aboutsummaryrefslogtreecommitdiff
path: root/accel/tcg/user-exec.c
blob: e9b6eb696f7c1662b4a3786562ad78eff308518f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
/*
 *  User emulator execution
 *
 *  Copyright (c) 2003-2005 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
#include "qemu/osdep.h"
#include "hw/core/tcg-cpu-ops.h"
#include "disas/disas.h"
#include "exec/exec-all.h"
#include "tcg/tcg.h"
#include "qemu/bitops.h"
#include "exec/cpu_ldst.h"
#include "exec/translate-all.h"
#include "exec/helper-proto.h"
#include "qemu/atomic128.h"
#include "trace/trace-root.h"
#include "internal.h"

__thread uintptr_t helper_retaddr;

//#define DEBUG_SIGNAL

/*
 * Adjust the pc to pass to cpu_restore_state; return the memop type.
 */
MMUAccessType adjust_signal_pc(uintptr_t *pc, bool is_write)
{
    switch (helper_retaddr) {
    default:
        /*
         * Fault during host memory operation within a helper function.
         * The helper's host return address, saved here, gives us a
         * pointer into the generated code that will unwind to the
         * correct guest pc.
         */
        *pc = helper_retaddr;
        break;

    case 0:
        /*
         * Fault during host memory operation within generated code.
         * (Or, a unrelated bug within qemu, but we can't tell from here).
         *
         * We take the host pc from the signal frame.  However, we cannot
         * use that value directly.  Within cpu_restore_state_from_tb, we
         * assume PC comes from GETPC(), as used by the helper functions,
         * so we adjust the address by -GETPC_ADJ to form an address that
         * is within the call insn, so that the address does not accidentally
         * match the beginning of the next guest insn.  However, when the
         * pc comes from the signal frame it points to the actual faulting
         * host memory insn and not the return from a call insn.
         *
         * Therefore, adjust to compensate for what will be done later
         * by cpu_restore_state_from_tb.
         */
        *pc += GETPC_ADJ;
        break;

    case 1:
        /*
         * Fault during host read for translation, or loosely, "execution".
         *
         * The guest pc is already pointing to the start of the TB for which
         * code is being generated.  If the guest translator manages the
         * page crossings correctly, this is exactly the correct address
         * (and if the translator doesn't handle page boundaries correctly
         * there's little we can do about that here).  Therefore, do not
         * trigger the unwinder.
         *
         * Like tb_gen_code, release the memory lock before cpu_loop_exit.
         */
        mmap_unlock();
        *pc = 0;
        return MMU_INST_FETCH;
    }

    return is_write ? MMU_DATA_STORE : MMU_DATA_LOAD;
}

/**
 * handle_sigsegv_accerr_write:
 * @cpu: the cpu context
 * @old_set: the sigset_t from the signal ucontext_t
 * @host_pc: the host pc, adjusted for the signal
 * @guest_addr: the guest address of the fault
 *
 * Return true if the write fault has been handled, and should be re-tried.
 *
 * Note that it is important that we don't call page_unprotect() unless
 * this is really a "write to nonwriteable page" fault, because
 * page_unprotect() assumes that if it is called for an access to
 * a page that's writeable this means we had two threads racing and
 * another thread got there first and already made the page writeable;
 * so we will retry the access. If we were to call page_unprotect()
 * for some other kind of fault that should really be passed to the
 * guest, we'd end up in an infinite loop of retrying the faulting access.
 */
bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set,
                                 uintptr_t host_pc, abi_ptr guest_addr)
{
    switch (page_unprotect(guest_addr, host_pc)) {
    case 0:
        /*
         * Fault not caused by a page marked unwritable to protect
         * cached translations, must be the guest binary's problem.
         */
        return false;
    case 1:
        /*
         * Fault caused by protection of cached translation; TBs
         * invalidated, so resume execution.
         */
        return true;
    case 2:
        /*
         * Fault caused by protection of cached translation, and the
         * currently executing TB was modified and must be exited immediately.
         */
        sigprocmask(SIG_SETMASK, old_set, NULL);
        cpu_loop_exit_noexc(cpu);
        /* NORETURN */
    default:
        g_assert_not_reached();
    }
}

/*
 * 'pc' is the host PC at which the exception was raised.
 * 'address' is the effective address of the memory exception.
 * 'is_write' is 1 if a write caused the exception and otherwise 0.
 * 'old_set' is the signal set which should be restored.
 */
static inline int handle_cpu_signal(uintptr_t pc, siginfo_t *info,
                                    int is_write, sigset_t *old_set)
{
    CPUState *cpu = current_cpu;
    CPUClass *cc;
    unsigned long host_addr = (unsigned long)info->si_addr;
    MMUAccessType access_type = adjust_signal_pc(&pc, is_write);
    abi_ptr guest_addr;

    /* For synchronous signals we expect to be coming from the vCPU
     * thread (so current_cpu should be valid) and either from running
     * code or during translation which can fault as we cross pages.
     *
     * If neither is true then something has gone wrong and we should
     * abort rather than try and restart the vCPU execution.
     */
    if (!cpu || !cpu->running) {
        printf("qemu:%s received signal outside vCPU context @ pc=0x%"
               PRIxPTR "\n",  __func__, pc);
        abort();
    }

#if defined(DEBUG_SIGNAL)
    printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
           pc, host_addr, is_write, *(unsigned long *)old_set);
#endif

    /* Convert forcefully to guest address space, invalid addresses
       are still valid segv ones */
    guest_addr = h2g_nocheck(host_addr);

    /* XXX: locking issue */
    if (is_write &&
        info->si_signo == SIGSEGV &&
        info->si_code == SEGV_ACCERR &&
        h2g_valid(host_addr) &&
        handle_sigsegv_accerr_write(cpu, old_set, pc, guest_addr)) {
        return 1;
    }

    /*
     * There is no way the target can handle this other than raising
     * an exception.  Undo signal and retaddr state prior to longjmp.
     */
    sigprocmask(SIG_SETMASK, old_set, NULL);

    cc = CPU_GET_CLASS(cpu);
    cc->tcg_ops->tlb_fill(cpu, guest_addr, 0, access_type,
                          MMU_USER_IDX, false, pc);
    g_assert_not_reached();
}

static int probe_access_internal(CPUArchState *env, target_ulong addr,
                                 int fault_size, MMUAccessType access_type,
                                 bool nonfault, uintptr_t ra)
{
    int flags;

    switch (access_type) {
    case MMU_DATA_STORE:
        flags = PAGE_WRITE;
        break;
    case MMU_DATA_LOAD:
        flags = PAGE_READ;
        break;
    case MMU_INST_FETCH:
        flags = PAGE_EXEC;
        break;
    default:
        g_assert_not_reached();
    }

    if (!guest_addr_valid_untagged(addr) ||
        page_check_range(addr, 1, flags) < 0) {
        if (nonfault) {
            return TLB_INVALID_MASK;
        } else {
            CPUState *cpu = env_cpu(env);
            CPUClass *cc = CPU_GET_CLASS(cpu);
            cc->tcg_ops->tlb_fill(cpu, addr, fault_size, access_type,
                                  MMU_USER_IDX, false, ra);
            g_assert_not_reached();
        }
    }
    return 0;
}

int probe_access_flags(CPUArchState *env, target_ulong addr,
                       MMUAccessType access_type, int mmu_idx,
                       bool nonfault, void **phost, uintptr_t ra)
{
    int flags;

    flags = probe_access_internal(env, addr, 0, access_type, nonfault, ra);
    *phost = flags ? NULL : g2h(env_cpu(env), addr);
    return flags;
}

void *probe_access(CPUArchState *env, target_ulong addr, int size,
                   MMUAccessType access_type, int mmu_idx, uintptr_t ra)
{
    int flags;

    g_assert(-(addr | TARGET_PAGE_MASK) >= size);
    flags = probe_access_internal(env, addr, size, access_type, false, ra);
    g_assert(flags == 0);

    return size ? g2h(env_cpu(env), addr) : NULL;
}

#if defined(__sparc__)

int cpu_signal_handler(int host_signum, void *pinfo,
                       void *puc)
{
    siginfo_t *info = pinfo;
    int is_write;
    uint32_t insn;
#if !defined(__arch64__) || defined(CONFIG_SOLARIS)
    uint32_t *regs = (uint32_t *)(info + 1);
    void *sigmask = (regs + 20);
    /* XXX: is there a standard glibc define ? */
    unsigned long pc = regs[1];
#else
#ifdef __linux__
    struct sigcontext *sc = puc;
    unsigned long pc = sc->sigc_regs.tpc;
    void *sigmask = (void *)sc->sigc_mask;
#elif defined(__OpenBSD__)
    struct sigcontext *uc = puc;
    unsigned long pc = uc->sc_pc;
    void *sigmask = (void *)(long)uc->sc_mask;
#elif defined(__NetBSD__)
    ucontext_t *uc = puc;
    unsigned long pc = _UC_MACHINE_PC(uc);
    void *sigmask = (void *)&uc->uc_sigmask;
#endif
#endif

    /* XXX: need kernel patch to get write flag faster */
    is_write = 0;
    insn = *(uint32_t *)pc;
    if ((insn >> 30) == 3) {
        switch ((insn >> 19) & 0x3f) {
        case 0x05: /* stb */
        case 0x15: /* stba */
        case 0x06: /* sth */
        case 0x16: /* stha */
        case 0x04: /* st */
        case 0x14: /* sta */
        case 0x07: /* std */
        case 0x17: /* stda */
        case 0x0e: /* stx */
        case 0x1e: /* stxa */
        case 0x24: /* stf */
        case 0x34: /* stfa */
        case 0x27: /* stdf */
        case 0x37: /* stdfa */
        case 0x26: /* stqf */
        case 0x36: /* stqfa */
        case 0x25: /* stfsr */
        case 0x3c: /* casa */
        case 0x3e: /* casxa */
            is_write = 1;
            break;
        }
    }
    return handle_cpu_signal(pc, info, is_write, sigmask);
}

#elif defined(__arm__)

#if defined(__NetBSD__)
#include <ucontext.h>
#include <sys/siginfo.h>
#endif

int cpu_signal_handler(int host_signum, void *pinfo,
                       void *puc)
{
    siginfo_t *info = pinfo;
#if defined(__NetBSD__)
    ucontext_t *uc = puc;
    siginfo_t *si = pinfo;
#else
    ucontext_t *uc = puc;
#endif
    unsigned long pc;
    uint32_t fsr;
    int is_write;

#if defined(__NetBSD__)
    pc = uc->uc_mcontext.__gregs[_REG_R15];
#elif defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
    pc = uc->uc_mcontext.gregs[R15];
#else
    pc = uc->uc_mcontext.arm_pc;
#endif

#ifdef __NetBSD__
    fsr = si->si_trap;
#else
    fsr = uc->uc_mcontext.error_code;
#endif
    /*
     * In the FSR, bit 11 is WnR, assuming a v6 or
     * later processor.  On v5 we will always report
     * this as a read, which will fail later.
     */
    is_write = extract32(fsr, 11, 1);
    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
}

#elif defined(__aarch64__)

#if defined(__NetBSD__)

#include <ucontext.h>
#include <sys/siginfo.h>

int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
{
    ucontext_t *uc = puc;
    siginfo_t *si = pinfo;
    unsigned long pc;
    int is_write;
    uint32_t esr;

    pc = uc->uc_mcontext.__gregs[_REG_PC];
    esr = si->si_trap;

    /*
     * siginfo_t::si_trap is the ESR value, for data aborts ESR.EC
     * is 0b10010x: then bit 6 is the WnR bit
     */
    is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
    return handle_cpu_signal(pc, si, is_write, &uc->uc_sigmask);
}

#else

#ifndef ESR_MAGIC
/* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
#define ESR_MAGIC 0x45535201
struct esr_context {
    struct _aarch64_ctx head;
    uint64_t esr;
};
#endif

static inline struct _aarch64_ctx *first_ctx(ucontext_t *uc)
{
    return (struct _aarch64_ctx *)&uc->uc_mcontext.__reserved;
}

static inline struct _aarch64_ctx *next_ctx(struct _aarch64_ctx *hdr)
{
    return (struct _aarch64_ctx *)((char *)hdr + hdr->size);
}

int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
{
    siginfo_t *info = pinfo;
    ucontext_t *uc = puc;
    uintptr_t pc = uc->uc_mcontext.pc;
    bool is_write;
    struct _aarch64_ctx *hdr;
    struct esr_context const *esrctx = NULL;

    /* Find the esr_context, which has the WnR bit in it */
    for (hdr = first_ctx(uc); hdr->magic; hdr = next_ctx(hdr)) {
        if (hdr->magic == ESR_MAGIC) {
            esrctx = (struct esr_context const *)hdr;
            break;
        }
    }

    if (esrctx) {
        /* For data aborts ESR.EC is 0b10010x: then bit 6 is the WnR bit */
        uint64_t esr = esrctx->esr;
        is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
    } else {
        /*
         * Fall back to parsing instructions; will only be needed
         * for really ancient (pre-3.16) kernels.
         */
        uint32_t insn = *(uint32_t *)pc;

        is_write = ((insn & 0xbfff0000) == 0x0c000000   /* C3.3.1 */
                    || (insn & 0xbfe00000) == 0x0c800000   /* C3.3.2 */
                    || (insn & 0xbfdf0000) == 0x0d000000   /* C3.3.3 */
                    || (insn & 0xbfc00000) == 0x0d800000   /* C3.3.4 */
                    || (insn & 0x3f400000) == 0x08000000   /* C3.3.6 */
                    || (insn & 0x3bc00000) == 0x39000000   /* C3.3.13 */
                    || (insn & 0x3fc00000) == 0x3d800000   /* ... 128bit */
                    /* Ignore bits 10, 11 & 21, controlling indexing.  */
                    || (insn & 0x3bc00000) == 0x38000000   /* C3.3.8-12 */
                    || (insn & 0x3fe00000) == 0x3c800000   /* ... 128bit */
                    /* Ignore bits 23 & 24, controlling indexing.  */
                    || (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */
    }
    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
}
#endif

#elif defined(__s390__)

int cpu_signal_handler(int host_signum, void *pinfo,
                       void *puc)
{
    siginfo_t *info = pinfo;
    ucontext_t *uc = puc;
    unsigned long pc;
    uint16_t *pinsn;
    int is_write = 0;

    pc = uc->uc_mcontext.psw.addr;

    /*
     * ??? On linux, the non-rt signal handler has 4 (!) arguments instead
     * of the normal 2 arguments.  The 4th argument contains the "Translation-
     * Exception Identification for DAT Exceptions" from the hardware (aka
     * "int_parm_long"), which does in fact contain the is_write value.
     * The rt signal handler, as far as I can tell, does not give this value
     * at all.  Not that we could get to it from here even if it were.
     * So fall back to parsing instructions.  Treat read-modify-write ones as
     * writes, which is not fully correct, but for tracking self-modifying code
     * this is better than treating them as reads.  Checking si_addr page flags
     * might be a viable improvement, albeit a racy one.
     */
    /* ??? This is not even close to complete.  */
    pinsn = (uint16_t *)pc;
    switch (pinsn[0] >> 8) {
    case 0x50: /* ST */
    case 0x42: /* STC */
    case 0x40: /* STH */
    case 0xba: /* CS */
    case 0xbb: /* CDS */
        is_write = 1;
        break;
    case 0xc4: /* RIL format insns */
        switch (pinsn[0] & 0xf) {
        case 0xf: /* STRL */
        case 0xb: /* STGRL */
        case 0x7: /* STHRL */
            is_write = 1;
        }
        break;
    case 0xc8: /* SSF format insns */
        switch (pinsn[0] & 0xf) {
        case 0x2: /* CSST */
            is_write = 1;
        }
        break;
    case 0xe3: /* RXY format insns */
        switch (pinsn[2] & 0xff) {
        case 0x50: /* STY */
        case 0x24: /* STG */
        case 0x72: /* STCY */
        case 0x70: /* STHY */
        case 0x8e: /* STPQ */
        case 0x3f: /* STRVH */
        case 0x3e: /* STRV */
        case 0x2f: /* STRVG */
            is_write = 1;
        }
        break;
    case 0xeb: /* RSY format insns */
        switch (pinsn[2] & 0xff) {
        case 0x14: /* CSY */
        case 0x30: /* CSG */
        case 0x31: /* CDSY */
        case 0x3e: /* CDSG */
        case 0xe4: /* LANG */
        case 0xe6: /* LAOG */
        case 0xe7: /* LAXG */
        case 0xe8: /* LAAG */
        case 0xea: /* LAALG */
        case 0xf4: /* LAN */
        case 0xf6: /* LAO */
        case 0xf7: /* LAX */
        case 0xfa: /* LAAL */
        case 0xf8: /* LAA */
            is_write = 1;
        }
        break;
    }

    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
}

#elif defined(__mips__)

#if defined(__misp16) || defined(__mips_micromips)
#error "Unsupported encoding"
#endif

int cpu_signal_handler(int host_signum, void *pinfo,
                       void *puc)
{
    siginfo_t *info = pinfo;
    ucontext_t *uc = puc;
    uintptr_t pc = uc->uc_mcontext.pc;
    uint32_t insn = *(uint32_t *)pc;
    int is_write = 0;

    /* Detect all store instructions at program counter. */
    switch((insn >> 26) & 077) {
    case 050: /* SB */
    case 051: /* SH */
    case 052: /* SWL */
    case 053: /* SW */
    case 054: /* SDL */
    case 055: /* SDR */
    case 056: /* SWR */
    case 070: /* SC */
    case 071: /* SWC1 */
    case 074: /* SCD */
    case 075: /* SDC1 */
    case 077: /* SD */
#if !defined(__mips_isa_rev) || __mips_isa_rev < 6
    case 072: /* SWC2 */
    case 076: /* SDC2 */
#endif
        is_write = 1;
        break;
    case 023: /* COP1X */
        /* Required in all versions of MIPS64 since
           MIPS64r1 and subsequent versions of MIPS32r2. */
        switch (insn & 077) {
        case 010: /* SWXC1 */
        case 011: /* SDXC1 */
        case 015: /* SUXC1 */
            is_write = 1;
        }
        break;
    }

    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
}

#elif defined(__riscv)

int cpu_signal_handler(int host_signum, void *pinfo,
                       void *puc)
{
    siginfo_t *info = pinfo;
    ucontext_t *uc = puc;
    greg_t pc = uc->uc_mcontext.__gregs[REG_PC];
    uint32_t insn = *(uint32_t *)pc;
    int is_write = 0;

    /* Detect store by reading the instruction at the program
       counter. Note: we currently only generate 32-bit
       instructions so we thus only detect 32-bit stores */
    switch (((insn >> 0) & 0b11)) {
    case 3:
        switch (((insn >> 2) & 0b11111)) {
        case 8:
            switch (((insn >> 12) & 0b111)) {
            case 0: /* sb */
            case 1: /* sh */
            case 2: /* sw */
            case 3: /* sd */
            case 4: /* sq */
                is_write = 1;
                break;
            default:
                break;
            }
            break;
        case 9:
            switch (((insn >> 12) & 0b111)) {
            case 2: /* fsw */
            case 3: /* fsd */
            case 4: /* fsq */
                is_write = 1;
                break;
            default:
                break;
            }
            break;
        default:
            break;
        }
    }

    /* Check for compressed instructions */
    switch (((insn >> 13) & 0b111)) {
    case 7:
        switch (insn & 0b11) {
        case 0: /*c.sd */
        case 2: /* c.sdsp */
            is_write = 1;
            break;
        default:
            break;
        }
        break;
    case 6:
        switch (insn & 0b11) {
        case 0: /* c.sw */
        case 3: /* c.swsp */
            is_write = 1;
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }

    return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
}
#endif

/* The softmmu versions of these helpers are in cputlb.c.  */

/*
 * Verify that we have passed the correct MemOp to the correct function.
 *
 * We could present one function to target code, and dispatch based on
 * the MemOp, but so far we have worked hard to avoid an indirect function
 * call along the memory path.
 */
static void validate_memop(MemOpIdx oi, MemOp expected)
{
#ifdef CONFIG_DEBUG_TCG
    MemOp have = get_memop(oi) & (MO_SIZE | MO_BSWAP);
    assert(have == expected);
#endif
}

static void *cpu_mmu_lookup(CPUArchState *env, target_ulong addr,
                            MemOpIdx oi, uintptr_t ra, MMUAccessType type)
{
    void *ret;

    /* TODO: Enforce guest required alignment.  */

    ret = g2h(env_cpu(env), addr);
    set_helper_retaddr(ra);
    return ret;
}

uint8_t cpu_ldb_mmu(CPUArchState *env, abi_ptr addr,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint8_t ret;

    validate_memop(oi, MO_UB);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = ldub_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint16_t cpu_ldw_be_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint16_t ret;

    validate_memop(oi, MO_BEUW);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = lduw_be_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint32_t cpu_ldl_be_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint32_t ret;

    validate_memop(oi, MO_BEUL);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = ldl_be_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint64_t cpu_ldq_be_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint64_t ret;

    validate_memop(oi, MO_BEQ);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = ldq_be_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint16_t cpu_ldw_le_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint16_t ret;

    validate_memop(oi, MO_LEUW);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = lduw_le_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint32_t cpu_ldl_le_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint32_t ret;

    validate_memop(oi, MO_LEUL);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = ldl_le_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

uint64_t cpu_ldq_le_mmu(CPUArchState *env, abi_ptr addr,
                        MemOpIdx oi, uintptr_t ra)
{
    void *haddr;
    uint64_t ret;

    validate_memop(oi, MO_LEQ);
    trace_guest_ld_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_LOAD);
    ret = ldq_le_p(haddr);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_R);
    return ret;
}

void cpu_stb_mmu(CPUArchState *env, abi_ptr addr, uint8_t val,
                 MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_UB);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stb_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stw_be_mmu(CPUArchState *env, abi_ptr addr, uint16_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_BEUW);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stw_be_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stl_be_mmu(CPUArchState *env, abi_ptr addr, uint32_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_BEUL);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stl_be_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stq_be_mmu(CPUArchState *env, abi_ptr addr, uint64_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_BEQ);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stq_be_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stw_le_mmu(CPUArchState *env, abi_ptr addr, uint16_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_LEUW);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stw_le_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stl_le_mmu(CPUArchState *env, abi_ptr addr, uint32_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_LEUL);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stl_le_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

void cpu_stq_le_mmu(CPUArchState *env, abi_ptr addr, uint64_t val,
                    MemOpIdx oi, uintptr_t ra)
{
    void *haddr;

    validate_memop(oi, MO_LEQ);
    trace_guest_st_before_exec(env_cpu(env), addr, oi);
    haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE);
    stq_le_p(haddr, val);
    clear_helper_retaddr();
    qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W);
}

uint32_t cpu_ldub_code(CPUArchState *env, abi_ptr ptr)
{
    uint32_t ret;

    set_helper_retaddr(1);
    ret = ldub_p(g2h_untagged(ptr));
    clear_helper_retaddr();
    return ret;
}

uint32_t cpu_lduw_code(CPUArchState *env, abi_ptr ptr)
{
    uint32_t ret;

    set_helper_retaddr(1);
    ret = lduw_p(g2h_untagged(ptr));
    clear_helper_retaddr();
    return ret;
}

uint32_t cpu_ldl_code(CPUArchState *env, abi_ptr ptr)
{
    uint32_t ret;

    set_helper_retaddr(1);
    ret = ldl_p(g2h_untagged(ptr));
    clear_helper_retaddr();
    return ret;
}

uint64_t cpu_ldq_code(CPUArchState *env, abi_ptr ptr)
{
    uint64_t ret;

    set_helper_retaddr(1);
    ret = ldq_p(g2h_untagged(ptr));
    clear_helper_retaddr();
    return ret;
}

#include "ldst_common.c.inc"

/*
 * Do not allow unaligned operations to proceed.  Return the host address.
 *
 * @prot may be PAGE_READ, PAGE_WRITE, or PAGE_READ|PAGE_WRITE.
 */
static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
                               MemOpIdx oi, int size, int prot,
                               uintptr_t retaddr)
{
    /* Enforce qemu required alignment.  */
    if (unlikely(addr & (size - 1))) {
        cpu_loop_exit_atomic(env_cpu(env), retaddr);
    }
    void *ret = g2h(env_cpu(env), addr);
    set_helper_retaddr(retaddr);
    return ret;
}

#include "atomic_common.c.inc"

/*
 * First set of functions passes in OI and RETADDR.
 * This makes them callable from other helpers.
 */

#define ATOMIC_NAME(X) \
    glue(glue(glue(cpu_atomic_ ## X, SUFFIX), END), _mmu)
#define ATOMIC_MMU_CLEANUP do { clear_helper_retaddr(); } while (0)
#define ATOMIC_MMU_IDX MMU_USER_IDX

#define DATA_SIZE 1
#include "atomic_template.h"

#define DATA_SIZE 2
#include "atomic_template.h"

#define DATA_SIZE 4
#include "atomic_template.h"

#ifdef CONFIG_ATOMIC64
#define DATA_SIZE 8
#include "atomic_template.h"
#endif

#if HAVE_ATOMIC128 || HAVE_CMPXCHG128
#define DATA_SIZE 16
#include "atomic_template.h"
#endif