operand types
34  */
35 #define OpNone             0ull
36 #define OpImplicit         1ull  /* No generic decode */
37 #define OpReg              2ull  /* Register */
38 #define OpMem              3ull  /* Memory */
39 #define OpAcc              4ull  /* Accumulator: AL/AX/EAX/RAX */
40 #define OpDI               5ull  /* ES:DI/EDI/RDI */
41 #define OpMem64            6ull  /* Memory, 64-bit */
42 #define OpImmUByte         7ull  /* Zero-extended 8-bit immediate */
43 #define OpDX               8ull  /* DX register */
44 #define OpCL               9ull  /* CL register (for shifts) */
45 #define OpImmByte         10ull  /* 8-bit sign extended immediate */
46 #define OpOne             11ull  /* Implied 1 */
47 #define OpImm             12ull  /* Sign extended up to 32-bit immediate */
48 #define OpMem16           13ull  /* Memory operand (16-bit). */
49 #define OpMem32           14ull  /* Memory operand (32-bit). */
50 #define OpImmU            15ull  /* Immediate operand, zero extended */
51 #define OpSI              16ull  /* SI/ESI/RSI */
52 #define OpImmFAddr        17ull  /* Immediate far address */
53 #define OpMemFAddr        18ull  /* Far address in memory */
54 #define OpImmU16          19ull  /* Immediate operand, 16 bits, zero extended */
55 #define OpES              20ull  /* ES */
56 #define OpCS              21ull  /* CS */
57 #define OpSS              22ull  /* SS */
58 #define OpDS              23ull  /* DS */
59 #define OpFS              24ull  /* FS */
60 #define OpGS              25ull  /* GS */
61 #define OpMem8            26ull  /* 8-bit zero extended memory operand */
62 #define OpImm64           27ull  /* Sign extended 16/32/64-bit immediate */
63 #define OpXLat            28ull  /* memory at BX/EBX/RBX + zero-extended AL */
64 #define OpAccLo           29ull  /* Low part of extended acc (AX/AX/EAX/RAX) */
65 #define OpAccHi           30ull  /* High part of extended acc (-/DX/EDX/RDX) */
66 
67 #define OpBits             5  /* Width of operand field */
68 #define OpMask             ((1ull << OpBits) - 1)
69 
70 /*
71  * Opcode effective-address decode tables.
72  * Note that we only emulate instructions that have at least one memory
73  * operand (excluding implicit stack references). We assume that stack
74  * references and instruction fetches will never occur in special memory
75  * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
76  * not be handled.
77  */
78 
79 /* Operand sizes: 8-bit operands or specified/overridden size. */
80 #define ByteOp      (1<<0)	/* 8-bit operands. */
81 /* Destination operand type. */
82 #define DstShift    1
83 #define ImplicitOps (OpImplicit << DstShift)
84 #define DstReg      (OpReg << DstShift)
85 #define DstMem      (OpMem << DstShift)
86 #define DstAcc      (OpAcc << DstShift)
87 #define DstDI       (OpDI << DstShift)
88 #define DstMem64    (OpMem64 << DstShift)
89 #define DstImmUByte (OpImmUByte << DstShift)
90 #define DstDX       (OpDX << DstShift)
91 #define DstAccLo    (OpAccLo << DstShift)
92 #define DstMask     (OpMask << DstShift)
93 /* Source operand type. */
94 #define SrcShift    6
95 #define SrcNone     (OpNone << SrcShift)
96 #define SrcReg      (OpReg << SrcShift)
97 #define SrcMem      (OpMem << SrcShift)
98 #define SrcMem16    (OpMem16 << SrcShift)
99 #define SrcMem32    (OpMem32 << SrcShift)
100 #define SrcImm      (OpImm << SrcShift)
101 #define SrcImmByte  (OpImmByte << SrcShift)
102 #define SrcOne      (OpOne << SrcShift)
103 #define SrcImmUByte (OpImmUByte << SrcShift)
104 #define SrcImmU     (OpImmU << SrcShift)
105 #define SrcSI       (OpSI << SrcShift)
106 #define SrcXLat     (OpXLat << SrcShift)
107 #define SrcImmFAddr (OpImmFAddr << SrcShift)
108 #define SrcMemFAddr (OpMemFAddr << SrcShift)
109 #define SrcAcc      (OpAcc << SrcShift)
110 #define SrcImmU16   (OpImmU16 << SrcShift)
111 #define SrcImm64    (OpImm64 << SrcShift)
112 #define SrcDX       (OpDX << SrcShift)
113 #define SrcMem8     (OpMem8 << SrcShift)
114 #define SrcAccHi    (OpAccHi << SrcShift)
115 #define SrcMask     (OpMask << SrcShift)
116 #define BitOp       (1<<11)
117 #define MemAbs      (1<<12)      /* Memory operand is absolute displacement */
118 #define String      (1<<13)     /* String instruction (rep capable) */
119 #define Stack       (1<<14)     /* Stack instruction (push/pop) */
120 #define GroupMask   (7<<15)     /* Opcode uses one of the group mechanisms */
121 #define Group       (1<<15)     /* Bits 3:5 of modrm byte extend opcode */
122 #define GroupDual   (2<<15)     /* Alternate decoding of mod == 3 */
123 #define Prefix      (3<<15)     /* Instruction varies with 66/f2/f3 prefix */
124 #define RMExt       (4<<15)     /* Opcode extension in ModRM r/m if mod == 3 */
125 #define Escape      (5<<15)     /* Escape to coprocessor instruction */
126 #define Sse         (1<<18)     /* SSE Vector instruction */
127 /* Generic ModRM decode. */
128 #define ModRM       (1<<19)
129 /* Destination is only written; never read. */
130 #define Mov         (1<<20)
131 /* Misc flags */
132 #define Prot        (1<<21) /* instruction generates #UD if not in prot-mode */
133 #define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */
134 #define NoAccess    (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
135 #define Op3264      (1<<24) /* Operand is 64b in long mode, 32b otherwise */
136 #define Undefined   (1<<25) /* No Such Instruction */
137 #define Lock        (1<<26) /* lock prefix is allowed for the instruction */
138 #define Priv        (1<<27) /* instruction generates #GP if current CPL != 0 */
139 #define No64	    (1<<28)
140 #define PageTable   (1 << 29)   /* instruction used to write page table */
141 #define NotImpl     (1 << 30)   /* instruction is not implemented */
142 /* Source 2 operand type */
143 #define Src2Shift   (31)
144 #define Src2None    (OpNone << Src2Shift)
145 #define Src2Mem     (OpMem << Src2Shift)
146 #define Src2CL      (OpCL << Src2Shift)
147 #define Src2ImmByte (OpImmByte << Src2Shift)
148 #define Src2One     (OpOne << Src2Shift)
149 #define Src2Imm     (OpImm << Src2Shift)
150 #define Src2ES      (OpES << Src2Shift)
151 #define Src2CS      (OpCS << Src2Shift)
152 #define Src2SS      (OpSS << Src2Shift)
153 #define Src2DS      (OpDS << Src2Shift)
154 #define Src2FS      (OpFS << Src2Shift)
155 #define Src2GS      (OpGS << Src2Shift)
156 #define Src2Mask    (OpMask << Src2Shift)
157 #define Mmx         ((u64)1 << 40)  /* MMX Vector instruction */
158 #define Aligned     ((u64)1 << 41)  /* Explicitly aligned (e.g. MOVDQA) */
159 #define Unaligned   ((u64)1 << 42)  /* Explicitly unaligned (e.g. MOVDQU) */
160 #define Avx         ((u64)1 << 43)  /* Advanced Vector Extensions */
161 #define Fastop      ((u64)1 << 44)  /* Use opcode::u.fastop */
162 #define NoWrite     ((u64)1 << 45)  /* No writeback */
163 #define SrcWrite    ((u64)1 << 46)  /* Write back src operand */
164 #define NoMod	    ((u64)1 << 47)  /* Mod field is ignored */
165 #define Intercept   ((u64)1 << 48)  /* Has valid intercept field */
166 #define CheckPerm   ((u64)1 << 49)  /* Has valid check_perm field */
167 #define NoBigReal   ((u64)1 << 50)  /* No big real mode */
168 #define PrivUD      ((u64)1 << 51)  /* #UD instead of #GP on CPL > 0 */
169 
170 #define DstXacc     (DstAccLo | SrcAccHi | SrcWrite)
171 
172 #define X2(x...) x, x
173 #define X3(x...) X2(x), x
174 #define X4(x...) X2(x), X2(x)
175 #define X5(x...) X4(x), x
176 #define X6(x...) X4(x), X2(x)
177 #define X7(x...) X4(x), X3(x)
178 #define X8(x...) X4(x), X4(x)
179 #define X16(x...) X8(x), X8(x)
180 
181 #define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
182 #define FASTOP_SIZE 8
183 
184 /*
185  * fastop functions have a special calling convention:
186  *
187  * dst:    rax        (in/out)
188  * src:    rdx        (in/out)
189  * src2:   rcx        (in)
190  * flags:  rflags     (in/out)
191  * ex:     rsi        (in:fastop pointer, out:zero if exception)
192  *
193  * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
194  * different operand sizes can be reached by calculation, rather than a jump
195  * table (which would be bigger than the code).
196  *
197  * fastop functions are declared as taking a never-defined fastop parameter,
198  * so they can't be called from C directly.
199  */
200 
201 struct fastop;
202 
203 struct opcode {
204 	u64 flags : 56;
205 	u64 intercept : 8;
206 	union {
207 		int (*execute)(struct x86_emulate_ctxt *ctxt);
208 		const struct opcode *group;
209 		const struct group_dual *gdual;
210 		const struct gprefix *gprefix;
211 		const struct escape *esc;
212 		void (*fastop)(struct fastop *fake);
213 	} u;
214 	int (*check_perm)(struct x86_emulate_ctxt *ctxt);
215 };
216 
217 struct group_dual {
218 	struct opcode mod012[8];
219 	struct opcode mod3[8];
220 };
221 
222 struct gprefix {
223 	struct opcode pfx_no;
224 	struct opcode pfx_66;
225 	struct opcode pfx_f2;
226 	struct opcode pfx_f3;
227 };
228 
229 struct escape {
230 	struct opcode op[8];
231 	struct opcode high[64];
232 };
233 
234 /* EFLAGS bit definitions. */
235 #define EFLG_ID (1<<21)
236 #define EFLG_VIP (1<<20)
237 #define EFLG_VIF (1<<19)
238 #define EFLG_AC (1<<18)
239 #define EFLG_VM (1<<17)
240 #define EFLG_RF (1<<16)
241 #define EFLG_IOPL (3<<12)
242 #define EFLG_NT (1<<14)
243 #define EFLG_OF (1<<11)
244 #define EFLG_DF (1<<10)
245 #define EFLG_IF (1<<9)
246 #define EFLG_TF (1<<8)
247 #define EFLG_SF (1<<7)
248 #define EFLG_ZF (1<<6)
249 #define EFLG_AF (1<<4)
250 #define EFLG_PF (1<<2)
251 #define EFLG_CF (1<<0)
252 
253 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
254 #define EFLG_RESERVED_ONE_MASK 2
255 
256 static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr)
257 {
258 	if (!(ctxt->regs_valid & (1 << nr))) {
259 		ctxt->regs_valid |= 1 << nr;
260 		ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr);
261 	}
262 	return ctxt->_regs[nr];
263 }
264 
265 static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr)
266 {
267 	ctxt->regs_valid |= 1 << nr;
268 	ctxt->regs_dirty |= 1 << nr;
269 	return &ctxt->_regs[nr];
270 }
271 
272 static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr)
273 {
274 	reg_read(ctxt, nr);
275 	return reg_write(ctxt, nr);
276 }
277 
278 static void writeback_registers(struct x86_emulate_ctxt *ctxt)
279 {
280 	unsigned reg;
281 
282 	for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16)
283 		ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]);
284 }
285 
286 static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
287 {
288 	ctxt->regs_dirty = 0;
289 	ctxt->regs_valid = 0;
290 }
291 
292 /*
293  * These EFLAGS bits are restored from saved value during emulation, and
294  * any changes are written back to the saved value after emulation.
295  */
296 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
297 
298 #ifdef CONFIG_X86_64
299 #define ON64(x) x
300 #else
301 #define ON64(x)
302 #endif
303 
304 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
305 
306 #define FOP_ALIGN ".align " __stringify(FASTOP_SIZE) " \n\t"
307 #define FOP_RET   "ret \n\t"
308 
309 #define FOP_START(op) \
310 	extern void em_##op(struct fastop *fake); \
311 	asm(".pushsection .text, \"ax\" \n\t" \
312 	    ".global em_" #op " \n\t" \
313             FOP_ALIGN \
314 	    "em_" #op ": \n\t"
315 
316 #define FOP_END \
317 	    ".popsection")
318 
319 #define FOPNOP() FOP_ALIGN FOP_RET
320 
321 #define FOP1E(op,  dst) \
322 	FOP_ALIGN "10: " #op " %" #dst " \n\t" FOP_RET
323 
324 #define FOP1EEX(op,  dst) \
325 	FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception)
326 
327 #define FASTOP1(op) \
328 	FOP_START(op) \
329 	FOP1E(op##b, al) \
330 	FOP1E(op##w, ax) \
331 	FOP1E(op##l, eax) \
332 	ON64(FOP1E(op##q, rax))	\
333 	FOP_END
334 
335 /* 1-operand, using src2 (for MUL/DIV r/m) */
336 #define FASTOP1SRC2(op, name) \
337 	FOP_START(name) \
338 	FOP1E(op, cl) \
339 	FOP1E(op, cx) \
340 	FOP1E(op, ecx) \
341 	ON64(FOP1E(op, rcx)) \
342 	FOP_END
343 
344 /* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */
345 #define FASTOP1SRC2EX(op, name) \
346 	FOP_START(name) \
347 	FOP1EEX(op, cl) \
348 	FOP1EEX(op, cx) \
349 	FOP1EEX(op, ecx) \
350 	ON64(FOP1EEX(op, rcx)) \
351 	FOP_END
352 
353 #define FOP2E(op,  dst, src)	   \
354 	FOP_ALIGN #op " %" #src ", %" #dst " \n\t" FOP_RET
355 
356 #define FASTOP2(op) \
357 	FOP_START(op) \
358 	FOP2E(op##b, al, dl) \
359 	FOP2E(op##w, ax, dx) \
360 	FOP2E(op##l, eax, edx) \
361 	ON64(FOP2E(op##q, rax, rdx)) \
362 	FOP_END
363 
364 /* 2 operand, word only */
365 #define FASTOP2W(op) \
366 	FOP_START(op) \
367 	FOPNOP() \
368 	FOP2E(op##w, ax, dx) \
369 	FOP2E(op##l, eax, edx) \
370 	ON64(FOP2E(op##q, rax, rdx)) \
371 	FOP_END
372 
373 /* 2 operand, src is CL */
374 #define FASTOP2CL(op) \
375 	FOP_START(op) \
376 	FOP2E(op##b, al, cl) \
377 	FOP2E(op##w, ax, cl) \
378 	FOP2E(op##l, eax, cl) \
379 	ON64(FOP2E(op##q, rax, cl)) \
380 	FOP_END
381 
382 #define FOP3E(op,  dst, src, src2) \
383 	FOP_ALIGN #op " %" #src2 ", %" #src ", %" #dst " \n\t" FOP_RET
384 
385 /* 3-operand, word-only, src2=cl */
386 #define FASTOP3WCL(op) \
387 	FOP_START(op) \
388 	FOPNOP() \
389 	FOP3E(op##w, ax, dx, cl) \
390 	FOP3E(op##l, eax, edx, cl) \
391 	ON64(FOP3E(op##q, rax, rdx, cl)) \
392 	FOP_END
393 
394 /* Special case for SETcc - 1 instruction per cc */
395 #define FOP_SETCC(op) ".align 4; " #op " %al; ret \n\t"
396 
397 asm(".global kvm_fastop_exception \n"
398     "kvm_fastop_exception: xor %esi, %esi; ret");
399 
400 FOP_START(setcc)
401 FOP_SETCC(seto)
402 FOP_SETCC(setno)
403 FOP_SETCC(setc)
404 FOP_SETCC(setnc)
405 FOP_SETCC(setz)
406 FOP_SETCC(setnz)
407 FOP_SETCC(setbe)
408 FOP_SETCC(setnbe)
409 FOP_SETCC(sets)
410 FOP_SETCC(setns)
411 FOP_SETCC(setp)
412 FOP_SETCC(setnp)
413 FOP_SETCC(setl)
414 FOP_SETCC(setnl)
415 FOP_SETCC(setle)
416 FOP_SETCC(setnle)
417 FOP_END;
418 
419 FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET
420 FOP_END;
421 
422 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
423 				    enum x86_intercept intercept,
424 				    enum x86_intercept_stage stage)
425 {
426 	struct x86_instruction_info info = {
427 		.intercept  = intercept,
428 		.rep_prefix = ctxt->rep_prefix,
429 		.modrm_mod  = ctxt->modrm_mod,
430 		.modrm_reg  = ctxt->modrm_reg,
431 		.modrm_rm   = ctxt->modrm_rm,
432 		.src_val    = ctxt->src.val64,
433 		.dst_val    = ctxt->dst.val64,
434 		.src_bytes  = ctxt->src.bytes,
435 		.dst_bytes  = ctxt->dst.bytes,
436 		.ad_bytes   = ctxt->ad_bytes,
437 		.next_rip   = ctxt->eip,
438 	};
439 
440 	return ctxt->ops->intercept(ctxt, &info, stage);
441 }
442 
443 static void assign_masked(ulong *dest, ulong src, ulong mask)
444 {
445 	*dest = (*dest & ~mask) | (src & mask);
446 }
447 
448 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
449 {
450 	return (1UL << (ctxt->ad_bytes << 3)) - 1;
451 }
452 
453 static ulong stack_mask(struct x86_emulate_ctxt *ctxt)
454 {
455 	u16 sel;
456 	struct desc_struct ss;
457 
458 	if (ctxt->mode == X86EMUL_MODE_PROT64)
459 		return ~0UL;
460 	ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS);
461 	return ~0U >> ((ss.d ^ 1) * 16);  /* d=0: 0xffff; d=1: 0xffffffff */
462 }
463 
464 static int stack_size(struct x86_emulate_ctxt *ctxt)
465 {
466 	return (__fls(stack_mask(ctxt)) + 1) >> 3;
467 }
468 
469 /* Access/update address held in a register, based on addressing mode. */
470 static inline unsigned long
471 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
472 {
473 	if (ctxt->ad_bytes == sizeof(unsigned long))
474 		return reg;
475 	else
476 		return reg & ad_mask(ctxt);
477 }
478 
479 static inline unsigned long
480 register_address(struct x86_emulate_ctxt *ctxt, unsigned long reg)
481 {
482 	return address_mask(ctxt, reg);
483 }
484 
485 static void masked_increment(ulong *reg, ulong mask, int inc)
486 {
487 	assign_masked(reg, *reg + inc, mask);
488 }
489 
490 static inline void
491 register_address_increment(struct x86_emulate_ctxt *ctxt, unsigned long *reg, int inc)
492 {
493 	ulong mask;
494 
495 	if (ctxt->ad_bytes == sizeof(unsigned long))
496 		mask = ~0UL;
497 	else
498 		mask = ad_mask(ctxt);
499 	masked_increment(reg, mask, inc);
500 }
501 
502 static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
503 {
504 	masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc);
505 }
506 
507 static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
508 {
509 	register_address_increment(ctxt, &ctxt->_eip, rel);
510 }
511 
512 static u32 desc_limit_scaled(struct desc_struct *desc)
513 {
514 	u32 limit = get_desc_limit(desc);
515 
516 	return desc->g ? (limit << 12) | 0xfff : limit;
517 }
518 
519 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
520 {
521 	if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
522 		return 0;
523 
524 	return ctxt->ops->get_cached_segment_base(ctxt, seg);
525 }
526 
527 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
528 			     u32 error, bool valid)
529 {
530 	WARN_ON(vec > 0x1f);
531 	ctxt->exception.vector = vec;
532 	ctxt->exception.error_code = error;
533 	ctxt->exception.error_code_valid = valid;
534 	return X86EMUL_PROPAGATE_FAULT;
535 }
536 
537 static int emulate_db(struct x86_emulate_ctxt *ctxt)
538 {
539 	return emulate_exception(ctxt, DB_VECTOR, 0, false);
540 }
541 
542 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
543 {
544 	return emulate_exception(ctxt, GP_VECTOR, err, true);
545 }
546 
547 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err)
548 {
549 	return emulate_exception(ctxt, SS_VECTOR, err, true);
550 }
551 
552 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
553 {
554 	return emulate_exception(ctxt, UD_VECTOR, 0, false);
555 }
556 
557 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
558 {
559 	return emulate_exception(ctxt, TS_VECTOR, err, true);
560 }
561 
562 static int emulate_de(struct x86_emulate_ctxt *ctxt)
563 {
564 	return emulate_exception(ctxt, DE_VECTOR, 0, false);
565 }
566 
567 static int emulate_nm(struct x86_emulate_ctxt *ctxt)
568 {
569 	return emulate_exception(ctxt, NM_VECTOR, 0, false);
570 }
571 
572 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
573 {
574 	u16 selector;
575 	struct desc_struct desc;
576 
577 	ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg);
578 	return selector;
579 }
580 
581 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
582 				 unsigned seg)
583 {
584 	u16 dummy;
585 	u32 base3;
586 	struct desc_struct desc;
587 
588 	ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg);
589 	ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg);
590 }
591 
592 /*
593  * x86 defines three classes of vector instructions: explicitly
594  * aligned, explicitly unaligned, and the rest, which change behaviour
595  * depending on whether they're AVX encoded or not.
596  *
597  * Also included is CMPXCHG16B which is not a vector instruction, yet it is
598  * subject to the same check.
599  */
600 static bool insn_aligned(struct x86_emulate_ctxt *ctxt, unsigned size)
601 {
602 	if (likely(size < 16))
603 		return false;
604 
605 	if (ctxt->d & Aligned)
606 		return true;
607 	else if (ctxt->d & Unaligned)
608 		return false;
609 	else if (ctxt->d & Avx)
610 		return false;
611 	else
612 		return true;
613 }
614 
615 static int __linearize(struct x86_emulate_ctxt *ctxt,
616 		     struct segmented_address addr,
617 		     unsigned size, bool write, bool fetch,
618 		     ulong *linear)
619 {
620 	struct desc_struct desc;
621 	bool usable;
622 	ulong la;
623 	u32 lim;
624 	u16 sel;
625 	unsigned cpl;
626 
627 	la = seg_base(ctxt, addr.seg) + addr.ea;
628 	switch (ctxt->mode) {
629 	case X86EMUL_MODE_PROT64:
630 		if (((signed long)la << 16) >> 16 != la)
631 			return emulate_gp(ctxt, 0);
632 		break;
633 	default:
634 		usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
635 						addr.seg);
636 		if (!usable)
637 			goto bad;
638 		/* code segment in protected mode or read-only data segment */
639 		if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8))
640 					|| !(desc.type & 2)) && write)
641 			goto bad;
642 		/* unreadable code segment */
643 		if (!fetch && (desc.type & 8) && !(desc.type & 2))
644 			goto bad;
645 		lim = desc_limit_scaled(&desc);
646 		if ((ctxt->mode == X86EMUL_MODE_REAL) && !fetch &&
647 		    (ctxt->d & NoBigReal)) {
648 			/* la is between zero and 0xffff */
649 			if (la > 0xffff || (u32)(la + size - 1) > 0xffff)
650 				goto bad;
651 		} else if ((desc.type & 8) || !(desc.type & 4)) {
652 			/* expand-up segment */
653 			if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
654 				goto bad;
655 		} else {
656 			/* expand-down segment */
657 			if (addr.ea <= lim || (u32)(addr.ea + size - 1) <= lim)
658 				goto bad;
659 			lim = desc.d ? 0xffffffff : 0xffff;
660 			if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
661 				goto bad;
662 		}
663 		cpl = ctxt->ops->cpl(ctxt);
664 		if (!(desc.type & 8)) {
665 			/* data segment */
666 			if (cpl > desc.dpl)
667 				goto bad;
668 		} else if ((desc.type & 8) && !(desc.type & 4)) {
669 			/* nonconforming code segment */
670 			if (cpl != desc.dpl)
671 				goto bad;
672 		} else if ((desc.type & 8) && (desc.type & 4)) {
673 			/* conforming code segment */
674 			if (cpl < desc.dpl)
675 				goto bad;
676 		}
677 		break;
678 	}
679 	if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : ctxt->ad_bytes != 8)
680 		la &= (u32)-1;
681 	if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
682 		return emulate_gp(ctxt, 0);
683 	*linear = la;
684 	return X86EMUL_CONTINUE;
685 bad:
686 	if (addr.seg == VCPU_SREG_SS)
687 		return emulate_ss(ctxt, sel);
688 	else
689 		return emulate_gp(ctxt, sel);
690 }
691 
692 static int linearize(struct x86_emulate_ctxt *ctxt,
693 		     struct segmented_address addr,
694 		     unsigned size, bool write,
695 		     ulong *linear)
696 {
697 	return __linearize(ctxt, addr, size, write, false, linear);
698 }
699 
700 
701 static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
702 			      struct segmented_address addr,
703 			      void *data,
704 			      unsigned size)
705 {
706 	int rc;
707 	ulong linear;
708 
709 	rc = linearize(ctxt, addr, size, false, &linear);
710 	if (rc != X86EMUL_CONTINUE)
711 		return rc;
712 	return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
713 }
714 
715 /*
716  * Prefetch the remaining bytes of the instruction without crossing page
717  * boundary if they are not in fetch_cache yet.
718  */
719 static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
720 {
721 	int rc;
722 	unsigned size;
723 	unsigned long linear;
724 	int cur_size = ctxt->fetch.end - ctxt->fetch.data;
725 	struct segmented_address addr = { .seg = VCPU_SREG_CS,
726 					   .ea = ctxt->eip + cur_size };
727 
728 	size = 15UL ^ cur_size;
729 	rc = __linearize(ctxt, addr, size, false, true, &linear);
730 	if (unlikely(rc != X86EMUL_CONTINUE))
731 		return rc;
732 
733 	size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear));
734 
735 	/*
736 	 * One instruction can only straddle two pages,
737 	 * and one has been loaded at the beginning of
738 	 * x86_decode_insn.  So, if not enough bytes
739 	 * still, we must have hit the 15-byte boundary.
740 	 */
741 	if (unlikely(size < op_size))
742 		return X86EMUL_UNHANDLEABLE;
743 	rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end,
744 			      size, &ctxt->exception);
745 	if (unlikely(rc != X86EMUL_CONTINUE))
746 		return rc;
747 	ctxt->fetch.end += size;
748 	return X86EMUL_CONTINUE;
749 }
750 
751 static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt,
752 					       unsigned size)
753 {
754 	if (unlikely(ctxt->fetch.end - ctxt->fetch.ptr < size))
755 		return __do_insn_fetch_bytes(ctxt, size);
756 	else
757 		return X86EMUL_CONTINUE;
758 }
759 
760 /* Fetch next part of the instruction being emulated. */
761 #define insn_fetch(_type, _ctxt)					\
762 ({	_type _x;							\
763 									\
764 	rc = do_insn_fetch_bytes(_ctxt, sizeof(_type));			\
765 	if (rc != X86EMUL_CONTINUE)					\
766 		goto done;						\
767 	ctxt->_eip += sizeof(_type);					\
768 	_x = *(_type __aligned(1) *) ctxt->fetch.ptr;			\
769 	ctxt->fetch.ptr += sizeof(_type);				\
770 	_x;								\
771 })
772 
773 #define insn_fetch_arr(_arr, _size, _ctxt)				\
774 ({									\
775 	rc = do_insn_fetch_bytes(_ctxt, _size);				\
776 	if (rc != X86EMUL_CONTINUE)					\
777 		goto done;						\
778 	ctxt->_eip += (_size);						\
779 	memcpy(_arr, ctxt->fetch.ptr, _size);				\
780 	ctxt->fetch.ptr += (_size);					\
781 })
782 
783 /*
784  * Given the 'reg' portion of a ModRM byte, and a register block, return a
785  * pointer into the block that addresses the relevant register.
786  * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
787  */
788 static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg,
789 			     int byteop)
790 {
791 	void *p;
792 	int highbyte_regs = (ctxt->rex_prefix == 0) && byteop;
793 
794 	if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
795 		p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1;
796 	else
797 		p = reg_rmw(ctxt, modrm_reg);
798 	return p;
799 }
800 
801 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
802 			   struct segmented_address addr,
803 			   u16 *size, unsigned long *address, int op_bytes)
804 {
805 	int rc;
806 
807 	if (op_bytes == 2)
808 		op_bytes = 3;
809 	*address = 0;
810 	rc = segmented_read_std(ctxt, addr, size, 2);
811 	if (rc != X86EMUL_CONTINUE)
812 		return rc;
813 	addr.ea += 2;
814 	rc = segmented_read_std(ctxt, addr, address, op_bytes);
815 	return rc;
816 }
817 
818 FASTOP2(add);
819 FASTOP2(or);
820 FASTOP2(adc);
821 FASTOP2(sbb);
822 FASTOP2(and);
823 FASTOP2(sub);
824 FASTOP2(xor);
825 FASTOP2(cmp);
826 FASTOP2(test);
827 
828 FASTOP1SRC2(mul, mul_ex);
829 FASTOP1SRC2(imul, imul_ex);
830 FASTOP1SRC2EX(div, div_ex);
831 FASTOP1SRC2EX(idiv, idiv_ex);
832 
833 FASTOP3WCL(shld);
834 FASTOP3WCL(shrd);
835 
836 FASTOP2W(imul);
837 
838 FASTOP1(not);
839 FASTOP1(neg);
840 FASTOP1(inc);
841 FASTOP1(dec);
842 
843 FASTOP2CL(rol);
844 FASTOP2CL(ror);
845 FASTOP2CL(rcl);
846 FASTOP2CL(rcr);
847 FASTOP2CL(shl);
848 FASTOP2CL(shr);
849 FASTOP2CL(sar);
850 
851 FASTOP2W(bsf);
852 FASTOP2W(bsr);
853 FASTOP2W(bt);
854 FASTOP2W(bts);
855 FASTOP2W(btr);
856 FASTOP2W(btc);
857 
858 FASTOP2(xadd);
859 
860 static u8 test_cc(unsigned int condition, unsigned long flags)
861 {
862 	u8 rc;
863 	void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
864 
865 	flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
866 	asm("push %[flags]; popf; call *%[fastop]"
867 	    : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags));
868 	return rc;
869 }
870 
871 static void fetch_register_operand(struct operand *op)
872 {
873 	switch (op->bytes) {
874 	case 1:
875 		op->val = *(u8 *)op->addr.reg;
876 		break;
877 	case 2:
878 		op->val = *(u16 *)op->addr.reg;
879 		break;
880 	case 4:
881 		op->val = *(u32 *)op->addr.reg;
882 		break;
883 	case 8:
884 		op->val = *(u64 *)op->addr.reg;
885 		break;
886 	}
887 }
888 
889 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
890 {
891 	ctxt->ops->get_fpu(ctxt);
892 	switch (reg) {
893 	case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
894 	case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
895 	case 2: asm("movdqa %%xmm2, %0" : "=m"(*data)); break;
896 	case 3: asm("movdqa %%xmm3, %0" : "=m"(*data)); break;
897 	case 4: asm("movdqa %%xmm4, %0" : "=m"(*data)); break;
898 	case 5: asm("movdqa %%xmm5, %0" : "=m"(*data)); break;
899 	case 6: asm("movdqa %%xmm6, %0" : "=m"(*data)); break;
900 	case 7: asm("movdqa %%xmm7, %0" : "=m"(*data)); break;
901 #ifdef CONFIG_X86_64
902 	case 8: asm("movdqa %%xmm8, %0" : "=m"(*data)); break;
903 	case 9: asm("movdqa %%xmm9, %0" : "=m"(*data)); break;
904 	case 10: asm("movdqa %%xmm10, %0" : "=m"(*data)); break;
905 	case 11: asm("movdqa %%xmm11, %0" : "=m"(*data)); break;
906 	case 12: asm("movdqa %%xmm12, %0" : "=m"(*data)); break;
907 	case 13: asm("movdqa %%xmm13, %0" : "=m"(*data)); break;
908 	case 14: asm("movdqa %%xmm14, %0" : "=m"(*data)); break;
909 	case 15: asm("movdqa %%xmm15, %0" : "=m"(*data)); break;
910 #endif
911 	default: BUG();
912 	}
913 	ctxt->ops->put_fpu(ctxt);
914 }
915 
916 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
917 			  int reg)
918 {
919 	ctxt->ops->get_fpu(ctxt);
920 	switch (reg) {
921 	case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
922 	case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
923 	case 2: asm("movdqa %0, %%xmm2" : : "m"(*data)); break;
924 	case 3: asm("movdqa %0, %%xmm3" : : "m"(*data)); break;
925 	case 4: asm("movdqa %0, %%xmm4" : : "m"(*data)); break;
926 	case 5: asm("movdqa %0, %%xmm5" : : "m"(*data)); break;
927 	case 6: asm("movdqa %0, %%xmm6" : : "m"(*data)); break;
928 	case 7: asm("movdqa %0, %%xmm7" : : "m"(*data)); break;
929 #ifdef CONFIG_X86_64
930 	case 8: asm("movdqa %0, %%xmm8" : : "m"(*data)); break;
931 	case 9: asm("movdqa %0, %%xmm9" : : "m"(*data)); break;
932 	case 10: asm("movdqa %0, %%xmm10" : : "m"(*data)); break;
933 	case 11: asm("movdqa %0, %%xmm11" : : "m"(*data)); break;
934 	case 12: asm("movdqa %0, %%xmm12" : : "m"(*data)); break;
935 	case 13: asm("movdqa %0, %%xmm13" : : "m"(*data)); break;
936 	case 14: asm("movdqa %0, %%xmm14" : : "m"(*data)); break;
937 	case 15: asm("movdqa %0, %%xmm15" : : "m"(*data)); break;
938 #endif
939 	default: BUG();
940 	}
941 	ctxt->ops->put_fpu(ctxt);
942 }
943 
944 static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
945 {
946 	ctxt->ops->get_fpu(ctxt);
947 	switch (reg) {
948 	case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
949 	case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
950 	case 2: asm("movq %%mm2, %0" : "=m"(*data)); break;
951 	case 3: asm("movq %%mm3, %0" : "=m"(*data)); break;
952 	case 4: asm("movq %%mm4, %0" : "=m"(*data)); break;
953 	case 5: asm("movq %%mm5, %0" : "=m"(*data)); break;
954 	case 6: asm("movq %%mm6, %0" : "=m"(*data)); break;
955 	case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
956 	default: BUG();
957 	}
958 	ctxt->ops->put_fpu(ctxt);
959 }
960 
961 static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
962 {
963 	ctxt->ops->get_fpu(ctxt);
964 	switch (reg) {
965 	case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
966 	case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
967 	case 2: asm("movq %0, %%mm2" : : "m"(*data)); break;
968 	case 3: asm("movq %0, %%mm3" : : "m"(*data)); break;
969 	case 4: asm("movq %0, %%mm4" : : "m"(*data)); break;
970 	case 5: asm("movq %0, %%mm5" : : "m"(*data)); break;
971 	case 6: asm("movq %0, %%mm6" : : "m"(*data)); break;
972 	case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
973 	default: BUG();
974 	}
975 	ctxt->ops->put_fpu(ctxt);
976 }
977 
978 static int em_fninit(struct x86_emulate_ctxt *ctxt)
979 {
980 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
981 		return emulate_nm(ctxt);
982 
983 	ctxt->ops->get_fpu(ctxt);
984 	asm volatile("fninit");
985 	ctxt->ops->put_fpu(ctxt);
986 	return X86EMUL_CONTINUE;
987 }
988 
989 static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
990 {
991 	u16 fcw;
992 
993 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
994 		return emulate_nm(ctxt);
995 
996 	ctxt->ops->get_fpu(ctxt);
997 	asm volatile("fnstcw %0": "+m"(fcw));
998 	ctxt->ops->put_fpu(ctxt);
999 
1000 	/* force 2 byte destination */
1001 	ctxt->dst.bytes = 2;
1002 	ctxt->dst.val = fcw;
1003 
1004 	return X86EMUL_CONTINUE;
1005 }
1006 
1007 static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
1008 {
1009 	u16 fsw;
1010 
1011 	if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1012 		return emulate_nm(ctxt);
1013 
1014 	ctxt->ops->get_fpu(ctxt);
1015 	asm volatile("fnstsw %0": "+m"(fsw));
1016 	ctxt->ops->put_fpu(ctxt);
1017 
1018 	/* force 2 byte destination */
1019 	ctxt->dst.bytes = 2;
1020 	ctxt->dst.val = fsw;
1021 
1022 	return X86EMUL_CONTINUE;
1023 }
1024 
1025 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
1026 				    struct operand *op)
1027 {
1028 	unsigned reg = ctxt->modrm_reg;
1029 
1030 	if (!(ctxt->d & ModRM))
1031 		reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
1032 
1033 	if (ctxt->d & Sse) {
1034 		op->type = OP_XMM;
1035 		op->bytes = 16;
1036 		op->addr.xmm = reg;
1037 		read_sse_reg(ctxt, &op->vec_val, reg);
1038 		return;
1039 	}
1040 	if (ctxt->d & Mmx) {
1041 		reg &= 7;
1042 		op->type = OP_MM;
1043 		op->bytes = 8;
1044 		op->addr.mm = reg;
1045 		return;
1046 	}
1047 
1048 	op->type = OP_REG;
1049 	op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1050 	op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp);
1051 
1052 	fetch_register_operand(op);
1053 	op->orig_val = op->val;
1054 }
1055 
1056 static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg)
1057 {
1058 	if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP)
1059 		ctxt->modrm_seg = VCPU_SREG_SS;
1060 }
1061 
1062 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
1063 			struct operand *op)
1064 {
1065 	u8 sib;
1066 	int index_reg, base_reg, scale;
1067 	int rc = X86EMUL_CONTINUE;
1068 	ulong modrm_ea = 0;
1069 
1070 	ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */
1071 	index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */
1072 	base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */
1073 
1074 	ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6;
1075 	ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3;
1076 	ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07);
1077 	ctxt->modrm_seg = VCPU_SREG_DS;
1078 
1079 	if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) {
1080 		op->type = OP_REG;
1081 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1082 		op->addr.reg = decode_register(ctxt, ctxt->modrm_rm,
1083 				ctxt->d & ByteOp);
1084 		if (ctxt->d & Sse) {
1085 			op->type = OP_XMM;
1086 			op->bytes = 16;
1087 			op->addr.xmm = ctxt->modrm_rm;
1088 			read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
1089 			return rc;
1090 		}
1091 		if (ctxt->d & Mmx) {
1092 			op->type = OP_MM;
1093 			op->bytes = 8;
1094 			op->addr.mm = ctxt->modrm_rm & 7;
1095 			return rc;
1096 		}
1097 		fetch_register_operand(op);
1098 		return rc;
1099 	}
1100 
1101 	op->type = OP_MEM;
1102 
1103 	if (ctxt->ad_bytes == 2) {
1104 		unsigned bx = reg_read(ctxt, VCPU_REGS_RBX);
1105 		unsigned bp = reg_read(ctxt, VCPU_REGS_RBP);
1106 		unsigned si = reg_read(ctxt, VCPU_REGS_RSI);
1107 		unsigned di = reg_read(ctxt, VCPU_REGS_RDI);
1108 
1109 		/* 16-bit ModR/M decode. */
1110 		switch (ctxt->modrm_mod) {
1111 		case 0:
1112 			if (ctxt->modrm_rm == 6)
1113 				modrm_ea += insn_fetch(u16, ctxt);
1114 			break;
1115 		case 1:
1116 			modrm_ea += insn_fetch(s8, ctxt);
1117 			break;
1118 		case 2:
1119 			modrm_ea += insn_fetch(u16, ctxt);
1120 			break;
1121 		}
1122 		switch (ctxt->modrm_rm) {
1123 		case 0:
1124 			modrm_ea += bx + si;
1125 			break;
1126 		case 1:
1127 			modrm_ea += bx + di;
1128 			break;
1129 		case 2:
1130 			modrm_ea += bp + si;
1131 			break;
1132 		case 3:
1133 			modrm_ea += bp + di;
1134 			break;
1135 		case 4:
1136 			modrm_ea += si;
1137 			break;
1138 		case 5:
1139 			modrm_ea += di;
1140 			break;
1141 		case 6:
1142 			if (ctxt->modrm_mod != 0)
1143 				modrm_ea += bp;
1144 			break;
1145 		case 7:
1146 			modrm_ea += bx;
1147 			break;
1148 		}
1149 		if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 ||
1150 		    (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0))
1151 			ctxt->modrm_seg = VCPU_SREG_SS;
1152 		modrm_ea = (u16)modrm_ea;
1153 	} else {
1154 		/* 32/64-bit ModR/M decode. */
1155 		if ((ctxt->modrm_rm & 7) == 4) {
1156 			sib = insn_fetch(u8, ctxt);
1157 			index_reg |= (sib >> 3) & 7;
1158 			base_reg |= sib & 7;
1159 			scale = sib >> 6;
1160 
1161 			if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0)
1162 				modrm_ea += insn_fetch(s32, ctxt);
1163 			else {
1164 				modrm_ea += reg_read(ctxt, base_reg);
1165 				adjust_modrm_seg(ctxt, base_reg);
1166 			}
1167 			if (index_reg != 4)
1168 				modrm_ea += reg_read(ctxt, index_reg) << scale;
1169 		} else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) {
1170 			if (ctxt->mode == X86EMUL_MODE_PROT64)
1171 				ctxt->rip_relative = 1;
1172 		} else {
1173 			base_reg = ctxt->modrm_rm;
1174 			modrm_ea += reg_read(ctxt, base_reg);
1175 			adjust_modrm_seg(ctxt, base_reg);
1176 		}
1177 		switch (ctxt->modrm_mod) {
1178 		case 0:
1179 			if (ctxt->modrm_rm == 5)
1180 				modrm_ea += insn_fetch(s32, ctxt);
1181 			break;
1182 		case 1:
1183 			modrm_ea += insn_fetch(s8, ctxt);
1184 			break;
1185 		case 2:
1186 			modrm_ea += insn_fetch(s32, ctxt);
1187 			break;
1188 		}
1189 	}
1190 	op->addr.mem.ea = modrm_ea;
1191 	if (ctxt->ad_bytes != 8)
1192 		ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
1193 
1194 done:
1195 	return rc;
1196 }
1197 
1198 static int decode_abs(struct x86_emulate_ctxt *ctxt,
1199 		      struct operand *op)
1200 {
1201 	int rc = X86EMUL_CONTINUE;
1202 
1203 	op->type = OP_MEM;
1204 	switch (ctxt->ad_bytes) {
1205 	case 2:
1206 		op->addr.mem.ea = insn_fetch(u16, ctxt);
1207 		break;
1208 	case 4:
1209 		op->addr.mem.ea = insn_fetch(u32, ctxt);
1210 		break;
1211 	case 8:
1212 		op->addr.mem.ea = insn_fetch(u64, ctxt);
1213 		break;
1214 	}
1215 done:
1216 	return rc;
1217 }
1218 
1219 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt)
1220 {
1221 	long sv = 0, mask;
1222 
1223 	if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) {
1224 		mask = ~((long)ctxt->dst.bytes * 8 - 1);
1225 
1226 		if (ctxt->src.bytes == 2)
1227 			sv = (s16)ctxt->src.val & (s16)mask;
1228 		else if (ctxt->src.bytes == 4)
1229 			sv = (s32)ctxt->src.val & (s32)mask;
1230 		else
1231 			sv = (s64)ctxt->src.val & (s64)mask;
1232 
1233 		ctxt->dst.addr.mem.ea += (sv >> 3);
1234 	}
1235 
1236 	/* only subword offset */
1237 	ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
1238 }
1239 
1240 static int read_emulated(struct x86_emulate_ctxt *ctxt,
1241 			 unsigned long addr, void *dest, unsigned size)
1242 {
1243 	int rc;
1244 	struct read_cache *mc = &ctxt->mem_read;
1245 
1246 	if (mc->pos < mc->end)
1247 		goto read_cached;
1248 
1249 	WARN_ON((mc->end + size) >= sizeof(mc->data));
1250 
1251 	rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size,
1252 				      &ctxt->exception);
1253 	if (rc != X86EMUL_CONTINUE)
1254 		return rc;
1255 
1256 	mc->end += size;
1257 
1258 read_cached:
1259 	memcpy(dest, mc->data + mc->pos, size);
1260 	mc->pos += size;
1261 	return X86EMUL_CONTINUE;
1262 }
1263 
1264 static int segmented_read(struct x86_emulate_ctxt *ctxt,
1265 			  struct segmented_address addr,
1266 			  void *data,
1267 			  unsigned size)
1268 {
1269 	int rc;
1270 	ulong linear;
1271 
1272 	rc = linearize(ctxt, addr, size, false, &linear);
1273 	if (rc != X86EMUL_CONTINUE)
1274 		return rc;
1275 	return read_emulated(ctxt, linear, data, size);
1276 }
1277 
1278 static int segmented_write(struct x86_emulate_ctxt *ctxt,
1279 			   struct segmented_address addr,
1280 			   const void *data,
1281 			   unsigned size)
1282 {
1283 	int rc;
1284 	ulong linear;
1285 
1286 	rc = linearize(ctxt, addr, size, true, &linear);
1287 	if (rc != X86EMUL_CONTINUE)
1288 		return rc;
1289 	return ctxt->ops->write_emulated(ctxt, linear, data, size,
1290 					 &ctxt->exception);
1291 }
1292 
1293 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
1294 			     struct segmented_address addr,
1295 			     const void *orig_data, const void *data,
1296 			     unsigned size)
1297 {
1298 	int rc;
1299 	ulong linear;
1300 
1301 	rc = linearize(ctxt, addr, size, true, &linear);
1302 	if (rc != X86EMUL_CONTINUE)
1303 		return rc;
1304 	return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data,
1305 					   size, &ctxt->exception);
1306 }
1307 
1308 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1309 			   unsigned int size, unsigned short port,
1310 			   void *dest)
1311 {
1312 	struct read_cache *rc = &ctxt->io_read;
1313 
1314 	if (rc->pos == rc->end) { /* refill pio read ahead */
1315 		unsigned int in_page, n;
1316 		unsigned int count = ctxt->rep_prefix ?
1317 			address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1;
1318 		in_page = (ctxt->eflags & EFLG_DF) ?
1319 			offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) :
1320 			PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI));
1321 		n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count);
1322 		if (n == 0)
1323 			n = 1;
1324 		rc->pos = rc->end = 0;
1325 		if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n))
1326 			return 0;
1327 		rc->end = n * size;
1328 	}
1329 
1330 	if (ctxt->rep_prefix && (ctxt->d & String) &&
1331 	    !(ctxt->eflags & EFLG_DF)) {
1332 		ctxt->dst.data = rc->data + rc->pos;
1333 		ctxt->dst.type = OP_MEM_STR;
1334 		ctxt->dst.count = (rc->end - rc->pos) / size;
1335 		rc->pos = rc->end;
1336 	} else {
1337 		memcpy(dest, rc->data + rc->pos, size);
1338 		rc->pos += size;
1339 	}
1340 	return 1;
1341 }
1342 
1343 static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
1344 				     u16 index, struct desc_struct *desc)
1345 {
1346 	struct desc_ptr dt;
1347 	ulong addr;
1348 
1349 	ctxt->ops->get_idt(ctxt, &dt);
1350 
1351 	if (dt.size < index * 8 + 7)
1352 		return emulate_gp(ctxt, index << 3 | 0x2);
1353 
1354 	addr = dt.address + index * 8;
1355 	return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1356 				   &ctxt->exception);
1357 }
1358 
1359 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1360 				     u16 selector, struct desc_ptr *dt)
1361 {
1362 	const struct x86_emulate_ops *ops = ctxt->ops;
1363 	u32 base3 = 0;
1364 
1365 	if (selector & 1 << 2) {
1366 		struct desc_struct desc;
1367 		u16 sel;
1368 
1369 		memset (dt, 0, sizeof *dt);
1370 		if (!ops->get_segment(ctxt, &sel, &desc, &base3,
1371 				      VCPU_SREG_LDTR))
1372 			return;
1373 
1374 		dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1375 		dt->address = get_desc_base(&desc) | ((u64)base3 << 32);
1376 	} else
1377 		ops->get_gdt(ctxt, dt);
1378 }
1379 
1380 /* allowed just for 8 bytes segments */
1381 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1382 				   u16 selector, struct desc_struct *desc,
1383 				   ulong *desc_addr_p)
1384 {
1385 	struct desc_ptr dt;
1386 	u16 index = selector >> 3;
1387 	ulong addr;
1388 
1389 	get_descriptor_table_ptr(ctxt, selector, &dt);
1390 
1391 	if (dt.size < index * 8 + 7)
1392 		return emulate_gp(ctxt, selector & 0xfffc);
1393 
1394 	*desc_addr_p = addr = dt.address + index * 8;
1395 	return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1396 				   &ctxt->exception);
1397 }
1398 
1399 /* allowed just for 8 bytes segments */
1400 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1401 				    u16 selector, struct desc_struct *desc)
1402 {
1403 	struct desc_ptr dt;
1404 	u16 index = selector >> 3;
1405 	ulong addr;
1406 
1407 	get_descriptor_table_ptr(ctxt, selector, &dt);
1408 
1409 	if (dt.size < index * 8 + 7)
1410 		return emulate_gp(ctxt, selector & 0xfffc);
1411 
1412 	addr = dt.address + index * 8;
1413 	return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
1414 				    &ctxt->exception);
1415 }
1416 
1417 /* Does not support long mode */
1418 static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1419 				     u16 selector, int seg, u8 cpl, bool in_task_switch)
1420 {
1421 	struct desc_struct seg_desc, old_desc;
1422 	u8 dpl, rpl;
1423 	unsigned err_vec = GP_VECTOR;
1424 	u32 err_code = 0;
1425 	bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1426 	ulong desc_addr;
1427 	int ret;
1428 	u16 dummy;
1429 	u32 base3 = 0;
1430 
1431 	memset(&seg_desc, 0, sizeof seg_desc);
1432 
1433 	if (ctxt->mode == X86EMUL_MODE_REAL) {
1434 		/* set real mode segment descriptor (keep limit etc. for
1435 		 * unreal mode) */
1436 		ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg);
1437 		set_desc_base(&seg_desc, selector << 4);
1438 		goto load;
1439 	} else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) {
1440 		/* VM86 needs a clean new segment descriptor */
1441 		set_desc_base(&seg_desc, selector << 4);
1442 		set_desc_limit(&seg_desc, 0xffff);
1443 		seg_desc.type = 3;
1444 		seg_desc.p = 1;
1445 		seg_desc.s = 1;
1446 		seg_desc.dpl = 3;
1447 		goto load;
1448 	}
1449 
1450 	rpl = selector & 3;
1451 
1452 	/* NULL selector is not valid for TR, CS and SS (except for long mode) */
1453 	if ((seg == VCPU_SREG_CS
1454 	     || (seg == VCPU_SREG_SS
1455 		 && (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl))
1456 	     || seg == VCPU_SREG_TR)
1457 	    && null_selector)
1458 		goto exception;
1459 
1460 	/* TR should be in GDT only */
1461 	if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1462 		goto exception;
1463 
1464 	if (null_selector) /* for NULL selector skip all following checks */
1465 		goto load;
1466 
1467 	ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr);
1468 	if (ret != X86EMUL_CONTINUE)
1469 		return ret;
1470 
1471 	err_code = selector & 0xfffc;
1472 	err_vec = in_task_switch ? TS_VECTOR : GP_VECTOR;
1473 
1474 	/* can't load system descriptor into segment selector */
1475 	if (seg <= VCPU_SREG_GS && !seg_desc.s)
1476 		goto exception;
1477 
1478 	if (!seg_desc.p) {
1479 		err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1480 		goto exception;
1481 	}
1482 
1483 	dpl = seg_desc.dpl;
1484 
1485 	switch (seg) {
1486 	case VCPU_SREG_SS:
1487 		/*
1488 		 * segment is not a writable data segment or segment
1489 		 * selector's RPL != CPL or segment selector's RPL != CPL
1490 		 */
1491 		if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1492 			goto exception;
1493 		break;
1494 	case VCPU_SREG_CS:
1495 		if (!(seg_desc.type & 8))
1496 			goto exception;
1497 
1498 		if (seg_desc.type & 4) {
1499 			/* conforming */
1500 			if (dpl > cpl)
1501 				goto exception;
1502 		} else {
1503 			/* nonconforming */
1504 			if (rpl > cpl || dpl != cpl)
1505 				goto exception;
1506 		}
1507 		/* in long-mode d/b must be clear if l is set */
1508 		if (seg_desc.d && seg_desc.l) {
1509 			u64 efer = 0;
1510 
1511 			ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
1512 			if (efer & EFER_LMA)
1513 				goto exception;
1514 		}
1515 
1516 		/* CS(RPL) <- CPL */
1517 		selector = (selector & 0xfffc) | cpl;
1518 		break;
1519 	case VCPU_SREG_TR:
1520 		if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1521 			goto exception;
1522 		old_desc = seg_desc;
1523 		seg_desc.type |= 2; /* busy */
1524 		ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc,
1525 						  sizeof(seg_desc), &ctxt->exception);
1526 		if (ret != X86EMUL_CONTINUE)
1527 			return ret;
1528 		break;
1529 	case VCPU_SREG_LDTR:
1530 		if (seg_desc.s || seg_desc.type != 2)
1531 			goto exception;
1532 		break;
1533 	default: /*  DS, ES, FS, or GS */
1534 		/*
1535 		 * segment is not a data or readable code segment or
1536 		 * ((segment is a data or nonconforming code segment)
1537 		 * and (both RPL and CPL > DPL))
1538 		 */
1539 		if ((seg_desc.type & 0xa) == 0x8 ||
1540 		    (((seg_desc.type & 0xc) != 0xc) &&
1541 		     (rpl > dpl && cpl > dpl)))
1542 			goto exception;
1543 		break;
1544 	}
1545 
1546 	if (seg_desc.s) {
1547 		/* mark segment as accessed */
1548 		seg_desc.type |= 1;
1549 		ret = write_segment_descriptor(ctxt, selector, &seg_desc);
1550 		if (ret != X86EMUL_CONTINUE)
1551 			return ret;
1552 	} else if (ctxt->mode == X86EMUL_MODE_PROT64) {
1553 		ret = ctxt->ops->read_std(ctxt, desc_addr+8, &base3,
1554 				sizeof(base3), &ctxt->exception);
1555 		if (ret != X86EMUL_CONTINUE)
1556 			return ret;
1557 	}
1558 load:
1559 	ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg);
1560 	return X86EMUL_CONTINUE;
1561 exception:
1562 	return emulate_exception(ctxt, err_vec, err_code, true);
1563 }
1564 
1565 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1566 				   u16 selector, int seg)
1567 {
1568 	u8 cpl = ctxt->ops->cpl(ctxt);
1569 	return __load_segment_descriptor(ctxt, selector, seg, cpl, false);
1570 }
1571 
1572 static void write_register_operand(struct operand *op)
1573 {
1574 	/* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1575 	switch (op->bytes) {
1576 	case 1:
1577 		*(u8 *)op->addr.reg = (u8)op->val;
1578 		break;
1579 	case 2:
1580 		*(u16 *)op->addr.reg = (u16)op->val;
1581 		break;
1582 	case 4:
1583 		*op->addr.reg = (u32)op->val;
1584 		break;	/* 64b: zero-extend */
1585 	case 8:
1586 		*op->addr.reg = op->val;
1587 		break;
1588 	}
1589 }
1590 
1591 static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
1592 {
1593 	switch (op->type) {
1594 	case OP_REG:
1595 		write_register_operand(op);
1596 		break;
1597 	case OP_MEM:
1598 		if (ctxt->lock_prefix)
1599 			return segmented_cmpxchg(ctxt,
1600 						 op->addr.mem,
1601 						 &op->orig_val,
1602 						 &op->val,
1603 						 op->bytes);
1604 		else
1605 			return segmented_write(ctxt,
1606 					       op->addr.mem,
1607 					       &op->val,
1608 					       op->bytes);
1609 		break;
1610 	case OP_MEM_STR:
1611 		return segmented_write(ctxt,
1612 				       op->addr.mem,
1613 				       op->data,
1614 				       op->bytes * op->count);
1615 		break;
1616 	case OP_XMM:
1617 		write_sse_reg(ctxt, &op->vec_val, op->addr.xmm);
1618 		break;
1619 	case OP_MM:
1620 		write_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
1621 		break;
1622 	case OP_NONE:
1623 		/* no writeback */
1624 		break;
1625 	default:
1626 		break;
1627 	}
1628 	return X86EMUL_CONTINUE;
1629 }
1630 
1631 static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes)
1632 {
1633 	struct segmented_address addr;
1634 
1635 	rsp_increment(ctxt, -bytes);
1636 	addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1637 	addr.seg = VCPU_SREG_SS;
1638 
1639 	return segmented_write(ctxt, addr, data, bytes);
1640 }
1641 
1642 static int em_push(struct x86_emulate_ctxt *ctxt)
1643 {
1644 	/* Disable writeback. */
1645 	ctxt->dst.type = OP_NONE;
1646 	return push(ctxt, &ctxt->src.val, ctxt->op_bytes);
1647 }
1648 
1649 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1650 		       void *dest, int len)
1651 {
1652 	int rc;
1653 	struct segmented_address addr;
1654 
1655 	addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1656 	addr.seg = VCPU_SREG_SS;
1657 	rc = segmented_read(ctxt, addr, dest, len);
1658 	if (rc != X86EMUL_CONTINUE)
1659 		return rc;
1660 
1661 	rsp_increment(ctxt, len);
1662 	return rc;
1663 }
1664 
1665 static int em_pop(struct x86_emulate_ctxt *ctxt)
1666 {
1667 	return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1668 }
1669 
1670 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1671 			void *dest, int len)
1672 {
1673 	int rc;
1674 	unsigned long val, change_mask;
1675 	int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1676 	int cpl = ctxt->ops->cpl(ctxt);
1677 
1678 	rc = emulate_pop(ctxt, &val, len);
1679 	if (rc != X86EMUL_CONTINUE)
1680 		return rc;
1681 
1682 	change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1683 		| EFLG_TF | EFLG_DF | EFLG_NT | EFLG_AC | EFLG_ID;
1684 
1685 	switch(ctxt->mode) {
1686 	case X86EMUL_MODE_PROT64:
1687 	case X86EMUL_MODE_PROT32:
1688 	case X86EMUL_MODE_PROT16:
1689 		if (cpl == 0)
1690 			change_mask |= EFLG_IOPL;
1691 		if (cpl <= iopl)
1692 			change_mask |= EFLG_IF;
1693 		break;
1694 	case X86EMUL_MODE_VM86:
1695 		if (iopl < 3)
1696 			return emulate_gp(ctxt, 0);
1697 		change_mask |= EFLG_IF;
1698 		break;
1699 	default: /* real mode */
1700 		change_mask |= (EFLG_IOPL | EFLG_IF);
1701 		break;
1702 	}
1703 
1704 	*(unsigned long *)dest =
1705 		(ctxt->eflags & ~change_mask) | (val & change_mask);
1706 
1707 	return rc;
1708 }
1709 
1710 static int em_popf(struct x86_emulate_ctxt *ctxt)
1711 {
1712 	ctxt->dst.type = OP_REG;
1713 	ctxt->dst.addr.reg = &ctxt->eflags;
1714 	ctxt->dst.bytes = ctxt->op_bytes;
1715 	return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1716 }
1717 
1718 static int em_enter(struct x86_emulate_ctxt *ctxt)
1719 {
1720 	int rc;
1721 	unsigned frame_size = ctxt->src.val;
1722 	unsigned nesting_level = ctxt->src2.val & 31;
1723 	ulong rbp;
1724 
1725 	if (nesting_level)
1726 		return X86EMUL_UNHANDLEABLE;
1727 
1728 	rbp = reg_read(ctxt, VCPU_REGS_RBP);
1729 	rc = push(ctxt, &rbp, stack_size(ctxt));
1730 	if (rc != X86EMUL_CONTINUE)
1731 		return rc;
1732 	assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP),
1733 		      stack_mask(ctxt));
1734 	assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP),
1735 		      reg_read(ctxt, VCPU_REGS_RSP) - frame_size,
1736 		      stack_mask(ctxt));
1737 	return X86EMUL_CONTINUE;
1738 }
1739 
1740 static int em_leave(struct x86_emulate_ctxt *ctxt)
1741 {
1742 	assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP),
1743 		      stack_mask(ctxt));
1744 	return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes);
1745 }
1746 
1747 static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
1748 {
1749 	int seg = ctxt->src2.val;
1750 
1751 	ctxt->src.val = get_segment_selector(ctxt, seg);
1752 
1753 	return em_push(ctxt);
1754 }
1755 
1756 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt)
1757 {
1758 	int seg = ctxt->src2.val;
1759 	unsigned long selector;
1760 	int rc;
1761 
1762 	rc = emulate_pop(ctxt, &selector, ctxt->op_bytes);
1763 	if (rc != X86EMUL_CONTINUE)
1764 		return rc;
1765 
1766 	if (ctxt->modrm_reg == VCPU_SREG_SS)
1767 		ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
1768 
1769 	rc = load_segment_descriptor(ctxt, (u16)selector, seg);
1770 	return rc;
1771 }
1772 
1773 static int em_pusha(struct x86_emulate_ctxt *ctxt)
1774 {
1775 	unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP);
1776 	int rc = X86EMUL_CONTINUE;
1777 	int reg = VCPU_REGS_RAX;
1778 
1779 	while (reg <= VCPU_REGS_RDI) {
1780 		(reg == VCPU_REGS_RSP) ?
1781 		(ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg));
1782 
1783 		rc = em_push(ctxt);
1784 		if (rc != X86EMUL_CONTINUE)
1785 			return rc;
1786 
1787 		++reg;
1788 	}
1789 
1790 	return rc;
1791 }
1792 
1793 static int em_pushf(struct x86_emulate_ctxt *ctxt)
1794 {
1795 	ctxt->src.val =  (unsigned long)ctxt->eflags;
1796 	return em_push(ctxt);
1797 }
1798 
1799 static int em_popa(struct x86_emulate_ctxt *ctxt)
1800 {
1801 	int rc = X86EMUL_CONTINUE;
1802 	int reg = VCPU_REGS_RDI;
1803 
1804 	while (reg >= VCPU_REGS_RAX) {
1805 		if (reg == VCPU_REGS_RSP) {
1806 			rsp_increment(ctxt, ctxt->op_bytes);
1807 			--reg;
1808 		}
1809 
1810 		rc = emulate_pop(ctxt, reg_rmw(ctxt, reg), ctxt->op_bytes);
1811 		if (rc != X86EMUL_CONTINUE)
1812 			break;
1813 		--reg;
1814 	}
1815 	return rc;
1816 }
1817 
1818 static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1819 {
1820 	const struct x86_emulate_ops *ops = ctxt->ops;
1821 	int rc;
1822 	struct desc_ptr dt;
1823 	gva_t cs_addr;
1824 	gva_t eip_addr;
1825 	u16 cs, eip;
1826 
1827 	/* TODO: Add limit checks */
1828 	ctxt->src.val = ctxt->eflags;
1829 	rc = em_push(ctxt);
1830 	if (rc != X86EMUL_CONTINUE)
1831 		return rc;
1832 
1833 	ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);
1834 
1835 	ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS);
1836 	rc = em_push(ctxt);
1837 	if (rc != X86EMUL_CONTINUE)
1838 		return rc;
1839 
1840 	ctxt->src.val = ctxt->_eip;
1841 	rc = em_push(ctxt);
1842 	if (rc != X86EMUL_CONTINUE)
1843 		return rc;
1844 
1845 	ops->get_idt(ctxt, &dt);
1846 
1847 	eip_addr = dt.address + (irq << 2);
1848 	cs_addr = dt.address + (irq << 2) + 2;
1849 
1850 	rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
1851 	if (rc != X86EMUL_CONTINUE)
1852 		return rc;
1853 
1854 	rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
1855 	if (rc != X86EMUL_CONTINUE)
1856 		return rc;
1857 
1858 	rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS);
1859 	if (rc != X86EMUL_CONTINUE)
1860 		return rc;
1861 
1862 	ctxt->_eip = eip;
1863 
1864 	return rc;
1865 }
1866 
1867 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1868 {
1869 	int rc;
1870 
1871 	invalidate_registers(ctxt);
1872 	rc = __emulate_int_real(ctxt, irq);
1873 	if (rc == X86EMUL_CONTINUE)
1874 		writeback_registers(ctxt);
1875 	return rc;
1876 }
1877 
1878 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq)
1879 {
1880 	switch(ctxt->mode) {
1881 	case X86EMUL_MODE_REAL:
1882 		return __emulate_int_real(ctxt, irq);
1883 	case X86EMUL_MODE_VM86:
1884 	case X86EMUL_MODE_PROT16:
1885 	case X86EMUL_MODE_PROT32:
1886 	case X86EMUL_MODE_PROT64:
1887 	default:
1888 		/* Protected mode interrupts unimplemented yet */
1889 		return X86EMUL_UNHANDLEABLE;
1890 	}
1891 }
1892 
1893 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
1894 {
1895 	int rc = X86EMUL_CONTINUE;
1896 	unsigned long temp_eip = 0;
1897 	unsigned long temp_eflags = 0;
1898 	unsigned long cs = 0;
1899 	unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
1900 			     EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
1901 			     EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
1902 	unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
1903 
1904 	/* TODO: Add stack limit check */
1905 
1906 	rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes);
1907 
1908 	if (rc != X86EMUL_CONTINUE)
1909 		return rc;
1910 
1911 	if (temp_eip & ~0xffff)
1912 		return emulate_gp(ctxt, 0);
1913 
1914 	rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1915 
1916 	if (rc != X86EMUL_CONTINUE)
1917 		return rc;
1918 
1919 	rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes);
1920 
1921 	if (rc != X86EMUL_CONTINUE)
1922 		return rc;
1923 
1924 	rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1925 
1926 	if (rc != X86EMUL_CONTINUE)
1927 		return rc;
1928 
1929 	ctxt->_eip = temp_eip;
1930 
1931 
1932 	if (ctxt->op_bytes == 4)
1933 		ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
1934 	else if (ctxt->op_bytes == 2) {
1935 		ctxt->eflags &= ~0xffff;
1936 		ctxt->eflags |= temp_eflags;
1937 	}
1938 
1939 	ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
1940 	ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
1941 
1942 	return rc;
1943 }
1944 
1945 static int em_iret(struct x86_emulate_ctxt *ctxt)
1946 {
1947 	switch(ctxt->mode) {
1948 	case X86EMUL_MODE_REAL:
1949 		return emulate_iret_real(ctxt);
1950 	case X86EMUL_MODE_VM86:
1951 	case X86EMUL_MODE_PROT16:
1952 	case X86EMUL_MODE_PROT32:
1953 	case X86EMUL_MODE_PROT64:
1954 	default:
1955 		/* iret from protected mode unimplemented yet */
1956 		return X86EMUL_UNHANDLEABLE;
1957 	}
1958 }
1959 
1960 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
1961 {
1962 	int rc;
1963 	unsigned short sel;
1964 
1965 	memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
1966 
1967 	rc = load_segment_descriptor(ctxt, sel, VCPU_SREG_CS);
1968 	if (rc != X86EMUL_CONTINUE)
1969 		return rc;
1970 
1971 	ctxt->_eip = 0;
1972 	memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
1973 	return X86EMUL_CONTINUE;
1974 }
1975 
1976 static int em_grp45(struct x86_emulate_ctxt *ctxt)
1977 {
1978 	int rc = X86EMUL_CONTINUE;
1979 
1980 	switch (ctxt->modrm_reg) {
1981 	case 2: /* call near abs */ {
1982 		long int old_eip;
1983 		old_eip = ctxt->_eip;
1984 		ctxt->_eip = ctxt->src.val;
1985 		ctxt->src.val = old_eip;
1986 		rc = em_push(ctxt);
1987 		break;
1988 	}
1989 	case 4: /* jmp abs */
1990 		ctxt->_eip = ctxt->src.val;
1991 		break;
1992 	case 5: /* jmp far */
1993 		rc = em_jmp_far(ctxt);
1994 		break;
1995 	case 6:	/* push */
1996 		rc = em_push(ctxt);
1997 		break;
1998 	}
1999 	return rc;
2000 }
2001 
2002 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt)
2003 {
2004 	u64 old = ctxt->dst.orig_val64;
2005 
2006 	if (ctxt->dst.bytes == 16)
2007 		return X86EMUL_UNHANDLEABLE;
2008 
2009 	if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) ||
2010 	    ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) {
2011 		*reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0);
2012 		*reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32);
2013 		ctxt->eflags &= ~EFLG_ZF;
2014 	} else {
2015 		ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) |
2016 			(u32) reg_read(ctxt, VCPU_REGS_RBX);
2017 
2018 		ctxt->eflags |= EFLG_ZF;
2019 	}
2020 	return X86EMUL_CONTINUE;
2021 }
2022 
2023 static int em_ret(struct x86_emulate_ctxt *ctxt)
2024 {
2025 	ctxt->dst.type = OP_REG;
2026 	ctxt->dst.addr.reg = &ctxt->_eip;
2027 	ctxt->dst.bytes = ctxt->op_bytes;
2028 	return em_pop(ctxt);
2029 }
2030 
2031 static int em_ret_far(struct x86_emulate_ctxt *ctxt)
2032 {
2033 	int rc;
2034 	unsigned long cs;
2035 	int cpl = ctxt->ops->cpl(ctxt);
2036 
2037 	rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes);
2038 	if (rc != X86EMUL_CONTINUE)
2039 		return rc;
2040 	if (ctxt->op_bytes == 4)
2041 		ctxt->_eip = (u32)ctxt->_eip;
2042 	rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
2043 	if (rc != X86EMUL_CONTINUE)
2044 		return rc;
2045 	/* Outer-privilege level return is not implemented */
2046 	if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl)
2047 		return X86EMUL_UNHANDLEABLE;
2048 	rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
2049 	return rc;
2050 }
2051 
2052 static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt)
2053 {
2054         int rc;
2055 
2056         rc = em_ret_far(ctxt);
2057         if (rc != X86EMUL_CONTINUE)
2058                 return rc;
2059         rsp_increment(ctxt, ctxt->src.val);
2060         return X86EMUL_CONTINUE;
2061 }
2062 
2063 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
2064 {
2065 	/* Save real source value, then compare EAX against destination. */
2066 	ctxt->dst.orig_val = ctxt->dst.val;
2067 	ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX);
2068 	ctxt->src.orig_val = ctxt->src.val;
2069 	ctxt->src.val = ctxt->dst.orig_val;
2070 	fastop(ctxt, em_cmp);
2071 
2072 	if (ctxt->eflags & EFLG_ZF) {
2073 		/* Success: write back to memory. */
2074 		ctxt->dst.val = ctxt->src.orig_val;
2075 	} else {
2076 		/* Failure: write the value we saw to EAX. */
2077 		ctxt->dst.type = OP_REG;
2078 		ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
2079 		ctxt->dst.val = ctxt->dst.orig_val;
2080 	}
2081 	return X86EMUL_CONTINUE;
2082 }
2083 
2084 static int em_lseg(struct x86_emulate_ctxt *ctxt)
2085 {
2086 	int seg = ctxt->src2.val;
2087 	unsigned short sel;
2088 	int rc;
2089 
2090 	memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2091 
2092 	rc = load_segment_descriptor(ctxt, sel, seg);
2093 	if (rc != X86EMUL_CONTINUE)
2094 		return rc;
2095 
2096 	ctxt->dst.val = ctxt->src.val;
2097 	return rc;
2098 }
2099 
2100 static void
2101 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
2102 			struct desc_struct *cs, struct desc_struct *ss)
2103 {
2104 	cs->l = 0;		/* will be adjusted later */
2105 	set_desc_base(cs, 0);	/* flat segment */
2106 	cs->g = 1;		/* 4kb granularity */
2107 	set_desc_limit(cs, 0xfffff);	/* 4GB limit */
2108 	cs->type = 0x0b;	/* Read, Execute, Accessed */
2109 	cs->s = 1;
2110 	cs->dpl = 0;		/* will be adjusted later */
2111 	cs->p = 1;
2112 	cs->d = 1;
2113 	cs->avl = 0;
2114 
2115 	set_desc_base(ss, 0);	/* flat segment */
2116 	set_desc_limit(ss, 0xfffff);	/* 4GB limit */
2117 	ss->g = 1;		/* 4kb granularity */
2118 	ss->s = 1;
2119 	ss->type = 0x03;	/* Read/Write, Accessed */
2120 	ss->d = 1;		/* 32bit stack segment */
2121 	ss->dpl = 0;
2122 	ss->p = 1;
2123 	ss->l = 0;
2124 	ss->avl = 0;
2125 }
2126 
2127 static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
2128 {
2129 	u32 eax, ebx, ecx, edx;
2130 
2131 	eax = ecx = 0;
2132 	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2133 	return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
2134 		&& ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
2135 		&& edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
2136 }
2137 
2138 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
2139 {
2140 	const struct x86_emulate_ops *ops = ctxt->ops;
2141 	u32 eax, ebx, ecx, edx;
2142 
2143 	/*
2144 	 * syscall should always be enabled in longmode - so only become
2145 	 * vendor specific (cpuid) if other modes are active...
2146 	 */
2147 	if (ctxt->mode == X86EMUL_MODE_PROT64)
2148 		return true;
2149 
2150 	eax = 0x00000000;
2151 	ecx = 0x00000000;
2152 	ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2153 	/*
2154 	 * Intel ("GenuineIntel")
2155 	 * remark: Intel CPUs only support "syscall" in 64bit
2156 	 * longmode. Also an 64bit guest with a
2157 	 * 32bit compat-app running will #UD !! While this
2158 	 * behaviour can be fixed (by emulating) into AMD
2159 	 * response - CPUs of AMD can't behave like Intel.
2160 	 */
2161 	if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
2162 	    ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
2163 	    edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
2164 		return false;
2165 
2166 	/* AMD ("AuthenticAMD") */
2167 	if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
2168 	    ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
2169 	    edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
2170 		return true;
2171 
2172 	/* AMD ("AMDisbetter!") */
2173 	if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
2174 	    ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
2175 	    edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
2176 		return true;
2177 
2178 	/* default: (not Intel, not AMD), apply Intel's stricter rules... */
2179 	return false;
2180 }
2181 
2182 static int em_syscall(struct x86_emulate_ctxt *ctxt)
2183 {
2184 	const struct x86_emulate_ops *ops = ctxt->ops;
2185 	struct desc_struct cs, ss;
2186 	u64 msr_data;
2187 	u16 cs_sel, ss_sel;
2188 	u64 efer = 0;
2189 
2190 	/* syscall is not available in real mode */
2191 	if (ctxt->mode == X86EMUL_MODE_REAL ||
2192 	    ctxt->mode == X86EMUL_MODE_VM86)
2193 		return emulate_ud(ctxt);
2194 
2195 	if (!(em_syscall_is_enabled(ctxt)))
2196 		return emulate_ud(ctxt);
2197 
2198 	ops->get_msr(ctxt, MSR_EFER, &efer);
2199 	setup_syscalls_segments(ctxt, &cs, &ss);
2200 
2201 	if (!(efer & EFER_SCE))
2202 		return emulate_ud(ctxt);
2203 
2204 	ops->get_msr(ctxt, MSR_STAR, &msr_data);
2205 	msr_data >>= 32;
2206 	cs_sel = (u16)(msr_data & 0xfffc);
2207 	ss_sel = (u16)(msr_data + 8);
2208 
2209 	if (efer & EFER_LMA) {
2210 		cs.d = 0;
2211 		cs.l = 1;
2212 	}
2213 	ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2214 	ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2215 
2216 	*reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip;
2217 	if (efer & EFER_LMA) {
2218 #ifdef CONFIG_X86_64
2219 		*reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags;
2220 
2221 		ops->get_msr(ctxt,
2222 			     ctxt->mode == X86EMUL_MODE_PROT64 ?
2223 			     MSR_LSTAR : MSR_CSTAR, &msr_data);
2224 		ctxt->_eip = msr_data;
2225 
2226 		ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
2227 		ctxt->eflags &= ~msr_data;
2228 #endif
2229 	} else {
2230 		/* legacy mode */
2231 		ops->get_msr(ctxt, MSR_STAR, &msr_data);
2232 		ctxt->_eip = (u32)msr_data;
2233 
2234 		ctxt->eflags &= ~(EFLG_VM | EFLG_IF);
2235 	}
2236 
2237 	return X86EMUL_CONTINUE;
2238 }
2239 
2240 static int em_sysenter(struct x86_emulate_ctxt *ctxt)
2241 {
2242 	const struct x86_emulate_ops *ops = ctxt->ops;
2243 	struct desc_struct cs, ss;
2244 	u64 msr_data;
2245 	u16 cs_sel, ss_sel;
2246 	u64 efer = 0;
2247 
2248 	ops->get_msr(ctxt, MSR_EFER, &efer);
2249 	/* inject #GP if in real mode */
2250 	if (ctxt->mode == X86EMUL_MODE_REAL)
2251 		return emulate_gp(ctxt, 0);
2252 
2253 	/*
2254 	 * Not recognized on AMD in compat mode (but is recognized in legacy
2255 	 * mode).
2256 	 */
2257 	if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA)
2258 	    && !vendor_intel(ctxt))
2259 		return emulate_ud(ctxt);
2260 
2261 	/* XXX sysenter/sysexit have not been tested in 64bit mode.
2262 	* Therefore, we inject an #UD.
2263 	*/
2264 	if (ctxt->mode == X86EMUL_MODE_PROT64)
2265 		return emulate_ud(ctxt);
2266 
2267 	setup_syscalls_segments(ctxt, &cs, &ss);
2268 
2269 	ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2270 	switch (ctxt->mode) {
2271 	case X86EMUL_MODE_PROT32:
2272 		if ((msr_data & 0xfffc) == 0x0)
2273 			return emulate_gp(ctxt, 0);
2274 		break;
2275 	case X86EMUL_MODE_PROT64:
2276 		if (msr_data == 0x0)
2277 			return emulate_gp(ctxt, 0);
2278 		break;
2279 	default:
2280 		break;
2281 	}
2282 
2283 	ctxt->eflags &= ~(EFLG_VM | EFLG_IF);
2284 	cs_sel = (u16)msr_data;
2285 	cs_sel &= ~SELECTOR_RPL_MASK;
2286 	ss_sel = cs_sel + 8;
2287 	ss_sel &= ~SELECTOR_RPL_MASK;
2288 	if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
2289 		cs.d = 0;
2290 		cs.l = 1;
2291 	}
2292 
2293 	ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2294 	ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2295 
2296 	ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
2297 	ctxt->_eip = msr_data;
2298 
2299 	ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
2300 	*reg_write(ctxt, VCPU_REGS_RSP) = msr_data;
2301 
2302 	return X86EMUL_CONTINUE;
2303 }
2304 
2305 static int em_sysexit(struct x86_emulate_ctxt *ctxt)
2306 {
2307 	const struct x86_emulate_ops *ops = ctxt->ops;
2308 	struct desc_struct cs, ss;
2309 	u64 msr_data;
2310 	int usermode;
2311 	u16 cs_sel = 0, ss_sel = 0;
2312 
2313 	/* inject #GP if in real mode or Virtual 8086 mode */
2314 	if (ctxt->mode == X86EMUL_MODE_REAL ||
2315 	    ctxt->mode == X86EMUL_MODE_VM86)
2316 		return emulate_gp(ctxt, 0);
2317 
2318 	setup_syscalls_segments(ctxt, &cs, &ss);
2319 
2320 	if ((ctxt->rex_prefix & 0x8) != 0x0)
2321 		usermode = X86EMUL_MODE_PROT64;
2322 	else
2323 		usermode = X86EMUL_MODE_PROT32;
2324 
2325 	cs.dpl = 3;
2326 	ss.dpl = 3;
2327 	ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2328 	switch (usermode) {
2329 	case X86EMUL_MODE_PROT32:
2330 		cs_sel = (u16)(msr_data + 16);
2331 		if ((msr_data & 0xfffc) == 0x0)
2332 			return emulate_gp(ctxt, 0);
2333 		ss_sel = (u16)(msr_data + 24);
2334 		break;
2335 	case X86EMUL_MODE_PROT64:
2336 		cs_sel = (u16)(msr_data + 32);
2337 		if (msr_data == 0x0)
2338 			return emulate_gp(ctxt, 0);
2339 		ss_sel = cs_sel + 8;
2340 		cs.d = 0;
2341 		cs.l = 1;
2342 		break;
2343 	}
2344 	cs_sel |= SELECTOR_RPL_MASK;
2345 	ss_sel |= SELECTOR_RPL_MASK;
2346 
2347 	ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2348 	ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2349 
2350 	ctxt->_eip = reg_read(ctxt, VCPU_REGS_RDX);
2351 	*reg_write(ctxt, VCPU_REGS_RSP) = reg_read(ctxt, VCPU_REGS_RCX);
2352 
2353 	return X86EMUL_CONTINUE;
2354 }
2355 
2356 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
2357 {
2358 	int iopl;
2359 	if (ctxt->mode == X86EMUL_MODE_REAL)
2360 		return false;
2361 	if (ctxt->mode == X86EMUL_MODE_VM86)
2362 		return true;
2363 	iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
2364 	return ctxt->ops->cpl(ctxt) > iopl;
2365 }
2366 
2367 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2368 					    u16 port, u16 len)
2369 {
2370 	const struct x86_emulate_ops *ops = ctxt->ops;
2371 	struct desc_struct tr_seg;
2372 	u32 base3;
2373 	int r;
2374 	u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7;
2375 	unsigned mask = (1 << len) - 1;
2376 	unsigned long base;
2377 
2378 	ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
2379 	if (!tr_seg.p)
2380 		return false;
2381 	if (desc_limit_scaled(&tr_seg) < 103)
2382 		return false;
2383 	base = get_desc_base(&tr_seg);
2384 #ifdef CONFIG_X86_64
2385 	base |= ((u64)base3) << 32;
2386 #endif
2387 	r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
2388 	if (r != X86EMUL_CONTINUE)
2389 		return false;
2390 	if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
2391 		return false;
2392 	r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
2393 	if (r != X86EMUL_CONTINUE)
2394 		return false;
2395 	if ((perm >> bit_idx) & mask)
2396 		return false;
2397 	return true;
2398 }
2399 
2400 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2401 				 u16 port, u16 len)
2402 {
2403 	if (ctxt->perm_ok)
2404 		return true;
2405 
2406 	if (emulator_bad_iopl(ctxt))
2407 		if (!emulator_io_port_access_allowed(ctxt, port, len))
2408 			return false;
2409 
2410 	ctxt->perm_ok = true;
2411 
2412 	return true;
2413 }
2414 
2415 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2416 				struct tss_segment_16 *tss)
2417 {
2418 	tss->ip = ctxt->_eip;
2419 	tss->flag = ctxt->eflags;
2420 	tss->ax = reg_read(ctxt, VCPU_REGS_RAX);
2421 	tss->cx = reg_read(ctxt, VCPU_REGS_RCX);
2422 	tss->dx = reg_read(ctxt, VCPU_REGS_RDX);
2423 	tss->bx = reg_read(ctxt, VCPU_REGS_RBX);
2424 	tss->sp = reg_read(ctxt, VCPU_REGS_RSP);
2425 	tss->bp = reg_read(ctxt, VCPU_REGS_RBP);
2426 	tss->si = reg_read(ctxt, VCPU_REGS_RSI);
2427 	tss->di = reg_read(ctxt, VCPU_REGS_RDI);
2428 
2429 	tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2430 	tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2431 	tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2432 	tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2433 	tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2434 }
2435 
2436 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2437 				 struct tss_segment_16 *tss)
2438 {
2439 	int ret;
2440 	u8 cpl;
2441 
2442 	ctxt->_eip = tss->ip;
2443 	ctxt->eflags = tss->flag | 2;
2444 	*reg_write(ctxt, VCPU_REGS_RAX) = tss->ax;
2445 	*reg_write(ctxt, VCPU_REGS_RCX) = tss->cx;
2446 	*reg_write(ctxt, VCPU_REGS_RDX) = tss->dx;
2447 	*reg_write(ctxt, VCPU_REGS_RBX) = tss->bx;
2448 	*reg_write(ctxt, VCPU_REGS_RSP) = tss->sp;
2449 	*reg_write(ctxt, VCPU_REGS_RBP) = tss->bp;
2450 	*reg_write(ctxt, VCPU_REGS_RSI) = tss->si;
2451 	*reg_write(ctxt, VCPU_REGS_RDI) = tss->di;
2452 
2453 	/*
2454 	 * SDM says that segment selectors are loaded before segment
2455 	 * descriptors
2456 	 */
2457 	set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR);
2458 	set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2459 	set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2460 	set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2461 	set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2462 
2463 	cpl = tss->cs & 3;
2464 
2465 	/*
2466 	 * Now load segment descriptors. If fault happens at this stage
2467 	 * it is handled in a context of new task
2468 	 */
2469 	ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl, true);
2470 	if (ret != X86EMUL_CONTINUE)
2471 		return ret;
2472 	ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, true);
2473 	if (ret != X86EMUL_CONTINUE)
2474 		return ret;
2475 	ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, true);
2476 	if (ret != X86EMUL_CONTINUE)
2477 		return ret;
2478 	ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, true);
2479 	if (ret != X86EMUL_CONTINUE)
2480 		return ret;
2481 	ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, true);
2482 	if (ret != X86EMUL_CONTINUE)
2483 		return ret;
2484 
2485 	return X86EMUL_CONTINUE;
2486 }
2487 
2488 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2489 			  u16 tss_selector, u16 old_tss_sel,
2490 			  ulong old_tss_base, struct desc_struct *new_desc)
2491 {
2492 	const struct x86_emulate_ops *ops = ctxt->ops;
2493 	struct tss_segment_16 tss_seg;
2494 	int ret;
2495 	u32 new_tss_base = get_desc_base(new_desc);
2496 
2497 	ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2498 			    &ctxt->exception);
2499 	if (ret != X86EMUL_CONTINUE)
2500 		/* FIXME: need to provide precise fault address */
2501 		return ret;
2502 
2503 	save_state_to_tss16(ctxt, &tss_seg);
2504 
2505 	ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2506 			     &ctxt->exception);
2507 	if (ret != X86EMUL_CONTINUE)
2508 		/* FIXME: need to provide precise fault address */
2509 		return ret;
2510 
2511 	ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2512 			    &ctxt->exception);
2513 	if (ret != X86EMUL_CONTINUE)
2514 		/* FIXME: need to provide precise fault address */
2515 		return ret;
2516 
2517 	if (old_tss_sel != 0xffff) {
2518 		tss_seg.prev_task_link = old_tss_sel;
2519 
2520 		ret = ops->write_std(ctxt, new_tss_base,
2521 				     &tss_seg.prev_task_link,
2522 				     sizeof tss_seg.prev_task_link,
2523 				     &ctxt->exception);
2524 		if (ret != X86EMUL_CONTINUE)
2525 			/* FIXME: need to provide precise fault address */
2526 			return ret;
2527 	}
2528 
2529 	return load_state_from_tss16(ctxt, &tss_seg);
2530 }
2531 
2532 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2533 				struct tss_segment_32 *tss)
2534 {
2535 	/* CR3 and ldt selector are not saved intentionally */
2536 	tss->eip = ctxt->_eip;
2537 	tss->eflags = ctxt->eflags;
2538 	tss->eax = reg_read(ctxt, VCPU_REGS_RAX);
2539 	tss->ecx = reg_read(ctxt, VCPU_REGS_RCX);
2540 	tss->edx = reg_read(ctxt, VCPU_REGS_RDX);
2541 	tss->ebx = reg_read(ctxt, VCPU_REGS_RBX);
2542 	tss->esp = reg_read(ctxt, VCPU_REGS_RSP);
2543 	tss->ebp = reg_read(ctxt, VCPU_REGS_RBP);
2544 	tss->esi = reg_read(ctxt, VCPU_REGS_RSI);
2545 	tss->edi = reg_read(ctxt, VCPU_REGS_RDI);
2546 
2547 	tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2548 	tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2549 	tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2550 	tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2551 	tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS);
2552 	tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS);
2553 }
2554 
2555 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2556 				 struct tss_segment_32 *tss)
2557 {
2558 	int ret;
2559 	u8 cpl;
2560 
2561 	if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
2562 		return emulate_gp(ctxt, 0);
2563 	ctxt->_eip = tss->eip;
2564 	ctxt->eflags = tss->eflags | 2;
2565 
2566 	/* General purpose registers */
2567 	*reg_write(ctxt, VCPU_REGS_RAX) = tss->eax;
2568 	*reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx;
2569 	*reg_write(ctxt, VCPU_REGS_RDX) = tss->edx;
2570 	*reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx;
2571 	*reg_write(ctxt, VCPU_REGS_RSP) = tss->esp;
2572 	*reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp;
2573 	*reg_write(ctxt, VCPU_REGS_RSI) = tss->esi;
2574 	*reg_write(ctxt, VCPU_REGS_RDI) = tss->edi;
2575 
2576 	/*
2577 	 * SDM says that segment selectors are loaded before segment
2578 	 * descriptors.  This is important because CPL checks will
2579 	 * use CS.RPL.
2580 	 */
2581 	set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2582 	set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2583 	set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2584 	set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2585 	set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2586 	set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
2587 	set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
2588 
2589 	/*
2590 	 * If we're switching between Protected Mode and VM86, we need to make
2591 	 * sure to update the mode before loading the segment descriptors so
2592 	 * that the selectors are interpreted correctly.
2593 	 */
2594 	if (ctxt->eflags & X86_EFLAGS_VM) {
2595 		ctxt->mode = X86EMUL_MODE_VM86;
2596 		cpl = 3;
2597 	} else {
2598 		ctxt->mode = X86EMUL_MODE_PROT32;
2599 		cpl = tss->cs & 3;
2600 	}
2601 
2602 	/*
2603 	 * Now load segment descriptors. If fault happenes at this stage
2604 	 * it is handled in a context of new task
2605 	 */
2606 	ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR, cpl, true);
2607 	if (ret != X86EMUL_CONTINUE)
2608 		return ret;
2609 	ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, true);
2610 	if (ret != X86EMUL_CONTINUE)
2611 		return ret;
2612 	ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, true);
2613 	if (ret != X86EMUL_CONTINUE)
2614 		return ret;
2615 	ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, true);
2616 	if (ret != X86EMUL_CONTINUE)
2617 		return ret;
2618 	ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, true);
2619 	if (ret != X86EMUL_CONTINUE)
2620 		return ret;
2621 	ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl, true);
2622 	if (ret != X86EMUL_CONTINUE)
2623 		return ret;
2624 	ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl, true);
2625 	if (ret != X86EMUL_CONTINUE)
2626 		return ret;
2627 
2628 	return X86EMUL_CONTINUE;
2629 }
2630 
2631 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2632 			  u16 tss_selector, u16 old_tss_sel,
2633 			  ulong old_tss_base, struct desc_struct *new_desc)
2634 {
2635 	const struct x86_emulate_ops *ops = ctxt->ops;
2636 	struct tss_segment_32 tss_seg;
2637 	int ret;
2638 	u32 new_tss_base = get_desc_base(new_desc);
2639 	u32 eip_offset = offsetof(struct tss_segment_32, eip);
2640 	u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector);
2641 
2642 	ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2643 			    &ctxt->exception);
2644 	if (ret != X86EMUL_CONTINUE)
2645 		/* FIXME: need to provide precise fault address */
2646 		return ret;
2647 
2648 	save_state_to_tss32(ctxt, &tss_seg);
2649 
2650 	/* Only GP registers and segment selectors are saved */
2651 	ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip,
2652 			     ldt_sel_offset - eip_offset, &ctxt->exception);
2653 	if (ret != X86EMUL_CONTINUE)
2654 		/* FIXME: need to provide precise fault address */
2655 		return ret;
2656 
2657 	ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2658 			    &ctxt->exception);
2659 	if (ret != X86EMUL_CONTINUE)
2660 		/* FIXME: need to provide precise fault address */
2661 		return ret;
2662 
2663 	if (old_tss_sel != 0xffff) {
2664 		tss_seg.prev_task_link = old_tss_sel;
2665 
2666 		ret = ops->write_std(ctxt, new_tss_base,
2667 				     &tss_seg.prev_task_link,
2668 				     sizeof tss_seg.prev_task_link,
2669 				     &ctxt->exception);
2670 		if (ret != X86EMUL_CONTINUE)
2671 			/* FIXME: need to provide precise fault address */
2672 			return ret;
2673 	}
2674 
2675 	return load_state_from_tss32(ctxt, &tss_seg);
2676 }
2677 
2678 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2679 				   u16 tss_selector, int idt_index, int reason,
2680 				   bool has_error_code, u32 error_code)
2681 {
2682 	const struct x86_emulate_ops *ops = ctxt->ops;
2683 	struct desc_struct curr_tss_desc, next_tss_desc;
2684 	int ret;
2685 	u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR);
2686 	ulong old_tss_base =
2687 		ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);
2688 	u32 desc_limit;
2689 	ulong desc_addr;
2690 
2691 	/* FIXME: old_tss_base == ~0 ? */
2692 
2693 	ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr);
2694 	if (ret != X86EMUL_CONTINUE)
2695 		return ret;
2696 	ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr);
2697 	if (ret != X86EMUL_CONTINUE)
2698 		return ret;
2699 
2700 	/* FIXME: check that next_tss_desc is tss */
2701 
2702 	/*
2703 	 * Check privileges. The three cases are task switch caused by...
2704 	 *
2705 	 * 1. jmp/call/int to task gate: Check against DPL of the task gate
2706 	 * 2. Exception/IRQ/iret: No check is performed
2707 	 * 3. jmp/call to TSS: Check against DPL of the TSS
2708 	 */
2709 	if (reason == TASK_SWITCH_GATE) {
2710 		if (idt_index != -1) {
2711 			/* Software interrupts */
2712 			struct desc_struct task_gate_desc;
2713 			int dpl;
2714 
2715 			ret = read_interrupt_descriptor(ctxt, idt_index,
2716 							&task_gate_desc);
2717 			if (ret != X86EMUL_CONTINUE)
2718 				return ret;
2719 
2720 			dpl = task_gate_desc.dpl;
2721 			if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
2722 				return emulate_gp(ctxt, (idt_index << 3) | 0x2);
2723 		}
2724 	} else if (reason != TASK_SWITCH_IRET) {
2725 		int dpl = next_tss_desc.dpl;
2726 		if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
2727 			return emulate_gp(ctxt, tss_selector);
2728 	}
2729 
2730 
2731 	desc_limit = desc_limit_scaled(&next_tss_desc);
2732 	if (!next_tss_desc.p ||
2733 	    ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2734 	     desc_limit < 0x2b)) {
2735 		return emulate_ts(ctxt, tss_selector & 0xfffc);
2736 	}
2737 
2738 	if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2739 		curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2740 		write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2741 	}
2742 
2743 	if (reason == TASK_SWITCH_IRET)
2744 		ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2745 
2746 	/* set back link to prev task only if NT bit is set in eflags
2747 	   note that old_tss_sel is not used after this point */
2748 	if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2749 		old_tss_sel = 0xffff;
2750 
2751 	if (next_tss_desc.type & 8)
2752 		ret = task_switch_32(ctxt, tss_selector, old_tss_sel,
2753 				     old_tss_base, &next_tss_desc);
2754 	else
2755 		ret = task_switch_16(ctxt, tss_selector, old_tss_sel,
2756 				     old_tss_base, &next_tss_desc);
2757 	if (ret != X86EMUL_CONTINUE)
2758 		return ret;
2759 
2760 	if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2761 		ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2762 
2763 	if (reason != TASK_SWITCH_IRET) {
2764 		next_tss_desc.type |= (1 << 1); /* set busy flag */
2765 		write_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2766 	}
2767 
2768 	ops->set_cr(ctxt, 0,  ops->get_cr(ctxt, 0) | X86_CR0_TS);
2769 	ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR);
2770 
2771 	if (has_error_code) {
2772 		ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2773 		ctxt->lock_prefix = 0;
2774 		ctxt->src.val = (unsigned long) error_code;
2775 		ret = em_push(ctxt);
2776 	}
2777 
2778 	return ret;
2779 }
2780 
2781 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2782 			 u16 tss_selector, int idt_index, int reason,
2783 			 bool has_error_code, u32 error_code)
2784 {
2785 	int rc;
2786 
2787 	invalidate_registers(ctxt);
2788 	ctxt->_eip = ctxt->eip;
2789 	ctxt->dst.type = OP_NONE;
2790 
2791 	rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason,
2792 				     has_error_code, error_code);
2793 
2794 	if (rc == X86EMUL_CONTINUE) {
2795 		ctxt->eip = ctxt->_eip;
2796 		writeback_registers(ctxt);
2797 	}
2798 
2799 	return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
2800 }
2801 
2802 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg,
2803 		struct operand *op)
2804 {
2805 	int df = (ctxt->eflags & EFLG_DF) ? -op->count : op->count;
2806 
2807 	register_address_increment(ctxt, reg_rmw(ctxt, reg), df * op->bytes);
2808 	op->addr.mem.ea = register_address(ctxt, reg_read(ctxt, reg));
2809 }
2810 
2811 static int em_das(struct x86_emulate_ctxt *ctxt)
2812 {
2813 	u8 al, old_al;
2814 	bool af, cf, old_cf;
2815 
2816 	cf = ctxt->eflags & X86_EFLAGS_CF;
2817 	al = ctxt->dst.val;
2818 
2819 	old_al = al;
2820 	old_cf = cf;
2821 	cf = false;
2822 	af = ctxt->eflags & X86_EFLAGS_AF;
2823 	if ((al & 0x0f) > 9 || af) {
2824 		al -= 6;
2825 		cf = old_cf | (al >= 250);
2826 		af = true;
2827 	} else {
2828 		af = false;
2829 	}
2830 	if (old_al > 0x99 || old_cf) {
2831 		al -= 0x60;
2832 		cf = true;
2833 	}
2834 
2835 	ctxt->dst.val = al;
2836 	/* Set PF, ZF, SF */
2837 	ctxt->src.type = OP_IMM;
2838 	ctxt->src.val = 0;
2839 	ctxt->src.bytes = 1;
2840 	fastop(ctxt, em_or);
2841 	ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
2842 	if (cf)
2843 		ctxt->eflags |= X86_EFLAGS_CF;
2844 	if (af)
2845 		ctxt->eflags |= X86_EFLAGS_AF;
2846 	return X86EMUL_CONTINUE;
2847 }
2848 
2849 static int em_aam(struct x86_emulate_ctxt *ctxt)
2850 {
2851 	u8 al, ah;
2852 
2853 	if (ctxt->src.val == 0)
2854 		return emulate_de(ctxt);
2855 
2856 	al = ctxt->dst.val & 0xff;
2857 	ah = al / ctxt->src.val;
2858 	al %= ctxt->src.val;
2859 
2860 	ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8);
2861 
2862 	/* Set PF, ZF, SF */
2863 	ctxt->src.type = OP_IMM;
2864 	ctxt->src.val = 0;
2865 	ctxt->src.bytes = 1;
2866 	fastop(ctxt, em_or);
2867 
2868 	return X86EMUL_CONTINUE;
2869 }
2870 
2871 static int em_aad(struct x86_emulate_ctxt *ctxt)
2872 {
2873 	u8 al = ctxt->dst.val & 0xff;
2874 	u8 ah = (ctxt->dst.val >> 8) & 0xff;
2875 
2876 	al = (al + (ah * ctxt->src.val)) & 0xff;
2877 
2878 	ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al;
2879 
2880 	/* Set PF, ZF, SF */
2881 	ctxt->src.type = OP_IMM;
2882 	ctxt->src.val = 0;
2883 	ctxt->src.bytes = 1;
2884 	fastop(ctxt, em_or);
2885 
2886 	return X86EMUL_CONTINUE;
2887 }
2888 
2889 static int em_call(struct x86_emulate_ctxt *ctxt)
2890 {
2891 	long rel = ctxt->src.val;
2892 
2893 	ctxt->src.val = (unsigned long)ctxt->_eip;
2894 	jmp_rel(ctxt, rel);
2895 	return em_push(ctxt);
2896 }
2897 
2898 static int em_call_far(struct x86_emulate_ctxt *ctxt)
2899 {
2900 	u16 sel, old_cs;
2901 	ulong old_eip;
2902 	int rc;
2903 
2904 	old_cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2905 	old_eip = ctxt->_eip;
2906 
2907 	memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2908 	if (load_segment_descriptor(ctxt, sel, VCPU_SREG_CS))
2909 		return X86EMUL_CONTINUE;
2910 
2911 	ctxt->_eip = 0;
2912 	memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
2913 
2914 	ctxt->src.val = old_cs;
2915 	rc = em_push(ctxt);
2916 	if (rc != X86EMUL_CONTINUE)
2917 		return rc;
2918 
2919 	ctxt->src.val = old_eip;
2920 	return em_push(ctxt);
2921 }
2922 
2923 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
2924 {
2925 	int rc;
2926 
2927 	ctxt->dst.type = OP_REG;
2928 	ctxt->dst.addr.reg = &ctxt->_eip;
2929 	ctxt->dst.bytes = ctxt->op_bytes;
2930 	rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
2931 	if (rc != X86EMUL_CONTINUE)
2932 		return rc;
2933 	rsp_increment(ctxt, ctxt->src.val);
2934 	return X86EMUL_CONTINUE;
2935 }
2936 
2937 static int em_xchg(struct x86_emulate_ctxt *ctxt)
2938 {
2939 	/* Write back the register source. */
2940 	ctxt->src.val = ctxt->dst.val;
2941 	write_register_operand(&ctxt->src);
2942 
2943 	/* Write back the memory destination with implicit LOCK prefix. */
2944 	ctxt->dst.val = ctxt->src.orig_val;
2945 	ctxt->lock_prefix = 1;
2946 	return X86EMUL_CONTINUE;
2947 }
2948 
2949 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
2950 {
2951 	ctxt->dst.val = ctxt->src2.val;
2952 	return fastop(ctxt, em_imul);
2953 }
2954 
2955 static int em_cwd(struct x86_emulate_ctxt *ctxt)
2956 {
2957 	ctxt->dst.type = OP_REG;
2958 	ctxt->dst.bytes = ctxt->src.bytes;
2959 	ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
2960 	ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1);
2961 
2962 	return X86EMUL_CONTINUE;
2963 }
2964 
2965 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
2966 {
2967 	u64 tsc = 0;
2968 
2969 	ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc);
2970 	*reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc;
2971 	*reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32;
2972 	return X86EMUL_CONTINUE;
2973 }
2974 
2975 static int em_rdpmc(struct x86_emulate_ctxt *ctxt)
2976 {
2977 	u64 pmc;
2978 
2979 	if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc))
2980 		return emulate_gp(ctxt, 0);
2981 	*reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc;
2982 	*reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32;
2983 	return X86EMUL_CONTINUE;
2984 }
2985 
2986 static int em_mov(struct x86_emulate_ctxt *ctxt)
2987 {
2988 	memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr));
2989 	return X86EMUL_CONTINUE;
2990 }
2991 
2992 #define FFL(x) bit(X86_FEATURE_##x)
2993 
2994 static int em_movbe(struct x86_emulate_ctxt *ctxt)
2995 {
2996 	u32 ebx, ecx, edx, eax = 1;
2997 	u16 tmp;
2998 
2999 	/*
3000 	 * Check MOVBE is set in the guest-visible CPUID leaf.
3001 	 */
3002 	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3003 	if (!(ecx & FFL(MOVBE)))
3004 		return emulate_ud(ctxt);
3005 
3006 	switch (ctxt->op_bytes) {
3007 	case 2:
3008 		/*
3009 		 * From MOVBE definition: "...When the operand size is 16 bits,
3010 		 * the upper word of the destination register remains unchanged
3011 		 * ..."
3012 		 *
3013 		 * Both casting ->valptr and ->val to u16 breaks strict aliasing
3014 		 * rules so we have to do the operation almost per hand.
3015 		 */
3016 		tmp = (u16)ctxt->src.val;
3017 		ctxt->dst.val &= ~0xffffUL;
3018 		ctxt->dst.val |= (unsigned long)swab16(tmp);
3019 		break;
3020 	case 4:
3021 		ctxt->dst.val = swab32((u32)ctxt->src.val);
3022 		break;
3023 	case 8:
3024 		ctxt->dst.val = swab64(ctxt->src.val);
3025 		break;
3026 	default:
3027 		BUG();
3028 	}
3029 	return X86EMUL_CONTINUE;
3030 }
3031 
3032 static int em_cr_write(struct x86_emulate_ctxt *ctxt)
3033 {
3034 	if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val))
3035 		return emulate_gp(ctxt, 0);
3036 
3037 	/* Disable writeback. */
3038 	ctxt->dst.type = OP_NONE;
3039 	return X86EMUL_CONTINUE;
3040 }
3041 
3042 static int em_dr_write(struct x86_emulate_ctxt *ctxt)
3043 {
3044 	unsigned long val;
3045 
3046 	if (ctxt->mode == X86EMUL_MODE_PROT64)
3047 		val = ctxt->src.val & ~0ULL;
3048 	else
3049 		val = ctxt->src.val & ~0U;
3050 
3051 	/* #UD condition is already handled. */
3052 	if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0)
3053 		return emulate_gp(ctxt, 0);
3054 
3055 	/* Disable writeback. */
3056 	ctxt->dst.type = OP_NONE;
3057 	return X86EMUL_CONTINUE;
3058 }
3059 
3060 static int em_wrmsr(struct x86_emulate_ctxt *ctxt)
3061 {
3062 	u64 msr_data;
3063 
3064 	msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX)
3065 		| ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32);
3066 	if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data))
3067 		return emulate_gp(ctxt, 0);
3068 
3069 	return X86EMUL_CONTINUE;
3070 }
3071 
3072 static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
3073 {
3074 	u64 msr_data;
3075 
3076 	if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data))
3077 		return emulate_gp(ctxt, 0);
3078 
3079 	*reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data;
3080 	*reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32;
3081 	return X86EMUL_CONTINUE;
3082 }
3083 
3084 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
3085 {
3086 	if (ctxt->modrm_reg > VCPU_SREG_GS)
3087 		return emulate_ud(ctxt);
3088 
3089 	ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
3090 	return X86EMUL_CONTINUE;
3091 }
3092 
3093 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
3094 {
3095 	u16 sel = ctxt->src.val;
3096 
3097 	if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS)
3098 		return emulate_ud(ctxt);
3099 
3100 	if (ctxt->modrm_reg == VCPU_SREG_SS)
3101 		ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
3102 
3103 	/* Disable writeback. */
3104 	ctxt->dst.type = OP_NONE;
3105 	return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
3106 }
3107 
3108 static int em_lldt(struct x86_emulate_ctxt *ctxt)
3109 {
3110 	u16 sel = ctxt->src.val;
3111 
3112 	/* Disable writeback. */
3113 	ctxt->dst.type = OP_NONE;
3114 	return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR);
3115 }
3116 
3117 static int em_ltr(struct x86_emulate_ctxt *ctxt)
3118 {
3119 	u16 sel = ctxt->src.val;
3120 
3121 	/* Disable writeback. */
3122 	ctxt->dst.type = OP_NONE;
3123 	return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR);
3124 }
3125 
3126 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
3127 {
3128 	int rc;
3129 	ulong linear;
3130 
3131 	rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
3132 	if (rc == X86EMUL_CONTINUE)
3133 		ctxt->ops->invlpg(ctxt, linear);
3134 	/* Disable writeback. */
3135 	ctxt->dst.type = OP_NONE;
3136 	return X86EMUL_CONTINUE;
3137 }
3138 
3139 static int em_clts(struct x86_emulate_ctxt *ctxt)
3140 {
3141 	ulong cr0;
3142 
3143 	cr0 = ctxt->ops->get_cr(ctxt, 0);
3144 	cr0 &= ~X86_CR0_TS;
3145 	ctxt->ops->set_cr(ctxt, 0, cr0);
3146 	return X86EMUL_CONTINUE;
3147 }
3148 
3149 static int em_vmcall(struct x86_emulate_ctxt *ctxt)
3150 {
3151 	int rc = ctxt->ops->fix_hypercall(ctxt);
3152 
3153 	if (rc != X86EMUL_CONTINUE)
3154 		return rc;
3155 
3156 	/* Let the processor re-execute the fixed hypercall */
3157 	ctxt->_eip = ctxt->eip;
3158 	/* Disable writeback. */
3159 	ctxt->dst.type = OP_NONE;
3160 	return X86EMUL_CONTINUE;
3161 }
3162 
3163 static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt,
3164 				  void (*get)(struct x86_emulate_ctxt *ctxt,
3165 					      struct desc_ptr *ptr))
3166 {
3167 	struct desc_ptr desc_ptr;
3168 
3169 	if (ctxt->mode == X86EMUL_MODE_PROT64)
3170 		ctxt->op_bytes = 8;
3171 	get(ctxt, &desc_ptr);
3172 	if (ctxt->op_bytes == 2) {
3173 		ctxt->op_bytes = 4;
3174 		desc_ptr.address &= 0x00ffffff;
3175 	}
3176 	/* Disable writeback. */
3177 	ctxt->dst.type = OP_NONE;
3178 	return segmented_write(ctxt, ctxt->dst.addr.mem,
3179 			       &desc_ptr, 2 + ctxt->op_bytes);
3180 }
3181 
3182 static int em_sgdt(struct x86_emulate_ctxt *ctxt)
3183 {
3184 	return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt);
3185 }
3186 
3187 static int em_sidt(struct x86_emulate_ctxt *ctxt)
3188 {
3189 	return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt);
3190 }
3191 
3192 static int em_lgdt(struct x86_emulate_ctxt *ctxt)
3193 {
3194 	struct desc_ptr desc_ptr;
3195 	int rc;
3196 
3197 	if (ctxt->mode == X86EMUL_MODE_PROT64)
3198 		ctxt->op_bytes = 8;
3199 	rc = read_descriptor(ctxt, ctxt->src.addr.mem,
3200 			     &desc_ptr.size, &desc_ptr.address,
3201 			     ctxt->op_bytes);
3202 	if (rc != X86EMUL_CONTINUE)
3203 		return rc;
3204 	ctxt->ops->set_gdt(ctxt, &desc_ptr);
3205 	/* Disable writeback. */
3206 	ctxt->dst.type = OP_NONE;
3207 	return X86EMUL_CONTINUE;
3208 }
3209 
3210 static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
3211 {
3212 	int rc;
3213 
3214 	rc = ctxt->ops->fix_hypercall(ctxt);
3215 
3216 	/* Disable writeback. */
3217 	ctxt->dst.type = OP_NONE;
3218 	return rc;
3219 }
3220 
3221 static int em_lidt(struct x86_emulate_ctxt *ctxt)
3222 {
3223 	struct desc_ptr desc_ptr;
3224 	int rc;
3225 
3226 	if (ctxt->mode == X86EMUL_MODE_PROT64)
3227 		ctxt->op_bytes = 8;
3228 	rc = read_descriptor(ctxt, ctxt->src.addr.mem,
3229 			     &desc_ptr.size, &desc_ptr.address,
3230 			     ctxt->op_bytes);
3231 	if (rc != X86EMUL_CONTINUE)
3232 		return rc;
3233 	ctxt->ops->set_idt(ctxt, &desc_ptr);
3234 	/* Disable writeback. */
3235 	ctxt->dst.type = OP_NONE;
3236 	return X86EMUL_CONTINUE;
3237 }
3238 
3239 static int em_smsw(struct x86_emulate_ctxt *ctxt)
3240 {
3241 	if (ctxt->dst.type == OP_MEM)
3242 		ctxt->dst.bytes = 2;
3243 	ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0);
3244 	return X86EMUL_CONTINUE;
3245 }
3246 
3247 static int em_lmsw(struct x86_emulate_ctxt *ctxt)
3248 {
3249 	ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul)
3250 			  | (ctxt->src.val & 0x0f));
3251 	ctxt->dst.type = OP_NONE;
3252 	return X86EMUL_CONTINUE;
3253 }
3254 
3255 static int em_loop(struct x86_emulate_ctxt *ctxt)
3256 {
3257 	register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -1);
3258 	if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) &&
3259 	    (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
3260 		jmp_rel(ctxt, ctxt->src.val);
3261 
3262 	return X86EMUL_CONTINUE;
3263 }
3264 
3265 static int em_jcxz(struct x86_emulate_ctxt *ctxt)
3266 {
3267 	if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0)
3268 		jmp_rel(ctxt, ctxt->src.val);
3269 
3270 	return X86EMUL_CONTINUE;
3271 }
3272 
3273 static int em_in(struct x86_emulate_ctxt *ctxt)
3274 {
3275 	if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val,
3276 			     &ctxt->dst.val))
3277 		return X86EMUL_IO_NEEDED;
3278 
3279 	return X86EMUL_CONTINUE;
3280 }
3281 
3282 static int em_out(struct x86_emulate_ctxt *ctxt)
3283 {
3284 	ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val,
3285 				    &ctxt->src.val, 1);
3286 	/* Disable writeback. */
3287 	ctxt->dst.type = OP_NONE;
3288 	return X86EMUL_CONTINUE;
3289 }
3290 
3291 static int em_cli(struct x86_emulate_ctxt *ctxt)
3292 {
3293 	if (emulator_bad_iopl(ctxt))
3294 		return emulate_gp(ctxt, 0);
3295 
3296 	ctxt->eflags &= ~X86_EFLAGS_IF;
3297 	return X86EMUL_CONTINUE;
3298 }
3299 
3300 static int em_sti(struct x86_emulate_ctxt *ctxt)
3301 {
3302 	if (emulator_bad_iopl(ctxt))
3303 		return emulate_gp(ctxt, 0);
3304 
3305 	ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
3306 	ctxt->eflags |= X86_EFLAGS_IF;
3307 	return X86EMUL_CONTINUE;
3308 }
3309 
3310 static int em_cpuid(struct x86_emulate_ctxt *ctxt)
3311 {
3312 	u32 eax, ebx, ecx, edx;
3313 
3314 	eax = reg_read(ctxt, VCPU_REGS_RAX);
3315 	ecx = reg_read(ctxt, VCPU_REGS_RCX);
3316 	ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3317 	*reg_write(ctxt, VCPU_REGS_RAX) = eax;
3318 	*reg_write(ctxt, VCPU_REGS_RBX) = ebx;
3319 	*reg_write(ctxt, VCPU_REGS_RCX) = ecx;
3320 	*reg_write(ctxt, VCPU_REGS_RDX) = edx;
3321 	return X86EMUL_CONTINUE;
3322 }
3323 
3324 static int em_sahf(struct x86_emulate_ctxt *ctxt)
3325 {
3326 	u32 flags;
3327 
3328 	flags = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF;
3329 	flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8;
3330 
3331 	ctxt->eflags &= ~0xffUL;
3332 	ctxt->eflags |= flags | X86_EFLAGS_FIXED;
3333 	return X86EMUL_CONTINUE;
3334 }
3335 
3336 static int em_lahf(struct x86_emulate_ctxt *ctxt)
3337 {
3338 	*reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL;
3339 	*reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8;
3340 	return X86EMUL_CONTINUE;
3341 }
3342 
3343 static int em_bswap(struct x86_emulate_ctxt *ctxt)
3344 {
3345 	switch (ctxt->op_bytes) {
3346 #ifdef CONFIG_X86_64
3347 	case 8:
3348 		asm("bswap %0" : "+r"(ctxt->dst.val));
3349 		break;
3350 #endif
3351 	default:
3352 		asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val));
3353 		break;
3354 	}
3355 	return X86EMUL_CONTINUE;
3356 }
3357 
3358 static bool valid_cr(int nr)
3359 {
3360 	switch (nr) {
3361 	case 0:
3362 	case 2 ... 4:
3363 	case 8:
3364 		return true;
3365 	default:
3366 		return false;
3367 	}
3368 }
3369 
3370 static int check_cr_read(struct x86_emulate_ctxt *ctxt)
3371 {
3372 	if (!valid_cr(ctxt->modrm_reg))
3373 		return emulate_ud(ctxt);
3374 
3375 	return X86EMUL_CONTINUE;
3376 }
3377 
3378 static int check_cr_write(struct x86_emulate_ctxt *ctxt)
3379 {
3380 	u64 new_val = ctxt->src.val64;
3381 	int cr = ctxt->modrm_reg;
3382 	u64 efer = 0;
3383 
3384 	static u64 cr_reserved_bits[] = {
3385 		0xffffffff00000000ULL,
3386 		0, 0, 0, /* CR3 checked later */
3387 		CR4_RESERVED_BITS,
3388 		0, 0, 0,
3389 		CR8_RESERVED_BITS,
3390 	};
3391 
3392 	if (!valid_cr(cr))
3393 		return emulate_ud(ctxt);
3394 
3395 	if (new_val & cr_reserved_bits[cr])
3396 		return emulate_gp(ctxt, 0);
3397 
3398 	switch (cr) {
3399 	case 0: {
3400 		u64 cr4;
3401 		if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
3402 		    ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
3403 			return emulate_gp(ctxt, 0);
3404 
3405 		cr4 = ctxt->ops->get_cr(ctxt, 4);
3406 		ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3407 
3408 		if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
3409 		    !(cr4 & X86_CR4_PAE))
3410 			return emulate_gp(ctxt, 0);
3411 
3412 		break;
3413 		}
3414 	case 3: {
3415 		u64 rsvd = 0;
3416 
3417 		ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3418 		if (efer & EFER_LMA)
3419 			rsvd = CR3_L_MODE_RESERVED_BITS;
3420 
3421 		if (new_val & rsvd)
3422 			return emulate_gp(ctxt, 0);
3423 
3424 		break;
3425 		}
3426 	case 4: {
3427 		ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3428 
3429 		if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
3430 			return emulate_gp(ctxt, 0);
3431 
3432 		break;
3433 		}
3434 	}
3435 
3436 	return X86EMUL_CONTINUE;
3437 }
3438 
3439 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
3440 {
3441 	unsigned long dr7;
3442 
3443 	ctxt->ops->get_dr(ctxt, 7, &dr7);
3444 
3445 	/* Check if DR7.Global_Enable is set */
3446 	return dr7 & (1 << 13);
3447 }
3448 
3449 static int check_dr_read(struct x86_emulate_ctxt *ctxt)
3450 {
3451 	int dr = ctxt->modrm_reg;
3452 	u64 cr4;
3453 
3454 	if (dr > 7)
3455 		return emulate_ud(ctxt);
3456 
3457 	cr4 = ctxt->ops->get_cr(ctxt, 4);
3458 	if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
3459 		return emulate_ud(ctxt);
3460 
3461 	if (check_dr7_gd(ctxt))
3462 		return emulate_db(ctxt);
3463 
3464 	return X86EMUL_CONTINUE;
3465 }
3466 
3467 static int check_dr_write(struct x86_emulate_ctxt *ctxt)
3468 {
3469 	u64 new_val = ctxt->src.val64;
3470 	int dr = ctxt->modrm_reg;
3471 
3472 	if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL))
3473 		return emulate_gp(ctxt, 0);
3474 
3475 	return check_dr_read(ctxt);
3476 }
3477 
3478 static int check_svme(struct x86_emulate_ctxt *ctxt)
3479 {
3480 	u64 efer;
3481 
3482 	ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3483 
3484 	if (!(efer & EFER_SVME))
3485 		return emulate_ud(ctxt);
3486 
3487 	return X86EMUL_CONTINUE;
3488 }
3489 
3490 static int check_svme_pa(struct x86_emulate_ctxt *ctxt)
3491 {
3492 	u64 rax = reg_read(ctxt, VCPU_REGS_RAX);
3493 
3494 	/* Valid physical address? */
3495 	if (rax & 0xffff000000000000ULL)
3496 		return emulate_gp(ctxt, 0);
3497 
3498 	return check_svme(ctxt);
3499 }
3500 
3501 static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
3502 {
3503 	u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3504 
3505 	if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
3506 		return emulate_ud(ctxt);
3507 
3508 	return X86EMUL_CONTINUE;
3509 }
3510 
3511 static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
3512 {
3513 	u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3514 	u64 rcx = reg_read(ctxt, VCPU_REGS_RCX);
3515 
3516 	if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) ||
3517 	    ctxt->ops->check_pmc(ctxt, rcx))
3518 		return emulate_gp(ctxt, 0);
3519 
3520 	return X86EMUL_CONTINUE;
3521 }
3522 
3523 static int check_perm_in(struct x86_emulate_ctxt *ctxt)
3524 {
3525 	ctxt->dst.bytes = min(ctxt->dst.bytes, 4u);
3526 	if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes))
3527 		return emulate_gp(ctxt, 0);
3528 
3529 	return X86EMUL_CONTINUE;
3530 }
3531 
3532 static int check_perm_out(struct x86_emulate_ctxt *ctxt)
3533 {
3534 	ctxt->src.bytes = min(ctxt->src.bytes, 4u);
3535 	if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes))
3536 		return emulate_gp(ctxt, 0);
3537 
3538 	return X86EMUL_CONTINUE;
3539 }
3540 
3541 #define D(_y) { .flags = (_y) }
3542 #define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i }
3543 #define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \
3544 		      .intercept = x86_intercept_##_i, .check_perm = (_p) }
3545 #define N    D(NotImpl)
3546 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
3547 #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) }
3548 #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) }
3549 #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) }
3550 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
3551 #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) }
3552 #define II(_f, _e, _i) \
3553 	{ .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i }
3554 #define IIP(_f, _e, _i, _p) \
3555 	{ .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \
3556 	  .intercept = x86_intercept_##_i, .check_perm = (_p) }
3557 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
3558 
3559 #define D2bv(_f)      D((_f) | ByteOp), D(_f)
3560 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)
3561 #define I2bv(_f, _e)  I((_f) | ByteOp, _e), I(_f, _e)
3562 #define F2bv(_f, _e)  F((_f) | ByteOp, _e), F(_f, _e)
3563 #define I2bvIP(_f, _e, _i, _p) \
3564 	IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p)
3565 
3566 #define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e),		\
3567 		F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e),	\
3568 		F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)
3569 
3570 static const struct opcode group7_rm0[] = {
3571 	N,
3572 	I(SrcNone | Priv | EmulateOnUD,	em_vmcall),
3573 	N, N, N, N, N, N,
3574 };
3575 
3576 static const struct opcode group7_rm1[] = {
3577 	DI(SrcNone | Priv, monitor),
3578 	DI(SrcNone | Priv, mwait),
3579 	N, N, N, N, N, N,
3580 };
3581 
3582 static const struct opcode group7_rm3[] = {
3583 	DIP(SrcNone | Prot | Priv,		vmrun,		check_svme_pa),
3584 	II(SrcNone  | Prot | EmulateOnUD,	em_vmmcall,	vmmcall),
3585 	DIP(SrcNone | Prot | Priv,		vmload,		check_svme_pa),
3586 	DIP(SrcNone | Prot | Priv,		vmsave,		check_svme_pa),
3587 	DIP(SrcNone | Prot | Priv,		stgi,		check_svme),
3588 	DIP(SrcNone | Prot | Priv,		clgi,		check_svme),
3589 	DIP(SrcNone | Prot | Priv,		skinit,		check_svme),
3590 	DIP(SrcNone | Prot | Priv,		invlpga,	check_svme),
3591 };
3592 
3593 static const struct opcode group7_rm7[] = {
3594 	N,
3595 	DIP(SrcNone, rdtscp, check_rdtsc),
3596 	N, N, N, N, N, N,
3597 };
3598 
3599 static const struct opcode group1[] = {
3600 	F(Lock, em_add),
3601 	F(Lock | PageTable, em_or),
3602 	F(Lock, em_adc),
3603 	F(Lock, em_sbb),
3604 	F(Lock | PageTable, em_and),
3605 	F(Lock, em_sub),
3606 	F(Lock, em_xor),
3607 	F(NoWrite, em_cmp),
3608 };
3609 
3610 static const struct opcode group1A[] = {
3611 	I(DstMem | SrcNone | Mov | Stack, em_pop), N, N, N, N, N, N, N,
3612 };
3613 
3614 static const struct opcode group2[] = {
3615 	F(DstMem | ModRM, em_rol),
3616 	F(DstMem | ModRM, em_ror),
3617 	F(DstMem | ModRM, em_rcl),
3618 	F(DstMem | ModRM, em_rcr),
3619 	F(DstMem | ModRM, em_shl),
3620 	F(DstMem | ModRM, em_shr),
3621 	F(DstMem | ModRM, em_shl),
3622 	F(DstMem | ModRM, em_sar),
3623 };
3624 
3625 static const struct opcode group3[] = {
3626 	F(DstMem | SrcImm | NoWrite, em_test),
3627 	F(DstMem | SrcImm | NoWrite, em_test),
3628 	F(DstMem | SrcNone | Lock, em_not),
3629 	F(DstMem | SrcNone | Lock, em_neg),
3630 	F(DstXacc | Src2Mem, em_mul_ex),
3631 	F(DstXacc | Src2Mem, em_imul_ex),
3632 	F(DstXacc | Src2Mem, em_div_ex),
3633 	F(DstXacc | Src2Mem, em_idiv_ex),
3634 };
3635 
3636 static const struct opcode group4[] = {
3637 	F(ByteOp | DstMem | SrcNone | Lock, em_inc),
3638 	F(ByteOp | DstMem | SrcNone | Lock, em_dec),
3639 	N, N, N, N, N, N,
3640 };
3641 
3642 static const struct opcode group5[] = {
3643 	F(DstMem | SrcNone | Lock,		em_inc),
3644 	F(DstMem | SrcNone | Lock,		em_dec),
3645 	I(SrcMem | Stack,			em_grp45),
3646 	I(SrcMemFAddr | ImplicitOps | Stack,	em_call_far),
3647 	I(SrcMem | Stack,			em_grp45),
3648 	I(SrcMemFAddr | ImplicitOps,		em_grp45),
3649 	I(SrcMem | Stack,			em_grp45), D(Undefined),
3650 };
3651 
3652 static const struct opcode group6[] = {
3653 	DI(Prot,	sldt),
3654 	DI(Prot,	str),
3655 	II(Prot | Priv | SrcMem16, em_lldt, lldt),
3656 	II(Prot | Priv | SrcMem16, em_ltr, ltr),
3657 	N, N, N, N,
3658 };
3659 
3660 static const struct group_dual group7 = { {
3661 	II(Mov | DstMem,			em_sgdt, sgdt),
3662 	II(Mov | DstMem,			em_sidt, sidt),
3663 	II(SrcMem | Priv,			em_lgdt, lgdt),
3664 	II(SrcMem | Priv,			em_lidt, lidt),
3665 	II(SrcNone | DstMem | Mov,		em_smsw, smsw), N,
3666 	II(SrcMem16 | Mov | Priv,		em_lmsw, lmsw),
3667 	II(SrcMem | ByteOp | Priv | NoAccess,	em_invlpg, invlpg),
3668 }, {
3669 	EXT(0, group7_rm0),
3670 	EXT(0, group7_rm1),
3671 	N, EXT(0, group7_rm3),
3672 	II(SrcNone | DstMem | Mov,		em_smsw, smsw), N,
3673 	II(SrcMem16 | Mov | Priv,		em_lmsw, lmsw),
3674 	EXT(0, group7_rm7),
3675 } };
3676 
3677 static const struct opcode group8[] = {
3678 	N, N, N, N,
3679 	F(DstMem | SrcImmByte | NoWrite,		em_bt),
3680 	F(DstMem | SrcImmByte | Lock | PageTable,	em_bts),
3681 	F(DstMem | SrcImmByte | Lock,			em_btr),
3682 	F(DstMem | SrcImmByte | Lock | PageTable,	em_btc),
3683 };
3684 
3685 static const struct group_dual group9 = { {
3686 	N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N,
3687 }, {
3688 	N, N, N, N, N, N, N, N,
3689 } };
3690 
3691 static const struct opcode group11[] = {
3692 	I(DstMem | SrcImm | Mov | PageTable, em_mov),
3693 	X7(D(Undefined)),
3694 };
3695 
3696 static const struct gprefix pfx_0f_6f_0f_7f = {
3697 	I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov),
3698 };
3699 
3700 static const struct gprefix pfx_0f_2b = {
3701 	I(0, em_mov), I(0, em_mov), N, N,
3702 };
3703 
3704 static const struct gprefix pfx_0f_28_0f_29 = {
3705 	I(Aligned, em_mov), I(Aligned, em_mov), N, N,
3706 };
3707 
3708 static const struct gprefix pfx_0f_e7 = {
3709 	N, I(Sse, em_mov), N, N,
3710 };
3711 
3712 static const struct escape escape_d9 = { {
3713 	N, N, N, N, N, N, N, I(DstMem, em_fnstcw),
3714 }, {
3715 	/* 0xC0 - 0xC7 */
3716 	N, N, N, N, N, N, N, N,
3717 	/* 0xC8 - 0xCF */
3718 	N, N, N, N, N, N, N, N,
3719 	/* 0xD0 - 0xC7 */
3720 	N, N, N, N, N, N, N, N,
3721 	/* 0xD8 - 0xDF */
3722 	N, N, N, N, N, N, N, N,
3723 	/* 0xE0 - 0xE7 */
3724 	N, N, N, N, N, N, N, N,
3725 	/* 0xE8 - 0xEF */
3726 	N, N, N, N, N, N, N, N,
3727 	/* 0xF0 - 0xF7 */
3728 	N, N, N, N, N, N, N, N,
3729 	/* 0xF8 - 0xFF */
3730 	N, N, N, N, N, N, N, N,
3731 } };
3732 
3733 static const struct escape escape_db = { {
3734 	N, N, N, N, N, N, N, N,
3735 }, {
3736 	/* 0xC0 - 0xC7 */
3737 	N, N, N, N, N, N, N, N,
3738 	/* 0xC8 - 0xCF */
3739 	N, N, N, N, N, N, N, N,
3740 	/* 0xD0 - 0xC7 */
3741 	N, N, N, N, N, N, N, N,
3742 	/* 0xD8 - 0xDF */
3743 	N, N, N, N, N, N, N, N,
3744 	/* 0xE0 - 0xE7 */
3745 	N, N, N, I(ImplicitOps, em_fninit), N, N, N, N,
3746 	/* 0xE8 - 0xEF */
3747 	N, N, N, N, N, N, N, N,
3748 	/* 0xF0 - 0xF7 */
3749 	N, N, N, N, N, N, N, N,
3750 	/* 0xF8 - 0xFF */
3751 	N, N, N, N, N, N, N, N,
3752 } };
3753 
3754 static const struct escape escape_dd = { {
3755 	N, N, N, N, N, N, N, I(DstMem, em_fnstsw),
3756 }, {
3757 	/* 0xC0 - 0xC7 */
3758 	N, N, N, N, N, N, N, N,
3759 	/* 0xC8 - 0xCF */
3760 	N, N, N, N, N, N, N, N,
3761 	/* 0xD0 - 0xC7 */
3762 	N, N, N, N, N, N, N, N,
3763 	/* 0xD8 - 0xDF */
3764 	N, N, N, N, N, N, N, N,
3765 	/* 0xE0 - 0xE7 */
3766 	N, N, N, N, N, N, N, N,
3767 	/* 0xE8 - 0xEF */
3768 	N, N, N, N, N, N, N, N,
3769 	/* 0xF0 - 0xF7 */
3770 	N, N, N, N, N, N, N, N,
3771 	/* 0xF8 - 0xFF */
3772 	N, N, N, N, N, N, N, N,
3773 } };
3774 
3775 static const struct opcode opcode_table[256] = {
3776 	/* 0x00 - 0x07 */
3777 	F6ALU(Lock, em_add),
3778 	I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),
3779 	I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),
3780 	/* 0x08 - 0x0F */
3781 	F6ALU(Lock | PageTable, em_or),
3782 	I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),
3783 	N,
3784 	/* 0x10 - 0x17 */
3785 	F6ALU(Lock, em_adc),
3786 	I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),
3787 	I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),
3788 	/* 0x18 - 0x1F */
3789 	F6ALU(Lock, em_sbb),
3790 	I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),
3791 	I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),
3792 	/* 0x20 - 0x27 */
3793 	F6ALU(Lock | PageTable, em_and), N, N,
3794 	/* 0x28 - 0x2F */
3795 	F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),
3796 	/* 0x30 - 0x37 */
3797 	F6ALU(Lock, em_xor), N, N,
3798 	/* 0x38 - 0x3F */
3799 	F6ALU(NoWrite, em_cmp), N, N,
3800 	/* 0x40 - 0x4F */
3801 	X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)),
3802 	/* 0x50 - 0x57 */
3803 	X8(I(SrcReg | Stack, em_push)),
3804 	/* 0x58 - 0x5F */
3805 	X8(I(DstReg | Stack, em_pop)),
3806 	/* 0x60 - 0x67 */
3807 	I(ImplicitOps | Stack | No64, em_pusha),
3808 	I(ImplicitOps | Stack | No64, em_popa),
3809 	N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ ,
3810 	N, N, N, N,
3811 	/* 0x68 - 0x6F */
3812 	I(SrcImm | Mov | Stack, em_push),
3813 	I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
3814 	I(SrcImmByte | Mov | Stack, em_push),
3815 	I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
3816 	I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */
3817 	I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */
3818 	/* 0x70 - 0x7F */
3819 	X16(D(SrcImmByte)),
3820 	/* 0x80 - 0x87 */
3821 	G(ByteOp | DstMem | SrcImm, group1),
3822 	G(DstMem | SrcImm, group1),
3823 	G(ByteOp | DstMem | SrcImm | No64, group1),
3824 	G(DstMem | SrcImmByte, group1),
3825 	F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test),
3826 	I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg),
3827 	/* 0x88 - 0x8F */
3828 	I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov),
3829 	I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
3830 	I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg),
3831 	D(ModRM | SrcMem | NoAccess | DstReg),
3832 	I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm),
3833 	G(0, group1A),
3834 	/* 0x90 - 0x97 */
3835 	DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
3836 	/* 0x98 - 0x9F */
3837 	D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
3838 	I(SrcImmFAddr | No64, em_call_far), N,
3839 	II(ImplicitOps | Stack, em_pushf, pushf),
3840 	II(ImplicitOps | Stack, em_popf, popf),
3841 	I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf),
3842 	/* 0xA0 - 0xA7 */
3843 	I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
3844 	I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
3845 	I2bv(SrcSI | DstDI | Mov | String, em_mov),
3846 	F2bv(SrcSI | DstDI | String | NoWrite, em_cmp),
3847 	/* 0xA8 - 0xAF */
3848 	F2bv(DstAcc | SrcImm | NoWrite, em_test),
3849 	I2bv(SrcAcc | DstDI | Mov | String, em_mov),
3850 	I2bv(SrcSI | DstAcc | Mov | String, em_mov),
3851 	F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp),
3852 	/* 0xB0 - 0xB7 */
3853 	X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
3854 	/* 0xB8 - 0xBF */
3855 	X8(I(DstReg | SrcImm64 | Mov, em_mov)),
3856 	/* 0xC0 - 0xC7 */
3857 	G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2),
3858 	I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
3859 	I(ImplicitOps | Stack, em_ret),
3860 	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
3861 	I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
3862 	G(ByteOp, group11), G(0, group11),
3863 	/* 0xC8 - 0xCF */
3864 	I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave),
3865 	I(ImplicitOps | Stack | SrcImmU16, em_ret_far_imm),
3866 	I(ImplicitOps | Stack, em_ret_far),
3867 	D(ImplicitOps), DI(SrcImmByte, intn),
3868 	D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
3869 	/* 0xD0 - 0xD7 */
3870 	G(Src2One | ByteOp, group2), G(Src2One, group2),
3871 	G(Src2CL | ByteOp, group2), G(Src2CL, group2),
3872 	I(DstAcc | SrcImmUByte | No64, em_aam),
3873 	I(DstAcc | SrcImmUByte | No64, em_aad),
3874 	F(DstAcc | ByteOp | No64, em_salc),
3875 	I(DstAcc | SrcXLat | ByteOp, em_mov),
3876 	/* 0xD8 - 0xDF */
3877 	N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
3878 	/* 0xE0 - 0xE7 */
3879 	X3(I(SrcImmByte, em_loop)),
3880 	I(SrcImmByte, em_jcxz),
3881 	I2bvIP(SrcImmUByte | DstAcc, em_in,  in,  check_perm_in),
3882 	I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),
3883 	/* 0xE8 - 0xEF */
3884 	I(SrcImm | Stack, em_call), D(SrcImm | ImplicitOps),
3885 	I(SrcImmFAddr | No64, em_jmp_far), D(SrcImmByte | ImplicitOps),
3886 	I2bvIP(SrcDX | DstAcc, em_in,  in,  check_perm_in),
3887 	I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),
3888 	/* 0xF0 - 0xF7 */
3889 	N, DI(ImplicitOps, icebp), N, N,
3890 	DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
3891 	G(ByteOp, group3), G(0, group3),
3892 	/* 0xF8 - 0xFF */
3893 	D(ImplicitOps), D(ImplicitOps),
3894 	I(ImplicitOps, em_cli), I(ImplicitOps, em_sti),
3895 	D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
3896 };
3897 
3898 static const struct opcode twobyte_table[256] = {
3899 	/* 0x00 - 0x0F */
3900 	G(0, group6), GD(0, &group7), N, N,
3901 	N, I(ImplicitOps | EmulateOnUD, em_syscall),
3902 	II(ImplicitOps | Priv, em_clts, clts), N,
3903 	DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
3904 	N, D(ImplicitOps | ModRM), N, N,
3905 	/* 0x10 - 0x1F */
3906 	N, N, N, N, N, N, N, N,
3907 	D(ImplicitOps | ModRM), N, N, N, N, N, N, D(ImplicitOps | ModRM),
3908 	/* 0x20 - 0x2F */
3909 	DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read),
3910 	DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read),
3911 	IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write,
3912 						check_cr_write),
3913 	IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write,
3914 						check_dr_write),
3915 	N, N, N, N,
3916 	GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29),
3917 	GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29),
3918 	N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b),
3919 	N, N, N, N,
3920 	/* 0x30 - 0x3F */
3921 	II(ImplicitOps | Priv, em_wrmsr, wrmsr),
3922 	IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
3923 	II(ImplicitOps | Priv, em_rdmsr, rdmsr),
3924 	IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
3925 	I(ImplicitOps | EmulateOnUD, em_sysenter),
3926 	I(ImplicitOps | Priv | EmulateOnUD, em_sysexit),
3927 	N, N,
3928 	N, N, N, N, N, N, N, N,
3929 	/* 0x40 - 0x4F */
3930 	X16(D(DstReg | SrcMem | ModRM)),
3931 	/* 0x50 - 0x5F */
3932 	N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3933 	/* 0x60 - 0x6F */
3934 	N, N, N, N,
3935 	N, N, N, N,
3936 	N, N, N, N,
3937 	N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f),
3938 	/* 0x70 - 0x7F */
3939 	N, N, N, N,
3940 	N, N, N, N,
3941 	N, N, N, N,
3942 	N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
3943 	/* 0x80 - 0x8F */
3944 	X16(D(SrcImm)),
3945 	/* 0x90 - 0x9F */
3946 	X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
3947 	/* 0xA0 - 0xA7 */
3948 	I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
3949 	II(ImplicitOps, em_cpuid, cpuid),
3950 	F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt),
3951 	F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld),
3952 	F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
3953 	/* 0xA8 - 0xAF */
3954 	I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
3955 	DI(ImplicitOps, rsm),
3956 	F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
3957 	F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
3958 	F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
3959 	D(ModRM), F(DstReg | SrcMem | ModRM, em_imul),
3960 	/* 0xB0 - 0xB7 */
3961 	I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
3962 	I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
3963 	F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
3964 	I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
3965 	I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
3966 	D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3967 	/* 0xB8 - 0xBF */
3968 	N, N,
3969 	G(BitOp, group8),
3970 	F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
3971 	F(DstReg | SrcMem | ModRM, em_bsf), F(DstReg | SrcMem | ModRM, em_bsr),
3972 	D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3973 	/* 0xC0 - 0xC7 */
3974 	F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),
3975 	N, D(DstMem | SrcReg | ModRM | Mov),
3976 	N, N, N, GD(0, &group9),
3977 	/* 0xC8 - 0xCF */
3978 	X8(I(DstReg, em_bswap)),
3979 	/* 0xD0 - 0xDF */
3980 	N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3981 	/* 0xE0 - 0xEF */
3982 	N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7),
3983 	N, N, N, N, N, N, N, N,
3984 	/* 0xF0 - 0xFF */
3985 	N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
3986 };
3987 
3988 static const struct gprefix three_byte_0f_38_f0 = {
3989 	I(DstReg | SrcMem | Mov, em_movbe), N, N, N
3990 };
3991 
3992 static const struct gprefix three_byte_0f_38_f1 = {
3993 	I(DstMem | SrcReg | Mov, em_movbe), N, N, N
3994 };
3995 
3996 /*
3997  * Insns below are selected by the prefix which indexed by the third opcode
3998  * byte.
3999  */
4000 static const struct opcode opcode_map_0f_38[256] = {
4001 	/* 0x00 - 0x7f */
4002 	X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4003 	/* 0x80 - 0xef */
4004 	X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4005 	/* 0xf0 - 0xf1 */
4006 	GP(EmulateOnUD | ModRM | Prefix, &three_byte_0f_38_f0),
4007 	GP(EmulateOnUD | ModRM | Prefix, &three_byte_0f_38_f1),
4008 	/* 0xf2 - 0xff */
4009 	N, N, X4(N), X8(N)
4010 };
4011 
4012 #undef D
4013 #undef N
4014 #undef G
4015 #undef GD
4016 #undef I
4017 #undef GP
4018 #undef EXT
4019 
4020 #undef D2bv
4021 #undef D2bvIP
4022 #undef I2bv
4023 #undef I2bvIP
4024 #undef I6ALU
4025 
4026 static unsigned imm_size(struct x86_emulate_ctxt *ctxt)
4027 {
4028 	unsigned size;
4029 
4030 	size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4031 	if (size == 8)
4032 		size = 4;
4033 	return size;
4034 }
4035 
4036 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
4037 		      unsigned size, bool sign_extension)
4038 {
4039 	int rc = X86EMUL_CONTINUE;
4040 
4041 	op->type = OP_IMM;
4042 	op->bytes = size;
4043 	op->addr.mem.ea = ctxt->_eip;
4044 	/* NB. Immediates are sign-extended as necessary. */
4045 	switch (op->bytes) {
4046 	case 1:
4047 		op->val = insn_fetch(s8, ctxt);
4048 		break;
4049 	case 2:
4050 		op->val = insn_fetch(s16, ctxt);
4051 		break;
4052 	case 4:
4053 		op->val = insn_fetch(s32, ctxt);
4054 		break;
4055 	case 8:
4056 		op->val = insn_fetch(s64, ctxt);
4057 		break;
4058 	}
4059 	if (!sign_extension) {
4060 		switch (op->bytes) {
4061 		case 1:
4062 			op->val &= 0xff;
4063 			break;
4064 		case 2:
4065 			op->val &= 0xffff;
4066 			break;
4067 		case 4:
4068 			op->val &= 0xffffffff;
4069 			break;
4070 		}
4071 	}
4072 done:
4073 	return rc;
4074 }
4075 
4076 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
4077 			  unsigned d)
4078 {
4079 	int rc = X86EMUL_CONTINUE;
4080 
4081 	switch (d) {
4082 	case OpReg:
4083 		decode_register_operand(ctxt, op);
4084 		break;
4085 	case OpImmUByte:
4086 		rc = decode_imm(ctxt, op, 1, false);
4087 		break;
4088 	case OpMem:
4089 		ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4090 	mem_common:
4091 		*op = ctxt->memop;
4092 		ctxt->memopp = op;
4093 		if (ctxt->d & BitOp)
4094 			fetch_bit_operand(ctxt);
4095 		op->orig_val = op->val;
4096 		break;
4097 	case OpMem64:
4098 		ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8;
4099 		goto mem_common;
4100 	case OpAcc:
4101 		op->type = OP_REG;
4102 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4103 		op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4104 		fetch_register_operand(op);
4105 		op->orig_val = op->val;
4106 		break;
4107 	case OpAccLo:
4108 		op->type = OP_REG;
4109 		op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes;
4110 		op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4111 		fetch_register_operand(op);
4112 		op->orig_val = op->val;
4113 		break;
4114 	case OpAccHi:
4115 		if (ctxt->d & ByteOp) {
4116 			op->type = OP_NONE;
4117 			break;
4118 		}
4119 		op->type = OP_REG;
4120 		op->bytes = ctxt->op_bytes;
4121 		op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4122 		fetch_register_operand(op);
4123 		op->orig_val = op->val;
4124 		break;
4125 	case OpDI:
4126 		op->type = OP_MEM;
4127 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4128 		op->addr.mem.ea =
4129 			register_address(ctxt, reg_read(ctxt, VCPU_REGS_RDI));
4130 		op->addr.mem.seg = VCPU_SREG_ES;
4131 		op->val = 0;
4132 		op->count = 1;
4133 		break;
4134 	case OpDX:
4135 		op->type = OP_REG;
4136 		op->bytes = 2;
4137 		op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4138 		fetch_register_operand(op);
4139 		break;
4140 	case OpCL:
4141 		op->bytes = 1;
4142 		op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff;
4143 		break;
4144 	case OpImmByte:
4145 		rc = decode_imm(ctxt, op, 1, true);
4146 		break;
4147 	case OpOne:
4148 		op->bytes = 1;
4149 		op->val = 1;
4150 		break;
4151 	case OpImm:
4152 		rc = decode_imm(ctxt, op, imm_size(ctxt), true);
4153 		break;
4154 	case OpImm64:
4155 		rc = decode_imm(ctxt, op, ctxt->op_bytes, true);
4156 		break;
4157 	case OpMem8:
4158 		ctxt->memop.bytes = 1;
4159 		if (ctxt->memop.type == OP_REG) {
4160 			ctxt->memop.addr.reg = decode_register(ctxt,
4161 					ctxt->modrm_rm, true);
4162 			fetch_register_operand(&ctxt->memop);
4163 		}
4164 		goto mem_common;
4165 	case OpMem16:
4166 		ctxt->memop.bytes = 2;
4167 		goto mem_common;
4168 	case OpMem32:
4169 		ctxt->memop.bytes = 4;
4170 		goto mem_common;
4171 	case OpImmU16:
4172 		rc = decode_imm(ctxt, op, 2, false);
4173 		break;
4174 	case OpImmU:
4175 		rc = decode_imm(ctxt, op, imm_size(ctxt), false);
4176 		break;
4177 	case OpSI:
4178 		op->type = OP_MEM;
4179 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4180 		op->addr.mem.ea =
4181 			register_address(ctxt, reg_read(ctxt, VCPU_REGS_RSI));
4182 		op->addr.mem.seg = ctxt->seg_override;
4183 		op->val = 0;
4184 		op->count = 1;
4185 		break;
4186 	case OpXLat:
4187 		op->type = OP_MEM;
4188 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4189 		op->addr.mem.ea =
4190 			register_address(ctxt,
4191 				reg_read(ctxt, VCPU_REGS_RBX) +
4192 				(reg_read(ctxt, VCPU_REGS_RAX) & 0xff));
4193 		op->addr.mem.seg = ctxt->seg_override;
4194 		op->val = 0;
4195 		break;
4196 	case OpImmFAddr:
4197 		op->type = OP_IMM;
4198 		op->addr.mem.ea = ctxt->_eip;
4199 		op->bytes = ctxt->op_bytes + 2;
4200 		insn_fetch_arr(op->valptr, op->bytes, ctxt);
4201 		break;
4202 	case OpMemFAddr:
4203 		ctxt->memop.bytes = ctxt->op_bytes + 2;
4204 		goto mem_common;
4205 	case OpES:
4206 		op->val = VCPU_SREG_ES;
4207 		break;
4208 	case OpCS:
4209 		op->val = VCPU_SREG_CS;
4210 		break;
4211 	case OpSS:
4212 		op->val = VCPU_SREG_SS;
4213 		break;
4214 	case OpDS:
4215 		op->val = VCPU_SREG_DS;
4216 		break;
4217 	case OpFS:
4218 		op->val = VCPU_SREG_FS;
4219 		break;
4220 	case OpGS:
4221 		op->val = VCPU_SREG_GS;
4222 		break;
4223 	case OpImplicit:
4224 		/* Special instructions do their own operand decoding. */
4225 	default:
4226 		op->type = OP_NONE; /* Disable writeback. */
4227 		break;
4228 	}
4229 
4230 done:
4231 	return rc;
4232 }
4233 
4234 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
4235 {
4236 	int rc = X86EMUL_CONTINUE;
4237 	int mode = ctxt->mode;
4238 	int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
4239 	bool op_prefix = false;
4240 	bool has_seg_override = false;
4241 	struct opcode opcode;
4242 
4243 	ctxt->memop.type = OP_NONE;
4244 	ctxt->memopp = NULL;
4245 	ctxt->_eip = ctxt->eip;
4246 	ctxt->fetch.ptr = ctxt->fetch.data;
4247 	ctxt->fetch.end = ctxt->fetch.data + insn_len;
4248 	ctxt->opcode_len = 1;
4249 	if (insn_len > 0)
4250 		memcpy(ctxt->fetch.data, insn, insn_len);
4251 	else {
4252 		rc = __do_insn_fetch_bytes(ctxt, 1);
4253 		if (rc != X86EMUL_CONTINUE)
4254 			return rc;
4255 	}
4256 
4257 	switch (mode) {
4258 	case X86EMUL_MODE_REAL:
4259 	case X86EMUL_MODE_VM86:
4260 	case X86EMUL_MODE_PROT16:
4261 		def_op_bytes = def_ad_bytes = 2;
4262 		break;
4263 	case X86EMUL_MODE_PROT32:
4264 		def_op_bytes = def_ad_bytes = 4;
4265 		break;
4266 #ifdef CONFIG_X86_64
4267 	case X86EMUL_MODE_PROT64:
4268 		def_op_bytes = 4;
4269 		def_ad_bytes = 8;
4270 		break;
4271 #endif
4272 	default:
4273 		return EMULATION_FAILED;
4274 	}
4275 
4276 	ctxt->op_bytes = def_op_bytes;
4277 	ctxt->ad_bytes = def_ad_bytes;
4278 
4279 	/* Legacy prefixes. */
4280 	for (;;) {
4281 		switch (ctxt->b = insn_fetch(u8, ctxt)) {
4282 		case 0x66:	/* operand-size override */
4283 			op_prefix = true;
4284 			/* switch between 2/4 bytes */
4285 			ctxt->op_bytes = def_op_bytes ^ 6;
4286 			break;
4287 		case 0x67:	/* address-size override */
4288 			if (mode == X86EMUL_MODE_PROT64)
4289 				/* switch between 4/8 bytes */
4290 				ctxt->ad_bytes = def_ad_bytes ^ 12;
4291 			else
4292 				/* switch between 2/4 bytes */
4293 				ctxt->ad_bytes = def_ad_bytes ^ 6;
4294 			break;
4295 		case 0x26:	/* ES override */
4296 		case 0x2e:	/* CS override */
4297 		case 0x36:	/* SS override */
4298 		case 0x3e:	/* DS override */
4299 			has_seg_override = true;
4300 			ctxt->seg_override = (ctxt->b >> 3) & 3;
4301 			break;
4302 		case 0x64:	/* FS override */
4303 		case 0x65:	/* GS override */
4304 			has_seg_override = true;
4305 			ctxt->seg_override = ctxt->b & 7;
4306 			break;
4307 		case 0x40 ... 0x4f: /* REX */
4308 			if (mode != X86EMUL_MODE_PROT64)
4309 				goto done_prefixes;
4310 			ctxt->rex_prefix = ctxt->b;
4311 			continue;
4312 		case 0xf0:	/* LOCK */
4313 			ctxt->lock_prefix = 1;
4314 			break;
4315 		case 0xf2:	/* REPNE/REPNZ */
4316 		case 0xf3:	/* REP/REPE/REPZ */
4317 			ctxt->rep_prefix = ctxt->b;
4318 			break;
4319 		default:
4320 			goto done_prefixes;
4321 		}
4322 
4323 		/* Any legacy prefix after a REX prefix nullifies its effect. */
4324 
4325 		ctxt->rex_prefix = 0;
4326 	}
4327 
4328 done_prefixes:
4329 
4330 	/* REX prefix. */
4331 	if (ctxt->rex_prefix & 8)
4332 		ctxt->op_bytes = 8;	/* REX.W */
4333 
4334 	/* Opcode byte(s). */
4335 	opcode = opcode_table[ctxt->b];
4336 	/* Two-byte opcode? */
4337 	if (ctxt->b == 0x0f) {
4338 		ctxt->opcode_len = 2;
4339 		ctxt->b = insn_fetch(u8, ctxt);
4340 		opcode = twobyte_table[ctxt->b];
4341 
4342 		/* 0F_38 opcode map */
4343 		if (ctxt->b == 0x38) {
4344 			ctxt->opcode_len = 3;
4345 			ctxt->b = insn_fetch(u8, ctxt);
4346 			opcode = opcode_map_0f_38[ctxt->b];
4347 		}
4348 	}
4349 	ctxt->d = opcode.flags;
4350 
4351 	if (ctxt->d & ModRM)
4352 		ctxt->modrm = insn_fetch(u8, ctxt);
4353 
4354 	/* vex-prefix instructions are not implemented */
4355 	if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) &&
4356 	    (mode == X86EMUL_MODE_PROT64 ||
4357 	    (mode >= X86EMUL_MODE_PROT16 && (ctxt->modrm & 0x80)))) {
4358 		ctxt->d = NotImpl;
4359 	}
4360 
4361 	while (ctxt->d & GroupMask) {
4362 		switch (ctxt->d & GroupMask) {
4363 		case Group:
4364 			goffset = (ctxt->modrm >> 3) & 7;
4365 			opcode = opcode.u.group[goffset];
4366 			break;
4367 		case GroupDual:
4368 			goffset = (ctxt->modrm >> 3) & 7;
4369 			if ((ctxt->modrm >> 6) == 3)
4370 				opcode = opcode.u.gdual->mod3[goffset];
4371 			else
4372 				opcode = opcode.u.gdual->mod012[goffset];
4373 			break;
4374 		case RMExt:
4375 			goffset = ctxt->modrm & 7;
4376 			opcode = opcode.u.group[goffset];
4377 			break;
4378 		case Prefix:
4379 			if (ctxt->rep_prefix && op_prefix)
4380 				return EMULATION_FAILED;
4381 			simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
4382 			switch (simd_prefix) {
4383 			case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
4384 			case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
4385 			case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
4386 			case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
4387 			}
4388 			break;
4389 		case Escape:
4390 			if (ctxt->modrm > 0xbf)
4391 				opcode = opcode.u.esc->high[ctxt->modrm - 0xc0];
4392 			else
4393 				opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7];
4394 			break;
4395 		default:
4396 			return EMULATION_FAILED;
4397 		}
4398 
4399 		ctxt->d &= ~(u64)GroupMask;
4400 		ctxt->d |= opcode.flags;
4401 	}
4402 
4403 	/* Unrecognised? */
4404 	if (ctxt->d == 0)
4405 		return EMULATION_FAILED;
4406 
4407 	ctxt->execute = opcode.u.execute;
4408 
4409 	if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD)))
4410 		return EMULATION_FAILED;
4411 
4412 	if (unlikely(ctxt->d &
4413 		     (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) {
4414 		/*
4415 		 * These are copied unconditionally here, and checked unconditionally
4416 		 * in x86_emulate_insn.
4417 		 */
4418 		ctxt->check_perm = opcode.check_perm;
4419 		ctxt->intercept = opcode.intercept;
4420 
4421 		if (ctxt->d & NotImpl)
4422 			return EMULATION_FAILED;
4423 
4424 		if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))
4425 			ctxt->op_bytes = 8;
4426 
4427 		if (ctxt->d & Op3264) {
4428 			if (mode == X86EMUL_MODE_PROT64)
4429 				ctxt->op_bytes = 8;
4430 			else
4431 				ctxt->op_bytes = 4;
4432 		}
4433 
4434 		if (ctxt->d & Sse)
4435 			ctxt->op_bytes = 16;
4436 		else if (ctxt->d & Mmx)
4437 			ctxt->op_bytes = 8;
4438 	}
4439 
4440 	/* ModRM and SIB bytes. */
4441 	if (ctxt->d & ModRM) {
4442 		rc = decode_modrm(ctxt, &ctxt->memop);
4443 		if (!has_seg_override) {
4444 			has_seg_override = true;
4445 			ctxt->seg_override = ctxt->modrm_seg;
4446 		}
4447 	} else if (ctxt->d & MemAbs)
4448 		rc = decode_abs(ctxt, &ctxt->memop);
4449 	if (rc != X86EMUL_CONTINUE)
4450 		goto done;
4451 
4452 	if (!has_seg_override)
4453 		ctxt->seg_override = VCPU_SREG_DS;
4454 
4455 	ctxt->memop.addr.mem.seg = ctxt->seg_override;
4456 
4457 	/*
4458 	 * Decode and fetch the source operand: register, memory
4459 	 * or immediate.
4460 	 */
4461 	rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask);
4462 	if (rc != X86EMUL_CONTINUE)
4463 		goto done;
4464 
4465 	/*
4466 	 * Decode and fetch the second source operand: register, memory
4467 	 * or immediate.
4468 	 */
4469 	rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask);
4470 	if (rc != X86EMUL_CONTINUE)
4471 		goto done;
4472 
4473 	/* Decode and fetch the destination operand: register or memory. */
4474 	rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
4475 
4476 done:
4477 	if (ctxt->rip_relative)
4478 		ctxt->memopp->addr.mem.ea += ctxt->_eip;
4479 
4480 	return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
4481 }
4482 
4483 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt)
4484 {
4485 	return ctxt->d & PageTable;
4486 }
4487 
4488 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
4489 {
4490 	/* The second termination condition only applies for REPE
4491 	 * and REPNE. Test if the repeat string operation prefix is
4492 	 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
4493 	 * corresponding termination condition according to:
4494 	 * 	- if REPE/REPZ and ZF = 0 then done
4495 	 * 	- if REPNE/REPNZ and ZF = 1 then done
4496 	 */
4497 	if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) ||
4498 	     (ctxt->b == 0xae) || (ctxt->b == 0xaf))
4499 	    && (((ctxt->rep_prefix == REPE_PREFIX) &&
4500 		 ((ctxt->eflags & EFLG_ZF) == 0))
4501 		|| ((ctxt->rep_prefix == REPNE_PREFIX) &&
4502 		    ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
4503 		return true;
4504 
4505 	return false;
4506 }
4507 
4508 static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
4509 {
4510 	bool fault = false;
4511 
4512 	ctxt->ops->get_fpu(ctxt);
4513 	asm volatile("1: fwait \n\t"
4514 		     "2: \n\t"
4515 		     ".pushsection .fixup,\"ax\" \n\t"
4516 		     "3: \n\t"
4517 		     "movb $1, %[fault] \n\t"
4518 		     "jmp 2b \n\t"
4519 		     ".popsection \n\t"
4520 		     _ASM_EXTABLE(1b, 3b)
4521 		     : [fault]"+qm"(fault));
4522 	ctxt->ops->put_fpu(ctxt);
4523 
4524 	if (unlikely(fault))
4525 		return emulate_exception(ctxt, MF_VECTOR, 0, false);
4526 
4527 	return X86EMUL_CONTINUE;
4528 }
4529 
4530 static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt,
4531 				       struct operand *op)
4532 {
4533 	if (op->type == OP_MM)
4534 		read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
4535 }
4536 
4537 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
4538 {
4539 	ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF;
4540 	if (!(ctxt->d & ByteOp))
4541 		fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE;
4542 	asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n"
4543 	    : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags),
4544 	      [fastop]"+S"(fop)
4545 	    : "c"(ctxt->src2.val));
4546 	ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);
4547 	if (!fop) /* exception is returned in fop variable */
4548 		return emulate_de(ctxt);
4549 	return X86EMUL_CONTINUE;
4550 }
4551 
4552 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
4553 {
4554 	memset(&ctxt->rip_relative, 0,
4555 	       (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
4556 
4557 	ctxt->io_read.pos = 0;
4558 	ctxt->io_read.end = 0;
4559 	ctxt->mem_read.end = 0;
4560 }
4561 
4562 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
4563 {
4564 	const struct x86_emulate_ops *ops = ctxt->ops;
4565 	int rc = X86EMUL_CONTINUE;
4566 	int saved_dst_type = ctxt->dst.type;
4567 
4568 	ctxt->mem_read.pos = 0;
4569 
4570 	/* LOCK prefix is allowed only with some instructions */
4571 	if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) {
4572 		rc = emulate_ud(ctxt);
4573 		goto done;
4574 	}
4575 
4576 	if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) {
4577 		rc = emulate_ud(ctxt);
4578 		goto done;
4579 	}
4580 
4581 	if (unlikely(ctxt->d &
4582 		     (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) {
4583 		if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) ||
4584 				(ctxt->d & Undefined)) {
4585 			rc = emulate_ud(ctxt);
4586 			goto done;
4587 		}
4588 
4589 		if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM)))
4590 		    || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) {
4591 			rc = emulate_ud(ctxt);
4592 			goto done;
4593 		}
4594 
4595 		if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) {
4596 			rc = emulate_nm(ctxt);
4597 			goto done;
4598 		}
4599 
4600 		if (ctxt->d & Mmx) {
4601 			rc = flush_pending_x87_faults(ctxt);
4602 			if (rc != X86EMUL_CONTINUE)
4603 				goto done;
4604 			/*
4605 			 * Now that we know the fpu is exception safe, we can fetch
4606 			 * operands from it.
4607 			 */
4608 			fetch_possible_mmx_operand(ctxt, &ctxt->src);
4609 			fetch_possible_mmx_operand(ctxt, &ctxt->src2);
4610 			if (!(ctxt->d & Mov))
4611 				fetch_possible_mmx_operand(ctxt, &ctxt->dst);
4612 		}
4613 
4614 		if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4615 			rc = emulator_check_intercept(ctxt, ctxt->intercept,
4616 						      X86_ICPT_PRE_EXCEPT);
4617 			if (rc != X86EMUL_CONTINUE)
4618 				goto done;
4619 		}
4620 
4621 		/* Privileged instruction can be executed only in CPL=0 */
4622 		if ((ctxt->d & Priv) && ops->cpl(ctxt)) {
4623 			if (ctxt->d & PrivUD)
4624 				rc = emulate_ud(ctxt);
4625 			else
4626 				rc = emulate_gp(ctxt, 0);
4627 			goto done;
4628 		}
4629 
4630 		/* Instruction can only be executed in protected mode */
4631 		if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) {
4632 			rc = emulate_ud(ctxt);
4633 			goto done;
4634 		}
4635 
4636 		/* Do instruction specific permission checks */
4637 		if (ctxt->d & CheckPerm) {
4638 			rc = ctxt->check_perm(ctxt);
4639 			if (rc != X86EMUL_CONTINUE)
4640 				goto done;
4641 		}
4642 
4643 		if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4644 			rc = emulator_check_intercept(ctxt, ctxt->intercept,
4645 						      X86_ICPT_POST_EXCEPT);
4646 			if (rc != X86EMUL_CONTINUE)
4647 				goto done;
4648 		}
4649 
4650 		if (ctxt->rep_prefix && (ctxt->d & String)) {
4651 			/* All REP prefixes have the same first termination condition */
4652 			if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) {
4653 				ctxt->eip = ctxt->_eip;
4654 				ctxt->eflags &= ~EFLG_RF;
4655 				goto done;
4656 			}
4657 		}
4658 	}
4659 
4660 	if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) {
4661 		rc = segmented_read(ctxt, ctxt->src.addr.mem,
4662 				    ctxt->src.valptr, ctxt->src.bytes);
4663 		if (rc != X86EMUL_CONTINUE)
4664 			goto done;
4665 		ctxt->src.orig_val64 = ctxt->src.val64;
4666 	}
4667 
4668 	if (ctxt->src2.type == OP_MEM) {
4669 		rc = segmented_read(ctxt, ctxt->src2.addr.mem,
4670 				    &ctxt->src2.val, ctxt->src2.bytes);
4671 		if (rc != X86EMUL_CONTINUE)
4672 			goto done;
4673 	}
4674 
4675 	if ((ctxt->d & DstMask) == ImplicitOps)
4676 		goto special_insn;
4677 
4678 
4679 	if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) {
4680 		/* optimisation - avoid slow emulated read if Mov */
4681 		rc = segmented_read(ctxt, ctxt->dst.addr.mem,
4682 				   &ctxt->dst.val, ctxt->dst.bytes);
4683 		if (rc != X86EMUL_CONTINUE)
4684 			goto done;
4685 	}
4686 	ctxt->dst.orig_val = ctxt->dst.val;
4687 
4688 special_insn:
4689 
4690 	if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4691 		rc = emulator_check_intercept(ctxt, ctxt->intercept,
4692 					      X86_ICPT_POST_MEMACCESS);
4693 		if (rc != X86EMUL_CONTINUE)
4694 			goto done;
4695 	}
4696 
4697 	if (ctxt->rep_prefix && (ctxt->d & String))
4698 		ctxt->eflags |= EFLG_RF;
4699 	else
4700 		ctxt->eflags &= ~EFLG_RF;
4701 
4702 	if (ctxt->execute) {
4703 		if (ctxt->d & Fastop) {
4704 			void (*fop)(struct fastop *) = (void *)ctxt->execute;
4705 			rc = fastop(ctxt, fop);
4706 			if (rc != X86EMUL_CONTINUE)
4707 				goto done;
4708 			goto writeback;
4709 		}
4710 		rc = ctxt->execute(ctxt);
4711 		if (rc != X86EMUL_CONTINUE)
4712 			goto done;
4713 		goto writeback;
4714 	}
4715 
4716 	if (ctxt->opcode_len == 2)
4717 		goto twobyte_insn;
4718 	else if (ctxt->opcode_len == 3)
4719 		goto threebyte_insn;
4720 
4721 	switch (ctxt->b) {
4722 	case 0x63:		/* movsxd */
4723 		if (ctxt->mode != X86EMUL_MODE_PROT64)
4724 			goto cannot_emulate;
4725 		ctxt->dst.val = (s32) ctxt->src.val;
4726 		break;
4727 	case 0x70 ... 0x7f: /* jcc (short) */
4728 		if (test_cc(ctxt->b, ctxt->eflags))
4729 			jmp_rel(ctxt, ctxt->src.val);
4730 		break;
4731 	case 0x8d: /* lea r16/r32, m */
4732 		ctxt->dst.val = ctxt->src.addr.mem.ea;
4733 		break;
4734 	case 0x90 ... 0x97: /* nop / xchg reg, rax */
4735 		if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX))
4736 			ctxt->dst.type = OP_NONE;
4737 		else
4738 			rc = em_xchg(ctxt);
4739 		break;
4740 	case 0x98: /* cbw/cwde/cdqe */
4741 		switch (ctxt->op_bytes) {
4742 		case 2: ctxt->dst.val = (s8)ctxt->dst.val; break;
4743 		case 4: ctxt->dst.val = (s16)ctxt->dst.val; break;
4744 		case 8: ctxt->dst.val = (s32)ctxt->dst.val; break;
4745 		}
4746 		break;
4747 	case 0xcc:		/* int3 */
4748 		rc = emulate_int(ctxt, 3);
4749 		break;
4750 	case 0xcd:		/* int n */
4751 		rc = emulate_int(ctxt, ctxt->src.val);
4752 		break;
4753 	case 0xce:		/* into */
4754 		if (ctxt->eflags & EFLG_OF)
4755 			rc = emulate_int(ctxt, 4);
4756 		break;
4757 	case 0xe9: /* jmp rel */
4758 	case 0xeb: /* jmp rel short */
4759 		jmp_rel(ctxt, ctxt->src.val);
4760 		ctxt->dst.type = OP_NONE; /* Disable writeback. */
4761 		break;
4762 	case 0xf4:              /* hlt */
4763 		ctxt->ops->halt(ctxt);
4764 		break;
4765 	case 0xf5:	/* cmc */
4766 		/* complement carry flag from eflags reg */
4767 		ctxt->eflags ^= EFLG_CF;
4768 		break;
4769 	case 0xf8: /* clc */
4770 		ctxt->eflags &= ~EFLG_CF;
4771 		break;
4772 	case 0xf9: /* stc */
4773 		ctxt->eflags |= EFLG_CF;
4774 		break;
4775 	case 0xfc: /* cld */
4776 		ctxt->eflags &= ~EFLG_DF;
4777 		break;
4778 	case 0xfd: /* std */
4779 		ctxt->eflags |= EFLG_DF;
4780 		break;
4781 	default:
4782 		goto cannot_emulate;
4783 	}
4784 
4785 	if (rc != X86EMUL_CONTINUE)
4786 		goto done;
4787 
4788 writeback:
4789 	if (ctxt->d & SrcWrite) {
4790 		BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR);
4791 		rc = writeback(ctxt, &ctxt->src);
4792 		if (rc != X86EMUL_CONTINUE)
4793 			goto done;
4794 	}
4795 	if (!(ctxt->d & NoWrite)) {
4796 		rc = writeback(ctxt, &ctxt->dst);
4797 		if (rc != X86EMUL_CONTINUE)
4798 			goto done;
4799 	}
4800 
4801 	/*
4802 	 * restore dst type in case the decoding will be reused
4803 	 * (happens for string instruction )
4804 	 */
4805 	ctxt->dst.type = saved_dst_type;
4806 
4807 	if ((ctxt->d & SrcMask) == SrcSI)
4808 		string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src);
4809 
4810 	if ((ctxt->d & DstMask) == DstDI)
4811 		string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst);
4812 
4813 	if (ctxt->rep_prefix && (ctxt->d & String)) {
4814 		unsigned int count;
4815 		struct read_cache *r = &ctxt->io_read;
4816 		if ((ctxt->d & SrcMask) == SrcSI)
4817 			count = ctxt->src.count;
4818 		else
4819 			count = ctxt->dst.count;
4820 		register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX),
4821 				-count);
4822 
4823 		if (!string_insn_completed(ctxt)) {
4824 			/*
4825 			 * Re-enter guest when pio read ahead buffer is empty
4826 			 * or, if it is not used, after each 1024 iteration.
4827 			 */
4828 			if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) &&
4829 			    (r->end == 0 || r->end != r->pos)) {
4830 				/*
4831 				 * Reset read cache. Usually happens before
4832 				 * decode, but since instruction is restarted
4833 				 * we have to do it here.
4834 				 */
4835 				ctxt->mem_read.end = 0;
4836 				writeback_registers(ctxt);
4837 				return EMULATION_RESTART;
4838 			}
4839 			goto done; /* skip rip writeback */
4840 		}
4841 		ctxt->eflags &= ~EFLG_RF;
4842 	}
4843 
4844 	ctxt->eip = ctxt->_eip;
4845 
4846 done:
4847 	if (rc == X86EMUL_PROPAGATE_FAULT) {
4848 		WARN_ON(ctxt->exception.vector > 0x1f);
4849 		ctxt->have_exception = true;
4850 	}
4851 	if (rc == X86EMUL_INTERCEPTED)
4852 		return EMULATION_INTERCEPTED;
4853 
4854 	if (rc == X86EMUL_CONTINUE)
4855 		writeback_registers(ctxt);
4856 
4857 	return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
4858 
4859 twobyte_insn:
4860 	switch (ctxt->b) {
4861 	case 0x09:		/* wbinvd */
4862 		(ctxt->ops->wbinvd)(ctxt);
4863 		break;
4864 	case 0x08:		/* invd */
4865 	case 0x0d:		/* GrpP (prefetch) */
4866 	case 0x18:		/* Grp16 (prefetch/nop) */
4867 	case 0x1f:		/* nop */
4868 		break;
4869 	case 0x20: /* mov cr, reg */
4870 		ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
4871 		break;
4872 	case 0x21: /* mov from dr to reg */
4873 		ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
4874 		break;
4875 	case 0x40 ... 0x4f:	/* cmov */
4876 		if (test_cc(ctxt->b, ctxt->eflags))
4877 			ctxt->dst.val = ctxt->src.val;
4878 		else if (ctxt->mode != X86EMUL_MODE_PROT64 ||
4879 			 ctxt->op_bytes != 4)
4880 			ctxt->dst.type = OP_NONE; /* no writeback */
4881 		break;
4882 	case 0x80 ... 0x8f: /* jnz rel, etc*/
4883 		if (test_cc(ctxt->b, ctxt->eflags))
4884 			jmp_rel(ctxt, ctxt->src.val);
4885 		break;
4886 	case 0x90 ... 0x9f:     /* setcc r/m8 */
4887 		ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
4888 		break;
4889 	case 0xae:              /* clflush */
4890 		break;
4891 	case 0xb6 ... 0xb7:	/* movzx */
4892 		ctxt->dst.bytes = ctxt->op_bytes;
4893 		ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val
4894 						       : (u16) ctxt->src.val;
4895 		break;
4896 	case 0xbe ... 0xbf:	/* movsx */
4897 		ctxt->dst.bytes = ctxt->op_bytes;
4898 		ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val :
4899 							(s16) ctxt->src.val;
4900 		break;
4901 	case 0xc3:		/* movnti */
4902 		ctxt->dst.bytes = ctxt->op_bytes;
4903 		ctxt->dst.val = (ctxt->op_bytes == 8) ? (u64) ctxt->src.val :
4904 							(u32) ctxt->src.val;
4905 		break;
4906 	default:
4907 		goto cannot_emulate;
4908 	}
4909 
4910 threebyte_insn:
4911 
4912 	if (rc != X86EMUL_CONTINUE)
4913 		goto done;
4914 
4915 	goto writeback;
4916 
4917 cannot_emulate:
4918 	return EMULATION_FAILED;
4919 }
4920 
4921 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt)
4922 {
4923 	invalidate_registers(ctxt);
4924 }
4925 
4926 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt)
4927 {
4928 	writeback_registers(ctxt);
4929 }
4930