aboutsummaryrefslogtreecommitdiff
path: root/hw/ufs/lu.c
blob: e1c46bddb11d0bbd3c04b8f591a3c25699ce2fb6 (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
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
/*
 * QEMU UFS Logical Unit
 *
 * Copyright (c) 2023 Samsung Electronics Co., Ltd. All rights reserved.
 *
 * Written by Jeuk Kim <jeuk20.kim@samsung.com>
 *
 * This code is licensed under the GNU GPL v2 or later.
 */

#include "qemu/osdep.h"
#include "qemu/units.h"
#include "qapi/error.h"
#include "qemu/memalign.h"
#include "hw/scsi/scsi.h"
#include "scsi/constants.h"
#include "sysemu/block-backend.h"
#include "qemu/cutils.h"
#include "trace.h"
#include "ufs.h"

/*
 * The code below handling SCSI commands is copied from hw/scsi/scsi-disk.c,
 * with minor adjustments to make it work for UFS.
 */

#define SCSI_DMA_BUF_SIZE (128 * KiB)
#define SCSI_MAX_INQUIRY_LEN 256
#define SCSI_INQUIRY_DATA_SIZE 36
#define SCSI_MAX_MODE_LEN 256

typedef struct UfsSCSIReq {
    SCSIRequest req;
    /* Both sector and sector_count are in terms of BDRV_SECTOR_SIZE bytes.  */
    uint64_t sector;
    uint32_t sector_count;
    uint32_t buflen;
    bool started;
    bool need_fua_emulation;
    struct iovec iov;
    QEMUIOVector qiov;
    BlockAcctCookie acct;
} UfsSCSIReq;

static void ufs_scsi_free_request(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);

    qemu_vfree(r->iov.iov_base);
}

static void scsi_check_condition(UfsSCSIReq *r, SCSISense sense)
{
    trace_ufs_scsi_check_condition(r->req.tag, sense.key, sense.asc,
                                   sense.ascq);
    scsi_req_build_sense(&r->req, sense);
    scsi_req_complete(&r->req, CHECK_CONDITION);
}

static int ufs_scsi_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf,
                                     uint32_t outbuf_len)
{
    UfsHc *u = UFS(req->bus->qbus.parent);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
    uint8_t page_code = req->cmd.buf[2];
    int start, buflen = 0;

    if (outbuf_len < SCSI_INQUIRY_DATA_SIZE) {
        return -1;
    }

    outbuf[buflen++] = lu->qdev.type & 0x1f;
    outbuf[buflen++] = page_code;
    outbuf[buflen++] = 0x00;
    outbuf[buflen++] = 0x00;
    start = buflen;

    switch (page_code) {
    case 0x00: /* Supported page codes, mandatory */
    {
        trace_ufs_scsi_emulate_vpd_page_00(req->cmd.xfer);
        outbuf[buflen++] = 0x00; /* list of supported pages (this page) */
        if (u->params.serial) {
            outbuf[buflen++] = 0x80; /* unit serial number */
        }
        outbuf[buflen++] = 0x87; /* mode page policy */
        break;
    }
    case 0x80: /* Device serial number, optional */
    {
        int l;

        if (!u->params.serial) {
            trace_ufs_scsi_emulate_vpd_page_80_not_supported();
            return -1;
        }

        l = strlen(u->params.serial);
        if (l > SCSI_INQUIRY_DATA_SIZE) {
            l = SCSI_INQUIRY_DATA_SIZE;
        }

        trace_ufs_scsi_emulate_vpd_page_80(req->cmd.xfer);
        memcpy(outbuf + buflen, u->params.serial, l);
        buflen += l;
        break;
    }
    case 0x87: /* Mode Page Policy, mandatory */
    {
        trace_ufs_scsi_emulate_vpd_page_87(req->cmd.xfer);
        outbuf[buflen++] = 0x3f; /* apply to all mode pages and subpages */
        outbuf[buflen++] = 0xff;
        outbuf[buflen++] = 0; /* shared */
        outbuf[buflen++] = 0;
        break;
    }
    default:
        return -1;
    }
    /* done with EVPD */
    assert(buflen - start <= 255);
    outbuf[start - 1] = buflen - start;
    return buflen;
}

static int ufs_scsi_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf,
                                    uint32_t outbuf_len)
{
    int buflen = 0;

    if (outbuf_len < SCSI_INQUIRY_DATA_SIZE) {
        return -1;
    }

    if (req->cmd.buf[1] & 0x1) {
        /* Vital product data */
        return ufs_scsi_emulate_vpd_page(req, outbuf, outbuf_len);
    }

    /* Standard INQUIRY data */
    if (req->cmd.buf[2] != 0) {
        return -1;
    }

    /* PAGE CODE == 0 */
    buflen = req->cmd.xfer;
    if (buflen > SCSI_MAX_INQUIRY_LEN) {
        buflen = SCSI_MAX_INQUIRY_LEN;
    }

    if (is_wlun(req->lun)) {
        outbuf[0] = TYPE_WLUN;
    } else {
        outbuf[0] = 0;
    }
    outbuf[1] = 0;

    strpadcpy((char *)&outbuf[16], 16, "QEMU UFS", ' ');
    strpadcpy((char *)&outbuf[8], 8, "QEMU", ' ');

    memset(&outbuf[32], 0, 4);

    outbuf[2] = 0x06; /* SPC-4 */
    outbuf[3] = 0x2;

    if (buflen > SCSI_INQUIRY_DATA_SIZE) {
        outbuf[4] = buflen - 5; /* Additional Length = (Len - 1) - 4 */
    } else {
        /*
         * If the allocation length of CDB is too small, the additional
         * length is not adjusted
         */
        outbuf[4] = SCSI_INQUIRY_DATA_SIZE - 5;
    }

    /* Support TCQ.  */
    outbuf[7] = req->bus->info->tcq ? 0x02 : 0;
    return buflen;
}

static int mode_sense_page(UfsLu *lu, int page, uint8_t **p_outbuf,
                           int page_control)
{
    static const int mode_sense_valid[0x3f] = {
        [MODE_PAGE_CACHING] = 1,
        [MODE_PAGE_R_W_ERROR] = 1,
        [MODE_PAGE_CONTROL] = 1,
    };

    uint8_t *p = *p_outbuf + 2;
    int length;

    assert(page < ARRAY_SIZE(mode_sense_valid));
    if ((mode_sense_valid[page]) == 0) {
        return -1;
    }

    /*
     * If Changeable Values are requested, a mask denoting those mode parameters
     * that are changeable shall be returned. As we currently don't support
     * parameter changes via MODE_SELECT all bits are returned set to zero.
     * The buffer was already memset to zero by the caller of this function.
     */
    switch (page) {
    case MODE_PAGE_CACHING:
        length = 0x12;
        if (page_control == 1 || /* Changeable Values */
            blk_enable_write_cache(lu->qdev.conf.blk)) {
            p[0] = 4; /* WCE */
        }
        break;

    case MODE_PAGE_R_W_ERROR:
        length = 10;
        if (page_control == 1) { /* Changeable Values */
            break;
        }
        p[0] = 0x80; /* Automatic Write Reallocation Enabled */
        break;

    case MODE_PAGE_CONTROL:
        length = 10;
        if (page_control == 1) { /* Changeable Values */
            break;
        }
        p[1] = 0x10; /* Queue Algorithm modifier */
        p[8] = 0xff; /* Busy Timeout Period */
        p[9] = 0xff;
        break;

    default:
        return -1;
    }

    assert(length < 256);
    (*p_outbuf)[0] = page;
    (*p_outbuf)[1] = length;
    *p_outbuf += length + 2;
    return length + 2;
}

static int ufs_scsi_emulate_mode_sense(UfsSCSIReq *r, uint8_t *outbuf)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    bool dbd;
    int page, buflen, ret, page_control;
    uint8_t *p;
    uint8_t dev_specific_param = 0;

    dbd = (r->req.cmd.buf[1] & 0x8) != 0;
    if (!dbd) {
        return -1;
    }

    page = r->req.cmd.buf[2] & 0x3f;
    page_control = (r->req.cmd.buf[2] & 0xc0) >> 6;

    trace_ufs_scsi_emulate_mode_sense((r->req.cmd.buf[0] == MODE_SENSE) ? 6 :
                                                                          10,
                                      page, r->req.cmd.xfer, page_control);
    memset(outbuf, 0, r->req.cmd.xfer);
    p = outbuf;

    if (!blk_is_writable(lu->qdev.conf.blk)) {
        dev_specific_param |= 0x80; /* Readonly.  */
    }

    p[2] = 0; /* Medium type.  */
    p[3] = dev_specific_param;
    p[6] = p[7] = 0; /* Block descriptor length.  */
    p += 8;

    if (page_control == 3) {
        /* Saved Values */
        scsi_check_condition(r, SENSE_CODE(SAVING_PARAMS_NOT_SUPPORTED));
        return -1;
    }

    if (page == 0x3f) {
        for (page = 0; page <= 0x3e; page++) {
            mode_sense_page(lu, page, &p, page_control);
        }
    } else {
        ret = mode_sense_page(lu, page, &p, page_control);
        if (ret == -1) {
            return -1;
        }
    }

    buflen = p - outbuf;
    /*
     * The mode data length field specifies the length in bytes of the
     * following data that is available to be transferred. The mode data
     * length does not include itself.
     */
    outbuf[0] = ((buflen - 2) >> 8) & 0xff;
    outbuf[1] = (buflen - 2) & 0xff;
    return buflen;
}

/*
 * scsi_handle_rw_error has two return values.  False means that the error
 * must be ignored, true means that the error has been processed and the
 * caller should not do anything else for this request.  Note that
 * scsi_handle_rw_error always manages its reference counts, independent
 * of the return value.
 */
static bool scsi_handle_rw_error(UfsSCSIReq *r, int ret, bool acct_failed)
{
    bool is_read = (r->req.cmd.mode == SCSI_XFER_FROM_DEV);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    SCSISense sense = SENSE_CODE(NO_SENSE);
    int error = 0;
    bool req_has_sense = false;
    BlockErrorAction action;
    int status;

    if (ret < 0) {
        status = scsi_sense_from_errno(-ret, &sense);
        error = -ret;
    } else {
        /* A passthrough command has completed with nonzero status.  */
        status = ret;
        if (status == CHECK_CONDITION) {
            req_has_sense = true;
            error = scsi_sense_buf_to_errno(r->req.sense, sizeof(r->req.sense));
        } else {
            error = EINVAL;
        }
    }

    /*
     * Check whether the error has to be handled by the guest or should
     * rather follow the rerror=/werror= settings.  Guest-handled errors
     * are usually retried immediately, so do not post them to QMP and
     * do not account them as failed I/O.
     */
    if (req_has_sense && scsi_sense_buf_is_guest_recoverable(
                             r->req.sense, sizeof(r->req.sense))) {
        action = BLOCK_ERROR_ACTION_REPORT;
        acct_failed = false;
    } else {
        action = blk_get_error_action(lu->qdev.conf.blk, is_read, error);
        blk_error_action(lu->qdev.conf.blk, action, is_read, error);
    }

    switch (action) {
    case BLOCK_ERROR_ACTION_REPORT:
        if (acct_failed) {
            block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
        }
        if (!req_has_sense && status == CHECK_CONDITION) {
            scsi_req_build_sense(&r->req, sense);
        }
        scsi_req_complete(&r->req, status);
        return true;

    case BLOCK_ERROR_ACTION_IGNORE:
        return false;

    case BLOCK_ERROR_ACTION_STOP:
        scsi_req_retry(&r->req);
        return true;

    default:
        g_assert_not_reached();
    }
}

static bool ufs_scsi_req_check_error(UfsSCSIReq *r, int ret, bool acct_failed)
{
    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        return true;
    }

    if (ret < 0) {
        return scsi_handle_rw_error(r, ret, acct_failed);
    }

    return false;
}

static void scsi_aio_complete(void *opaque, int ret)
{
    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;
    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
    if (ufs_scsi_req_check_error(r, ret, true)) {
        goto done;
    }

    block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    scsi_req_complete(&r->req, GOOD);

done:
    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
    scsi_req_unref(&r->req);
}

static int32_t ufs_scsi_emulate_command(SCSIRequest *req, uint8_t *buf)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
    uint32_t last_block = 0;
    uint8_t *outbuf;
    int buflen;

    switch (req->cmd.buf[0]) {
    case INQUIRY:
    case MODE_SENSE_10:
    case START_STOP:
    case REQUEST_SENSE:
        break;

    default:
        if (!blk_is_available(lu->qdev.conf.blk)) {
            scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
            return 0;
        }
        break;
    }

    /*
     * FIXME: we shouldn't return anything bigger than 4k, but the code
     * requires the buffer to be as big as req->cmd.xfer in several
     * places.  So, do not allow CDBs with a very large ALLOCATION
     * LENGTH.  The real fix would be to modify scsi_read_data and
     * dma_buf_read, so that they return data beyond the buflen
     * as all zeros.
     */
    if (req->cmd.xfer > 65536) {
        goto illegal_request;
    }
    r->buflen = MAX(4096, req->cmd.xfer);

    if (!r->iov.iov_base) {
        r->iov.iov_base = blk_blockalign(lu->qdev.conf.blk, r->buflen);
    }

    outbuf = r->iov.iov_base;
    memset(outbuf, 0, r->buflen);
    switch (req->cmd.buf[0]) {
    case TEST_UNIT_READY:
        assert(blk_is_available(lu->qdev.conf.blk));
        break;
    case INQUIRY:
        buflen = ufs_scsi_emulate_inquiry(req, outbuf, r->buflen);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case MODE_SENSE_10:
        buflen = ufs_scsi_emulate_mode_sense(r, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case READ_CAPACITY_10:
        /* The normal LEN field for this command is zero.  */
        memset(outbuf, 0, 8);
        if (lu->qdev.max_lba > 0) {
            last_block = lu->qdev.max_lba - 1;
        };
        outbuf[0] = (last_block >> 24) & 0xff;
        outbuf[1] = (last_block >> 16) & 0xff;
        outbuf[2] = (last_block >> 8) & 0xff;
        outbuf[3] = last_block & 0xff;
        outbuf[4] = (lu->qdev.blocksize >> 24) & 0xff;
        outbuf[5] = (lu->qdev.blocksize >> 16) & 0xff;
        outbuf[6] = (lu->qdev.blocksize >> 8) & 0xff;
        outbuf[7] = lu->qdev.blocksize & 0xff;
        break;
    case REQUEST_SENSE:
        /* Just return "NO SENSE".  */
        buflen = scsi_convert_sense(NULL, 0, outbuf, r->buflen,
                                    (req->cmd.buf[1] & 1) == 0);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case SYNCHRONIZE_CACHE:
        /* The request is used as the AIO opaque value, so add a ref.  */
        scsi_req_ref(&r->req);
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
        return 0;
    case VERIFY_10:
        trace_ufs_scsi_emulate_command_VERIFY((req->cmd.buf[1] >> 1) & 3);
        if (req->cmd.buf[1] & 6) {
            goto illegal_request;
        }
        break;
    case SERVICE_ACTION_IN_16:
        /* Service Action In subcommands. */
        if ((req->cmd.buf[1] & 31) == SAI_READ_CAPACITY_16) {
            trace_ufs_scsi_emulate_command_SAI_16();
            memset(outbuf, 0, req->cmd.xfer);

            if (lu->qdev.max_lba > 0) {
                last_block = lu->qdev.max_lba - 1;
            };
            outbuf[0] = 0;
            outbuf[1] = 0;
            outbuf[2] = 0;
            outbuf[3] = 0;
            outbuf[4] = (last_block >> 24) & 0xff;
            outbuf[5] = (last_block >> 16) & 0xff;
            outbuf[6] = (last_block >> 8) & 0xff;
            outbuf[7] = last_block & 0xff;
            outbuf[8] = (lu->qdev.blocksize >> 24) & 0xff;
            outbuf[9] = (lu->qdev.blocksize >> 16) & 0xff;
            outbuf[10] = (lu->qdev.blocksize >> 8) & 0xff;
            outbuf[11] = lu->qdev.blocksize & 0xff;
            outbuf[12] = 0;
            outbuf[13] = get_physical_block_exp(&lu->qdev.conf);

            if (lu->unit_desc.provisioning_type == 2 ||
                lu->unit_desc.provisioning_type == 3) {
                outbuf[14] = 0x80;
            }
            /* Protection, exponent and lowest lba field left blank. */
            break;
        }
        trace_ufs_scsi_emulate_command_SAI_unsupported();
        goto illegal_request;
    case MODE_SELECT_10:
        trace_ufs_scsi_emulate_command_MODE_SELECT_10(r->req.cmd.xfer);
        break;
    case START_STOP:
        /*
         * TODO: START_STOP is not yet implemented. It always returns success.
         * Revisit it when ufs power management is implemented.
         */
        trace_ufs_scsi_emulate_command_START_STOP();
        break;
    case FORMAT_UNIT:
        trace_ufs_scsi_emulate_command_FORMAT_UNIT();
        break;
    case SEND_DIAGNOSTIC:
        trace_ufs_scsi_emulate_command_SEND_DIAGNOSTIC();
        break;
    default:
        trace_ufs_scsi_emulate_command_UNKNOWN(buf[0],
                                               scsi_command_name(buf[0]));
        scsi_check_condition(r, SENSE_CODE(INVALID_OPCODE));
        return 0;
    }
    assert(!r->req.aiocb);
    r->iov.iov_len = MIN(r->buflen, req->cmd.xfer);
    if (r->iov.iov_len == 0) {
        scsi_req_complete(&r->req, GOOD);
    }
    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        assert(r->iov.iov_len == req->cmd.xfer);
        return -r->iov.iov_len;
    } else {
        return r->iov.iov_len;
    }

illegal_request:
    if (r->req.status == -1) {
        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
    }
    return 0;
}

static void ufs_scsi_emulate_read_data(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
    int buflen = r->iov.iov_len;

    if (buflen) {
        trace_ufs_scsi_emulate_read_data(buflen);
        r->iov.iov_len = 0;
        r->started = true;
        scsi_req_data(&r->req, buflen);
        return;
    }

    /* This also clears the sense buffer for REQUEST SENSE.  */
    scsi_req_complete(&r->req, GOOD);
}

static int ufs_scsi_check_mode_select(UfsLu *lu, int page, uint8_t *inbuf,
                                      int inlen)
{
    uint8_t mode_current[SCSI_MAX_MODE_LEN];
    uint8_t mode_changeable[SCSI_MAX_MODE_LEN];
    uint8_t *p;
    int len, expected_len, changeable_len, i;

    /*
     * The input buffer does not include the page header, so it is
     * off by 2 bytes.
     */
    expected_len = inlen + 2;
    if (expected_len > SCSI_MAX_MODE_LEN) {
        return -1;
    }

    /* MODE_PAGE_ALLS is only valid for MODE SENSE commands */
    if (page == MODE_PAGE_ALLS) {
        return -1;
    }

    p = mode_current;
    memset(mode_current, 0, inlen + 2);
    len = mode_sense_page(lu, page, &p, 0);
    if (len < 0 || len != expected_len) {
        return -1;
    }

    p = mode_changeable;
    memset(mode_changeable, 0, inlen + 2);
    changeable_len = mode_sense_page(lu, page, &p, 1);
    assert(changeable_len == len);

    /*
     * Check that unchangeable bits are the same as what MODE SENSE
     * would return.
     */
    for (i = 2; i < len; i++) {
        if (((mode_current[i] ^ inbuf[i - 2]) & ~mode_changeable[i]) != 0) {
            return -1;
        }
    }
    return 0;
}

static void ufs_scsi_apply_mode_select(UfsLu *lu, int page, uint8_t *p)
{
    switch (page) {
    case MODE_PAGE_CACHING:
        blk_set_enable_write_cache(lu->qdev.conf.blk, (p[0] & 4) != 0);
        break;

    default:
        break;
    }
}

static int mode_select_pages(UfsSCSIReq *r, uint8_t *p, int len, bool change)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    while (len > 0) {
        int page, page_len;

        page = p[0] & 0x3f;
        if (p[0] & 0x40) {
            goto invalid_param;
        } else {
            if (len < 2) {
                goto invalid_param_len;
            }
            page_len = p[1];
            p += 2;
            len -= 2;
        }

        if (page_len > len) {
            goto invalid_param_len;
        }

        if (!change) {
            if (ufs_scsi_check_mode_select(lu, page, p, page_len) < 0) {
                goto invalid_param;
            }
        } else {
            ufs_scsi_apply_mode_select(lu, page, p);
        }

        p += page_len;
        len -= page_len;
    }
    return 0;

invalid_param:
    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM));
    return -1;

invalid_param_len:
    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
    return -1;
}

static void ufs_scsi_emulate_mode_select(UfsSCSIReq *r, uint8_t *inbuf)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    uint8_t *p = inbuf;
    int len = r->req.cmd.xfer;
    int hdr_len = 8;
    int bd_len;
    int pass;

    /* We only support PF=1, SP=0.  */
    if ((r->req.cmd.buf[1] & 0x11) != 0x10) {
        goto invalid_field;
    }

    if (len < hdr_len) {
        goto invalid_param_len;
    }

    bd_len = lduw_be_p(&p[6]);
    if (bd_len != 0) {
        goto invalid_param;
    }

    len -= hdr_len;
    p += hdr_len;

    /* Ensure no change is made if there is an error!  */
    for (pass = 0; pass < 2; pass++) {
        if (mode_select_pages(r, p, len, pass == 1) < 0) {
            assert(pass == 0);
            return;
        }
    }

    if (!blk_enable_write_cache(lu->qdev.conf.blk)) {
        /* The request is used as the AIO opaque value, so add a ref.  */
        scsi_req_ref(&r->req);
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
        return;
    }

    scsi_req_complete(&r->req, GOOD);
    return;

invalid_param:
    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM));
    return;

invalid_param_len:
    scsi_check_condition(r, SENSE_CODE(INVALID_PARAM_LEN));
    return;

invalid_field:
    scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
}

/* block_num and nb_blocks expected to be in qdev blocksize */
static inline bool check_lba_range(UfsLu *lu, uint64_t block_num,
                                   uint32_t nb_blocks)
{
    /*
     * The first line tests that no overflow happens when computing the last
     * block.  The second line tests that the last accessed block is in
     * range.
     *
     * Careful, the computations should not underflow for nb_blocks == 0,
     * and a 0-block read to the first LBA beyond the end of device is
     * valid.
     */
    return (block_num <= block_num + nb_blocks &&
            block_num + nb_blocks <= lu->qdev.max_lba + 1);
}

static void ufs_scsi_emulate_write_data(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);

    if (r->iov.iov_len) {
        int buflen = r->iov.iov_len;
        trace_ufs_scsi_emulate_write_data(buflen);
        r->iov.iov_len = 0;
        scsi_req_data(&r->req, buflen);
        return;
    }

    switch (req->cmd.buf[0]) {
    case MODE_SELECT_10:
        /* This also clears the sense buffer for REQUEST SENSE.  */
        ufs_scsi_emulate_mode_select(r, r->iov.iov_base);
        break;
    default:
        abort();
    }
}

/* Return a pointer to the data buffer.  */
static uint8_t *ufs_scsi_get_buf(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);

    return (uint8_t *)r->iov.iov_base;
}

static int32_t ufs_scsi_dma_command(SCSIRequest *req, uint8_t *buf)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, req->dev);
    uint32_t len;
    uint8_t command;

    command = buf[0];

    if (!blk_is_available(lu->qdev.conf.blk)) {
        scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
        return 0;
    }

    len = scsi_data_cdb_xfer(r->req.cmd.buf);
    switch (command) {
    case READ_6:
    case READ_10:
        trace_ufs_scsi_dma_command_READ(r->req.cmd.lba, len);
        if (r->req.cmd.buf[1] & 0xe0) {
            goto illegal_request;
        }
        if (!check_lba_range(lu, r->req.cmd.lba, len)) {
            goto illegal_lba;
        }
        r->sector = r->req.cmd.lba * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
        r->sector_count = len * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
        break;
    case WRITE_6:
    case WRITE_10:
        trace_ufs_scsi_dma_command_WRITE(r->req.cmd.lba, len);
        if (!blk_is_writable(lu->qdev.conf.blk)) {
            scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
            return 0;
        }
        if (r->req.cmd.buf[1] & 0xe0) {
            goto illegal_request;
        }
        if (!check_lba_range(lu, r->req.cmd.lba, len)) {
            goto illegal_lba;
        }
        r->sector = r->req.cmd.lba * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
        r->sector_count = len * (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
        break;
    default:
        abort();
    illegal_request:
        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
        return 0;
    illegal_lba:
        scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
        return 0;
    }
    r->need_fua_emulation = ((r->req.cmd.buf[1] & 8) != 0);
    if (r->sector_count == 0) {
        scsi_req_complete(&r->req, GOOD);
    }
    assert(r->iov.iov_len == 0);
    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        return -r->sector_count * BDRV_SECTOR_SIZE;
    } else {
        return r->sector_count * BDRV_SECTOR_SIZE;
    }
}

static void scsi_write_do_fua(UfsSCSIReq *r)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb == NULL);
    assert(!r->req.io_canceled);

    if (r->need_fua_emulation) {
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_aio_complete, r);
        return;
    }

    scsi_req_complete(&r->req, GOOD);
    scsi_req_unref(&r->req);
}

static void scsi_dma_complete_noio(UfsSCSIReq *r, int ret)
{
    assert(r->req.aiocb == NULL);
    if (ufs_scsi_req_check_error(r, ret, false)) {
        goto done;
    }

    r->sector += r->sector_count;
    r->sector_count = 0;
    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        scsi_write_do_fua(r);
        return;
    } else {
        scsi_req_complete(&r->req, GOOD);
    }

done:
    scsi_req_unref(&r->req);
}

static void scsi_dma_complete(void *opaque, int ret)
{
    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;

    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
    if (ret < 0) {
        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    } else {
        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    }
    scsi_dma_complete_noio(r, ret);
    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
}

static BlockAIOCB *scsi_dma_readv(int64_t offset, QEMUIOVector *iov,
                                  BlockCompletionFunc *cb, void *cb_opaque,
                                  void *opaque)
{
    UfsSCSIReq *r = opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    return blk_aio_preadv(lu->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
}

static void scsi_init_iovec(UfsSCSIReq *r, size_t size)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    if (!r->iov.iov_base) {
        r->buflen = size;
        r->iov.iov_base = blk_blockalign(lu->qdev.conf.blk, r->buflen);
    }
    r->iov.iov_len = MIN(r->sector_count * BDRV_SECTOR_SIZE, r->buflen);
    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
}

static void scsi_read_complete_noio(UfsSCSIReq *r, int ret)
{
    uint32_t n;

    assert(r->req.aiocb == NULL);
    if (ufs_scsi_req_check_error(r, ret, false)) {
        goto done;
    }

    n = r->qiov.size / BDRV_SECTOR_SIZE;
    r->sector += n;
    r->sector_count -= n;
    scsi_req_data(&r->req, r->qiov.size);

done:
    scsi_req_unref(&r->req);
}

static void scsi_read_complete(void *opaque, int ret)
{
    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;
    trace_ufs_scsi_read_data_count(r->sector_count);
    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
    if (ret < 0) {
        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    } else {
        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
        trace_ufs_scsi_read_complete(r->req.tag, r->qiov.size);
    }
    scsi_read_complete_noio(r, ret);
    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
}

/* Actually issue a read to the block device.  */
static void scsi_do_read(UfsSCSIReq *r, int ret)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb == NULL);
    if (ufs_scsi_req_check_error(r, ret, false)) {
        goto done;
    }

    /* The request is used as the AIO opaque value, so add a ref.  */
    scsi_req_ref(&r->req);

    if (r->req.sg) {
        dma_acct_start(lu->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_READ);
        r->req.residual -= r->req.sg->size;
        r->req.aiocb = dma_blk_io(
            blk_get_aio_context(lu->qdev.conf.blk), r->req.sg,
            r->sector << BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE, scsi_dma_readv, r,
            scsi_dma_complete, r, DMA_DIRECTION_FROM_DEVICE);
    } else {
        scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct,
                         r->qiov.size, BLOCK_ACCT_READ);
        r->req.aiocb = scsi_dma_readv(r->sector << BDRV_SECTOR_BITS, &r->qiov,
                                      scsi_read_complete, r, r);
    }

done:
    scsi_req_unref(&r->req);
}

static void scsi_do_read_cb(void *opaque, int ret)
{
    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;

    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
    if (ret < 0) {
        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    } else {
        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    }
    scsi_do_read(opaque, ret);
    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
}

/* Read more data from scsi device into buffer.  */
static void scsi_read_data(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    bool first;

    trace_ufs_scsi_read_data_count(r->sector_count);
    if (r->sector_count == 0) {
        /* This also clears the sense buffer for REQUEST SENSE.  */
        scsi_req_complete(&r->req, GOOD);
        return;
    }

    /* No data transfer may already be in progress */
    assert(r->req.aiocb == NULL);

    /* The request is used as the AIO opaque value, so add a ref.  */
    scsi_req_ref(&r->req);
    if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
        trace_ufs_scsi_read_data_invalid();
        scsi_read_complete_noio(r, -EINVAL);
        return;
    }

    if (!blk_is_available(req->dev->conf.blk)) {
        scsi_read_complete_noio(r, -ENOMEDIUM);
        return;
    }

    first = !r->started;
    r->started = true;
    if (first && r->need_fua_emulation) {
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(lu->qdev.conf.blk, scsi_do_read_cb, r);
    } else {
        scsi_do_read(r, 0);
    }
}

static void scsi_write_complete_noio(UfsSCSIReq *r, int ret)
{
    uint32_t n;

    assert(r->req.aiocb == NULL);
    if (ufs_scsi_req_check_error(r, ret, false)) {
        goto done;
    }

    n = r->qiov.size / BDRV_SECTOR_SIZE;
    r->sector += n;
    r->sector_count -= n;
    if (r->sector_count == 0) {
        scsi_write_do_fua(r);
        return;
    } else {
        scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
        trace_ufs_scsi_write_complete_noio(r->req.tag, r->qiov.size);
        scsi_req_data(&r->req, r->qiov.size);
    }

done:
    scsi_req_unref(&r->req);
}

static void scsi_write_complete(void *opaque, int ret)
{
    UfsSCSIReq *r = (UfsSCSIReq *)opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;

    aio_context_acquire(blk_get_aio_context(lu->qdev.conf.blk));
    if (ret < 0) {
        block_acct_failed(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    } else {
        block_acct_done(blk_get_stats(lu->qdev.conf.blk), &r->acct);
    }
    scsi_write_complete_noio(r, ret);
    aio_context_release(blk_get_aio_context(lu->qdev.conf.blk));
}

static BlockAIOCB *scsi_dma_writev(int64_t offset, QEMUIOVector *iov,
                                   BlockCompletionFunc *cb, void *cb_opaque,
                                   void *opaque)
{
    UfsSCSIReq *r = opaque;
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);
    return blk_aio_pwritev(lu->qdev.conf.blk, offset, iov, 0, cb, cb_opaque);
}

static void scsi_write_data(SCSIRequest *req)
{
    UfsSCSIReq *r = DO_UPCAST(UfsSCSIReq, req, req);
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, r->req.dev);

    /* No data transfer may already be in progress */
    assert(r->req.aiocb == NULL);

    /* The request is used as the AIO opaque value, so add a ref.  */
    scsi_req_ref(&r->req);
    if (r->req.cmd.mode != SCSI_XFER_TO_DEV) {
        trace_ufs_scsi_write_data_invalid();
        scsi_write_complete_noio(r, -EINVAL);
        return;
    }

    if (!r->req.sg && !r->qiov.size) {
        /* Called for the first time.  Ask the driver to send us more data.  */
        r->started = true;
        scsi_write_complete_noio(r, 0);
        return;
    }
    if (!blk_is_available(req->dev->conf.blk)) {
        scsi_write_complete_noio(r, -ENOMEDIUM);
        return;
    }

    if (r->req.sg) {
        dma_acct_start(lu->qdev.conf.blk, &r->acct, r->req.sg,
                       BLOCK_ACCT_WRITE);
        r->req.residual -= r->req.sg->size;
        r->req.aiocb = dma_blk_io(
            blk_get_aio_context(lu->qdev.conf.blk), r->req.sg,
            r->sector << BDRV_SECTOR_BITS, BDRV_SECTOR_SIZE, scsi_dma_writev, r,
            scsi_dma_complete, r, DMA_DIRECTION_TO_DEVICE);
    } else {
        block_acct_start(blk_get_stats(lu->qdev.conf.blk), &r->acct,
                         r->qiov.size, BLOCK_ACCT_WRITE);
        r->req.aiocb = scsi_dma_writev(r->sector << BDRV_SECTOR_BITS, &r->qiov,
                                       scsi_write_complete, r, r);
    }
}

static const SCSIReqOps ufs_scsi_emulate_reqops = {
    .size = sizeof(UfsSCSIReq),
    .free_req = ufs_scsi_free_request,
    .send_command = ufs_scsi_emulate_command,
    .read_data = ufs_scsi_emulate_read_data,
    .write_data = ufs_scsi_emulate_write_data,
    .get_buf = ufs_scsi_get_buf,
};

static const SCSIReqOps ufs_scsi_dma_reqops = {
    .size = sizeof(UfsSCSIReq),
    .free_req = ufs_scsi_free_request,
    .send_command = ufs_scsi_dma_command,
    .read_data = scsi_read_data,
    .write_data = scsi_write_data,
    .get_buf = ufs_scsi_get_buf,
};

/*
 * Following commands are not yet supported
 * PRE_FETCH(10),
 * UNMAP,
 * WRITE_BUFFER, READ_BUFFER,
 * SECURITY_PROTOCOL_IN, SECURITY_PROTOCOL_OUT
 */
static const SCSIReqOps *const ufs_scsi_reqops_dispatch[256] = {
    [TEST_UNIT_READY] = &ufs_scsi_emulate_reqops,
    [INQUIRY] = &ufs_scsi_emulate_reqops,
    [MODE_SENSE_10] = &ufs_scsi_emulate_reqops,
    [START_STOP] = &ufs_scsi_emulate_reqops,
    [READ_CAPACITY_10] = &ufs_scsi_emulate_reqops,
    [REQUEST_SENSE] = &ufs_scsi_emulate_reqops,
    [SYNCHRONIZE_CACHE] = &ufs_scsi_emulate_reqops,
    [MODE_SELECT_10] = &ufs_scsi_emulate_reqops,
    [VERIFY_10] = &ufs_scsi_emulate_reqops,
    [FORMAT_UNIT] = &ufs_scsi_emulate_reqops,
    [SERVICE_ACTION_IN_16] = &ufs_scsi_emulate_reqops,
    [SEND_DIAGNOSTIC] = &ufs_scsi_emulate_reqops,

    [READ_6] = &ufs_scsi_dma_reqops,
    [READ_10] = &ufs_scsi_dma_reqops,
    [WRITE_6] = &ufs_scsi_dma_reqops,
    [WRITE_10] = &ufs_scsi_dma_reqops,
};

static SCSIRequest *scsi_new_request(SCSIDevice *dev, uint32_t tag,
                                     uint32_t lun, uint8_t *buf,
                                     void *hba_private)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);
    SCSIRequest *req;
    const SCSIReqOps *ops;
    uint8_t command;

    command = buf[0];
    ops = ufs_scsi_reqops_dispatch[command];
    if (!ops) {
        ops = &ufs_scsi_emulate_reqops;
    }
    req = scsi_req_alloc(ops, &lu->qdev, tag, lun, hba_private);

    return req;
}

static Property ufs_lu_props[] = {
    DEFINE_PROP_DRIVE("drive", UfsLu, qdev.conf.blk),
    DEFINE_PROP_END_OF_LIST(),
};

static bool ufs_lu_brdv_init(UfsLu *lu, Error **errp)
{
    SCSIDevice *dev = &lu->qdev;
    bool read_only;

    if (!lu->qdev.conf.blk) {
        error_setg(errp, "drive property not set");
        return false;
    }

    if (!blkconf_blocksizes(&lu->qdev.conf, errp)) {
        return false;
    }

    if (blk_get_aio_context(lu->qdev.conf.blk) != qemu_get_aio_context() &&
        !lu->qdev.hba_supports_iothread) {
        error_setg(errp, "HBA does not support iothreads");
        return false;
    }

    read_only = !blk_supports_write_perm(lu->qdev.conf.blk);

    if (!blkconf_apply_backend_options(&dev->conf, read_only,
                                       dev->type == TYPE_DISK, errp)) {
        return false;
    }

    if (blk_is_sg(lu->qdev.conf.blk)) {
        error_setg(errp, "unwanted /dev/sg*");
        return false;
    }

    blk_iostatus_enable(lu->qdev.conf.blk);
    return true;
}

static bool ufs_add_lu(UfsHc *u, UfsLu *lu, Error **errp)
{
    BlockBackend *blk = lu->qdev.conf.blk;
    int64_t brdv_len = blk_getlength(blk);
    uint64_t raw_dev_cap =
        be64_to_cpu(u->geometry_desc.total_raw_device_capacity);

    if (u->device_desc.number_lu >= UFS_MAX_LUS) {
        error_setg(errp, "ufs host controller has too many logical units.");
        return false;
    }

    if (u->lus[lu->lun] != NULL) {
        error_setg(errp, "ufs logical unit %d already exists.", lu->lun);
        return false;
    }

    u->lus[lu->lun] = lu;
    u->device_desc.number_lu++;
    raw_dev_cap += (brdv_len >> UFS_GEOMETRY_CAPACITY_SHIFT);
    u->geometry_desc.total_raw_device_capacity = cpu_to_be64(raw_dev_cap);
    return true;
}

static inline uint8_t ufs_log2(uint64_t input)
{
    int log = 0;
    while (input >>= 1) {
        log++;
    }
    return log;
}

static void ufs_init_lu(UfsLu *lu)
{
    BlockBackend *blk = lu->qdev.conf.blk;
    int64_t brdv_len = blk_getlength(blk);

    lu->lun = lu->qdev.lun;
    memset(&lu->unit_desc, 0, sizeof(lu->unit_desc));
    lu->unit_desc.length = sizeof(UnitDescriptor);
    lu->unit_desc.descriptor_idn = UFS_QUERY_DESC_IDN_UNIT;
    lu->unit_desc.lu_enable = 0x01;
    lu->unit_desc.logical_block_size = ufs_log2(lu->qdev.blocksize);
    lu->unit_desc.unit_index = lu->qdev.lun;
    lu->unit_desc.logical_block_count =
        cpu_to_be64(brdv_len / (1 << lu->unit_desc.logical_block_size));
}

static bool ufs_lu_check_constraints(UfsLu *lu, Error **errp)
{
    if (!lu->qdev.conf.blk) {
        error_setg(errp, "drive property not set");
        return false;
    }

    if (lu->qdev.channel != 0) {
        error_setg(errp, "ufs logical unit does not support channel");
        return false;
    }

    if (lu->qdev.lun >= UFS_MAX_LUS) {
        error_setg(errp, "lun must be between 1 and %d", UFS_MAX_LUS - 1);
        return false;
    }

    return true;
}

static void ufs_lu_realize(SCSIDevice *dev, Error **errp)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);
    BusState *s = qdev_get_parent_bus(&dev->qdev);
    UfsHc *u = UFS(s->parent);
    AioContext *ctx = NULL;
    uint64_t nb_sectors, nb_blocks;

    if (!ufs_lu_check_constraints(lu, errp)) {
        return;
    }

    if (lu->qdev.conf.blk) {
        ctx = blk_get_aio_context(lu->qdev.conf.blk);
        aio_context_acquire(ctx);
        if (!blkconf_blocksizes(&lu->qdev.conf, errp)) {
            goto out;
        }
    }
    lu->qdev.blocksize = UFS_BLOCK_SIZE;
    blk_get_geometry(lu->qdev.conf.blk, &nb_sectors);
    nb_blocks = nb_sectors / (lu->qdev.blocksize / BDRV_SECTOR_SIZE);
    if (nb_blocks > UINT32_MAX) {
        nb_blocks = UINT32_MAX;
    }
    lu->qdev.max_lba = nb_blocks;
    lu->qdev.type = TYPE_DISK;

    ufs_init_lu(lu);
    if (!ufs_add_lu(u, lu, errp)) {
        goto out;
    }

    ufs_lu_brdv_init(lu, errp);
out:
    if (ctx) {
        aio_context_release(ctx);
    }
}

static void ufs_lu_unrealize(SCSIDevice *dev)
{
    UfsLu *lu = DO_UPCAST(UfsLu, qdev, dev);

    blk_drain(lu->qdev.conf.blk);
}

static void ufs_wlu_realize(DeviceState *qdev, Error **errp)
{
    UfsWLu *wlu = UFSWLU(qdev);
    SCSIDevice *dev = &wlu->qdev;

    if (!is_wlun(dev->lun)) {
        error_setg(errp, "not well-known logical unit number");
        return;
    }

    QTAILQ_INIT(&dev->requests);
}

static void ufs_lu_class_init(ObjectClass *oc, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(oc);
    SCSIDeviceClass *sc = SCSI_DEVICE_CLASS(oc);

    sc->realize = ufs_lu_realize;
    sc->unrealize = ufs_lu_unrealize;
    sc->alloc_req = scsi_new_request;
    dc->bus_type = TYPE_UFS_BUS;
    device_class_set_props(dc, ufs_lu_props);
    dc->desc = "Virtual UFS logical unit";
}

static void ufs_wlu_class_init(ObjectClass *oc, void *data)
{
    DeviceClass *dc = DEVICE_CLASS(oc);
    SCSIDeviceClass *sc = SCSI_DEVICE_CLASS(oc);

    /*
     * The realize() function of TYPE_SCSI_DEVICE causes a segmentation fault
     * if a block drive does not exist. Define a new realize function for
     * well-known LUs that do not have a block drive.
     */
    dc->realize = ufs_wlu_realize;
    sc->alloc_req = scsi_new_request;
    dc->bus_type = TYPE_UFS_BUS;
    dc->desc = "Virtual UFS well-known logical unit";
}

static const TypeInfo ufs_lu_info = {
    .name = TYPE_UFS_LU,
    .parent = TYPE_SCSI_DEVICE,
    .class_init = ufs_lu_class_init,
    .instance_size = sizeof(UfsLu),
};

static const TypeInfo ufs_wlu_info = {
    .name = TYPE_UFS_WLU,
    .parent = TYPE_SCSI_DEVICE,
    .class_init = ufs_wlu_class_init,
    .instance_size = sizeof(UfsWLu),
};

static void ufs_lu_register_types(void)
{
    type_register_static(&ufs_lu_info);
    type_register_static(&ufs_wlu_info);
}

type_init(ufs_lu_register_types)