xref: /netbsd-src/lib/libnvmm/libnvmm_x86.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: libnvmm_x86.c,v 1.40 2020/09/05 07:22:25 maxv Exp $	*/
2 
3 /*
4  * Copyright (c) 2018-2020 Maxime Villard, m00nbsd.net
5  * All rights reserved.
6  *
7  * This code is part of the NVMM hypervisor.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <errno.h>
39 #include <sys/ioctl.h>
40 #include <sys/mman.h>
41 #include <machine/vmparam.h>
42 #include <machine/pte.h>
43 #include <machine/psl.h>
44 
45 #define MIN(X, Y) (((X) < (Y)) ? (X) : (Y))
46 #define __cacheline_aligned __attribute__((__aligned__(64)))
47 
48 #include <x86/specialreg.h>
49 
50 /* -------------------------------------------------------------------------- */
51 
52 /*
53  * Undocumented debugging function. Helpful.
54  */
55 int
56 nvmm_vcpu_dump(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu)
57 {
58 	struct nvmm_x64_state *state = vcpu->state;
59 	uint16_t *attr;
60 	size_t i;
61 	int ret;
62 
63 	const char *segnames[] = {
64 		"ES", "CS", "SS", "DS", "FS", "GS", "GDT", "IDT", "LDT", "TR"
65 	};
66 
67 	ret = nvmm_vcpu_getstate(mach, vcpu, NVMM_X64_STATE_ALL);
68 	if (ret == -1)
69 		return -1;
70 
71 	printf("+ VCPU id=%d\n", (int)vcpu->cpuid);
72 	printf("| -> RAX=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RAX]);
73 	printf("| -> RCX=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RCX]);
74 	printf("| -> RDX=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RDX]);
75 	printf("| -> RBX=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RBX]);
76 	printf("| -> RSP=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RSP]);
77 	printf("| -> RBP=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RBP]);
78 	printf("| -> RSI=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RSI]);
79 	printf("| -> RDI=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RDI]);
80 	printf("| -> RIP=%"PRIx64"\n", state->gprs[NVMM_X64_GPR_RIP]);
81 	printf("| -> RFLAGS=%p\n", (void *)state->gprs[NVMM_X64_GPR_RFLAGS]);
82 	for (i = 0; i < NVMM_X64_NSEG; i++) {
83 		attr = (uint16_t *)&state->segs[i].attrib;
84 		printf("| -> %s: sel=0x%x base=%"PRIx64", limit=%x, "
85 		    "attrib=%x [type=%d,l=%d,def=%d]\n",
86 		    segnames[i],
87 		    state->segs[i].selector,
88 		    state->segs[i].base,
89 		    state->segs[i].limit,
90 		    *attr,
91 		    state->segs[i].attrib.type,
92 		    state->segs[i].attrib.l,
93 		    state->segs[i].attrib.def);
94 	}
95 	printf("| -> MSR_EFER=%"PRIx64"\n", state->msrs[NVMM_X64_MSR_EFER]);
96 	printf("| -> CR0=%"PRIx64"\n", state->crs[NVMM_X64_CR_CR0]);
97 	printf("| -> CR3=%"PRIx64"\n", state->crs[NVMM_X64_CR_CR3]);
98 	printf("| -> CR4=%"PRIx64"\n", state->crs[NVMM_X64_CR_CR4]);
99 	printf("| -> CR8=%"PRIx64"\n", state->crs[NVMM_X64_CR_CR8]);
100 
101 	return 0;
102 }
103 
104 /* -------------------------------------------------------------------------- */
105 
106 #define PTE32_L1_SHIFT	12
107 #define PTE32_L2_SHIFT	22
108 
109 #define PTE32_L2_MASK	0xffc00000
110 #define PTE32_L1_MASK	0x003ff000
111 
112 #define PTE32_L2_FRAME	(PTE32_L2_MASK)
113 #define PTE32_L1_FRAME	(PTE32_L2_FRAME|PTE32_L1_MASK)
114 
115 #define pte32_l1idx(va)	(((va) & PTE32_L1_MASK) >> PTE32_L1_SHIFT)
116 #define pte32_l2idx(va)	(((va) & PTE32_L2_MASK) >> PTE32_L2_SHIFT)
117 
118 #define CR3_FRAME_32BIT	__BITS(31, 12)
119 
120 typedef uint32_t pte_32bit_t;
121 
122 static int
123 x86_gva_to_gpa_32bit(struct nvmm_machine *mach, uint64_t cr3,
124     gvaddr_t gva, gpaddr_t *gpa, bool has_pse, nvmm_prot_t *prot)
125 {
126 	gpaddr_t L2gpa, L1gpa;
127 	uintptr_t L2hva, L1hva;
128 	pte_32bit_t *pdir, pte;
129 	nvmm_prot_t pageprot;
130 
131 	/* We begin with an RWXU access. */
132 	*prot = NVMM_PROT_ALL;
133 
134 	/* Parse L2. */
135 	L2gpa = (cr3 & CR3_FRAME_32BIT);
136 	if (nvmm_gpa_to_hva(mach, L2gpa, &L2hva, &pageprot) == -1)
137 		return -1;
138 	pdir = (pte_32bit_t *)L2hva;
139 	pte = pdir[pte32_l2idx(gva)];
140 	if ((pte & PTE_P) == 0)
141 		return -1;
142 	if ((pte & PTE_U) == 0)
143 		*prot &= ~NVMM_PROT_USER;
144 	if ((pte & PTE_W) == 0)
145 		*prot &= ~NVMM_PROT_WRITE;
146 	if ((pte & PTE_PS) && !has_pse)
147 		return -1;
148 	if (pte & PTE_PS) {
149 		*gpa = (pte & PTE32_L2_FRAME);
150 		*gpa = *gpa + (gva & PTE32_L1_MASK);
151 		return 0;
152 	}
153 
154 	/* Parse L1. */
155 	L1gpa = (pte & PTE_FRAME);
156 	if (nvmm_gpa_to_hva(mach, L1gpa, &L1hva, &pageprot) == -1)
157 		return -1;
158 	pdir = (pte_32bit_t *)L1hva;
159 	pte = pdir[pte32_l1idx(gva)];
160 	if ((pte & PTE_P) == 0)
161 		return -1;
162 	if ((pte & PTE_U) == 0)
163 		*prot &= ~NVMM_PROT_USER;
164 	if ((pte & PTE_W) == 0)
165 		*prot &= ~NVMM_PROT_WRITE;
166 	if (pte & PTE_PS)
167 		return -1;
168 
169 	*gpa = (pte & PTE_FRAME);
170 	return 0;
171 }
172 
173 /* -------------------------------------------------------------------------- */
174 
175 #define	PTE32_PAE_L1_SHIFT	12
176 #define	PTE32_PAE_L2_SHIFT	21
177 #define	PTE32_PAE_L3_SHIFT	30
178 
179 #define	PTE32_PAE_L3_MASK	0xc0000000
180 #define	PTE32_PAE_L2_MASK	0x3fe00000
181 #define	PTE32_PAE_L1_MASK	0x001ff000
182 
183 #define	PTE32_PAE_L3_FRAME	(PTE32_PAE_L3_MASK)
184 #define	PTE32_PAE_L2_FRAME	(PTE32_PAE_L3_FRAME|PTE32_PAE_L2_MASK)
185 #define	PTE32_PAE_L1_FRAME	(PTE32_PAE_L2_FRAME|PTE32_PAE_L1_MASK)
186 
187 #define pte32_pae_l1idx(va)	(((va) & PTE32_PAE_L1_MASK) >> PTE32_PAE_L1_SHIFT)
188 #define pte32_pae_l2idx(va)	(((va) & PTE32_PAE_L2_MASK) >> PTE32_PAE_L2_SHIFT)
189 #define pte32_pae_l3idx(va)	(((va) & PTE32_PAE_L3_MASK) >> PTE32_PAE_L3_SHIFT)
190 
191 #define CR3_FRAME_32BIT_PAE	__BITS(31, 5)
192 
193 typedef uint64_t pte_32bit_pae_t;
194 
195 static int
196 x86_gva_to_gpa_32bit_pae(struct nvmm_machine *mach, uint64_t cr3,
197     gvaddr_t gva, gpaddr_t *gpa, nvmm_prot_t *prot)
198 {
199 	gpaddr_t L3gpa, L2gpa, L1gpa;
200 	uintptr_t L3hva, L2hva, L1hva;
201 	pte_32bit_pae_t *pdir, pte;
202 	nvmm_prot_t pageprot;
203 
204 	/* We begin with an RWXU access. */
205 	*prot = NVMM_PROT_ALL;
206 
207 	/* Parse L3. */
208 	L3gpa = (cr3 & CR3_FRAME_32BIT_PAE);
209 	if (nvmm_gpa_to_hva(mach, L3gpa, &L3hva, &pageprot) == -1)
210 		return -1;
211 	pdir = (pte_32bit_pae_t *)L3hva;
212 	pte = pdir[pte32_pae_l3idx(gva)];
213 	if ((pte & PTE_P) == 0)
214 		return -1;
215 	if (pte & PTE_NX)
216 		*prot &= ~NVMM_PROT_EXEC;
217 	if (pte & PTE_PS)
218 		return -1;
219 
220 	/* Parse L2. */
221 	L2gpa = (pte & PTE_FRAME);
222 	if (nvmm_gpa_to_hva(mach, L2gpa, &L2hva, &pageprot) == -1)
223 		return -1;
224 	pdir = (pte_32bit_pae_t *)L2hva;
225 	pte = pdir[pte32_pae_l2idx(gva)];
226 	if ((pte & PTE_P) == 0)
227 		return -1;
228 	if ((pte & PTE_U) == 0)
229 		*prot &= ~NVMM_PROT_USER;
230 	if ((pte & PTE_W) == 0)
231 		*prot &= ~NVMM_PROT_WRITE;
232 	if (pte & PTE_NX)
233 		*prot &= ~NVMM_PROT_EXEC;
234 	if (pte & PTE_PS) {
235 		*gpa = (pte & PTE32_PAE_L2_FRAME);
236 		*gpa = *gpa + (gva & PTE32_PAE_L1_MASK);
237 		return 0;
238 	}
239 
240 	/* Parse L1. */
241 	L1gpa = (pte & PTE_FRAME);
242 	if (nvmm_gpa_to_hva(mach, L1gpa, &L1hva, &pageprot) == -1)
243 		return -1;
244 	pdir = (pte_32bit_pae_t *)L1hva;
245 	pte = pdir[pte32_pae_l1idx(gva)];
246 	if ((pte & PTE_P) == 0)
247 		return -1;
248 	if ((pte & PTE_U) == 0)
249 		*prot &= ~NVMM_PROT_USER;
250 	if ((pte & PTE_W) == 0)
251 		*prot &= ~NVMM_PROT_WRITE;
252 	if (pte & PTE_NX)
253 		*prot &= ~NVMM_PROT_EXEC;
254 	if (pte & PTE_PS)
255 		return -1;
256 
257 	*gpa = (pte & PTE_FRAME);
258 	return 0;
259 }
260 
261 /* -------------------------------------------------------------------------- */
262 
263 #define PTE64_L1_SHIFT	12
264 #define PTE64_L2_SHIFT	21
265 #define PTE64_L3_SHIFT	30
266 #define PTE64_L4_SHIFT	39
267 
268 #define PTE64_L4_MASK	0x0000ff8000000000
269 #define PTE64_L3_MASK	0x0000007fc0000000
270 #define PTE64_L2_MASK	0x000000003fe00000
271 #define PTE64_L1_MASK	0x00000000001ff000
272 
273 #define PTE64_L4_FRAME	PTE64_L4_MASK
274 #define PTE64_L3_FRAME	(PTE64_L4_FRAME|PTE64_L3_MASK)
275 #define PTE64_L2_FRAME	(PTE64_L3_FRAME|PTE64_L2_MASK)
276 #define PTE64_L1_FRAME	(PTE64_L2_FRAME|PTE64_L1_MASK)
277 
278 #define pte64_l1idx(va)	(((va) & PTE64_L1_MASK) >> PTE64_L1_SHIFT)
279 #define pte64_l2idx(va)	(((va) & PTE64_L2_MASK) >> PTE64_L2_SHIFT)
280 #define pte64_l3idx(va)	(((va) & PTE64_L3_MASK) >> PTE64_L3_SHIFT)
281 #define pte64_l4idx(va)	(((va) & PTE64_L4_MASK) >> PTE64_L4_SHIFT)
282 
283 #define CR3_FRAME_64BIT	__BITS(51, 12)
284 
285 typedef uint64_t pte_64bit_t;
286 
287 static inline bool
288 x86_gva_64bit_canonical(gvaddr_t gva)
289 {
290 	/* Bits 63:47 must have the same value. */
291 #define SIGN_EXTEND	0xffff800000000000ULL
292 	return (gva & SIGN_EXTEND) == 0 || (gva & SIGN_EXTEND) == SIGN_EXTEND;
293 }
294 
295 static int
296 x86_gva_to_gpa_64bit(struct nvmm_machine *mach, uint64_t cr3,
297     gvaddr_t gva, gpaddr_t *gpa, nvmm_prot_t *prot)
298 {
299 	gpaddr_t L4gpa, L3gpa, L2gpa, L1gpa;
300 	uintptr_t L4hva, L3hva, L2hva, L1hva;
301 	pte_64bit_t *pdir, pte;
302 	nvmm_prot_t pageprot;
303 
304 	/* We begin with an RWXU access. */
305 	*prot = NVMM_PROT_ALL;
306 
307 	if (!x86_gva_64bit_canonical(gva))
308 		return -1;
309 
310 	/* Parse L4. */
311 	L4gpa = (cr3 & CR3_FRAME_64BIT);
312 	if (nvmm_gpa_to_hva(mach, L4gpa, &L4hva, &pageprot) == -1)
313 		return -1;
314 	pdir = (pte_64bit_t *)L4hva;
315 	pte = pdir[pte64_l4idx(gva)];
316 	if ((pte & PTE_P) == 0)
317 		return -1;
318 	if ((pte & PTE_U) == 0)
319 		*prot &= ~NVMM_PROT_USER;
320 	if ((pte & PTE_W) == 0)
321 		*prot &= ~NVMM_PROT_WRITE;
322 	if (pte & PTE_NX)
323 		*prot &= ~NVMM_PROT_EXEC;
324 	if (pte & PTE_PS)
325 		return -1;
326 
327 	/* Parse L3. */
328 	L3gpa = (pte & PTE_FRAME);
329 	if (nvmm_gpa_to_hva(mach, L3gpa, &L3hva, &pageprot) == -1)
330 		return -1;
331 	pdir = (pte_64bit_t *)L3hva;
332 	pte = pdir[pte64_l3idx(gva)];
333 	if ((pte & PTE_P) == 0)
334 		return -1;
335 	if ((pte & PTE_U) == 0)
336 		*prot &= ~NVMM_PROT_USER;
337 	if ((pte & PTE_W) == 0)
338 		*prot &= ~NVMM_PROT_WRITE;
339 	if (pte & PTE_NX)
340 		*prot &= ~NVMM_PROT_EXEC;
341 	if (pte & PTE_PS) {
342 		*gpa = (pte & PTE64_L3_FRAME);
343 		*gpa = *gpa + (gva & (PTE64_L2_MASK|PTE64_L1_MASK));
344 		return 0;
345 	}
346 
347 	/* Parse L2. */
348 	L2gpa = (pte & PTE_FRAME);
349 	if (nvmm_gpa_to_hva(mach, L2gpa, &L2hva, &pageprot) == -1)
350 		return -1;
351 	pdir = (pte_64bit_t *)L2hva;
352 	pte = pdir[pte64_l2idx(gva)];
353 	if ((pte & PTE_P) == 0)
354 		return -1;
355 	if ((pte & PTE_U) == 0)
356 		*prot &= ~NVMM_PROT_USER;
357 	if ((pte & PTE_W) == 0)
358 		*prot &= ~NVMM_PROT_WRITE;
359 	if (pte & PTE_NX)
360 		*prot &= ~NVMM_PROT_EXEC;
361 	if (pte & PTE_PS) {
362 		*gpa = (pte & PTE64_L2_FRAME);
363 		*gpa = *gpa + (gva & PTE64_L1_MASK);
364 		return 0;
365 	}
366 
367 	/* Parse L1. */
368 	L1gpa = (pte & PTE_FRAME);
369 	if (nvmm_gpa_to_hva(mach, L1gpa, &L1hva, &pageprot) == -1)
370 		return -1;
371 	pdir = (pte_64bit_t *)L1hva;
372 	pte = pdir[pte64_l1idx(gva)];
373 	if ((pte & PTE_P) == 0)
374 		return -1;
375 	if ((pte & PTE_U) == 0)
376 		*prot &= ~NVMM_PROT_USER;
377 	if ((pte & PTE_W) == 0)
378 		*prot &= ~NVMM_PROT_WRITE;
379 	if (pte & PTE_NX)
380 		*prot &= ~NVMM_PROT_EXEC;
381 	if (pte & PTE_PS)
382 		return -1;
383 
384 	*gpa = (pte & PTE_FRAME);
385 	return 0;
386 }
387 
388 static inline int
389 x86_gva_to_gpa(struct nvmm_machine *mach, struct nvmm_x64_state *state,
390     gvaddr_t gva, gpaddr_t *gpa, nvmm_prot_t *prot)
391 {
392 	bool is_pae, is_lng, has_pse;
393 	uint64_t cr3;
394 	size_t off;
395 	int ret;
396 
397 	if ((state->crs[NVMM_X64_CR_CR0] & CR0_PG) == 0) {
398 		/* No paging. */
399 		*prot = NVMM_PROT_ALL;
400 		*gpa = gva;
401 		return 0;
402 	}
403 
404 	off = (gva & PAGE_MASK);
405 	gva &= ~PAGE_MASK;
406 
407 	is_pae = (state->crs[NVMM_X64_CR_CR4] & CR4_PAE) != 0;
408 	is_lng = (state->msrs[NVMM_X64_MSR_EFER] & EFER_LMA) != 0;
409 	has_pse = (state->crs[NVMM_X64_CR_CR4] & CR4_PSE) != 0;
410 	cr3 = state->crs[NVMM_X64_CR_CR3];
411 
412 	if (is_pae && is_lng) {
413 		/* 64bit */
414 		ret = x86_gva_to_gpa_64bit(mach, cr3, gva, gpa, prot);
415 	} else if (is_pae && !is_lng) {
416 		/* 32bit PAE */
417 		ret = x86_gva_to_gpa_32bit_pae(mach, cr3, gva, gpa, prot);
418 	} else if (!is_pae && !is_lng) {
419 		/* 32bit */
420 		ret = x86_gva_to_gpa_32bit(mach, cr3, gva, gpa, has_pse, prot);
421 	} else {
422 		ret = -1;
423 	}
424 
425 	if (ret == -1) {
426 		errno = EFAULT;
427 	}
428 
429 	*gpa = *gpa + off;
430 
431 	return ret;
432 }
433 
434 int
435 nvmm_gva_to_gpa(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
436     gvaddr_t gva, gpaddr_t *gpa, nvmm_prot_t *prot)
437 {
438 	struct nvmm_x64_state *state = vcpu->state;
439 	int ret;
440 
441 	ret = nvmm_vcpu_getstate(mach, vcpu,
442 	    NVMM_X64_STATE_CRS | NVMM_X64_STATE_MSRS);
443 	if (ret == -1)
444 		return -1;
445 
446 	return x86_gva_to_gpa(mach, state, gva, gpa, prot);
447 }
448 
449 /* -------------------------------------------------------------------------- */
450 
451 #define DISASSEMBLER_BUG()	\
452 	do {			\
453 		errno = EINVAL;	\
454 		return -1;	\
455 	} while (0);
456 
457 static inline bool
458 is_long_mode(struct nvmm_x64_state *state)
459 {
460 	return (state->msrs[NVMM_X64_MSR_EFER] & EFER_LMA) != 0;
461 }
462 
463 static inline bool
464 is_64bit(struct nvmm_x64_state *state)
465 {
466 	return (state->segs[NVMM_X64_SEG_CS].attrib.l != 0);
467 }
468 
469 static inline bool
470 is_32bit(struct nvmm_x64_state *state)
471 {
472 	return (state->segs[NVMM_X64_SEG_CS].attrib.l == 0) &&
473 	    (state->segs[NVMM_X64_SEG_CS].attrib.def == 1);
474 }
475 
476 static inline bool
477 is_16bit(struct nvmm_x64_state *state)
478 {
479 	return (state->segs[NVMM_X64_SEG_CS].attrib.l == 0) &&
480 	    (state->segs[NVMM_X64_SEG_CS].attrib.def == 0);
481 }
482 
483 static int
484 segment_check(struct nvmm_x64_state_seg *seg, gvaddr_t gva, size_t size)
485 {
486 	uint64_t limit;
487 
488 	/*
489 	 * This is incomplete. We should check topdown, etc, really that's
490 	 * tiring.
491 	 */
492 	if (__predict_false(!seg->attrib.p)) {
493 		goto error;
494 	}
495 
496 	limit = (uint64_t)seg->limit + 1;
497 	if (__predict_true(seg->attrib.g)) {
498 		limit *= PAGE_SIZE;
499 	}
500 
501 	if (__predict_false(gva + size > limit)) {
502 		goto error;
503 	}
504 
505 	return 0;
506 
507 error:
508 	errno = EFAULT;
509 	return -1;
510 }
511 
512 static inline void
513 segment_apply(struct nvmm_x64_state_seg *seg, gvaddr_t *gva)
514 {
515 	*gva += seg->base;
516 }
517 
518 static inline uint64_t
519 size_to_mask(size_t size)
520 {
521 	switch (size) {
522 	case 1:
523 		return 0x00000000000000FF;
524 	case 2:
525 		return 0x000000000000FFFF;
526 	case 4:
527 		return 0x00000000FFFFFFFF;
528 	case 8:
529 	default:
530 		return 0xFFFFFFFFFFFFFFFF;
531 	}
532 }
533 
534 static uint64_t
535 rep_get_cnt(struct nvmm_x64_state *state, size_t adsize)
536 {
537 	uint64_t mask, cnt;
538 
539 	mask = size_to_mask(adsize);
540 	cnt = state->gprs[NVMM_X64_GPR_RCX] & mask;
541 
542 	return cnt;
543 }
544 
545 static void
546 rep_set_cnt(struct nvmm_x64_state *state, size_t adsize, uint64_t cnt)
547 {
548 	uint64_t mask;
549 
550 	/* XXX: should we zero-extend? */
551 	mask = size_to_mask(adsize);
552 	state->gprs[NVMM_X64_GPR_RCX] &= ~mask;
553 	state->gprs[NVMM_X64_GPR_RCX] |= cnt;
554 }
555 
556 static int
557 read_guest_memory(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
558     gvaddr_t gva, uint8_t *data, size_t size)
559 {
560 	struct nvmm_x64_state *state = vcpu->state;
561 	struct nvmm_mem mem;
562 	nvmm_prot_t prot;
563 	gpaddr_t gpa;
564 	uintptr_t hva;
565 	bool is_mmio;
566 	int ret, remain;
567 
568 	ret = x86_gva_to_gpa(mach, state, gva, &gpa, &prot);
569 	if (__predict_false(ret == -1)) {
570 		return -1;
571 	}
572 	if (__predict_false(!(prot & NVMM_PROT_READ))) {
573 		errno = EFAULT;
574 		return -1;
575 	}
576 
577 	if ((gva & PAGE_MASK) + size > PAGE_SIZE) {
578 		remain = ((gva & PAGE_MASK) + size - PAGE_SIZE);
579 	} else {
580 		remain = 0;
581 	}
582 	size -= remain;
583 
584 	ret = nvmm_gpa_to_hva(mach, gpa, &hva, &prot);
585 	is_mmio = (ret == -1);
586 
587 	if (is_mmio) {
588 		mem.mach = mach;
589 		mem.vcpu = vcpu;
590 		mem.data = data;
591 		mem.gpa = gpa;
592 		mem.write = false;
593 		mem.size = size;
594 		(*vcpu->cbs.mem)(&mem);
595 	} else {
596 		if (__predict_false(!(prot & NVMM_PROT_READ))) {
597 			errno = EFAULT;
598 			return -1;
599 		}
600 		memcpy(data, (uint8_t *)hva, size);
601 	}
602 
603 	if (remain > 0) {
604 		ret = read_guest_memory(mach, vcpu, gva + size,
605 		    data + size, remain);
606 	} else {
607 		ret = 0;
608 	}
609 
610 	return ret;
611 }
612 
613 static int
614 write_guest_memory(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
615     gvaddr_t gva, uint8_t *data, size_t size)
616 {
617 	struct nvmm_x64_state *state = vcpu->state;
618 	struct nvmm_mem mem;
619 	nvmm_prot_t prot;
620 	gpaddr_t gpa;
621 	uintptr_t hva;
622 	bool is_mmio;
623 	int ret, remain;
624 
625 	ret = x86_gva_to_gpa(mach, state, gva, &gpa, &prot);
626 	if (__predict_false(ret == -1)) {
627 		return -1;
628 	}
629 	if (__predict_false(!(prot & NVMM_PROT_WRITE))) {
630 		errno = EFAULT;
631 		return -1;
632 	}
633 
634 	if ((gva & PAGE_MASK) + size > PAGE_SIZE) {
635 		remain = ((gva & PAGE_MASK) + size - PAGE_SIZE);
636 	} else {
637 		remain = 0;
638 	}
639 	size -= remain;
640 
641 	ret = nvmm_gpa_to_hva(mach, gpa, &hva, &prot);
642 	is_mmio = (ret == -1);
643 
644 	if (is_mmio) {
645 		mem.mach = mach;
646 		mem.vcpu = vcpu;
647 		mem.data = data;
648 		mem.gpa = gpa;
649 		mem.write = true;
650 		mem.size = size;
651 		(*vcpu->cbs.mem)(&mem);
652 	} else {
653 		if (__predict_false(!(prot & NVMM_PROT_WRITE))) {
654 			errno = EFAULT;
655 			return -1;
656 		}
657 		memcpy((uint8_t *)hva, data, size);
658 	}
659 
660 	if (remain > 0) {
661 		ret = write_guest_memory(mach, vcpu, gva + size,
662 		    data + size, remain);
663 	} else {
664 		ret = 0;
665 	}
666 
667 	return ret;
668 }
669 
670 /* -------------------------------------------------------------------------- */
671 
672 static int fetch_segment(struct nvmm_machine *, struct nvmm_vcpu *);
673 
674 #define NVMM_IO_BATCH_SIZE	32
675 
676 static int
677 assist_io_batch(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
678     struct nvmm_io *io, gvaddr_t gva, uint64_t cnt)
679 {
680 	uint8_t iobuf[NVMM_IO_BATCH_SIZE];
681 	size_t i, iosize, iocnt;
682 	int ret;
683 
684 	cnt = MIN(cnt, NVMM_IO_BATCH_SIZE);
685 	iosize = MIN(io->size * cnt, NVMM_IO_BATCH_SIZE);
686 	iocnt = iosize / io->size;
687 
688 	io->data = iobuf;
689 
690 	if (!io->in) {
691 		ret = read_guest_memory(mach, vcpu, gva, iobuf, iosize);
692 		if (ret == -1)
693 			return -1;
694 	}
695 
696 	for (i = 0; i < iocnt; i++) {
697 		(*vcpu->cbs.io)(io);
698 		io->data += io->size;
699 	}
700 
701 	if (io->in) {
702 		ret = write_guest_memory(mach, vcpu, gva, iobuf, iosize);
703 		if (ret == -1)
704 			return -1;
705 	}
706 
707 	return iocnt;
708 }
709 
710 int
711 nvmm_assist_io(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu)
712 {
713 	struct nvmm_x64_state *state = vcpu->state;
714 	struct nvmm_vcpu_exit *exit = vcpu->exit;
715 	struct nvmm_io io;
716 	uint64_t cnt = 0; /* GCC */
717 	uint8_t iobuf[8];
718 	int iocnt = 1;
719 	gvaddr_t gva = 0; /* GCC */
720 	int reg = 0; /* GCC */
721 	int ret, seg;
722 	bool psld = false;
723 
724 	if (__predict_false(exit->reason != NVMM_VCPU_EXIT_IO)) {
725 		errno = EINVAL;
726 		return -1;
727 	}
728 
729 	io.mach = mach;
730 	io.vcpu = vcpu;
731 	io.port = exit->u.io.port;
732 	io.in = exit->u.io.in;
733 	io.size = exit->u.io.operand_size;
734 	io.data = iobuf;
735 
736 	ret = nvmm_vcpu_getstate(mach, vcpu,
737 	    NVMM_X64_STATE_GPRS | NVMM_X64_STATE_SEGS |
738 	    NVMM_X64_STATE_CRS | NVMM_X64_STATE_MSRS);
739 	if (ret == -1)
740 		return -1;
741 
742 	if (exit->u.io.rep) {
743 		cnt = rep_get_cnt(state, exit->u.io.address_size);
744 		if (__predict_false(cnt == 0)) {
745 			state->gprs[NVMM_X64_GPR_RIP] = exit->u.io.npc;
746 			goto out;
747 		}
748 	}
749 
750 	if (__predict_false(state->gprs[NVMM_X64_GPR_RFLAGS] & PSL_D)) {
751 		psld = true;
752 	}
753 
754 	/*
755 	 * Determine GVA.
756 	 */
757 	if (exit->u.io.str) {
758 		if (io.in) {
759 			reg = NVMM_X64_GPR_RDI;
760 		} else {
761 			reg = NVMM_X64_GPR_RSI;
762 		}
763 
764 		gva = state->gprs[reg];
765 		gva &= size_to_mask(exit->u.io.address_size);
766 
767 		if (exit->u.io.seg != -1) {
768 			seg = exit->u.io.seg;
769 		} else {
770 			if (io.in) {
771 				seg = NVMM_X64_SEG_ES;
772 			} else {
773 				seg = fetch_segment(mach, vcpu);
774 				if (seg == -1)
775 					return -1;
776 			}
777 		}
778 
779 		if (__predict_true(is_long_mode(state))) {
780 			if (seg == NVMM_X64_SEG_GS || seg == NVMM_X64_SEG_FS) {
781 				segment_apply(&state->segs[seg], &gva);
782 			}
783 		} else {
784 			ret = segment_check(&state->segs[seg], gva, io.size);
785 			if (ret == -1)
786 				return -1;
787 			segment_apply(&state->segs[seg], &gva);
788 		}
789 
790 		if (exit->u.io.rep && !psld) {
791 			iocnt = assist_io_batch(mach, vcpu, &io, gva, cnt);
792 			if (iocnt == -1)
793 				return -1;
794 			goto done;
795 		}
796 	}
797 
798 	if (!io.in) {
799 		if (!exit->u.io.str) {
800 			memcpy(io.data, &state->gprs[NVMM_X64_GPR_RAX], io.size);
801 		} else {
802 			ret = read_guest_memory(mach, vcpu, gva, io.data,
803 			    io.size);
804 			if (ret == -1)
805 				return -1;
806 		}
807 	}
808 
809 	(*vcpu->cbs.io)(&io);
810 
811 	if (io.in) {
812 		if (!exit->u.io.str) {
813 			memcpy(&state->gprs[NVMM_X64_GPR_RAX], io.data, io.size);
814 			if (io.size == 4) {
815 				/* Zero-extend to 64 bits. */
816 				state->gprs[NVMM_X64_GPR_RAX] &= size_to_mask(4);
817 			}
818 		} else {
819 			ret = write_guest_memory(mach, vcpu, gva, io.data,
820 			    io.size);
821 			if (ret == -1)
822 				return -1;
823 		}
824 	}
825 
826 done:
827 	if (exit->u.io.str) {
828 		if (__predict_false(psld)) {
829 			state->gprs[reg] -= iocnt * io.size;
830 		} else {
831 			state->gprs[reg] += iocnt * io.size;
832 		}
833 	}
834 
835 	if (exit->u.io.rep) {
836 		cnt -= iocnt;
837 		rep_set_cnt(state, exit->u.io.address_size, cnt);
838 		if (cnt == 0) {
839 			state->gprs[NVMM_X64_GPR_RIP] = exit->u.io.npc;
840 		}
841 	} else {
842 		state->gprs[NVMM_X64_GPR_RIP] = exit->u.io.npc;
843 	}
844 
845 out:
846 	ret = nvmm_vcpu_setstate(mach, vcpu, NVMM_X64_STATE_GPRS);
847 	if (ret == -1)
848 		return -1;
849 
850 	return 0;
851 }
852 
853 /* -------------------------------------------------------------------------- */
854 
855 struct x86_emul {
856 	bool readreg;
857 	bool backprop;
858 	bool notouch;
859 	void (*func)(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
860 };
861 
862 static void x86_func_or(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
863 static void x86_func_and(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
864 static void x86_func_xchg(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
865 static void x86_func_sub(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
866 static void x86_func_xor(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
867 static void x86_func_cmp(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
868 static void x86_func_test(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
869 static void x86_func_mov(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
870 static void x86_func_stos(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
871 static void x86_func_lods(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
872 static void x86_func_movs(struct nvmm_vcpu *, struct nvmm_mem *, uint64_t *);
873 
874 static const struct x86_emul x86_emul_or = {
875 	.readreg = true,
876 	.func = x86_func_or
877 };
878 
879 static const struct x86_emul x86_emul_and = {
880 	.readreg = true,
881 	.func = x86_func_and
882 };
883 
884 static const struct x86_emul x86_emul_xchg = {
885 	.readreg = true,
886 	.backprop = true,
887 	.func = x86_func_xchg
888 };
889 
890 static const struct x86_emul x86_emul_sub = {
891 	.readreg = true,
892 	.func = x86_func_sub
893 };
894 
895 static const struct x86_emul x86_emul_xor = {
896 	.readreg = true,
897 	.func = x86_func_xor
898 };
899 
900 static const struct x86_emul x86_emul_cmp = {
901 	.notouch = true,
902 	.func = x86_func_cmp
903 };
904 
905 static const struct x86_emul x86_emul_test = {
906 	.notouch = true,
907 	.func = x86_func_test
908 };
909 
910 static const struct x86_emul x86_emul_mov = {
911 	.func = x86_func_mov
912 };
913 
914 static const struct x86_emul x86_emul_stos = {
915 	.func = x86_func_stos
916 };
917 
918 static const struct x86_emul x86_emul_lods = {
919 	.func = x86_func_lods
920 };
921 
922 static const struct x86_emul x86_emul_movs = {
923 	.func = x86_func_movs
924 };
925 
926 /* Legacy prefixes. */
927 #define LEG_LOCK	0xF0
928 #define LEG_REPN	0xF2
929 #define LEG_REP		0xF3
930 #define LEG_OVR_CS	0x2E
931 #define LEG_OVR_SS	0x36
932 #define LEG_OVR_DS	0x3E
933 #define LEG_OVR_ES	0x26
934 #define LEG_OVR_FS	0x64
935 #define LEG_OVR_GS	0x65
936 #define LEG_OPR_OVR	0x66
937 #define LEG_ADR_OVR	0x67
938 
939 struct x86_legpref {
940 	bool opr_ovr:1;
941 	bool adr_ovr:1;
942 	bool rep:1;
943 	bool repn:1;
944 	int8_t seg;
945 };
946 
947 struct x86_rexpref {
948 	bool b:1;
949 	bool x:1;
950 	bool r:1;
951 	bool w:1;
952 	bool present:1;
953 };
954 
955 struct x86_reg {
956 	int num;	/* NVMM GPR state index */
957 	uint64_t mask;
958 };
959 
960 struct x86_dualreg {
961 	int reg1;
962 	int reg2;
963 };
964 
965 enum x86_disp_type {
966 	DISP_NONE,
967 	DISP_0,
968 	DISP_1,
969 	DISP_2,
970 	DISP_4
971 };
972 
973 struct x86_disp {
974 	enum x86_disp_type type;
975 	uint64_t data; /* 4 bytes, but can be sign-extended */
976 };
977 
978 struct x86_regmodrm {
979 	uint8_t mod:2;
980 	uint8_t reg:3;
981 	uint8_t rm:3;
982 };
983 
984 struct x86_immediate {
985 	uint64_t data;
986 };
987 
988 struct x86_sib {
989 	uint8_t scale;
990 	const struct x86_reg *idx;
991 	const struct x86_reg *bas;
992 };
993 
994 enum x86_store_type {
995 	STORE_NONE,
996 	STORE_REG,
997 	STORE_DUALREG,
998 	STORE_IMM,
999 	STORE_SIB,
1000 	STORE_DMO
1001 };
1002 
1003 struct x86_store {
1004 	enum x86_store_type type;
1005 	union {
1006 		const struct x86_reg *reg;
1007 		struct x86_dualreg dualreg;
1008 		struct x86_immediate imm;
1009 		struct x86_sib sib;
1010 		uint64_t dmo;
1011 	} u;
1012 	struct x86_disp disp;
1013 	int hardseg;
1014 };
1015 
1016 struct x86_instr {
1017 	uint8_t len;
1018 	struct x86_legpref legpref;
1019 	struct x86_rexpref rexpref;
1020 	struct x86_regmodrm regmodrm;
1021 	uint8_t operand_size;
1022 	uint8_t address_size;
1023 	uint64_t zeroextend_mask;
1024 
1025 	const struct x86_opcode *opcode;
1026 	const struct x86_emul *emul;
1027 
1028 	struct x86_store src;
1029 	struct x86_store dst;
1030 	struct x86_store *strm;
1031 };
1032 
1033 struct x86_decode_fsm {
1034 	/* vcpu */
1035 	bool is64bit;
1036 	bool is32bit;
1037 	bool is16bit;
1038 
1039 	/* fsm */
1040 	int (*fn)(struct x86_decode_fsm *, struct x86_instr *);
1041 	uint8_t *buf;
1042 	uint8_t *end;
1043 };
1044 
1045 struct x86_opcode {
1046 	bool valid:1;
1047 	bool regmodrm:1;
1048 	bool regtorm:1;
1049 	bool dmo:1;
1050 	bool todmo:1;
1051 	bool movs:1;
1052 	bool stos:1;
1053 	bool lods:1;
1054 	bool szoverride:1;
1055 	bool group1:1;
1056 	bool group3:1;
1057 	bool group11:1;
1058 	bool immediate:1;
1059 	uint8_t defsize;
1060 	uint8_t flags;
1061 	const struct x86_emul *emul;
1062 };
1063 
1064 struct x86_group_entry {
1065 	const struct x86_emul *emul;
1066 };
1067 
1068 #define OPSIZE_BYTE 0x01
1069 #define OPSIZE_WORD 0x02 /* 2 bytes */
1070 #define OPSIZE_DOUB 0x04 /* 4 bytes */
1071 #define OPSIZE_QUAD 0x08 /* 8 bytes */
1072 
1073 #define FLAG_imm8	0x01
1074 #define FLAG_immz	0x02
1075 #define FLAG_ze		0x04
1076 
1077 static const struct x86_group_entry group1[8] __cacheline_aligned = {
1078 	[1] = { .emul = &x86_emul_or },
1079 	[4] = { .emul = &x86_emul_and },
1080 	[6] = { .emul = &x86_emul_xor },
1081 	[7] = { .emul = &x86_emul_cmp }
1082 };
1083 
1084 static const struct x86_group_entry group3[8] __cacheline_aligned = {
1085 	[0] = { .emul = &x86_emul_test },
1086 	[1] = { .emul = &x86_emul_test }
1087 };
1088 
1089 static const struct x86_group_entry group11[8] __cacheline_aligned = {
1090 	[0] = { .emul = &x86_emul_mov }
1091 };
1092 
1093 static const struct x86_opcode primary_opcode_table[256] __cacheline_aligned = {
1094 	/*
1095 	 * Group1
1096 	 */
1097 	[0x80] = {
1098 		/* Eb, Ib */
1099 		.valid = true,
1100 		.regmodrm = true,
1101 		.regtorm = true,
1102 		.szoverride = false,
1103 		.defsize = OPSIZE_BYTE,
1104 		.group1 = true,
1105 		.immediate = true,
1106 		.emul = NULL /* group1 */
1107 	},
1108 	[0x81] = {
1109 		/* Ev, Iz */
1110 		.valid = true,
1111 		.regmodrm = true,
1112 		.regtorm = true,
1113 		.szoverride = true,
1114 		.defsize = -1,
1115 		.group1 = true,
1116 		.immediate = true,
1117 		.flags = FLAG_immz,
1118 		.emul = NULL /* group1 */
1119 	},
1120 	[0x83] = {
1121 		/* Ev, Ib */
1122 		.valid = true,
1123 		.regmodrm = true,
1124 		.regtorm = true,
1125 		.szoverride = true,
1126 		.defsize = -1,
1127 		.group1 = true,
1128 		.immediate = true,
1129 		.flags = FLAG_imm8,
1130 		.emul = NULL /* group1 */
1131 	},
1132 
1133 	/*
1134 	 * Group3
1135 	 */
1136 	[0xF6] = {
1137 		/* Eb, Ib */
1138 		.valid = true,
1139 		.regmodrm = true,
1140 		.regtorm = true,
1141 		.szoverride = false,
1142 		.defsize = OPSIZE_BYTE,
1143 		.group3 = true,
1144 		.immediate = true,
1145 		.emul = NULL /* group3 */
1146 	},
1147 	[0xF7] = {
1148 		/* Ev, Iz */
1149 		.valid = true,
1150 		.regmodrm = true,
1151 		.regtorm = true,
1152 		.szoverride = true,
1153 		.defsize = -1,
1154 		.group3 = true,
1155 		.immediate = true,
1156 		.flags = FLAG_immz,
1157 		.emul = NULL /* group3 */
1158 	},
1159 
1160 	/*
1161 	 * Group11
1162 	 */
1163 	[0xC6] = {
1164 		/* Eb, Ib */
1165 		.valid = true,
1166 		.regmodrm = true,
1167 		.regtorm = true,
1168 		.szoverride = false,
1169 		.defsize = OPSIZE_BYTE,
1170 		.group11 = true,
1171 		.immediate = true,
1172 		.emul = NULL /* group11 */
1173 	},
1174 	[0xC7] = {
1175 		/* Ev, Iz */
1176 		.valid = true,
1177 		.regmodrm = true,
1178 		.regtorm = true,
1179 		.szoverride = true,
1180 		.defsize = -1,
1181 		.group11 = true,
1182 		.immediate = true,
1183 		.flags = FLAG_immz,
1184 		.emul = NULL /* group11 */
1185 	},
1186 
1187 	/*
1188 	 * OR
1189 	 */
1190 	[0x08] = {
1191 		/* Eb, Gb */
1192 		.valid = true,
1193 		.regmodrm = true,
1194 		.regtorm = true,
1195 		.szoverride = false,
1196 		.defsize = OPSIZE_BYTE,
1197 		.emul = &x86_emul_or
1198 	},
1199 	[0x09] = {
1200 		/* Ev, Gv */
1201 		.valid = true,
1202 		.regmodrm = true,
1203 		.regtorm = true,
1204 		.szoverride = true,
1205 		.defsize = -1,
1206 		.emul = &x86_emul_or
1207 	},
1208 	[0x0A] = {
1209 		/* Gb, Eb */
1210 		.valid = true,
1211 		.regmodrm = true,
1212 		.regtorm = false,
1213 		.szoverride = false,
1214 		.defsize = OPSIZE_BYTE,
1215 		.emul = &x86_emul_or
1216 	},
1217 	[0x0B] = {
1218 		/* Gv, Ev */
1219 		.valid = true,
1220 		.regmodrm = true,
1221 		.regtorm = false,
1222 		.szoverride = true,
1223 		.defsize = -1,
1224 		.emul = &x86_emul_or
1225 	},
1226 
1227 	/*
1228 	 * AND
1229 	 */
1230 	[0x20] = {
1231 		/* Eb, Gb */
1232 		.valid = true,
1233 		.regmodrm = true,
1234 		.regtorm = true,
1235 		.szoverride = false,
1236 		.defsize = OPSIZE_BYTE,
1237 		.emul = &x86_emul_and
1238 	},
1239 	[0x21] = {
1240 		/* Ev, Gv */
1241 		.valid = true,
1242 		.regmodrm = true,
1243 		.regtorm = true,
1244 		.szoverride = true,
1245 		.defsize = -1,
1246 		.emul = &x86_emul_and
1247 	},
1248 	[0x22] = {
1249 		/* Gb, Eb */
1250 		.valid = true,
1251 		.regmodrm = true,
1252 		.regtorm = false,
1253 		.szoverride = false,
1254 		.defsize = OPSIZE_BYTE,
1255 		.emul = &x86_emul_and
1256 	},
1257 	[0x23] = {
1258 		/* Gv, Ev */
1259 		.valid = true,
1260 		.regmodrm = true,
1261 		.regtorm = false,
1262 		.szoverride = true,
1263 		.defsize = -1,
1264 		.emul = &x86_emul_and
1265 	},
1266 
1267 	/*
1268 	 * SUB
1269 	 */
1270 	[0x28] = {
1271 		/* Eb, Gb */
1272 		.valid = true,
1273 		.regmodrm = true,
1274 		.regtorm = true,
1275 		.szoverride = false,
1276 		.defsize = OPSIZE_BYTE,
1277 		.emul = &x86_emul_sub
1278 	},
1279 	[0x29] = {
1280 		/* Ev, Gv */
1281 		.valid = true,
1282 		.regmodrm = true,
1283 		.regtorm = true,
1284 		.szoverride = true,
1285 		.defsize = -1,
1286 		.emul = &x86_emul_sub
1287 	},
1288 	[0x2A] = {
1289 		/* Gb, Eb */
1290 		.valid = true,
1291 		.regmodrm = true,
1292 		.regtorm = false,
1293 		.szoverride = false,
1294 		.defsize = OPSIZE_BYTE,
1295 		.emul = &x86_emul_sub
1296 	},
1297 	[0x2B] = {
1298 		/* Gv, Ev */
1299 		.valid = true,
1300 		.regmodrm = true,
1301 		.regtorm = false,
1302 		.szoverride = true,
1303 		.defsize = -1,
1304 		.emul = &x86_emul_sub
1305 	},
1306 
1307 	/*
1308 	 * XOR
1309 	 */
1310 	[0x30] = {
1311 		/* Eb, Gb */
1312 		.valid = true,
1313 		.regmodrm = true,
1314 		.regtorm = true,
1315 		.szoverride = false,
1316 		.defsize = OPSIZE_BYTE,
1317 		.emul = &x86_emul_xor
1318 	},
1319 	[0x31] = {
1320 		/* Ev, Gv */
1321 		.valid = true,
1322 		.regmodrm = true,
1323 		.regtorm = true,
1324 		.szoverride = true,
1325 		.defsize = -1,
1326 		.emul = &x86_emul_xor
1327 	},
1328 	[0x32] = {
1329 		/* Gb, Eb */
1330 		.valid = true,
1331 		.regmodrm = true,
1332 		.regtorm = false,
1333 		.szoverride = false,
1334 		.defsize = OPSIZE_BYTE,
1335 		.emul = &x86_emul_xor
1336 	},
1337 	[0x33] = {
1338 		/* Gv, Ev */
1339 		.valid = true,
1340 		.regmodrm = true,
1341 		.regtorm = false,
1342 		.szoverride = true,
1343 		.defsize = -1,
1344 		.emul = &x86_emul_xor
1345 	},
1346 
1347 	/*
1348 	 * XCHG
1349 	 */
1350 	[0x86] = {
1351 		/* Eb, Gb */
1352 		.valid = true,
1353 		.regmodrm = true,
1354 		.regtorm = true,
1355 		.szoverride = false,
1356 		.defsize = OPSIZE_BYTE,
1357 		.emul = &x86_emul_xchg
1358 	},
1359 	[0x87] = {
1360 		/* Ev, Gv */
1361 		.valid = true,
1362 		.regmodrm = true,
1363 		.regtorm = true,
1364 		.szoverride = true,
1365 		.defsize = -1,
1366 		.emul = &x86_emul_xchg
1367 	},
1368 
1369 	/*
1370 	 * MOV
1371 	 */
1372 	[0x88] = {
1373 		/* Eb, Gb */
1374 		.valid = true,
1375 		.regmodrm = true,
1376 		.regtorm = true,
1377 		.szoverride = false,
1378 		.defsize = OPSIZE_BYTE,
1379 		.emul = &x86_emul_mov
1380 	},
1381 	[0x89] = {
1382 		/* Ev, Gv */
1383 		.valid = true,
1384 		.regmodrm = true,
1385 		.regtorm = true,
1386 		.szoverride = true,
1387 		.defsize = -1,
1388 		.emul = &x86_emul_mov
1389 	},
1390 	[0x8A] = {
1391 		/* Gb, Eb */
1392 		.valid = true,
1393 		.regmodrm = true,
1394 		.regtorm = false,
1395 		.szoverride = false,
1396 		.defsize = OPSIZE_BYTE,
1397 		.emul = &x86_emul_mov
1398 	},
1399 	[0x8B] = {
1400 		/* Gv, Ev */
1401 		.valid = true,
1402 		.regmodrm = true,
1403 		.regtorm = false,
1404 		.szoverride = true,
1405 		.defsize = -1,
1406 		.emul = &x86_emul_mov
1407 	},
1408 	[0xA0] = {
1409 		/* AL, Ob */
1410 		.valid = true,
1411 		.dmo = true,
1412 		.todmo = false,
1413 		.szoverride = false,
1414 		.defsize = OPSIZE_BYTE,
1415 		.emul = &x86_emul_mov
1416 	},
1417 	[0xA1] = {
1418 		/* rAX, Ov */
1419 		.valid = true,
1420 		.dmo = true,
1421 		.todmo = false,
1422 		.szoverride = true,
1423 		.defsize = -1,
1424 		.emul = &x86_emul_mov
1425 	},
1426 	[0xA2] = {
1427 		/* Ob, AL */
1428 		.valid = true,
1429 		.dmo = true,
1430 		.todmo = true,
1431 		.szoverride = false,
1432 		.defsize = OPSIZE_BYTE,
1433 		.emul = &x86_emul_mov
1434 	},
1435 	[0xA3] = {
1436 		/* Ov, rAX */
1437 		.valid = true,
1438 		.dmo = true,
1439 		.todmo = true,
1440 		.szoverride = true,
1441 		.defsize = -1,
1442 		.emul = &x86_emul_mov
1443 	},
1444 
1445 	/*
1446 	 * MOVS
1447 	 */
1448 	[0xA4] = {
1449 		/* Yb, Xb */
1450 		.valid = true,
1451 		.movs = true,
1452 		.szoverride = false,
1453 		.defsize = OPSIZE_BYTE,
1454 		.emul = &x86_emul_movs
1455 	},
1456 	[0xA5] = {
1457 		/* Yv, Xv */
1458 		.valid = true,
1459 		.movs = true,
1460 		.szoverride = true,
1461 		.defsize = -1,
1462 		.emul = &x86_emul_movs
1463 	},
1464 
1465 	/*
1466 	 * STOS
1467 	 */
1468 	[0xAA] = {
1469 		/* Yb, AL */
1470 		.valid = true,
1471 		.stos = true,
1472 		.szoverride = false,
1473 		.defsize = OPSIZE_BYTE,
1474 		.emul = &x86_emul_stos
1475 	},
1476 	[0xAB] = {
1477 		/* Yv, rAX */
1478 		.valid = true,
1479 		.stos = true,
1480 		.szoverride = true,
1481 		.defsize = -1,
1482 		.emul = &x86_emul_stos
1483 	},
1484 
1485 	/*
1486 	 * LODS
1487 	 */
1488 	[0xAC] = {
1489 		/* AL, Xb */
1490 		.valid = true,
1491 		.lods = true,
1492 		.szoverride = false,
1493 		.defsize = OPSIZE_BYTE,
1494 		.emul = &x86_emul_lods
1495 	},
1496 	[0xAD] = {
1497 		/* rAX, Xv */
1498 		.valid = true,
1499 		.lods = true,
1500 		.szoverride = true,
1501 		.defsize = -1,
1502 		.emul = &x86_emul_lods
1503 	},
1504 };
1505 
1506 static const struct x86_opcode secondary_opcode_table[256] __cacheline_aligned = {
1507 	/*
1508 	 * MOVZX
1509 	 */
1510 	[0xB6] = {
1511 		/* Gv, Eb */
1512 		.valid = true,
1513 		.regmodrm = true,
1514 		.regtorm = false,
1515 		.szoverride = true,
1516 		.defsize = OPSIZE_BYTE,
1517 		.flags = FLAG_ze,
1518 		.emul = &x86_emul_mov
1519 	},
1520 	[0xB7] = {
1521 		/* Gv, Ew */
1522 		.valid = true,
1523 		.regmodrm = true,
1524 		.regtorm = false,
1525 		.szoverride = true,
1526 		.defsize = OPSIZE_WORD,
1527 		.flags = FLAG_ze,
1528 		.emul = &x86_emul_mov
1529 	},
1530 };
1531 
1532 static const struct x86_reg gpr_map__rip = { NVMM_X64_GPR_RIP, 0xFFFFFFFFFFFFFFFF };
1533 
1534 /* [REX-present][enc][opsize] */
1535 static const struct x86_reg gpr_map__special[2][4][8] __cacheline_aligned = {
1536 	[false] = {
1537 		/* No REX prefix. */
1538 		[0b00] = {
1539 			[0] = { NVMM_X64_GPR_RAX, 0x000000000000FF00 }, /* AH */
1540 			[1] = { NVMM_X64_GPR_RSP, 0x000000000000FFFF }, /* SP */
1541 			[2] = { -1, 0 },
1542 			[3] = { NVMM_X64_GPR_RSP, 0x00000000FFFFFFFF }, /* ESP */
1543 			[4] = { -1, 0 },
1544 			[5] = { -1, 0 },
1545 			[6] = { -1, 0 },
1546 			[7] = { -1, 0 },
1547 		},
1548 		[0b01] = {
1549 			[0] = { NVMM_X64_GPR_RCX, 0x000000000000FF00 }, /* CH */
1550 			[1] = { NVMM_X64_GPR_RBP, 0x000000000000FFFF }, /* BP */
1551 			[2] = { -1, 0 },
1552 			[3] = { NVMM_X64_GPR_RBP, 0x00000000FFFFFFFF },	/* EBP */
1553 			[4] = { -1, 0 },
1554 			[5] = { -1, 0 },
1555 			[6] = { -1, 0 },
1556 			[7] = { -1, 0 },
1557 		},
1558 		[0b10] = {
1559 			[0] = { NVMM_X64_GPR_RDX, 0x000000000000FF00 }, /* DH */
1560 			[1] = { NVMM_X64_GPR_RSI, 0x000000000000FFFF }, /* SI */
1561 			[2] = { -1, 0 },
1562 			[3] = { NVMM_X64_GPR_RSI, 0x00000000FFFFFFFF }, /* ESI */
1563 			[4] = { -1, 0 },
1564 			[5] = { -1, 0 },
1565 			[6] = { -1, 0 },
1566 			[7] = { -1, 0 },
1567 		},
1568 		[0b11] = {
1569 			[0] = { NVMM_X64_GPR_RBX, 0x000000000000FF00 }, /* BH */
1570 			[1] = { NVMM_X64_GPR_RDI, 0x000000000000FFFF }, /* DI */
1571 			[2] = { -1, 0 },
1572 			[3] = { NVMM_X64_GPR_RDI, 0x00000000FFFFFFFF }, /* EDI */
1573 			[4] = { -1, 0 },
1574 			[5] = { -1, 0 },
1575 			[6] = { -1, 0 },
1576 			[7] = { -1, 0 },
1577 		}
1578 	},
1579 	[true] = {
1580 		/* Has REX prefix. */
1581 		[0b00] = {
1582 			[0] = { NVMM_X64_GPR_RSP, 0x00000000000000FF }, /* SPL */
1583 			[1] = { NVMM_X64_GPR_RSP, 0x000000000000FFFF }, /* SP */
1584 			[2] = { -1, 0 },
1585 			[3] = { NVMM_X64_GPR_RSP, 0x00000000FFFFFFFF }, /* ESP */
1586 			[4] = { -1, 0 },
1587 			[5] = { -1, 0 },
1588 			[6] = { -1, 0 },
1589 			[7] = { NVMM_X64_GPR_RSP, 0xFFFFFFFFFFFFFFFF }, /* RSP */
1590 		},
1591 		[0b01] = {
1592 			[0] = { NVMM_X64_GPR_RBP, 0x00000000000000FF }, /* BPL */
1593 			[1] = { NVMM_X64_GPR_RBP, 0x000000000000FFFF }, /* BP */
1594 			[2] = { -1, 0 },
1595 			[3] = { NVMM_X64_GPR_RBP, 0x00000000FFFFFFFF }, /* EBP */
1596 			[4] = { -1, 0 },
1597 			[5] = { -1, 0 },
1598 			[6] = { -1, 0 },
1599 			[7] = { NVMM_X64_GPR_RBP, 0xFFFFFFFFFFFFFFFF }, /* RBP */
1600 		},
1601 		[0b10] = {
1602 			[0] = { NVMM_X64_GPR_RSI, 0x00000000000000FF }, /* SIL */
1603 			[1] = { NVMM_X64_GPR_RSI, 0x000000000000FFFF }, /* SI */
1604 			[2] = { -1, 0 },
1605 			[3] = { NVMM_X64_GPR_RSI, 0x00000000FFFFFFFF }, /* ESI */
1606 			[4] = { -1, 0 },
1607 			[5] = { -1, 0 },
1608 			[6] = { -1, 0 },
1609 			[7] = { NVMM_X64_GPR_RSI, 0xFFFFFFFFFFFFFFFF }, /* RSI */
1610 		},
1611 		[0b11] = {
1612 			[0] = { NVMM_X64_GPR_RDI, 0x00000000000000FF }, /* DIL */
1613 			[1] = { NVMM_X64_GPR_RDI, 0x000000000000FFFF }, /* DI */
1614 			[2] = { -1, 0 },
1615 			[3] = { NVMM_X64_GPR_RDI, 0x00000000FFFFFFFF }, /* EDI */
1616 			[4] = { -1, 0 },
1617 			[5] = { -1, 0 },
1618 			[6] = { -1, 0 },
1619 			[7] = { NVMM_X64_GPR_RDI, 0xFFFFFFFFFFFFFFFF }, /* RDI */
1620 		}
1621 	}
1622 };
1623 
1624 /* [depends][enc][size] */
1625 static const struct x86_reg gpr_map[2][8][8] __cacheline_aligned = {
1626 	[false] = {
1627 		/* Not extended. */
1628 		[0b000] = {
1629 			[0] = { NVMM_X64_GPR_RAX, 0x00000000000000FF }, /* AL */
1630 			[1] = { NVMM_X64_GPR_RAX, 0x000000000000FFFF }, /* AX */
1631 			[2] = { -1, 0 },
1632 			[3] = { NVMM_X64_GPR_RAX, 0x00000000FFFFFFFF }, /* EAX */
1633 			[4] = { -1, 0 },
1634 			[5] = { -1, 0 },
1635 			[6] = { -1, 0 },
1636 			[7] = { NVMM_X64_GPR_RAX, 0xFFFFFFFFFFFFFFFF }, /* RAX */
1637 		},
1638 		[0b001] = {
1639 			[0] = { NVMM_X64_GPR_RCX, 0x00000000000000FF }, /* CL */
1640 			[1] = { NVMM_X64_GPR_RCX, 0x000000000000FFFF }, /* CX */
1641 			[2] = { -1, 0 },
1642 			[3] = { NVMM_X64_GPR_RCX, 0x00000000FFFFFFFF }, /* ECX */
1643 			[4] = { -1, 0 },
1644 			[5] = { -1, 0 },
1645 			[6] = { -1, 0 },
1646 			[7] = { NVMM_X64_GPR_RCX, 0xFFFFFFFFFFFFFFFF }, /* RCX */
1647 		},
1648 		[0b010] = {
1649 			[0] = { NVMM_X64_GPR_RDX, 0x00000000000000FF }, /* DL */
1650 			[1] = { NVMM_X64_GPR_RDX, 0x000000000000FFFF }, /* DX */
1651 			[2] = { -1, 0 },
1652 			[3] = { NVMM_X64_GPR_RDX, 0x00000000FFFFFFFF }, /* EDX */
1653 			[4] = { -1, 0 },
1654 			[5] = { -1, 0 },
1655 			[6] = { -1, 0 },
1656 			[7] = { NVMM_X64_GPR_RDX, 0xFFFFFFFFFFFFFFFF }, /* RDX */
1657 		},
1658 		[0b011] = {
1659 			[0] = { NVMM_X64_GPR_RBX, 0x00000000000000FF }, /* BL */
1660 			[1] = { NVMM_X64_GPR_RBX, 0x000000000000FFFF }, /* BX */
1661 			[2] = { -1, 0 },
1662 			[3] = { NVMM_X64_GPR_RBX, 0x00000000FFFFFFFF }, /* EBX */
1663 			[4] = { -1, 0 },
1664 			[5] = { -1, 0 },
1665 			[6] = { -1, 0 },
1666 			[7] = { NVMM_X64_GPR_RBX, 0xFFFFFFFFFFFFFFFF }, /* RBX */
1667 		},
1668 		[0b100] = {
1669 			[0] = { -1, 0 }, /* SPECIAL */
1670 			[1] = { -1, 0 }, /* SPECIAL */
1671 			[2] = { -1, 0 },
1672 			[3] = { -1, 0 }, /* SPECIAL */
1673 			[4] = { -1, 0 },
1674 			[5] = { -1, 0 },
1675 			[6] = { -1, 0 },
1676 			[7] = { -1, 0 }, /* SPECIAL */
1677 		},
1678 		[0b101] = {
1679 			[0] = { -1, 0 }, /* SPECIAL */
1680 			[1] = { -1, 0 }, /* SPECIAL */
1681 			[2] = { -1, 0 },
1682 			[3] = { -1, 0 }, /* SPECIAL */
1683 			[4] = { -1, 0 },
1684 			[5] = { -1, 0 },
1685 			[6] = { -1, 0 },
1686 			[7] = { -1, 0 }, /* SPECIAL */
1687 		},
1688 		[0b110] = {
1689 			[0] = { -1, 0 }, /* SPECIAL */
1690 			[1] = { -1, 0 }, /* SPECIAL */
1691 			[2] = { -1, 0 },
1692 			[3] = { -1, 0 }, /* SPECIAL */
1693 			[4] = { -1, 0 },
1694 			[5] = { -1, 0 },
1695 			[6] = { -1, 0 },
1696 			[7] = { -1, 0 }, /* SPECIAL */
1697 		},
1698 		[0b111] = {
1699 			[0] = { -1, 0 }, /* SPECIAL */
1700 			[1] = { -1, 0 }, /* SPECIAL */
1701 			[2] = { -1, 0 },
1702 			[3] = { -1, 0 }, /* SPECIAL */
1703 			[4] = { -1, 0 },
1704 			[5] = { -1, 0 },
1705 			[6] = { -1, 0 },
1706 			[7] = { -1, 0 }, /* SPECIAL */
1707 		},
1708 	},
1709 	[true] = {
1710 		/* Extended. */
1711 		[0b000] = {
1712 			[0] = { NVMM_X64_GPR_R8, 0x00000000000000FF }, /* R8B */
1713 			[1] = { NVMM_X64_GPR_R8, 0x000000000000FFFF }, /* R8W */
1714 			[2] = { -1, 0 },
1715 			[3] = { NVMM_X64_GPR_R8, 0x00000000FFFFFFFF }, /* R8D */
1716 			[4] = { -1, 0 },
1717 			[5] = { -1, 0 },
1718 			[6] = { -1, 0 },
1719 			[7] = { NVMM_X64_GPR_R8, 0xFFFFFFFFFFFFFFFF }, /* R8 */
1720 		},
1721 		[0b001] = {
1722 			[0] = { NVMM_X64_GPR_R9, 0x00000000000000FF }, /* R9B */
1723 			[1] = { NVMM_X64_GPR_R9, 0x000000000000FFFF }, /* R9W */
1724 			[2] = { -1, 0 },
1725 			[3] = { NVMM_X64_GPR_R9, 0x00000000FFFFFFFF }, /* R9D */
1726 			[4] = { -1, 0 },
1727 			[5] = { -1, 0 },
1728 			[6] = { -1, 0 },
1729 			[7] = { NVMM_X64_GPR_R9, 0xFFFFFFFFFFFFFFFF }, /* R9 */
1730 		},
1731 		[0b010] = {
1732 			[0] = { NVMM_X64_GPR_R10, 0x00000000000000FF }, /* R10B */
1733 			[1] = { NVMM_X64_GPR_R10, 0x000000000000FFFF }, /* R10W */
1734 			[2] = { -1, 0 },
1735 			[3] = { NVMM_X64_GPR_R10, 0x00000000FFFFFFFF }, /* R10D */
1736 			[4] = { -1, 0 },
1737 			[5] = { -1, 0 },
1738 			[6] = { -1, 0 },
1739 			[7] = { NVMM_X64_GPR_R10, 0xFFFFFFFFFFFFFFFF }, /* R10 */
1740 		},
1741 		[0b011] = {
1742 			[0] = { NVMM_X64_GPR_R11, 0x00000000000000FF }, /* R11B */
1743 			[1] = { NVMM_X64_GPR_R11, 0x000000000000FFFF }, /* R11W */
1744 			[2] = { -1, 0 },
1745 			[3] = { NVMM_X64_GPR_R11, 0x00000000FFFFFFFF }, /* R11D */
1746 			[4] = { -1, 0 },
1747 			[5] = { -1, 0 },
1748 			[6] = { -1, 0 },
1749 			[7] = { NVMM_X64_GPR_R11, 0xFFFFFFFFFFFFFFFF }, /* R11 */
1750 		},
1751 		[0b100] = {
1752 			[0] = { NVMM_X64_GPR_R12, 0x00000000000000FF }, /* R12B */
1753 			[1] = { NVMM_X64_GPR_R12, 0x000000000000FFFF }, /* R12W */
1754 			[2] = { -1, 0 },
1755 			[3] = { NVMM_X64_GPR_R12, 0x00000000FFFFFFFF }, /* R12D */
1756 			[4] = { -1, 0 },
1757 			[5] = { -1, 0 },
1758 			[6] = { -1, 0 },
1759 			[7] = { NVMM_X64_GPR_R12, 0xFFFFFFFFFFFFFFFF }, /* R12 */
1760 		},
1761 		[0b101] = {
1762 			[0] = { NVMM_X64_GPR_R13, 0x00000000000000FF }, /* R13B */
1763 			[1] = { NVMM_X64_GPR_R13, 0x000000000000FFFF }, /* R13W */
1764 			[2] = { -1, 0 },
1765 			[3] = { NVMM_X64_GPR_R13, 0x00000000FFFFFFFF }, /* R13D */
1766 			[4] = { -1, 0 },
1767 			[5] = { -1, 0 },
1768 			[6] = { -1, 0 },
1769 			[7] = { NVMM_X64_GPR_R13, 0xFFFFFFFFFFFFFFFF }, /* R13 */
1770 		},
1771 		[0b110] = {
1772 			[0] = { NVMM_X64_GPR_R14, 0x00000000000000FF }, /* R14B */
1773 			[1] = { NVMM_X64_GPR_R14, 0x000000000000FFFF }, /* R14W */
1774 			[2] = { -1, 0 },
1775 			[3] = { NVMM_X64_GPR_R14, 0x00000000FFFFFFFF }, /* R14D */
1776 			[4] = { -1, 0 },
1777 			[5] = { -1, 0 },
1778 			[6] = { -1, 0 },
1779 			[7] = { NVMM_X64_GPR_R14, 0xFFFFFFFFFFFFFFFF }, /* R14 */
1780 		},
1781 		[0b111] = {
1782 			[0] = { NVMM_X64_GPR_R15, 0x00000000000000FF }, /* R15B */
1783 			[1] = { NVMM_X64_GPR_R15, 0x000000000000FFFF }, /* R15W */
1784 			[2] = { -1, 0 },
1785 			[3] = { NVMM_X64_GPR_R15, 0x00000000FFFFFFFF }, /* R15D */
1786 			[4] = { -1, 0 },
1787 			[5] = { -1, 0 },
1788 			[6] = { -1, 0 },
1789 			[7] = { NVMM_X64_GPR_R15, 0xFFFFFFFFFFFFFFFF }, /* R15 */
1790 		},
1791 	}
1792 };
1793 
1794 /* [enc] */
1795 static const int gpr_dual_reg1_rm[8] __cacheline_aligned = {
1796 	[0b000] = NVMM_X64_GPR_RBX, /* BX (+SI) */
1797 	[0b001] = NVMM_X64_GPR_RBX, /* BX (+DI) */
1798 	[0b010] = NVMM_X64_GPR_RBP, /* BP (+SI) */
1799 	[0b011] = NVMM_X64_GPR_RBP, /* BP (+DI) */
1800 	[0b100] = NVMM_X64_GPR_RSI, /* SI */
1801 	[0b101] = NVMM_X64_GPR_RDI, /* DI */
1802 	[0b110] = NVMM_X64_GPR_RBP, /* BP */
1803 	[0b111] = NVMM_X64_GPR_RBX, /* BX */
1804 };
1805 
1806 static int
1807 node_overflow(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1808 {
1809 	fsm->fn = NULL;
1810 	return -1;
1811 }
1812 
1813 static int
1814 fsm_read(struct x86_decode_fsm *fsm, uint8_t *bytes, size_t n)
1815 {
1816 	if (fsm->buf + n > fsm->end) {
1817 		return -1;
1818 	}
1819 	memcpy(bytes, fsm->buf, n);
1820 	return 0;
1821 }
1822 
1823 static inline void
1824 fsm_advance(struct x86_decode_fsm *fsm, size_t n,
1825     int (*fn)(struct x86_decode_fsm *, struct x86_instr *))
1826 {
1827 	fsm->buf += n;
1828 	if (fsm->buf > fsm->end) {
1829 		fsm->fn = node_overflow;
1830 	} else {
1831 		fsm->fn = fn;
1832 	}
1833 }
1834 
1835 static const struct x86_reg *
1836 resolve_special_register(struct x86_instr *instr, uint8_t enc, size_t regsize)
1837 {
1838 	enc &= 0b11;
1839 	if (regsize == 8) {
1840 		/* May be 64bit without REX */
1841 		return &gpr_map__special[1][enc][regsize-1];
1842 	}
1843 	return &gpr_map__special[instr->rexpref.present][enc][regsize-1];
1844 }
1845 
1846 /*
1847  * Special node, for MOVS. Fake two displacements of zero on the source and
1848  * destination registers.
1849  */
1850 static int
1851 node_movs(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1852 {
1853 	size_t adrsize;
1854 
1855 	adrsize = instr->address_size;
1856 
1857 	/* DS:RSI */
1858 	instr->src.type = STORE_REG;
1859 	instr->src.u.reg = &gpr_map__special[1][2][adrsize-1];
1860 	instr->src.disp.type = DISP_0;
1861 
1862 	/* ES:RDI, force ES */
1863 	instr->dst.type = STORE_REG;
1864 	instr->dst.u.reg = &gpr_map__special[1][3][adrsize-1];
1865 	instr->dst.disp.type = DISP_0;
1866 	instr->dst.hardseg = NVMM_X64_SEG_ES;
1867 
1868 	fsm_advance(fsm, 0, NULL);
1869 
1870 	return 0;
1871 }
1872 
1873 /*
1874  * Special node, for STOS and LODS. Fake a displacement of zero on the
1875  * destination register.
1876  */
1877 static int
1878 node_stlo(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1879 {
1880 	const struct x86_opcode *opcode = instr->opcode;
1881 	struct x86_store *stlo, *streg;
1882 	size_t adrsize, regsize;
1883 
1884 	adrsize = instr->address_size;
1885 	regsize = instr->operand_size;
1886 
1887 	if (opcode->stos) {
1888 		streg = &instr->src;
1889 		stlo = &instr->dst;
1890 	} else {
1891 		streg = &instr->dst;
1892 		stlo = &instr->src;
1893 	}
1894 
1895 	streg->type = STORE_REG;
1896 	streg->u.reg = &gpr_map[0][0][regsize-1]; /* ?AX */
1897 
1898 	stlo->type = STORE_REG;
1899 	if (opcode->stos) {
1900 		/* ES:RDI, force ES */
1901 		stlo->u.reg = &gpr_map__special[1][3][adrsize-1];
1902 		stlo->hardseg = NVMM_X64_SEG_ES;
1903 	} else {
1904 		/* DS:RSI */
1905 		stlo->u.reg = &gpr_map__special[1][2][adrsize-1];
1906 	}
1907 	stlo->disp.type = DISP_0;
1908 
1909 	fsm_advance(fsm, 0, NULL);
1910 
1911 	return 0;
1912 }
1913 
1914 static int
1915 node_dmo(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1916 {
1917 	const struct x86_opcode *opcode = instr->opcode;
1918 	struct x86_store *stdmo, *streg;
1919 	size_t adrsize, regsize;
1920 
1921 	adrsize = instr->address_size;
1922 	regsize = instr->operand_size;
1923 
1924 	if (opcode->todmo) {
1925 		streg = &instr->src;
1926 		stdmo = &instr->dst;
1927 	} else {
1928 		streg = &instr->dst;
1929 		stdmo = &instr->src;
1930 	}
1931 
1932 	streg->type = STORE_REG;
1933 	streg->u.reg = &gpr_map[0][0][regsize-1]; /* ?AX */
1934 
1935 	stdmo->type = STORE_DMO;
1936 	if (fsm_read(fsm, (uint8_t *)&stdmo->u.dmo, adrsize) == -1) {
1937 		return -1;
1938 	}
1939 	fsm_advance(fsm, adrsize, NULL);
1940 
1941 	return 0;
1942 }
1943 
1944 static inline uint64_t
1945 sign_extend(uint64_t val, int size)
1946 {
1947 	if (size == 1) {
1948 		if (val & __BIT(7))
1949 			val |= 0xFFFFFFFFFFFFFF00;
1950 	} else if (size == 2) {
1951 		if (val & __BIT(15))
1952 			val |= 0xFFFFFFFFFFFF0000;
1953 	} else if (size == 4) {
1954 		if (val & __BIT(31))
1955 			val |= 0xFFFFFFFF00000000;
1956 	}
1957 	return val;
1958 }
1959 
1960 static int
1961 node_immediate(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1962 {
1963 	const struct x86_opcode *opcode = instr->opcode;
1964 	struct x86_store *store;
1965 	uint8_t immsize;
1966 	size_t sesize = 0;
1967 
1968 	/* The immediate is the source */
1969 	store = &instr->src;
1970 	immsize = instr->operand_size;
1971 
1972 	if (opcode->flags & FLAG_imm8) {
1973 		sesize = immsize;
1974 		immsize = 1;
1975 	} else if ((opcode->flags & FLAG_immz) && (immsize == 8)) {
1976 		sesize = immsize;
1977 		immsize = 4;
1978 	}
1979 
1980 	store->type = STORE_IMM;
1981 	if (fsm_read(fsm, (uint8_t *)&store->u.imm.data, immsize) == -1) {
1982 		return -1;
1983 	}
1984 	fsm_advance(fsm, immsize, NULL);
1985 
1986 	if (sesize != 0) {
1987 		store->u.imm.data = sign_extend(store->u.imm.data, sesize);
1988 	}
1989 
1990 	return 0;
1991 }
1992 
1993 static int
1994 node_disp(struct x86_decode_fsm *fsm, struct x86_instr *instr)
1995 {
1996 	const struct x86_opcode *opcode = instr->opcode;
1997 	uint64_t data = 0;
1998 	size_t n;
1999 
2000 	if (instr->strm->disp.type == DISP_1) {
2001 		n = 1;
2002 	} else if (instr->strm->disp.type == DISP_2) {
2003 		n = 2;
2004 	} else if (instr->strm->disp.type == DISP_4) {
2005 		n = 4;
2006 	} else {
2007 		DISASSEMBLER_BUG();
2008 	}
2009 
2010 	if (fsm_read(fsm, (uint8_t *)&data, n) == -1) {
2011 		return -1;
2012 	}
2013 
2014 	if (__predict_true(fsm->is64bit)) {
2015 		data = sign_extend(data, n);
2016 	}
2017 
2018 	instr->strm->disp.data = data;
2019 
2020 	if (opcode->immediate) {
2021 		fsm_advance(fsm, n, node_immediate);
2022 	} else {
2023 		fsm_advance(fsm, n, NULL);
2024 	}
2025 
2026 	return 0;
2027 }
2028 
2029 /*
2030  * Special node to handle 16bit addressing encoding, which can reference two
2031  * registers at once.
2032  */
2033 static int
2034 node_dual(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2035 {
2036 	int reg1, reg2;
2037 
2038 	reg1 = gpr_dual_reg1_rm[instr->regmodrm.rm];
2039 
2040 	if (instr->regmodrm.rm == 0b000 ||
2041 	    instr->regmodrm.rm == 0b010) {
2042 		reg2 = NVMM_X64_GPR_RSI;
2043 	} else if (instr->regmodrm.rm == 0b001 ||
2044 	    instr->regmodrm.rm == 0b011) {
2045 		reg2 = NVMM_X64_GPR_RDI;
2046 	} else {
2047 		DISASSEMBLER_BUG();
2048 	}
2049 
2050 	instr->strm->type = STORE_DUALREG;
2051 	instr->strm->u.dualreg.reg1 = reg1;
2052 	instr->strm->u.dualreg.reg2 = reg2;
2053 
2054 	if (instr->strm->disp.type == DISP_NONE) {
2055 		DISASSEMBLER_BUG();
2056 	} else if (instr->strm->disp.type == DISP_0) {
2057 		/* Indirect register addressing mode */
2058 		if (instr->opcode->immediate) {
2059 			fsm_advance(fsm, 1, node_immediate);
2060 		} else {
2061 			fsm_advance(fsm, 1, NULL);
2062 		}
2063 	} else {
2064 		fsm_advance(fsm, 1, node_disp);
2065 	}
2066 
2067 	return 0;
2068 }
2069 
2070 static const struct x86_reg *
2071 get_register_idx(struct x86_instr *instr, uint8_t index)
2072 {
2073 	uint8_t enc = index;
2074 	const struct x86_reg *reg;
2075 	size_t regsize;
2076 
2077 	regsize = instr->address_size;
2078 	reg = &gpr_map[instr->rexpref.x][enc][regsize-1];
2079 
2080 	if (reg->num == -1) {
2081 		reg = resolve_special_register(instr, enc, regsize);
2082 	}
2083 
2084 	return reg;
2085 }
2086 
2087 static const struct x86_reg *
2088 get_register_bas(struct x86_instr *instr, uint8_t base)
2089 {
2090 	uint8_t enc = base;
2091 	const struct x86_reg *reg;
2092 	size_t regsize;
2093 
2094 	regsize = instr->address_size;
2095 	reg = &gpr_map[instr->rexpref.b][enc][regsize-1];
2096 	if (reg->num == -1) {
2097 		reg = resolve_special_register(instr, enc, regsize);
2098 	}
2099 
2100 	return reg;
2101 }
2102 
2103 static int
2104 node_sib(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2105 {
2106 	const struct x86_opcode *opcode;
2107 	uint8_t scale, index, base;
2108 	bool noindex, nobase;
2109 	uint8_t byte;
2110 
2111 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2112 		return -1;
2113 	}
2114 
2115 	scale = ((byte & 0b11000000) >> 6);
2116 	index = ((byte & 0b00111000) >> 3);
2117 	base  = ((byte & 0b00000111) >> 0);
2118 
2119 	opcode = instr->opcode;
2120 
2121 	noindex = false;
2122 	nobase = false;
2123 
2124 	if (index == 0b100 && !instr->rexpref.x) {
2125 		/* Special case: the index is null */
2126 		noindex = true;
2127 	}
2128 
2129 	if (instr->regmodrm.mod == 0b00 && base == 0b101) {
2130 		/* Special case: the base is null + disp32 */
2131 		instr->strm->disp.type = DISP_4;
2132 		nobase = true;
2133 	}
2134 
2135 	instr->strm->type = STORE_SIB;
2136 	instr->strm->u.sib.scale = (1 << scale);
2137 	if (!noindex)
2138 		instr->strm->u.sib.idx = get_register_idx(instr, index);
2139 	if (!nobase)
2140 		instr->strm->u.sib.bas = get_register_bas(instr, base);
2141 
2142 	/* May have a displacement, or an immediate */
2143 	if (instr->strm->disp.type == DISP_1 ||
2144 	    instr->strm->disp.type == DISP_2 ||
2145 	    instr->strm->disp.type == DISP_4) {
2146 		fsm_advance(fsm, 1, node_disp);
2147 	} else if (opcode->immediate) {
2148 		fsm_advance(fsm, 1, node_immediate);
2149 	} else {
2150 		fsm_advance(fsm, 1, NULL);
2151 	}
2152 
2153 	return 0;
2154 }
2155 
2156 static const struct x86_reg *
2157 get_register_reg(struct x86_instr *instr, const struct x86_opcode *opcode)
2158 {
2159 	uint8_t enc = instr->regmodrm.reg;
2160 	const struct x86_reg *reg;
2161 	size_t regsize;
2162 
2163 	regsize = instr->operand_size;
2164 
2165 	reg = &gpr_map[instr->rexpref.r][enc][regsize-1];
2166 	if (reg->num == -1) {
2167 		reg = resolve_special_register(instr, enc, regsize);
2168 	}
2169 
2170 	return reg;
2171 }
2172 
2173 static const struct x86_reg *
2174 get_register_rm(struct x86_instr *instr, const struct x86_opcode *opcode)
2175 {
2176 	uint8_t enc = instr->regmodrm.rm;
2177 	const struct x86_reg *reg;
2178 	size_t regsize;
2179 
2180 	if (instr->strm->disp.type == DISP_NONE) {
2181 		regsize = instr->operand_size;
2182 	} else {
2183 		/* Indirect access, the size is that of the address. */
2184 		regsize = instr->address_size;
2185 	}
2186 
2187 	reg = &gpr_map[instr->rexpref.b][enc][regsize-1];
2188 	if (reg->num == -1) {
2189 		reg = resolve_special_register(instr, enc, regsize);
2190 	}
2191 
2192 	return reg;
2193 }
2194 
2195 static inline bool
2196 has_sib(struct x86_instr *instr)
2197 {
2198 	return (instr->address_size != 2 && /* no SIB in 16bit addressing */
2199 	    instr->regmodrm.mod != 0b11 &&
2200 	    instr->regmodrm.rm == 0b100);
2201 }
2202 
2203 static inline bool
2204 is_rip_relative(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2205 {
2206 	return (fsm->is64bit && /* RIP-relative only in 64bit mode */
2207 	    instr->regmodrm.mod == 0b00 &&
2208 	    instr->regmodrm.rm == 0b101);
2209 }
2210 
2211 static inline bool
2212 is_disp32_only(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2213 {
2214 	return (!fsm->is64bit && /* no disp32-only in 64bit mode */
2215 	    instr->address_size != 2 && /* no disp32-only in 16bit addressing */
2216 	    instr->regmodrm.mod == 0b00 &&
2217 	    instr->regmodrm.rm == 0b101);
2218 }
2219 
2220 static inline bool
2221 is_disp16_only(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2222 {
2223 	return (instr->address_size == 2 && /* disp16-only only in 16bit addr */
2224 	    instr->regmodrm.mod == 0b00 &&
2225 	    instr->regmodrm.rm == 0b110);
2226 }
2227 
2228 static inline bool
2229 is_dual(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2230 {
2231 	return (instr->address_size == 2 &&
2232 	    instr->regmodrm.mod != 0b11 &&
2233 	    instr->regmodrm.rm <= 0b011);
2234 }
2235 
2236 static enum x86_disp_type
2237 get_disp_type(struct x86_instr *instr)
2238 {
2239 	switch (instr->regmodrm.mod) {
2240 	case 0b00:	/* indirect */
2241 		return DISP_0;
2242 	case 0b01:	/* indirect+1 */
2243 		return DISP_1;
2244 	case 0b10:	/* indirect+{2,4} */
2245 		if (__predict_false(instr->address_size == 2)) {
2246 			return DISP_2;
2247 		}
2248 		return DISP_4;
2249 	case 0b11:	/* direct */
2250 	default:	/* llvm */
2251 		return DISP_NONE;
2252 	}
2253 	__unreachable();
2254 }
2255 
2256 static int
2257 node_regmodrm(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2258 {
2259 	struct x86_store *strg, *strm;
2260 	const struct x86_opcode *opcode;
2261 	const struct x86_reg *reg;
2262 	uint8_t byte;
2263 
2264 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2265 		return -1;
2266 	}
2267 
2268 	opcode = instr->opcode;
2269 
2270 	instr->regmodrm.rm  = ((byte & 0b00000111) >> 0);
2271 	instr->regmodrm.reg = ((byte & 0b00111000) >> 3);
2272 	instr->regmodrm.mod = ((byte & 0b11000000) >> 6);
2273 
2274 	if (opcode->regtorm) {
2275 		strg = &instr->src;
2276 		strm = &instr->dst;
2277 	} else { /* RM to REG */
2278 		strm = &instr->src;
2279 		strg = &instr->dst;
2280 	}
2281 
2282 	/* Save for later use. */
2283 	instr->strm = strm;
2284 
2285 	/*
2286 	 * Special cases: Groups. The REG field of REGMODRM is the index in
2287 	 * the group. op1 gets overwritten in the Immediate node, if any.
2288 	 */
2289 	if (opcode->group1) {
2290 		if (group1[instr->regmodrm.reg].emul == NULL) {
2291 			return -1;
2292 		}
2293 		instr->emul = group1[instr->regmodrm.reg].emul;
2294 	} else if (opcode->group3) {
2295 		if (group3[instr->regmodrm.reg].emul == NULL) {
2296 			return -1;
2297 		}
2298 		instr->emul = group3[instr->regmodrm.reg].emul;
2299 	} else if (opcode->group11) {
2300 		if (group11[instr->regmodrm.reg].emul == NULL) {
2301 			return -1;
2302 		}
2303 		instr->emul = group11[instr->regmodrm.reg].emul;
2304 	}
2305 
2306 	if (!opcode->immediate) {
2307 		reg = get_register_reg(instr, opcode);
2308 		if (reg == NULL) {
2309 			return -1;
2310 		}
2311 		strg->type = STORE_REG;
2312 		strg->u.reg = reg;
2313 	}
2314 
2315 	/* The displacement applies to RM. */
2316 	strm->disp.type = get_disp_type(instr);
2317 
2318 	if (has_sib(instr)) {
2319 		/* Overwrites RM */
2320 		fsm_advance(fsm, 1, node_sib);
2321 		return 0;
2322 	}
2323 
2324 	if (is_rip_relative(fsm, instr)) {
2325 		/* Overwrites RM */
2326 		strm->type = STORE_REG;
2327 		strm->u.reg = &gpr_map__rip;
2328 		strm->disp.type = DISP_4;
2329 		fsm_advance(fsm, 1, node_disp);
2330 		return 0;
2331 	}
2332 
2333 	if (is_disp32_only(fsm, instr)) {
2334 		/* Overwrites RM */
2335 		strm->type = STORE_REG;
2336 		strm->u.reg = NULL;
2337 		strm->disp.type = DISP_4;
2338 		fsm_advance(fsm, 1, node_disp);
2339 		return 0;
2340 	}
2341 
2342 	if (__predict_false(is_disp16_only(fsm, instr))) {
2343 		/* Overwrites RM */
2344 		strm->type = STORE_REG;
2345 		strm->u.reg = NULL;
2346 		strm->disp.type = DISP_2;
2347 		fsm_advance(fsm, 1, node_disp);
2348 		return 0;
2349 	}
2350 
2351 	if (__predict_false(is_dual(fsm, instr))) {
2352 		/* Overwrites RM */
2353 		fsm_advance(fsm, 0, node_dual);
2354 		return 0;
2355 	}
2356 
2357 	reg = get_register_rm(instr, opcode);
2358 	if (reg == NULL) {
2359 		return -1;
2360 	}
2361 	strm->type = STORE_REG;
2362 	strm->u.reg = reg;
2363 
2364 	if (strm->disp.type == DISP_NONE) {
2365 		/* Direct register addressing mode */
2366 		if (opcode->immediate) {
2367 			fsm_advance(fsm, 1, node_immediate);
2368 		} else {
2369 			fsm_advance(fsm, 1, NULL);
2370 		}
2371 	} else if (strm->disp.type == DISP_0) {
2372 		/* Indirect register addressing mode */
2373 		if (opcode->immediate) {
2374 			fsm_advance(fsm, 1, node_immediate);
2375 		} else {
2376 			fsm_advance(fsm, 1, NULL);
2377 		}
2378 	} else {
2379 		fsm_advance(fsm, 1, node_disp);
2380 	}
2381 
2382 	return 0;
2383 }
2384 
2385 static size_t
2386 get_operand_size(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2387 {
2388 	const struct x86_opcode *opcode = instr->opcode;
2389 	int opsize;
2390 
2391 	/* Get the opsize */
2392 	if (!opcode->szoverride) {
2393 		opsize = opcode->defsize;
2394 	} else if (instr->rexpref.present && instr->rexpref.w) {
2395 		opsize = 8;
2396 	} else {
2397 		if (!fsm->is16bit) {
2398 			if (instr->legpref.opr_ovr) {
2399 				opsize = 2;
2400 			} else {
2401 				opsize = 4;
2402 			}
2403 		} else { /* 16bit */
2404 			if (instr->legpref.opr_ovr) {
2405 				opsize = 4;
2406 			} else {
2407 				opsize = 2;
2408 			}
2409 		}
2410 	}
2411 
2412 	return opsize;
2413 }
2414 
2415 static size_t
2416 get_address_size(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2417 {
2418 	if (fsm->is64bit) {
2419 		if (__predict_false(instr->legpref.adr_ovr)) {
2420 			return 4;
2421 		}
2422 		return 8;
2423 	}
2424 
2425 	if (fsm->is32bit) {
2426 		if (__predict_false(instr->legpref.adr_ovr)) {
2427 			return 2;
2428 		}
2429 		return 4;
2430 	}
2431 
2432 	/* 16bit. */
2433 	if (__predict_false(instr->legpref.adr_ovr)) {
2434 		return 4;
2435 	}
2436 	return 2;
2437 }
2438 
2439 static int
2440 node_primary_opcode(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2441 {
2442 	const struct x86_opcode *opcode;
2443 	uint8_t byte;
2444 
2445 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2446 		return -1;
2447 	}
2448 
2449 	opcode = &primary_opcode_table[byte];
2450 	if (__predict_false(!opcode->valid)) {
2451 		return -1;
2452 	}
2453 
2454 	instr->opcode = opcode;
2455 	instr->emul = opcode->emul;
2456 	instr->operand_size = get_operand_size(fsm, instr);
2457 	instr->address_size = get_address_size(fsm, instr);
2458 
2459 	if (fsm->is64bit && (instr->operand_size == 4)) {
2460 		/* Zero-extend to 64 bits. */
2461 		instr->zeroextend_mask = ~size_to_mask(4);
2462 	}
2463 
2464 	if (opcode->regmodrm) {
2465 		fsm_advance(fsm, 1, node_regmodrm);
2466 	} else if (opcode->dmo) {
2467 		/* Direct-Memory Offsets */
2468 		fsm_advance(fsm, 1, node_dmo);
2469 	} else if (opcode->stos || opcode->lods) {
2470 		fsm_advance(fsm, 1, node_stlo);
2471 	} else if (opcode->movs) {
2472 		fsm_advance(fsm, 1, node_movs);
2473 	} else {
2474 		return -1;
2475 	}
2476 
2477 	return 0;
2478 }
2479 
2480 static int
2481 node_secondary_opcode(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2482 {
2483 	const struct x86_opcode *opcode;
2484 	uint8_t byte;
2485 
2486 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2487 		return -1;
2488 	}
2489 
2490 	opcode = &secondary_opcode_table[byte];
2491 	if (__predict_false(!opcode->valid)) {
2492 		return -1;
2493 	}
2494 
2495 	instr->opcode = opcode;
2496 	instr->emul = opcode->emul;
2497 	instr->operand_size = get_operand_size(fsm, instr);
2498 	instr->address_size = get_address_size(fsm, instr);
2499 
2500 	if (fsm->is64bit && (instr->operand_size == 4)) {
2501 		/* Zero-extend to 64 bits. */
2502 		instr->zeroextend_mask = ~size_to_mask(4);
2503 	}
2504 
2505 	if (opcode->flags & FLAG_ze) {
2506 		/*
2507 		 * Compute the mask for zero-extend. Update the operand size,
2508 		 * we move fewer bytes.
2509 		 */
2510 		instr->zeroextend_mask |= size_to_mask(instr->operand_size);
2511 		instr->zeroextend_mask &= ~size_to_mask(opcode->defsize);
2512 		instr->operand_size = opcode->defsize;
2513 	}
2514 
2515 	if (opcode->regmodrm) {
2516 		fsm_advance(fsm, 1, node_regmodrm);
2517 	} else {
2518 		return -1;
2519 	}
2520 
2521 	return 0;
2522 }
2523 
2524 static int
2525 node_main(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2526 {
2527 	uint8_t byte;
2528 
2529 #define ESCAPE	0x0F
2530 #define VEX_1	0xC5
2531 #define VEX_2	0xC4
2532 #define XOP	0x8F
2533 
2534 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2535 		return -1;
2536 	}
2537 
2538 	/*
2539 	 * We don't take XOP. It is AMD-specific, and it was removed shortly
2540 	 * after being introduced.
2541 	 */
2542 	if (byte == ESCAPE) {
2543 		fsm_advance(fsm, 1, node_secondary_opcode);
2544 	} else if (!instr->rexpref.present) {
2545 		if (byte == VEX_1) {
2546 			return -1;
2547 		} else if (byte == VEX_2) {
2548 			return -1;
2549 		} else {
2550 			fsm->fn = node_primary_opcode;
2551 		}
2552 	} else {
2553 		fsm->fn = node_primary_opcode;
2554 	}
2555 
2556 	return 0;
2557 }
2558 
2559 static int
2560 node_rex_prefix(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2561 {
2562 	struct x86_rexpref *rexpref = &instr->rexpref;
2563 	uint8_t byte;
2564 	size_t n = 0;
2565 
2566 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2567 		return -1;
2568 	}
2569 
2570 	if (byte >= 0x40 && byte <= 0x4F) {
2571 		if (__predict_false(!fsm->is64bit)) {
2572 			return -1;
2573 		}
2574 		rexpref->b = ((byte & 0x1) != 0);
2575 		rexpref->x = ((byte & 0x2) != 0);
2576 		rexpref->r = ((byte & 0x4) != 0);
2577 		rexpref->w = ((byte & 0x8) != 0);
2578 		rexpref->present = true;
2579 		n = 1;
2580 	}
2581 
2582 	fsm_advance(fsm, n, node_main);
2583 	return 0;
2584 }
2585 
2586 static int
2587 node_legacy_prefix(struct x86_decode_fsm *fsm, struct x86_instr *instr)
2588 {
2589 	uint8_t byte;
2590 
2591 	if (fsm_read(fsm, &byte, sizeof(byte)) == -1) {
2592 		return -1;
2593 	}
2594 
2595 	if (byte == LEG_OPR_OVR) {
2596 		instr->legpref.opr_ovr = 1;
2597 	} else if (byte == LEG_OVR_DS) {
2598 		instr->legpref.seg = NVMM_X64_SEG_DS;
2599 	} else if (byte == LEG_OVR_ES) {
2600 		instr->legpref.seg = NVMM_X64_SEG_ES;
2601 	} else if (byte == LEG_REP) {
2602 		instr->legpref.rep = 1;
2603 	} else if (byte == LEG_OVR_GS) {
2604 		instr->legpref.seg = NVMM_X64_SEG_GS;
2605 	} else if (byte == LEG_OVR_FS) {
2606 		instr->legpref.seg = NVMM_X64_SEG_FS;
2607 	} else if (byte == LEG_ADR_OVR) {
2608 		instr->legpref.adr_ovr = 1;
2609 	} else if (byte == LEG_OVR_CS) {
2610 		instr->legpref.seg = NVMM_X64_SEG_CS;
2611 	} else if (byte == LEG_OVR_SS) {
2612 		instr->legpref.seg = NVMM_X64_SEG_SS;
2613 	} else if (byte == LEG_REPN) {
2614 		instr->legpref.repn = 1;
2615 	} else if (byte == LEG_LOCK) {
2616 		/* ignore */
2617 	} else {
2618 		/* not a legacy prefix */
2619 		fsm_advance(fsm, 0, node_rex_prefix);
2620 		return 0;
2621 	}
2622 
2623 	fsm_advance(fsm, 1, node_legacy_prefix);
2624 	return 0;
2625 }
2626 
2627 static int
2628 x86_decode(uint8_t *inst_bytes, size_t inst_len, struct x86_instr *instr,
2629     struct nvmm_x64_state *state)
2630 {
2631 	struct x86_decode_fsm fsm;
2632 	int ret;
2633 
2634 	memset(instr, 0, sizeof(*instr));
2635 	instr->legpref.seg = -1;
2636 	instr->src.hardseg = -1;
2637 	instr->dst.hardseg = -1;
2638 
2639 	fsm.is64bit = is_64bit(state);
2640 	fsm.is32bit = is_32bit(state);
2641 	fsm.is16bit = is_16bit(state);
2642 
2643 	fsm.fn = node_legacy_prefix;
2644 	fsm.buf = inst_bytes;
2645 	fsm.end = inst_bytes + inst_len;
2646 
2647 	while (fsm.fn != NULL) {
2648 		ret = (*fsm.fn)(&fsm, instr);
2649 		if (ret == -1)
2650 			return -1;
2651 	}
2652 
2653 	instr->len = fsm.buf - inst_bytes;
2654 
2655 	return 0;
2656 }
2657 
2658 /* -------------------------------------------------------------------------- */
2659 
2660 #define EXEC_INSTR(sz, instr)						\
2661 static uint##sz##_t							\
2662 exec_##instr##sz(uint##sz##_t op1, uint##sz##_t op2, uint64_t *rflags)	\
2663 {									\
2664 	uint##sz##_t res;						\
2665 	__asm __volatile (						\
2666 		#instr"	%2, %3;"					\
2667 		"mov	%3, %1;"					\
2668 		"pushfq;"						\
2669 		"popq	%0"						\
2670 	    : "=r" (*rflags), "=r" (res)				\
2671 	    : "r" (op1), "r" (op2));					\
2672 	return res;							\
2673 }
2674 
2675 #define EXEC_DISPATCHER(instr)						\
2676 static uint64_t								\
2677 exec_##instr(uint64_t op1, uint64_t op2, uint64_t *rflags, size_t opsize) \
2678 {									\
2679 	switch (opsize) {						\
2680 	case 1:								\
2681 		return exec_##instr##8(op1, op2, rflags);		\
2682 	case 2:								\
2683 		return exec_##instr##16(op1, op2, rflags);		\
2684 	case 4:								\
2685 		return exec_##instr##32(op1, op2, rflags);		\
2686 	default:							\
2687 		return exec_##instr##64(op1, op2, rflags);		\
2688 	}								\
2689 }
2690 
2691 /* SUB: ret = op1 - op2 */
2692 #define PSL_SUB_MASK	(PSL_V|PSL_C|PSL_Z|PSL_N|PSL_PF|PSL_AF)
2693 EXEC_INSTR(8, sub)
2694 EXEC_INSTR(16, sub)
2695 EXEC_INSTR(32, sub)
2696 EXEC_INSTR(64, sub)
2697 EXEC_DISPATCHER(sub)
2698 
2699 /* OR:  ret = op1 | op2 */
2700 #define PSL_OR_MASK	(PSL_V|PSL_C|PSL_Z|PSL_N|PSL_PF)
2701 EXEC_INSTR(8, or)
2702 EXEC_INSTR(16, or)
2703 EXEC_INSTR(32, or)
2704 EXEC_INSTR(64, or)
2705 EXEC_DISPATCHER(or)
2706 
2707 /* AND: ret = op1 & op2 */
2708 #define PSL_AND_MASK	(PSL_V|PSL_C|PSL_Z|PSL_N|PSL_PF)
2709 EXEC_INSTR(8, and)
2710 EXEC_INSTR(16, and)
2711 EXEC_INSTR(32, and)
2712 EXEC_INSTR(64, and)
2713 EXEC_DISPATCHER(and)
2714 
2715 /* XOR: ret = op1 ^ op2 */
2716 #define PSL_XOR_MASK	(PSL_V|PSL_C|PSL_Z|PSL_N|PSL_PF)
2717 EXEC_INSTR(8, xor)
2718 EXEC_INSTR(16, xor)
2719 EXEC_INSTR(32, xor)
2720 EXEC_INSTR(64, xor)
2721 EXEC_DISPATCHER(xor)
2722 
2723 /* -------------------------------------------------------------------------- */
2724 
2725 /*
2726  * Emulation functions. We don't care about the order of the operands, except
2727  * for SUB, CMP and TEST. For these ones we look at mem->write to determine who
2728  * is op1 and who is op2.
2729  */
2730 
2731 static void
2732 x86_func_or(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2733 {
2734 	uint64_t *retval = (uint64_t *)mem->data;
2735 	const bool write = mem->write;
2736 	uint64_t *op1, op2, fl, ret;
2737 
2738 	op1 = (uint64_t *)mem->data;
2739 	op2 = 0;
2740 
2741 	/* Fetch the value to be OR'ed (op2). */
2742 	mem->data = (uint8_t *)&op2;
2743 	mem->write = false;
2744 	(*vcpu->cbs.mem)(mem);
2745 
2746 	/* Perform the OR. */
2747 	ret = exec_or(*op1, op2, &fl, mem->size);
2748 
2749 	if (write) {
2750 		/* Write back the result. */
2751 		mem->data = (uint8_t *)&ret;
2752 		mem->write = true;
2753 		(*vcpu->cbs.mem)(mem);
2754 	} else {
2755 		/* Return data to the caller. */
2756 		*retval = ret;
2757 	}
2758 
2759 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_OR_MASK;
2760 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_OR_MASK);
2761 }
2762 
2763 static void
2764 x86_func_and(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2765 {
2766 	uint64_t *retval = (uint64_t *)mem->data;
2767 	const bool write = mem->write;
2768 	uint64_t *op1, op2, fl, ret;
2769 
2770 	op1 = (uint64_t *)mem->data;
2771 	op2 = 0;
2772 
2773 	/* Fetch the value to be AND'ed (op2). */
2774 	mem->data = (uint8_t *)&op2;
2775 	mem->write = false;
2776 	(*vcpu->cbs.mem)(mem);
2777 
2778 	/* Perform the AND. */
2779 	ret = exec_and(*op1, op2, &fl, mem->size);
2780 
2781 	if (write) {
2782 		/* Write back the result. */
2783 		mem->data = (uint8_t *)&ret;
2784 		mem->write = true;
2785 		(*vcpu->cbs.mem)(mem);
2786 	} else {
2787 		/* Return data to the caller. */
2788 		*retval = ret;
2789 	}
2790 
2791 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_AND_MASK;
2792 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_AND_MASK);
2793 }
2794 
2795 static void
2796 x86_func_xchg(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2797 {
2798 	uint64_t *op1, op2;
2799 
2800 	op1 = (uint64_t *)mem->data;
2801 	op2 = 0;
2802 
2803 	/* Fetch op2. */
2804 	mem->data = (uint8_t *)&op2;
2805 	mem->write = false;
2806 	(*vcpu->cbs.mem)(mem);
2807 
2808 	/* Write op1 in op2. */
2809 	mem->data = (uint8_t *)op1;
2810 	mem->write = true;
2811 	(*vcpu->cbs.mem)(mem);
2812 
2813 	/* Write op2 in op1. */
2814 	*op1 = op2;
2815 }
2816 
2817 static void
2818 x86_func_sub(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2819 {
2820 	uint64_t *retval = (uint64_t *)mem->data;
2821 	const bool write = mem->write;
2822 	uint64_t *op1, *op2, fl, ret;
2823 	uint64_t tmp;
2824 	bool memop1;
2825 
2826 	memop1 = !mem->write;
2827 	op1 = memop1 ? &tmp : (uint64_t *)mem->data;
2828 	op2 = memop1 ? (uint64_t *)mem->data : &tmp;
2829 
2830 	/* Fetch the value to be SUB'ed (op1 or op2). */
2831 	mem->data = (uint8_t *)&tmp;
2832 	mem->write = false;
2833 	(*vcpu->cbs.mem)(mem);
2834 
2835 	/* Perform the SUB. */
2836 	ret = exec_sub(*op1, *op2, &fl, mem->size);
2837 
2838 	if (write) {
2839 		/* Write back the result. */
2840 		mem->data = (uint8_t *)&ret;
2841 		mem->write = true;
2842 		(*vcpu->cbs.mem)(mem);
2843 	} else {
2844 		/* Return data to the caller. */
2845 		*retval = ret;
2846 	}
2847 
2848 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_SUB_MASK;
2849 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_SUB_MASK);
2850 }
2851 
2852 static void
2853 x86_func_xor(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2854 {
2855 	uint64_t *retval = (uint64_t *)mem->data;
2856 	const bool write = mem->write;
2857 	uint64_t *op1, op2, fl, ret;
2858 
2859 	op1 = (uint64_t *)mem->data;
2860 	op2 = 0;
2861 
2862 	/* Fetch the value to be XOR'ed (op2). */
2863 	mem->data = (uint8_t *)&op2;
2864 	mem->write = false;
2865 	(*vcpu->cbs.mem)(mem);
2866 
2867 	/* Perform the XOR. */
2868 	ret = exec_xor(*op1, op2, &fl, mem->size);
2869 
2870 	if (write) {
2871 		/* Write back the result. */
2872 		mem->data = (uint8_t *)&ret;
2873 		mem->write = true;
2874 		(*vcpu->cbs.mem)(mem);
2875 	} else {
2876 		/* Return data to the caller. */
2877 		*retval = ret;
2878 	}
2879 
2880 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_XOR_MASK;
2881 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_XOR_MASK);
2882 }
2883 
2884 static void
2885 x86_func_cmp(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2886 {
2887 	uint64_t *op1, *op2, fl;
2888 	uint64_t tmp;
2889 	bool memop1;
2890 
2891 	memop1 = !mem->write;
2892 	op1 = memop1 ? &tmp : (uint64_t *)mem->data;
2893 	op2 = memop1 ? (uint64_t *)mem->data : &tmp;
2894 
2895 	/* Fetch the value to be CMP'ed (op1 or op2). */
2896 	mem->data = (uint8_t *)&tmp;
2897 	mem->write = false;
2898 	(*vcpu->cbs.mem)(mem);
2899 
2900 	/* Perform the CMP. */
2901 	exec_sub(*op1, *op2, &fl, mem->size);
2902 
2903 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_SUB_MASK;
2904 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_SUB_MASK);
2905 }
2906 
2907 static void
2908 x86_func_test(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2909 {
2910 	uint64_t *op1, *op2, fl;
2911 	uint64_t tmp;
2912 	bool memop1;
2913 
2914 	memop1 = !mem->write;
2915 	op1 = memop1 ? &tmp : (uint64_t *)mem->data;
2916 	op2 = memop1 ? (uint64_t *)mem->data : &tmp;
2917 
2918 	/* Fetch the value to be TEST'ed (op1 or op2). */
2919 	mem->data = (uint8_t *)&tmp;
2920 	mem->write = false;
2921 	(*vcpu->cbs.mem)(mem);
2922 
2923 	/* Perform the TEST. */
2924 	exec_and(*op1, *op2, &fl, mem->size);
2925 
2926 	gprs[NVMM_X64_GPR_RFLAGS] &= ~PSL_AND_MASK;
2927 	gprs[NVMM_X64_GPR_RFLAGS] |= (fl & PSL_AND_MASK);
2928 }
2929 
2930 static void
2931 x86_func_mov(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2932 {
2933 	/*
2934 	 * Nothing special, just move without emulation.
2935 	 */
2936 	(*vcpu->cbs.mem)(mem);
2937 }
2938 
2939 static void
2940 x86_func_stos(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2941 {
2942 	/*
2943 	 * Just move, and update RDI.
2944 	 */
2945 	(*vcpu->cbs.mem)(mem);
2946 
2947 	if (gprs[NVMM_X64_GPR_RFLAGS] & PSL_D) {
2948 		gprs[NVMM_X64_GPR_RDI] -= mem->size;
2949 	} else {
2950 		gprs[NVMM_X64_GPR_RDI] += mem->size;
2951 	}
2952 }
2953 
2954 static void
2955 x86_func_lods(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2956 {
2957 	/*
2958 	 * Just move, and update RSI.
2959 	 */
2960 	(*vcpu->cbs.mem)(mem);
2961 
2962 	if (gprs[NVMM_X64_GPR_RFLAGS] & PSL_D) {
2963 		gprs[NVMM_X64_GPR_RSI] -= mem->size;
2964 	} else {
2965 		gprs[NVMM_X64_GPR_RSI] += mem->size;
2966 	}
2967 }
2968 
2969 static void
2970 x86_func_movs(struct nvmm_vcpu *vcpu, struct nvmm_mem *mem, uint64_t *gprs)
2971 {
2972 	/*
2973 	 * Special instruction: double memory operand. Don't call the cb,
2974 	 * because the storage has already been performed earlier.
2975 	 */
2976 
2977 	if (gprs[NVMM_X64_GPR_RFLAGS] & PSL_D) {
2978 		gprs[NVMM_X64_GPR_RSI] -= mem->size;
2979 		gprs[NVMM_X64_GPR_RDI] -= mem->size;
2980 	} else {
2981 		gprs[NVMM_X64_GPR_RSI] += mem->size;
2982 		gprs[NVMM_X64_GPR_RDI] += mem->size;
2983 	}
2984 }
2985 
2986 /* -------------------------------------------------------------------------- */
2987 
2988 static inline uint64_t
2989 gpr_read_address(struct x86_instr *instr, struct nvmm_x64_state *state, int gpr)
2990 {
2991 	uint64_t val;
2992 
2993 	val = state->gprs[gpr];
2994 	val &= size_to_mask(instr->address_size);
2995 
2996 	return val;
2997 }
2998 
2999 static int
3000 store_to_gva(struct nvmm_x64_state *state, struct x86_instr *instr,
3001     struct x86_store *store, gvaddr_t *gvap, size_t size)
3002 {
3003 	struct x86_sib *sib;
3004 	gvaddr_t gva = 0;
3005 	uint64_t reg;
3006 	int ret, seg;
3007 
3008 	if (store->type == STORE_SIB) {
3009 		sib = &store->u.sib;
3010 		if (sib->bas != NULL)
3011 			gva += gpr_read_address(instr, state, sib->bas->num);
3012 		if (sib->idx != NULL) {
3013 			reg = gpr_read_address(instr, state, sib->idx->num);
3014 			gva += sib->scale * reg;
3015 		}
3016 	} else if (store->type == STORE_REG) {
3017 		if (store->u.reg == NULL) {
3018 			/* The base is null. Happens with disp32-only and
3019 			 * disp16-only. */
3020 		} else {
3021 			gva = gpr_read_address(instr, state, store->u.reg->num);
3022 		}
3023 	} else if (store->type == STORE_DUALREG) {
3024 		gva = gpr_read_address(instr, state, store->u.dualreg.reg1) +
3025 		    gpr_read_address(instr, state, store->u.dualreg.reg2);
3026 	} else {
3027 		gva = store->u.dmo;
3028 	}
3029 
3030 	if (store->disp.type != DISP_NONE) {
3031 		gva += store->disp.data;
3032 	}
3033 
3034 	if (store->hardseg != -1) {
3035 		seg = store->hardseg;
3036 	} else {
3037 		if (__predict_false(instr->legpref.seg != -1)) {
3038 			seg = instr->legpref.seg;
3039 		} else {
3040 			seg = NVMM_X64_SEG_DS;
3041 		}
3042 	}
3043 
3044 	if (__predict_true(is_long_mode(state))) {
3045 		if (seg == NVMM_X64_SEG_GS || seg == NVMM_X64_SEG_FS) {
3046 			segment_apply(&state->segs[seg], &gva);
3047 		}
3048 	} else {
3049 		ret = segment_check(&state->segs[seg], gva, size);
3050 		if (ret == -1)
3051 			return -1;
3052 		segment_apply(&state->segs[seg], &gva);
3053 	}
3054 
3055 	*gvap = gva;
3056 	return 0;
3057 }
3058 
3059 static int
3060 fetch_segment(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu)
3061 {
3062 	struct nvmm_x64_state *state = vcpu->state;
3063 	uint8_t inst_bytes[5], byte;
3064 	size_t i, fetchsize;
3065 	gvaddr_t gva;
3066 	int ret, seg;
3067 
3068 	fetchsize = sizeof(inst_bytes);
3069 
3070 	gva = state->gprs[NVMM_X64_GPR_RIP];
3071 	if (__predict_false(!is_long_mode(state))) {
3072 		ret = segment_check(&state->segs[NVMM_X64_SEG_CS], gva,
3073 		    fetchsize);
3074 		if (ret == -1)
3075 			return -1;
3076 		segment_apply(&state->segs[NVMM_X64_SEG_CS], &gva);
3077 	}
3078 
3079 	ret = read_guest_memory(mach, vcpu, gva, inst_bytes, fetchsize);
3080 	if (ret == -1)
3081 		return -1;
3082 
3083 	seg = NVMM_X64_SEG_DS;
3084 	for (i = 0; i < fetchsize; i++) {
3085 		byte = inst_bytes[i];
3086 
3087 		if (byte == LEG_OVR_DS) {
3088 			seg = NVMM_X64_SEG_DS;
3089 		} else if (byte == LEG_OVR_ES) {
3090 			seg = NVMM_X64_SEG_ES;
3091 		} else if (byte == LEG_OVR_GS) {
3092 			seg = NVMM_X64_SEG_GS;
3093 		} else if (byte == LEG_OVR_FS) {
3094 			seg = NVMM_X64_SEG_FS;
3095 		} else if (byte == LEG_OVR_CS) {
3096 			seg = NVMM_X64_SEG_CS;
3097 		} else if (byte == LEG_OVR_SS) {
3098 			seg = NVMM_X64_SEG_SS;
3099 		} else if (byte == LEG_OPR_OVR) {
3100 			/* nothing */
3101 		} else if (byte == LEG_ADR_OVR) {
3102 			/* nothing */
3103 		} else if (byte == LEG_REP) {
3104 			/* nothing */
3105 		} else if (byte == LEG_REPN) {
3106 			/* nothing */
3107 		} else if (byte == LEG_LOCK) {
3108 			/* nothing */
3109 		} else {
3110 			return seg;
3111 		}
3112 	}
3113 
3114 	return seg;
3115 }
3116 
3117 static int
3118 fetch_instruction(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
3119     struct nvmm_vcpu_exit *exit)
3120 {
3121 	struct nvmm_x64_state *state = vcpu->state;
3122 	size_t fetchsize;
3123 	gvaddr_t gva;
3124 	int ret;
3125 
3126 	fetchsize = sizeof(exit->u.mem.inst_bytes);
3127 
3128 	gva = state->gprs[NVMM_X64_GPR_RIP];
3129 	if (__predict_false(!is_long_mode(state))) {
3130 		ret = segment_check(&state->segs[NVMM_X64_SEG_CS], gva,
3131 		    fetchsize);
3132 		if (ret == -1)
3133 			return -1;
3134 		segment_apply(&state->segs[NVMM_X64_SEG_CS], &gva);
3135 	}
3136 
3137 	ret = read_guest_memory(mach, vcpu, gva, exit->u.mem.inst_bytes,
3138 	    fetchsize);
3139 	if (ret == -1)
3140 		return -1;
3141 
3142 	exit->u.mem.inst_len = fetchsize;
3143 
3144 	return 0;
3145 }
3146 
3147 static int
3148 assist_mem_double(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
3149     struct x86_instr *instr)
3150 {
3151 	struct nvmm_x64_state *state = vcpu->state;
3152 	struct nvmm_mem mem;
3153 	uint8_t data[8];
3154 	gvaddr_t gva;
3155 	size_t size;
3156 	int ret;
3157 
3158 	size = instr->operand_size;
3159 
3160 	/* Source. */
3161 	ret = store_to_gva(state, instr, &instr->src, &gva, size);
3162 	if (ret == -1)
3163 		return -1;
3164 	ret = read_guest_memory(mach, vcpu, gva, data, size);
3165 	if (ret == -1)
3166 		return -1;
3167 
3168 	/* Destination. */
3169 	ret = store_to_gva(state, instr, &instr->dst, &gva, size);
3170 	if (ret == -1)
3171 		return -1;
3172 	ret = write_guest_memory(mach, vcpu, gva, data, size);
3173 	if (ret == -1)
3174 		return -1;
3175 
3176 	mem.size = size;
3177 	(*instr->emul->func)(vcpu, &mem, state->gprs);
3178 
3179 	return 0;
3180 }
3181 
3182 static int
3183 assist_mem_single(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu,
3184     struct x86_instr *instr)
3185 {
3186 	struct nvmm_x64_state *state = vcpu->state;
3187 	struct nvmm_vcpu_exit *exit = vcpu->exit;
3188 	struct nvmm_mem mem;
3189 	uint8_t membuf[8];
3190 	uint64_t val;
3191 
3192 	memset(membuf, 0, sizeof(membuf));
3193 
3194 	mem.mach = mach;
3195 	mem.vcpu = vcpu;
3196 	mem.gpa = exit->u.mem.gpa;
3197 	mem.size = instr->operand_size;
3198 	mem.data = membuf;
3199 
3200 	/* Determine the direction. */
3201 	switch (instr->src.type) {
3202 	case STORE_REG:
3203 		if (instr->src.disp.type != DISP_NONE) {
3204 			/* Indirect access. */
3205 			mem.write = false;
3206 		} else {
3207 			/* Direct access. */
3208 			mem.write = true;
3209 		}
3210 		break;
3211 	case STORE_DUALREG:
3212 		if (instr->src.disp.type == DISP_NONE) {
3213 			DISASSEMBLER_BUG();
3214 		}
3215 		mem.write = false;
3216 		break;
3217 	case STORE_IMM:
3218 		mem.write = true;
3219 		break;
3220 	case STORE_SIB:
3221 		mem.write = false;
3222 		break;
3223 	case STORE_DMO:
3224 		mem.write = false;
3225 		break;
3226 	default:
3227 		DISASSEMBLER_BUG();
3228 	}
3229 
3230 	if (mem.write) {
3231 		switch (instr->src.type) {
3232 		case STORE_REG:
3233 			/* The instruction was "reg -> mem". Fetch the register
3234 			 * in membuf. */
3235 			if (__predict_false(instr->src.disp.type != DISP_NONE)) {
3236 				DISASSEMBLER_BUG();
3237 			}
3238 			val = state->gprs[instr->src.u.reg->num];
3239 			val = __SHIFTOUT(val, instr->src.u.reg->mask);
3240 			memcpy(mem.data, &val, mem.size);
3241 			break;
3242 		case STORE_IMM:
3243 			/* The instruction was "imm -> mem". Fetch the immediate
3244 			 * in membuf. */
3245 			memcpy(mem.data, &instr->src.u.imm.data, mem.size);
3246 			break;
3247 		default:
3248 			DISASSEMBLER_BUG();
3249 		}
3250 	} else if (instr->emul->readreg) {
3251 		/* The instruction was "mem -> reg", but the value of the
3252 		 * register matters for the emul func. Fetch it in membuf. */
3253 		if (__predict_false(instr->dst.type != STORE_REG)) {
3254 			DISASSEMBLER_BUG();
3255 		}
3256 		if (__predict_false(instr->dst.disp.type != DISP_NONE)) {
3257 			DISASSEMBLER_BUG();
3258 		}
3259 		val = state->gprs[instr->dst.u.reg->num];
3260 		val = __SHIFTOUT(val, instr->dst.u.reg->mask);
3261 		memcpy(mem.data, &val, mem.size);
3262 	}
3263 
3264 	(*instr->emul->func)(vcpu, &mem, state->gprs);
3265 
3266 	if (instr->emul->notouch) {
3267 		/* We're done. */
3268 		return 0;
3269 	}
3270 
3271 	if (!mem.write) {
3272 		/* The instruction was "mem -> reg". The emul func has filled
3273 		 * membuf with the memory content. Install membuf in the
3274 		 * register. */
3275 		if (__predict_false(instr->dst.type != STORE_REG)) {
3276 			DISASSEMBLER_BUG();
3277 		}
3278 		if (__predict_false(instr->dst.disp.type != DISP_NONE)) {
3279 			DISASSEMBLER_BUG();
3280 		}
3281 		memcpy(&val, membuf, sizeof(uint64_t));
3282 		val = __SHIFTIN(val, instr->dst.u.reg->mask);
3283 		state->gprs[instr->dst.u.reg->num] &= ~instr->dst.u.reg->mask;
3284 		state->gprs[instr->dst.u.reg->num] |= val;
3285 		state->gprs[instr->dst.u.reg->num] &= ~instr->zeroextend_mask;
3286 	} else if (instr->emul->backprop) {
3287 		/* The instruction was "reg -> mem", but the memory must be
3288 		 * back-propagated to the register. Install membuf in the
3289 		 * register. */
3290 		if (__predict_false(instr->src.type != STORE_REG)) {
3291 			DISASSEMBLER_BUG();
3292 		}
3293 		if (__predict_false(instr->src.disp.type != DISP_NONE)) {
3294 			DISASSEMBLER_BUG();
3295 		}
3296 		memcpy(&val, membuf, sizeof(uint64_t));
3297 		val = __SHIFTIN(val, instr->src.u.reg->mask);
3298 		state->gprs[instr->src.u.reg->num] &= ~instr->src.u.reg->mask;
3299 		state->gprs[instr->src.u.reg->num] |= val;
3300 		state->gprs[instr->src.u.reg->num] &= ~instr->zeroextend_mask;
3301 	}
3302 
3303 	return 0;
3304 }
3305 
3306 int
3307 nvmm_assist_mem(struct nvmm_machine *mach, struct nvmm_vcpu *vcpu)
3308 {
3309 	struct nvmm_x64_state *state = vcpu->state;
3310 	struct nvmm_vcpu_exit *exit = vcpu->exit;
3311 	struct x86_instr instr;
3312 	uint64_t cnt = 0; /* GCC */
3313 	int ret;
3314 
3315 	if (__predict_false(exit->reason != NVMM_VCPU_EXIT_MEMORY)) {
3316 		errno = EINVAL;
3317 		return -1;
3318 	}
3319 
3320 	ret = nvmm_vcpu_getstate(mach, vcpu,
3321 	    NVMM_X64_STATE_GPRS | NVMM_X64_STATE_SEGS |
3322 	    NVMM_X64_STATE_CRS | NVMM_X64_STATE_MSRS);
3323 	if (ret == -1)
3324 		return -1;
3325 
3326 	if (exit->u.mem.inst_len == 0) {
3327 		/*
3328 		 * The instruction was not fetched from the kernel. Fetch
3329 		 * it ourselves.
3330 		 */
3331 		ret = fetch_instruction(mach, vcpu, exit);
3332 		if (ret == -1)
3333 			return -1;
3334 	}
3335 
3336 	ret = x86_decode(exit->u.mem.inst_bytes, exit->u.mem.inst_len,
3337 	    &instr, state);
3338 	if (ret == -1) {
3339 		errno = ENODEV;
3340 		return -1;
3341 	}
3342 
3343 	if (instr.legpref.rep || instr.legpref.repn) {
3344 		cnt = rep_get_cnt(state, instr.address_size);
3345 		if (__predict_false(cnt == 0)) {
3346 			state->gprs[NVMM_X64_GPR_RIP] += instr.len;
3347 			goto out;
3348 		}
3349 	}
3350 
3351 	if (instr.opcode->movs) {
3352 		ret = assist_mem_double(mach, vcpu, &instr);
3353 	} else {
3354 		ret = assist_mem_single(mach, vcpu, &instr);
3355 	}
3356 	if (ret == -1) {
3357 		errno = ENODEV;
3358 		return -1;
3359 	}
3360 
3361 	if (instr.legpref.rep || instr.legpref.repn) {
3362 		cnt -= 1;
3363 		rep_set_cnt(state, instr.address_size, cnt);
3364 		if (cnt == 0) {
3365 			state->gprs[NVMM_X64_GPR_RIP] += instr.len;
3366 		} else if (__predict_false(instr.legpref.repn)) {
3367 			if (state->gprs[NVMM_X64_GPR_RFLAGS] & PSL_Z) {
3368 				state->gprs[NVMM_X64_GPR_RIP] += instr.len;
3369 			}
3370 		}
3371 	} else {
3372 		state->gprs[NVMM_X64_GPR_RIP] += instr.len;
3373 	}
3374 
3375 out:
3376 	ret = nvmm_vcpu_setstate(mach, vcpu, NVMM_X64_STATE_GPRS);
3377 	if (ret == -1)
3378 		return -1;
3379 
3380 	return 0;
3381 }
3382