summaryrefslogtreecommitdiffstats
path: root/qemu/hw/scsi/scsi-disk.c
blob: c3ce54a203a8fc1c25d58e605a7561eac5453537 (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
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
/*
 * SCSI Device emulation
 *
 * Copyright (c) 2006 CodeSourcery.
 * Based on code by Fabrice Bellard
 *
 * Written by Paul Brook
 * Modifications:
 *  2009-Dec-12 Artyom Tarasenko : implemented stamdard inquiry for the case
 *                                 when the allocation length of CDB is smaller
 *                                 than 36.
 *  2009-Oct-13 Artyom Tarasenko : implemented the block descriptor in the
 *                                 MODE SENSE response.
 *
 * This code is licensed under the LGPL.
 *
 * Note that this file only handles the SCSI architecture model and device
 * commands.  Emulation of interface/link layer protocols is handled by
 * the host adapter emulator.
 */

//#define DEBUG_SCSI

#ifdef DEBUG_SCSI
#define DPRINTF(fmt, ...) \
do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#endif

#include "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "hw/scsi/scsi.h"
#include "block/scsi.h"
#include "sysemu/sysemu.h"
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "hw/block/block.h"
#include "sysemu/dma.h"
#include "qemu/cutils.h"

#ifdef __linux
#include <scsi/sg.h>
#endif

#define SCSI_WRITE_SAME_MAX         524288
#define SCSI_DMA_BUF_SIZE           131072
#define SCSI_MAX_INQUIRY_LEN        256
#define SCSI_MAX_MODE_LEN           256

#define DEFAULT_DISCARD_GRANULARITY 4096
#define DEFAULT_MAX_UNMAP_SIZE      (1 << 30)   /* 1 GB */
#define DEFAULT_MAX_IO_SIZE         INT_MAX     /* 2 GB - 1 block */

typedef struct SCSIDiskState SCSIDiskState;

typedef struct SCSIDiskReq {
    SCSIRequest req;
    /* Both sector and sector_count are in terms of qemu 512 byte blocks.  */
    uint64_t sector;
    uint32_t sector_count;
    uint32_t buflen;
    bool started;
    struct iovec iov;
    QEMUIOVector qiov;
    BlockAcctCookie acct;
} SCSIDiskReq;

#define SCSI_DISK_F_REMOVABLE             0
#define SCSI_DISK_F_DPOFUA                1
#define SCSI_DISK_F_NO_REMOVABLE_DEVOPS   2

struct SCSIDiskState
{
    SCSIDevice qdev;
    uint32_t features;
    bool media_changed;
    bool media_event;
    bool eject_request;
    uint16_t port_index;
    uint64_t max_unmap_size;
    uint64_t max_io_size;
    QEMUBH *bh;
    char *version;
    char *serial;
    char *vendor;
    char *product;
    bool tray_open;
    bool tray_locked;
};

static int scsi_handle_rw_error(SCSIDiskReq *r, int error, bool acct_failed);

static void scsi_free_request(SCSIRequest *req)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);

    qemu_vfree(r->iov.iov_base);
}

/* Helper function for command completion with sense.  */
static void scsi_check_condition(SCSIDiskReq *r, SCSISense sense)
{
    DPRINTF("Command complete tag=0x%x sense=%d/%d/%d\n",
            r->req.tag, sense.key, sense.asc, sense.ascq);
    scsi_req_build_sense(&r->req, sense);
    scsi_req_complete(&r->req, CHECK_CONDITION);
}

static uint32_t scsi_init_iovec(SCSIDiskReq *r, size_t size)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

    if (!r->iov.iov_base) {
        r->buflen = size;
        r->iov.iov_base = blk_blockalign(s->qdev.conf.blk, r->buflen);
    }
    r->iov.iov_len = MIN(r->sector_count * 512, r->buflen);
    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
    return r->qiov.size / 512;
}

static void scsi_disk_save_request(QEMUFile *f, SCSIRequest *req)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);

    qemu_put_be64s(f, &r->sector);
    qemu_put_be32s(f, &r->sector_count);
    qemu_put_be32s(f, &r->buflen);
    if (r->buflen) {
        if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
            qemu_put_buffer(f, r->iov.iov_base, r->iov.iov_len);
        } else if (!req->retry) {
            uint32_t len = r->iov.iov_len;
            qemu_put_be32s(f, &len);
            qemu_put_buffer(f, r->iov.iov_base, r->iov.iov_len);
        }
    }
}

static void scsi_disk_load_request(QEMUFile *f, SCSIRequest *req)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);

    qemu_get_be64s(f, &r->sector);
    qemu_get_be32s(f, &r->sector_count);
    qemu_get_be32s(f, &r->buflen);
    if (r->buflen) {
        scsi_init_iovec(r, r->buflen);
        if (r->req.cmd.mode == SCSI_XFER_TO_DEV) {
            qemu_get_buffer(f, r->iov.iov_base, r->iov.iov_len);
        } else if (!r->req.retry) {
            uint32_t len;
            qemu_get_be32s(f, &len);
            r->iov.iov_len = len;
            assert(r->iov.iov_len <= r->buflen);
            qemu_get_buffer(f, r->iov.iov_base, r->iov.iov_len);
        }
    }

    qemu_iovec_init_external(&r->qiov, &r->iov, 1);
}

static void scsi_aio_complete(void *opaque, int ret)
{
    SCSIDiskReq *r = (SCSIDiskReq *)opaque;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;
    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_error(r, -ret, true)) {
            goto done;
        }
    }

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

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

static bool scsi_is_cmd_fua(SCSICommand *cmd)
{
    switch (cmd->buf[0]) {
    case READ_10:
    case READ_12:
    case READ_16:
    case WRITE_10:
    case WRITE_12:
    case WRITE_16:
        return (cmd->buf[1] & 8) != 0;

    case VERIFY_10:
    case VERIFY_12:
    case VERIFY_16:
    case WRITE_VERIFY_10:
    case WRITE_VERIFY_12:
    case WRITE_VERIFY_16:
        return true;

    case READ_6:
    case WRITE_6:
    default:
        return false;
    }
}

static void scsi_write_do_fua(SCSIDiskReq *r)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

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

    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

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

    scsi_req_complete(&r->req, GOOD);

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

static void scsi_dma_complete_noio(SCSIDiskReq *r, int ret)
{
    assert(r->req.aiocb == NULL);

    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_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)
{
    SCSIDiskReq *r = (SCSIDiskReq *)opaque;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

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

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

static void scsi_read_complete(void * opaque, int ret)
{
    SCSIDiskReq *r = (SCSIDiskReq *)opaque;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    int n;

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;
    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_error(r, -ret, true)) {
            goto done;
        }
    }

    block_acct_done(blk_get_stats(s->qdev.conf.blk), &r->acct);
    DPRINTF("Data ready tag=0x%x len=%zd\n", r->req.tag, r->qiov.size);

    n = r->qiov.size / 512;
    r->sector += n;
    r->sector_count -= n;
    scsi_req_data(&r->req, r->qiov.size);

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

/* Actually issue a read to the block device.  */
static void scsi_do_read(SCSIDiskReq *r, int ret)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint32_t n;

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

    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_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(s->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_READ);
        r->req.resid -= r->req.sg->size;
        r->req.aiocb = dma_blk_read(s->qdev.conf.blk, r->req.sg, r->sector,
                                    scsi_dma_complete, r);
    } else {
        n = scsi_init_iovec(r, SCSI_DMA_BUF_SIZE);
        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                         n * BDRV_SECTOR_SIZE, BLOCK_ACCT_READ);
        r->req.aiocb = blk_aio_readv(s->qdev.conf.blk, r->sector, &r->qiov, n,
                                     scsi_read_complete, r);
    }

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

static void scsi_do_read_cb(void *opaque, int ret)
{
    SCSIDiskReq *r = (SCSIDiskReq *)opaque;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

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

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

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

    DPRINTF("Read sector_count=%d\n", 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) {
        DPRINTF("Data transfer direction invalid\n");
        scsi_read_complete(r, -EINVAL);
        return;
    }

    if (s->tray_open) {
        scsi_read_complete(r, -ENOMEDIUM);
        return;
    }

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

/*
 * scsi_handle_rw_error has two return values.  0 means that the error
 * must be ignored, 1 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 int scsi_handle_rw_error(SCSIDiskReq *r, int error, bool acct_failed)
{
    bool is_read = (r->req.cmd.mode == SCSI_XFER_FROM_DEV);
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    BlockErrorAction action = blk_get_error_action(s->qdev.conf.blk,
                                                   is_read, error);

    if (action == BLOCK_ERROR_ACTION_REPORT) {
        if (acct_failed) {
            block_acct_failed(blk_get_stats(s->qdev.conf.blk), &r->acct);
        }
        switch (error) {
        case ENOMEDIUM:
            scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
            break;
        case ENOMEM:
            scsi_check_condition(r, SENSE_CODE(TARGET_FAILURE));
            break;
        case EINVAL:
            scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
            break;
        case ENOSPC:
            scsi_check_condition(r, SENSE_CODE(SPACE_ALLOC_FAILED));
            break;
        default:
            scsi_check_condition(r, SENSE_CODE(IO_ERROR));
            break;
        }
    }
    blk_error_action(s->qdev.conf.blk, action, is_read, error);
    if (action == BLOCK_ERROR_ACTION_STOP) {
        scsi_req_retry(&r->req);
    }
    return action != BLOCK_ERROR_ACTION_IGNORE;
}

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

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

    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_error(r, -ret, false)) {
            goto done;
        }
    }

    n = r->qiov.size / 512;
    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);
        DPRINTF("Write complete tag=0x%x more=%zd\n", 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)
{
    SCSIDiskReq *r = (SCSIDiskReq *)opaque;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

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

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

static void scsi_write_data(SCSIRequest *req)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint32_t n;

    /* 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) {
        DPRINTF("Data transfer direction invalid\n");
        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 (s->tray_open) {
        scsi_write_complete_noio(r, -ENOMEDIUM);
        return;
    }

    if (r->req.cmd.buf[0] == VERIFY_10 || r->req.cmd.buf[0] == VERIFY_12 ||
        r->req.cmd.buf[0] == VERIFY_16) {
        if (r->req.sg) {
            scsi_dma_complete_noio(r, 0);
        } else {
            scsi_write_complete_noio(r, 0);
        }
        return;
    }

    if (r->req.sg) {
        dma_acct_start(s->qdev.conf.blk, &r->acct, r->req.sg, BLOCK_ACCT_WRITE);
        r->req.resid -= r->req.sg->size;
        r->req.aiocb = dma_blk_write(s->qdev.conf.blk, r->req.sg, r->sector,
                                     scsi_dma_complete, r);
    } else {
        n = r->qiov.size / 512;
        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                         n * BDRV_SECTOR_SIZE, BLOCK_ACCT_WRITE);
        r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, r->sector, &r->qiov, n,
                                      scsi_write_complete, r);
    }
}

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

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

static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    int buflen = 0;
    int start;

    if (req->cmd.buf[1] & 0x1) {
        /* Vital product data */
        uint8_t page_code = req->cmd.buf[2];

        outbuf[buflen++] = s->qdev.type & 0x1f;
        outbuf[buflen++] = page_code ; // this page
        outbuf[buflen++] = 0x00;
        outbuf[buflen++] = 0x00;
        start = buflen;

        switch (page_code) {
        case 0x00: /* Supported page codes, mandatory */
        {
            DPRINTF("Inquiry EVPD[Supported pages] "
                    "buffer size %zd\n", req->cmd.xfer);
            outbuf[buflen++] = 0x00; // list of supported pages (this page)
            if (s->serial) {
                outbuf[buflen++] = 0x80; // unit serial number
            }
            outbuf[buflen++] = 0x83; // device identification
            if (s->qdev.type == TYPE_DISK) {
                outbuf[buflen++] = 0xb0; // block limits
                outbuf[buflen++] = 0xb2; // thin provisioning
            }
            break;
        }
        case 0x80: /* Device serial number, optional */
        {
            int l;

            if (!s->serial) {
                DPRINTF("Inquiry (EVPD[Serial number] not supported\n");
                return -1;
            }

            l = strlen(s->serial);
            if (l > 20) {
                l = 20;
            }

            DPRINTF("Inquiry EVPD[Serial number] "
                    "buffer size %zd\n", req->cmd.xfer);
            memcpy(outbuf+buflen, s->serial, l);
            buflen += l;
            break;
        }

        case 0x83: /* Device identification page, mandatory */
        {
            const char *str = s->serial ?: blk_name(s->qdev.conf.blk);
            int max_len = s->serial ? 20 : 255 - 8;
            int id_len = strlen(str);

            if (id_len > max_len) {
                id_len = max_len;
            }
            DPRINTF("Inquiry EVPD[Device identification] "
                    "buffer size %zd\n", req->cmd.xfer);

            outbuf[buflen++] = 0x2; // ASCII
            outbuf[buflen++] = 0;   // not officially assigned
            outbuf[buflen++] = 0;   // reserved
            outbuf[buflen++] = id_len; // length of data following
            memcpy(outbuf+buflen, str, id_len);
            buflen += id_len;

            if (s->qdev.wwn) {
                outbuf[buflen++] = 0x1; // Binary
                outbuf[buflen++] = 0x3; // NAA
                outbuf[buflen++] = 0;   // reserved
                outbuf[buflen++] = 8;
                stq_be_p(&outbuf[buflen], s->qdev.wwn);
                buflen += 8;
            }

            if (s->qdev.port_wwn) {
                outbuf[buflen++] = 0x61; // SAS / Binary
                outbuf[buflen++] = 0x93; // PIV / Target port / NAA
                outbuf[buflen++] = 0;    // reserved
                outbuf[buflen++] = 8;
                stq_be_p(&outbuf[buflen], s->qdev.port_wwn);
                buflen += 8;
            }

            if (s->port_index) {
                outbuf[buflen++] = 0x61; // SAS / Binary
                outbuf[buflen++] = 0x94; // PIV / Target port / relative target port
                outbuf[buflen++] = 0;    // reserved
                outbuf[buflen++] = 4;
                stw_be_p(&outbuf[buflen + 2], s->port_index);
                buflen += 4;
            }
            break;
        }
        case 0xb0: /* block limits */
        {
            unsigned int unmap_sectors =
                    s->qdev.conf.discard_granularity / s->qdev.blocksize;
            unsigned int min_io_size =
                    s->qdev.conf.min_io_size / s->qdev.blocksize;
            unsigned int opt_io_size =
                    s->qdev.conf.opt_io_size / s->qdev.blocksize;
            unsigned int max_unmap_sectors =
                    s->max_unmap_size / s->qdev.blocksize;
            unsigned int max_io_sectors =
                    s->max_io_size / s->qdev.blocksize;

            if (s->qdev.type == TYPE_ROM) {
                DPRINTF("Inquiry (EVPD[%02X] not supported for CDROM\n",
                        page_code);
                return -1;
            }
            /* required VPD size with unmap support */
            buflen = 0x40;
            memset(outbuf + 4, 0, buflen - 4);

            outbuf[4] = 0x1; /* wsnz */

            /* optimal transfer length granularity */
            outbuf[6] = (min_io_size >> 8) & 0xff;
            outbuf[7] = min_io_size & 0xff;

            /* maximum transfer length */
            outbuf[8] = (max_io_sectors >> 24) & 0xff;
            outbuf[9] = (max_io_sectors >> 16) & 0xff;
            outbuf[10] = (max_io_sectors >> 8) & 0xff;
            outbuf[11] = max_io_sectors & 0xff;

            /* optimal transfer length */
            outbuf[12] = (opt_io_size >> 24) & 0xff;
            outbuf[13] = (opt_io_size >> 16) & 0xff;
            outbuf[14] = (opt_io_size >> 8) & 0xff;
            outbuf[15] = opt_io_size & 0xff;

            /* max unmap LBA count, default is 1GB */
            outbuf[20] = (max_unmap_sectors >> 24) & 0xff;
            outbuf[21] = (max_unmap_sectors >> 16) & 0xff;
            outbuf[22] = (max_unmap_sectors >> 8) & 0xff;
            outbuf[23] = max_unmap_sectors & 0xff;

            /* max unmap descriptors, 255 fit in 4 kb with an 8-byte header.  */
            outbuf[24] = 0;
            outbuf[25] = 0;
            outbuf[26] = 0;
            outbuf[27] = 255;

            /* optimal unmap granularity */
            outbuf[28] = (unmap_sectors >> 24) & 0xff;
            outbuf[29] = (unmap_sectors >> 16) & 0xff;
            outbuf[30] = (unmap_sectors >> 8) & 0xff;
            outbuf[31] = unmap_sectors & 0xff;

            /* max write same size */
            outbuf[36] = 0;
            outbuf[37] = 0;
            outbuf[38] = 0;
            outbuf[39] = 0;

            outbuf[40] = (max_io_sectors >> 24) & 0xff;
            outbuf[41] = (max_io_sectors >> 16) & 0xff;
            outbuf[42] = (max_io_sectors >> 8) & 0xff;
            outbuf[43] = max_io_sectors & 0xff;
            break;
        }
        case 0xb2: /* thin provisioning */
        {
            buflen = 8;
            outbuf[4] = 0;
            outbuf[5] = 0xe0; /* unmap & write_same 10/16 all supported */
            outbuf[6] = s->qdev.conf.discard_granularity ? 2 : 1;
            outbuf[7] = 0;
            break;
        }
        default:
            return -1;
        }
        /* done with EVPD */
        assert(buflen - start <= 255);
        outbuf[start - 1] = buflen - start;
        return buflen;
    }

    /* 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;
    }

    outbuf[0] = s->qdev.type & 0x1f;
    outbuf[1] = (s->features & (1 << SCSI_DISK_F_REMOVABLE)) ? 0x80 : 0;

    strpadcpy((char *) &outbuf[16], 16, s->product, ' ');
    strpadcpy((char *) &outbuf[8], 8, s->vendor, ' ');

    memset(&outbuf[32], 0, 4);
    memcpy(&outbuf[32], s->version, MIN(4, strlen(s->version)));
    /*
     * We claim conformance to SPC-3, which is required for guests
     * to ask for modern features like READ CAPACITY(16) or the
     * block characteristics VPD page by default.  Not all of SPC-3
     * is actually implemented, but we're good enough.
     */
    outbuf[2] = 5;
    outbuf[3] = 2 | 0x10; /* Format 2, HiSup */

    if (buflen > 36) {
        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] = 36 - 5;
    }

    /* Sync data transfer and TCQ.  */
    outbuf[7] = 0x10 | (req->bus->info->tcq ? 0x02 : 0);
    return buflen;
}

static inline bool media_is_dvd(SCSIDiskState *s)
{
    uint64_t nb_sectors;
    if (s->qdev.type != TYPE_ROM) {
        return false;
    }
    if (!blk_is_inserted(s->qdev.conf.blk)) {
        return false;
    }
    if (s->tray_open) {
        return false;
    }
    blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
    return nb_sectors > CD_MAX_SECTORS;
}

static inline bool media_is_cd(SCSIDiskState *s)
{
    uint64_t nb_sectors;
    if (s->qdev.type != TYPE_ROM) {
        return false;
    }
    if (!blk_is_inserted(s->qdev.conf.blk)) {
        return false;
    }
    if (s->tray_open) {
        return false;
    }
    blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
    return nb_sectors <= CD_MAX_SECTORS;
}

static int scsi_read_disc_information(SCSIDiskState *s, SCSIDiskReq *r,
                                      uint8_t *outbuf)
{
    uint8_t type = r->req.cmd.buf[1] & 7;

    if (s->qdev.type != TYPE_ROM) {
        return -1;
    }

    /* Types 1/2 are only defined for Blu-Ray.  */
    if (type != 0) {
        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
        return -1;
    }

    memset(outbuf, 0, 34);
    outbuf[1] = 32;
    outbuf[2] = 0xe; /* last session complete, disc finalized */
    outbuf[3] = 1;   /* first track on disc */
    outbuf[4] = 1;   /* # of sessions */
    outbuf[5] = 1;   /* first track of last session */
    outbuf[6] = 1;   /* last track of last session */
    outbuf[7] = 0x20; /* unrestricted use */
    outbuf[8] = 0x00; /* CD-ROM or DVD-ROM */
    /* 9-10-11: most significant byte corresponding bytes 4-5-6 */
    /* 12-23: not meaningful for CD-ROM or DVD-ROM */
    /* 24-31: disc bar code */
    /* 32: disc application code */
    /* 33: number of OPC tables */

    return 34;
}

static int scsi_read_dvd_structure(SCSIDiskState *s, SCSIDiskReq *r,
                                   uint8_t *outbuf)
{
    static const int rds_caps_size[5] = {
        [0] = 2048 + 4,
        [1] = 4 + 4,
        [3] = 188 + 4,
        [4] = 2048 + 4,
    };

    uint8_t media = r->req.cmd.buf[1];
    uint8_t layer = r->req.cmd.buf[6];
    uint8_t format = r->req.cmd.buf[7];
    int size = -1;

    if (s->qdev.type != TYPE_ROM) {
        return -1;
    }
    if (media != 0) {
        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
        return -1;
    }

    if (format != 0xff) {
        if (s->tray_open || !blk_is_inserted(s->qdev.conf.blk)) {
            scsi_check_condition(r, SENSE_CODE(NO_MEDIUM));
            return -1;
        }
        if (media_is_cd(s)) {
            scsi_check_condition(r, SENSE_CODE(INCOMPATIBLE_FORMAT));
            return -1;
        }
        if (format >= ARRAY_SIZE(rds_caps_size)) {
            return -1;
        }
        size = rds_caps_size[format];
        memset(outbuf, 0, size);
    }

    switch (format) {
    case 0x00: {
        /* Physical format information */
        uint64_t nb_sectors;
        if (layer != 0) {
            goto fail;
        }
        blk_get_geometry(s->qdev.conf.blk, &nb_sectors);

        outbuf[4] = 1;   /* DVD-ROM, part version 1 */
        outbuf[5] = 0xf; /* 120mm disc, minimum rate unspecified */
        outbuf[6] = 1;   /* one layer, read-only (per MMC-2 spec) */
        outbuf[7] = 0;   /* default densities */

        stl_be_p(&outbuf[12], (nb_sectors >> 2) - 1); /* end sector */
        stl_be_p(&outbuf[16], (nb_sectors >> 2) - 1); /* l0 end sector */
        break;
    }

    case 0x01: /* DVD copyright information, all zeros */
        break;

    case 0x03: /* BCA information - invalid field for no BCA info */
        return -1;

    case 0x04: /* DVD disc manufacturing information, all zeros */
        break;

    case 0xff: { /* List capabilities */
        int i;
        size = 4;
        for (i = 0; i < ARRAY_SIZE(rds_caps_size); i++) {
            if (!rds_caps_size[i]) {
                continue;
            }
            outbuf[size] = i;
            outbuf[size + 1] = 0x40; /* Not writable, readable */
            stw_be_p(&outbuf[size + 2], rds_caps_size[i]);
            size += 4;
        }
        break;
     }

    default:
        return -1;
    }

    /* Size of buffer, not including 2 byte size field */
    stw_be_p(outbuf, size - 2);
    return size;

fail:
    return -1;
}

static int scsi_event_status_media(SCSIDiskState *s, uint8_t *outbuf)
{
    uint8_t event_code, media_status;

    media_status = 0;
    if (s->tray_open) {
        media_status = MS_TRAY_OPEN;
    } else if (blk_is_inserted(s->qdev.conf.blk)) {
        media_status = MS_MEDIA_PRESENT;
    }

    /* Event notification descriptor */
    event_code = MEC_NO_CHANGE;
    if (media_status != MS_TRAY_OPEN) {
        if (s->media_event) {
            event_code = MEC_NEW_MEDIA;
            s->media_event = false;
        } else if (s->eject_request) {
            event_code = MEC_EJECT_REQUESTED;
            s->eject_request = false;
        }
    }

    outbuf[0] = event_code;
    outbuf[1] = media_status;

    /* These fields are reserved, just clear them. */
    outbuf[2] = 0;
    outbuf[3] = 0;
    return 4;
}

static int scsi_get_event_status_notification(SCSIDiskState *s, SCSIDiskReq *r,
                                              uint8_t *outbuf)
{
    int size;
    uint8_t *buf = r->req.cmd.buf;
    uint8_t notification_class_request = buf[4];
    if (s->qdev.type != TYPE_ROM) {
        return -1;
    }
    if ((buf[1] & 1) == 0) {
        /* asynchronous */
        return -1;
    }

    size = 4;
    outbuf[0] = outbuf[1] = 0;
    outbuf[3] = 1 << GESN_MEDIA; /* supported events */
    if (notification_class_request & (1 << GESN_MEDIA)) {
        outbuf[2] = GESN_MEDIA;
        size += scsi_event_status_media(s, &outbuf[size]);
    } else {
        outbuf[2] = 0x80;
    }
    stw_be_p(outbuf, size - 4);
    return size;
}

static int scsi_get_configuration(SCSIDiskState *s, uint8_t *outbuf)
{
    int current;

    if (s->qdev.type != TYPE_ROM) {
        return -1;
    }

    if (media_is_dvd(s)) {
        current = MMC_PROFILE_DVD_ROM;
    } else if (media_is_cd(s)) {
        current = MMC_PROFILE_CD_ROM;
    } else {
        current = MMC_PROFILE_NONE;
    }

    memset(outbuf, 0, 40);
    stl_be_p(&outbuf[0], 36); /* Bytes after the data length field */
    stw_be_p(&outbuf[6], current);
    /* outbuf[8] - outbuf[19]: Feature 0 - Profile list */
    outbuf[10] = 0x03; /* persistent, current */
    outbuf[11] = 8; /* two profiles */
    stw_be_p(&outbuf[12], MMC_PROFILE_DVD_ROM);
    outbuf[14] = (current == MMC_PROFILE_DVD_ROM);
    stw_be_p(&outbuf[16], MMC_PROFILE_CD_ROM);
    outbuf[18] = (current == MMC_PROFILE_CD_ROM);
    /* outbuf[20] - outbuf[31]: Feature 1 - Core feature */
    stw_be_p(&outbuf[20], 1);
    outbuf[22] = 0x08 | 0x03; /* version 2, persistent, current */
    outbuf[23] = 8;
    stl_be_p(&outbuf[24], 1); /* SCSI */
    outbuf[28] = 1; /* DBE = 1, mandatory */
    /* outbuf[32] - outbuf[39]: Feature 3 - Removable media feature */
    stw_be_p(&outbuf[32], 3);
    outbuf[34] = 0x08 | 0x03; /* version 2, persistent, current */
    outbuf[35] = 4;
    outbuf[36] = 0x39; /* tray, load=1, eject=1, unlocked at powerup, lock=1 */
    /* TODO: Random readable, CD read, DVD read, drive serial number,
       power management */
    return 40;
}

static int scsi_emulate_mechanism_status(SCSIDiskState *s, uint8_t *outbuf)
{
    if (s->qdev.type != TYPE_ROM) {
        return -1;
    }
    memset(outbuf, 0, 8);
    outbuf[5] = 1; /* CD-ROM */
    return 8;
}

static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
                           int page_control)
{
    static const int mode_sense_valid[0x3f] = {
        [MODE_PAGE_HD_GEOMETRY]            = (1 << TYPE_DISK),
        [MODE_PAGE_FLEXIBLE_DISK_GEOMETRY] = (1 << TYPE_DISK),
        [MODE_PAGE_CACHING]                = (1 << TYPE_DISK) | (1 << TYPE_ROM),
        [MODE_PAGE_R_W_ERROR]              = (1 << TYPE_DISK) | (1 << TYPE_ROM),
        [MODE_PAGE_AUDIO_CTL]              = (1 << TYPE_ROM),
        [MODE_PAGE_CAPABILITIES]           = (1 << TYPE_ROM),
    };

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

    if ((mode_sense_valid[page] & (1 << s->qdev.type)) == 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 menset to zero by the caller of this function.
     *
     * The offsets here are off by two compared to the descriptions in the
     * SCSI specs, because those include a 2-byte header.  This is unfortunate,
     * but it is done so that offsets are consistent within our implementation
     * of MODE SENSE and MODE SELECT.  MODE SELECT has to deal with both
     * 2-byte and 4-byte headers.
     */
    switch (page) {
    case MODE_PAGE_HD_GEOMETRY:
        length = 0x16;
        if (page_control == 1) { /* Changeable Values */
            break;
        }
        /* if a geometry hint is available, use it */
        p[0] = (s->qdev.conf.cyls >> 16) & 0xff;
        p[1] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[2] = s->qdev.conf.cyls & 0xff;
        p[3] = s->qdev.conf.heads & 0xff;
        /* Write precomp start cylinder, disabled */
        p[4] = (s->qdev.conf.cyls >> 16) & 0xff;
        p[5] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[6] = s->qdev.conf.cyls & 0xff;
        /* Reduced current start cylinder, disabled */
        p[7] = (s->qdev.conf.cyls >> 16) & 0xff;
        p[8] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[9] = s->qdev.conf.cyls & 0xff;
        /* Device step rate [ns], 200ns */
        p[10] = 0;
        p[11] = 200;
        /* Landing zone cylinder */
        p[12] = 0xff;
        p[13] =  0xff;
        p[14] = 0xff;
        /* Medium rotation rate [rpm], 5400 rpm */
        p[18] = (5400 >> 8) & 0xff;
        p[19] = 5400 & 0xff;
        break;

    case MODE_PAGE_FLEXIBLE_DISK_GEOMETRY:
        length = 0x1e;
        if (page_control == 1) { /* Changeable Values */
            break;
        }
        /* Transfer rate [kbit/s], 5Mbit/s */
        p[0] = 5000 >> 8;
        p[1] = 5000 & 0xff;
        /* if a geometry hint is available, use it */
        p[2] = s->qdev.conf.heads & 0xff;
        p[3] = s->qdev.conf.secs & 0xff;
        p[4] = s->qdev.blocksize >> 8;
        p[6] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[7] = s->qdev.conf.cyls & 0xff;
        /* Write precomp start cylinder, disabled */
        p[8] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[9] = s->qdev.conf.cyls & 0xff;
        /* Reduced current start cylinder, disabled */
        p[10] = (s->qdev.conf.cyls >> 8) & 0xff;
        p[11] = s->qdev.conf.cyls & 0xff;
        /* Device step rate [100us], 100us */
        p[12] = 0;
        p[13] = 1;
        /* Device step pulse width [us], 1us */
        p[14] = 1;
        /* Device head settle delay [100us], 100us */
        p[15] = 0;
        p[16] = 1;
        /* Motor on delay [0.1s], 0.1s */
        p[17] = 1;
        /* Motor off delay [0.1s], 0.1s */
        p[18] = 1;
        /* Medium rotation rate [rpm], 5400 rpm */
        p[26] = (5400 >> 8) & 0xff;
        p[27] = 5400 & 0xff;
        break;

    case MODE_PAGE_CACHING:
        length = 0x12;
        if (page_control == 1 || /* Changeable Values */
            blk_enable_write_cache(s->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 */
        if (s->qdev.type == TYPE_ROM) {
            p[1] = 0x20; /* Read Retry Count */
        }
        break;

    case MODE_PAGE_AUDIO_CTL:
        length = 14;
        break;

    case MODE_PAGE_CAPABILITIES:
        length = 0x14;
        if (page_control == 1) { /* Changeable Values */
            break;
        }

        p[0] = 0x3b; /* CD-R & CD-RW read */
        p[1] = 0; /* Writing not supported */
        p[2] = 0x7f; /* Audio, composite, digital out,
                        mode 2 form 1&2, multi session */
        p[3] = 0xff; /* CD DA, DA accurate, RW supported,
                        RW corrected, C2 errors, ISRC,
                        UPC, Bar code */
        p[4] = 0x2d | (s->tray_locked ? 2 : 0);
        /* Locking supported, jumper present, eject, tray */
        p[5] = 0; /* no volume & mute control, no
                     changer */
        p[6] = (50 * 176) >> 8; /* 50x read speed */
        p[7] = (50 * 176) & 0xff;
        p[8] = 2 >> 8; /* Two volume levels */
        p[9] = 2 & 0xff;
        p[10] = 2048 >> 8; /* 2M buffer */
        p[11] = 2048 & 0xff;
        p[12] = (16 * 176) >> 8; /* 16x read speed current */
        p[13] = (16 * 176) & 0xff;
        p[16] = (16 * 176) >> 8; /* 16x write speed */
        p[17] = (16 * 176) & 0xff;
        p[18] = (16 * 176) >> 8; /* 16x write speed current */
        p[19] = (16 * 176) & 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 scsi_disk_emulate_mode_sense(SCSIDiskReq *r, uint8_t *outbuf)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint64_t nb_sectors;
    bool dbd;
    int page, buflen, ret, page_control;
    uint8_t *p;
    uint8_t dev_specific_param;

    dbd = (r->req.cmd.buf[1] & 0x8) != 0;
    page = r->req.cmd.buf[2] & 0x3f;
    page_control = (r->req.cmd.buf[2] & 0xc0) >> 6;
    DPRINTF("Mode Sense(%d) (page %d, xfer %zd, page_control %d)\n",
        (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 (s->qdev.type == TYPE_DISK) {
        dev_specific_param = s->features & (1 << SCSI_DISK_F_DPOFUA) ? 0x10 : 0;
        if (blk_is_read_only(s->qdev.conf.blk)) {
            dev_specific_param |= 0x80; /* Readonly.  */
        }
    } else {
        /* MMC prescribes that CD/DVD drives have no block descriptors,
         * and defines no device-specific parameter.  */
        dev_specific_param = 0x00;
        dbd = true;
    }

    if (r->req.cmd.buf[0] == MODE_SENSE) {
        p[1] = 0; /* Default media type.  */
        p[2] = dev_specific_param;
        p[3] = 0; /* Block descriptor length.  */
        p += 4;
    } else { /* MODE_SENSE_10 */
        p[2] = 0; /* Default media type.  */
        p[3] = dev_specific_param;
        p[6] = p[7] = 0; /* Block descriptor length.  */
        p += 8;
    }

    blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
    if (!dbd && nb_sectors) {
        if (r->req.cmd.buf[0] == MODE_SENSE) {
            outbuf[3] = 8; /* Block descriptor length  */
        } else { /* MODE_SENSE_10 */
            outbuf[7] = 8; /* Block descriptor length  */
        }
        nb_sectors /= (s->qdev.blocksize / 512);
        if (nb_sectors > 0xffffff) {
            nb_sectors = 0;
        }
        p[0] = 0; /* media density code */
        p[1] = (nb_sectors >> 16) & 0xff;
        p[2] = (nb_sectors >> 8) & 0xff;
        p[3] = nb_sectors & 0xff;
        p[4] = 0; /* reserved */
        p[5] = 0; /* bytes 5-7 are the sector size in bytes */
        p[6] = s->qdev.blocksize >> 8;
        p[7] = 0;
        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(s, page, &p, page_control);
        }
    } else {
        ret = mode_sense_page(s, 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.
     */
    if (r->req.cmd.buf[0] == MODE_SENSE) {
        outbuf[0] = buflen - 1;
    } else { /* MODE_SENSE_10 */
        outbuf[0] = ((buflen - 2) >> 8) & 0xff;
        outbuf[1] = (buflen - 2) & 0xff;
    }
    return buflen;
}

static int scsi_disk_emulate_read_toc(SCSIRequest *req, uint8_t *outbuf)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    int start_track, format, msf, toclen;
    uint64_t nb_sectors;

    msf = req->cmd.buf[1] & 2;
    format = req->cmd.buf[2] & 0xf;
    start_track = req->cmd.buf[6];
    blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
    DPRINTF("Read TOC (track %d format %d msf %d)\n", start_track, format, msf >> 1);
    nb_sectors /= s->qdev.blocksize / 512;
    switch (format) {
    case 0:
        toclen = cdrom_read_toc(nb_sectors, outbuf, msf, start_track);
        break;
    case 1:
        /* multi session : only a single session defined */
        toclen = 12;
        memset(outbuf, 0, 12);
        outbuf[1] = 0x0a;
        outbuf[2] = 0x01;
        outbuf[3] = 0x01;
        break;
    case 2:
        toclen = cdrom_read_toc_raw(nb_sectors, outbuf, msf, start_track);
        break;
    default:
        return -1;
    }
    return toclen;
}

static int scsi_disk_emulate_start_stop(SCSIDiskReq *r)
{
    SCSIRequest *req = &r->req;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    bool start = req->cmd.buf[4] & 1;
    bool loej = req->cmd.buf[4] & 2; /* load on start, eject on !start */
    int pwrcnd = req->cmd.buf[4] & 0xf0;

    if (pwrcnd) {
        /* eject/load only happens for power condition == 0 */
        return 0;
    }

    if ((s->features & (1 << SCSI_DISK_F_REMOVABLE)) && loej) {
        if (!start && !s->tray_open && s->tray_locked) {
            scsi_check_condition(r,
                                 blk_is_inserted(s->qdev.conf.blk)
                                 ? SENSE_CODE(ILLEGAL_REQ_REMOVAL_PREVENTED)
                                 : SENSE_CODE(NOT_READY_REMOVAL_PREVENTED));
            return -1;
        }

        if (s->tray_open != !start) {
            blk_eject(s->qdev.conf.blk, !start);
            s->tray_open = !start;
        }
    }
    return 0;
}

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

    if (buflen) {
        DPRINTF("Read buf_len=%d\n", 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 scsi_disk_check_mode_select(SCSIDiskState *s, 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;
    }

    p = mode_current;
    memset(mode_current, 0, inlen + 2);
    len = mode_sense_page(s, 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(s, 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 scsi_disk_apply_mode_select(SCSIDiskState *s, int page, uint8_t *p)
{
    switch (page) {
    case MODE_PAGE_CACHING:
        blk_set_enable_write_cache(s->qdev.conf.blk, (p[0] & 4) != 0);
        break;

    default:
        break;
    }
}

static int mode_select_pages(SCSIDiskReq *r, uint8_t *p, int len, bool change)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

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

        /* Parse both possible formats for the mode page headers.  */
        page = p[0] & 0x3f;
        if (p[0] & 0x40) {
            if (len < 4) {
                goto invalid_param_len;
            }
            subpage = p[1];
            page_len = lduw_be_p(&p[2]);
            p += 4;
            len -= 4;
        } else {
            if (len < 2) {
                goto invalid_param_len;
            }
            subpage = 0;
            page_len = p[1];
            p += 2;
            len -= 2;
        }

        if (subpage) {
            goto invalid_param;
        }
        if (page_len > len) {
            goto invalid_param_len;
        }

        if (!change) {
            if (scsi_disk_check_mode_select(s, page, p, page_len) < 0) {
                goto invalid_param;
            }
        } else {
            scsi_disk_apply_mode_select(s, 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 scsi_disk_emulate_mode_select(SCSIDiskReq *r, uint8_t *inbuf)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint8_t *p = inbuf;
    int cmd = r->req.cmd.buf[0];
    int len = r->req.cmd.xfer;
    int hdr_len = (cmd == MODE_SELECT ? 4 : 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 = (cmd == MODE_SELECT ? p[3] : lduw_be_p(&p[6]));
    len -= hdr_len;
    p += hdr_len;
    if (len < bd_len) {
        goto invalid_param_len;
    }
    if (bd_len != 0 && bd_len != 8) {
        goto invalid_param;
    }

    len -= bd_len;
    p += bd_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(s->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(s->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(s->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));
}

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

typedef struct UnmapCBData {
    SCSIDiskReq *r;
    uint8_t *inbuf;
    int count;
} UnmapCBData;

static void scsi_unmap_complete(void *opaque, int ret);

static void scsi_unmap_complete_noio(UnmapCBData *data, int ret)
{
    SCSIDiskReq *r = data->r;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint64_t sector_num;
    uint32_t nb_sectors;

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

    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_error(r, -ret, false)) {
            goto done;
        }
    }

    if (data->count > 0) {
        sector_num = ldq_be_p(&data->inbuf[0]);
        nb_sectors = ldl_be_p(&data->inbuf[8]) & 0xffffffffULL;
        if (!check_lba_range(s, sector_num, nb_sectors)) {
            scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
            goto done;
        }

        r->req.aiocb = blk_aio_discard(s->qdev.conf.blk,
                                       sector_num * (s->qdev.blocksize / 512),
                                       nb_sectors * (s->qdev.blocksize / 512),
                                       scsi_unmap_complete, data);
        data->count--;
        data->inbuf += 16;
        return;
    }

    scsi_req_complete(&r->req, GOOD);

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

static void scsi_unmap_complete(void *opaque, int ret)
{
    UnmapCBData *data = opaque;
    SCSIDiskReq *r = data->r;

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

    scsi_unmap_complete_noio(data, ret);
}

static void scsi_disk_emulate_unmap(SCSIDiskReq *r, uint8_t *inbuf)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
    uint8_t *p = inbuf;
    int len = r->req.cmd.xfer;
    UnmapCBData *data;

    /* Reject ANCHOR=1.  */
    if (r->req.cmd.buf[1] & 0x1) {
        goto invalid_field;
    }

    if (len < 8) {
        goto invalid_param_len;
    }
    if (len < lduw_be_p(&p[0]) + 2) {
        goto invalid_param_len;
    }
    if (len < lduw_be_p(&p[2]) + 8) {
        goto invalid_param_len;
    }
    if (lduw_be_p(&p[2]) & 15) {
        goto invalid_param_len;
    }

    if (blk_is_read_only(s->qdev.conf.blk)) {
        scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
        return;
    }

    data = g_new0(UnmapCBData, 1);
    data->r = r;
    data->inbuf = &p[8];
    data->count = lduw_be_p(&p[2]) >> 4;

    /* The matching unref is in scsi_unmap_complete, before data is freed.  */
    scsi_req_ref(&r->req);
    scsi_unmap_complete_noio(data, 0);
    return;

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

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

typedef struct WriteSameCBData {
    SCSIDiskReq *r;
    int64_t sector;
    int nb_sectors;
    QEMUIOVector qiov;
    struct iovec iov;
} WriteSameCBData;

static void scsi_write_same_complete(void *opaque, int ret)
{
    WriteSameCBData *data = opaque;
    SCSIDiskReq *r = data->r;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);

    assert(r->req.aiocb != NULL);
    r->req.aiocb = NULL;
    if (r->req.io_canceled) {
        scsi_req_cancel_complete(&r->req);
        goto done;
    }

    if (ret < 0) {
        if (scsi_handle_rw_error(r, -ret, true)) {
            goto done;
        }
    }

    block_acct_done(blk_get_stats(s->qdev.conf.blk), &r->acct);

    data->nb_sectors -= data->iov.iov_len / 512;
    data->sector += data->iov.iov_len / 512;
    data->iov.iov_len = MIN(data->nb_sectors * 512, data->iov.iov_len);
    if (data->iov.iov_len) {
        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                         data->iov.iov_len, BLOCK_ACCT_WRITE);
        /* blk_aio_write doesn't like the qiov size being different from
         * nb_sectors, make sure they match.
         */
        qemu_iovec_init_external(&data->qiov, &data->iov, 1);
        r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, data->sector,
                                      &data->qiov, data->iov.iov_len / 512,
                                      scsi_write_same_complete, data);
        return;
    }

    scsi_req_complete(&r->req, GOOD);

done:
    scsi_req_unref(&r->req);
    qemu_vfree(data->iov.iov_base);
    g_free(data);
}

static void scsi_disk_emulate_write_same(SCSIDiskReq *r, uint8_t *inbuf)
{
    SCSIRequest *req = &r->req;
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    uint32_t nb_sectors = scsi_data_cdb_xfer(r->req.cmd.buf);
    WriteSameCBData *data;
    uint8_t *buf;
    int i;

    /* Fail if PBDATA=1 or LBDATA=1 or ANCHOR=1.  */
    if (nb_sectors == 0 || (req->cmd.buf[1] & 0x16)) {
        scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
        return;
    }

    if (blk_is_read_only(s->qdev.conf.blk)) {
        scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
        return;
    }
    if (!check_lba_range(s, r->req.cmd.lba, nb_sectors)) {
        scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
        return;
    }

    if (buffer_is_zero(inbuf, s->qdev.blocksize)) {
        int flags = (req->cmd.buf[1] & 0x8) ? BDRV_REQ_MAY_UNMAP : 0;

        /* The request is used as the AIO opaque value, so add a ref.  */
        scsi_req_ref(&r->req);
        block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                         nb_sectors * s->qdev.blocksize,
                        BLOCK_ACCT_WRITE);
        r->req.aiocb = blk_aio_write_zeroes(s->qdev.conf.blk,
                                r->req.cmd.lba * (s->qdev.blocksize / 512),
                                nb_sectors * (s->qdev.blocksize / 512),
                                flags, scsi_aio_complete, r);
        return;
    }

    data = g_new0(WriteSameCBData, 1);
    data->r = r;
    data->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
    data->nb_sectors = nb_sectors * (s->qdev.blocksize / 512);
    data->iov.iov_len = MIN(data->nb_sectors * 512, SCSI_WRITE_SAME_MAX);
    data->iov.iov_base = buf = blk_blockalign(s->qdev.conf.blk,
                                              data->iov.iov_len);
    qemu_iovec_init_external(&data->qiov, &data->iov, 1);

    for (i = 0; i < data->iov.iov_len; i += s->qdev.blocksize) {
        memcpy(&buf[i], inbuf, s->qdev.blocksize);
    }

    scsi_req_ref(&r->req);
    block_acct_start(blk_get_stats(s->qdev.conf.blk), &r->acct,
                     data->iov.iov_len, BLOCK_ACCT_WRITE);
    r->req.aiocb = blk_aio_writev(s->qdev.conf.blk, data->sector,
                                  &data->qiov, data->iov.iov_len / 512,
                                  scsi_write_same_complete, data);
}

static void scsi_disk_emulate_write_data(SCSIRequest *req)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);

    if (r->iov.iov_len) {
        int buflen = r->iov.iov_len;
        DPRINTF("Write buf_len=%d\n", buflen);
        r->iov.iov_len = 0;
        scsi_req_data(&r->req, buflen);
        return;
    }

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

    case UNMAP:
        scsi_disk_emulate_unmap(r, r->iov.iov_base);
        break;

    case VERIFY_10:
    case VERIFY_12:
    case VERIFY_16:
        if (r->req.status == -1) {
            scsi_check_condition(r, SENSE_CODE(INVALID_FIELD));
        }
        break;

    case WRITE_SAME_10:
    case WRITE_SAME_16:
        scsi_disk_emulate_write_same(r, r->iov.iov_base);
        break;

    default:
        abort();
    }
}

static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    uint64_t nb_sectors;
    uint8_t *outbuf;
    int buflen;

    switch (req->cmd.buf[0]) {
    case INQUIRY:
    case MODE_SENSE:
    case MODE_SENSE_10:
    case RESERVE:
    case RESERVE_10:
    case RELEASE:
    case RELEASE_10:
    case START_STOP:
    case ALLOW_MEDIUM_REMOVAL:
    case GET_CONFIGURATION:
    case GET_EVENT_STATUS_NOTIFICATION:
    case MECHANISM_STATUS:
    case REQUEST_SENSE:
        break;

    default:
        if (s->tray_open || !blk_is_inserted(s->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(s->qdev.conf.blk, r->buflen);
    }

    buflen = req->cmd.xfer;
    outbuf = r->iov.iov_base;
    memset(outbuf, 0, r->buflen);
    switch (req->cmd.buf[0]) {
    case TEST_UNIT_READY:
        assert(!s->tray_open && blk_is_inserted(s->qdev.conf.blk));
        break;
    case INQUIRY:
        buflen = scsi_disk_emulate_inquiry(req, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case MODE_SENSE:
    case MODE_SENSE_10:
        buflen = scsi_disk_emulate_mode_sense(r, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case READ_TOC:
        buflen = scsi_disk_emulate_read_toc(req, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case RESERVE:
        if (req->cmd.buf[1] & 1) {
            goto illegal_request;
        }
        break;
    case RESERVE_10:
        if (req->cmd.buf[1] & 3) {
            goto illegal_request;
        }
        break;
    case RELEASE:
        if (req->cmd.buf[1] & 1) {
            goto illegal_request;
        }
        break;
    case RELEASE_10:
        if (req->cmd.buf[1] & 3) {
            goto illegal_request;
        }
        break;
    case START_STOP:
        if (scsi_disk_emulate_start_stop(r) < 0) {
            return 0;
        }
        break;
    case ALLOW_MEDIUM_REMOVAL:
        s->tray_locked = req->cmd.buf[4] & 1;
        blk_lock_medium(s->qdev.conf.blk, req->cmd.buf[4] & 1);
        break;
    case READ_CAPACITY_10:
        /* The normal LEN field for this command is zero.  */
        memset(outbuf, 0, 8);
        blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
        if (!nb_sectors) {
            scsi_check_condition(r, SENSE_CODE(LUN_NOT_READY));
            return 0;
        }
        if ((req->cmd.buf[8] & 1) == 0 && req->cmd.lba) {
            goto illegal_request;
        }
        nb_sectors /= s->qdev.blocksize / 512;
        /* Returned value is the address of the last sector.  */
        nb_sectors--;
        /* Remember the new size for read/write sanity checking. */
        s->qdev.max_lba = nb_sectors;
        /* Clip to 2TB, instead of returning capacity modulo 2TB. */
        if (nb_sectors > UINT32_MAX) {
            nb_sectors = UINT32_MAX;
        }
        outbuf[0] = (nb_sectors >> 24) & 0xff;
        outbuf[1] = (nb_sectors >> 16) & 0xff;
        outbuf[2] = (nb_sectors >> 8) & 0xff;
        outbuf[3] = nb_sectors & 0xff;
        outbuf[4] = 0;
        outbuf[5] = 0;
        outbuf[6] = s->qdev.blocksize >> 8;
        outbuf[7] = 0;
        break;
    case REQUEST_SENSE:
        /* Just return "NO SENSE".  */
        buflen = scsi_build_sense(NULL, 0, outbuf, r->buflen,
                                  (req->cmd.buf[1] & 1) == 0);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case MECHANISM_STATUS:
        buflen = scsi_emulate_mechanism_status(s, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case GET_CONFIGURATION:
        buflen = scsi_get_configuration(s, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case GET_EVENT_STATUS_NOTIFICATION:
        buflen = scsi_get_event_status_notification(s, r, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case READ_DISC_INFORMATION:
        buflen = scsi_read_disc_information(s, r, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case READ_DVD_STRUCTURE:
        buflen = scsi_read_dvd_structure(s, r, outbuf);
        if (buflen < 0) {
            goto illegal_request;
        }
        break;
    case SERVICE_ACTION_IN_16:
        /* Service Action In subcommands. */
        if ((req->cmd.buf[1] & 31) == SAI_READ_CAPACITY_16) {
            DPRINTF("SAI READ CAPACITY(16)\n");
            memset(outbuf, 0, req->cmd.xfer);
            blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
            if (!nb_sectors) {
                scsi_check_condition(r, SENSE_CODE(LUN_NOT_READY));
                return 0;
            }
            if ((req->cmd.buf[14] & 1) == 0 && req->cmd.lba) {
                goto illegal_request;
            }
            nb_sectors /= s->qdev.blocksize / 512;
            /* Returned value is the address of the last sector.  */
            nb_sectors--;
            /* Remember the new size for read/write sanity checking. */
            s->qdev.max_lba = nb_sectors;
            outbuf[0] = (nb_sectors >> 56) & 0xff;
            outbuf[1] = (nb_sectors >> 48) & 0xff;
            outbuf[2] = (nb_sectors >> 40) & 0xff;
            outbuf[3] = (nb_sectors >> 32) & 0xff;
            outbuf[4] = (nb_sectors >> 24) & 0xff;
            outbuf[5] = (nb_sectors >> 16) & 0xff;
            outbuf[6] = (nb_sectors >> 8) & 0xff;
            outbuf[7] = nb_sectors & 0xff;
            outbuf[8] = 0;
            outbuf[9] = 0;
            outbuf[10] = s->qdev.blocksize >> 8;
            outbuf[11] = 0;
            outbuf[12] = 0;
            outbuf[13] = get_physical_block_exp(&s->qdev.conf);

            /* set TPE bit if the format supports discard */
            if (s->qdev.conf.discard_granularity) {
                outbuf[14] = 0x80;
            }

            /* Protection, exponent and lowest lba field left blank. */
            break;
        }
        DPRINTF("Unsupported Service Action In\n");
        goto illegal_request;
    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(s->qdev.conf.blk), &r->acct, 0,
                         BLOCK_ACCT_FLUSH);
        r->req.aiocb = blk_aio_flush(s->qdev.conf.blk, scsi_aio_complete, r);
        return 0;
    case SEEK_10:
        DPRINTF("Seek(10) (sector %" PRId64 ")\n", r->req.cmd.lba);
        if (r->req.cmd.lba > s->qdev.max_lba) {
            goto illegal_lba;
        }
        break;
    case MODE_SELECT:
        DPRINTF("Mode Select(6) (len %lu)\n", (long)r->req.cmd.xfer);
        break;
    case MODE_SELECT_10:
        DPRINTF("Mode Select(10) (len %lu)\n", (long)r->req.cmd.xfer);
        break;
    case UNMAP:
        DPRINTF("Unmap (len %lu)\n", (long)r->req.cmd.xfer);
        break;
    case VERIFY_10:
    case VERIFY_12:
    case VERIFY_16:
        DPRINTF("Verify (bytchk %d)\n", (req->cmd.buf[1] >> 1) & 3);
        if (req->cmd.buf[1] & 6) {
            goto illegal_request;
        }
        break;
    case WRITE_SAME_10:
    case WRITE_SAME_16:
        DPRINTF("WRITE SAME %d (len %lu)\n",
                req->cmd.buf[0] == WRITE_SAME_10 ? 10 : 16,
                (long)r->req.cmd.xfer);
        break;
    default:
        DPRINTF("Unknown SCSI command (%2.2x=%s)\n", 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;

illegal_lba:
    scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
    return 0;
}

/* Execute a scsi command.  Returns the length of the data expected by the
   command.  This will be Positive for data transfers from the device
   (eg. disk reads), negative for transfers to the device (eg. disk writes),
   and zero if the command does not transfer any data.  */

static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
{
    SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
    uint32_t len;
    uint8_t command;

    command = buf[0];

    if (s->tray_open || !blk_is_inserted(s->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:
    case READ_12:
    case READ_16:
        DPRINTF("Read (sector %" PRId64 ", count %u)\n", r->req.cmd.lba, len);
        if (r->req.cmd.buf[1] & 0xe0) {
            goto illegal_request;
        }
        if (!check_lba_range(s, r->req.cmd.lba, len)) {
            goto illegal_lba;
        }
        r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
        r->sector_count = len * (s->qdev.blocksize / 512);
        break;
    case WRITE_6:
    case WRITE_10:
    case WRITE_12:
    case WRITE_16:
    case WRITE_VERIFY_10:
    case WRITE_VERIFY_12:
    case WRITE_VERIFY_16:
        if (blk_is_read_only(s->qdev.conf.blk)) {
            scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
            return 0;
        }
        DPRINTF("Write %s(sector %" PRId64 ", count %u)\n",
                (command & 0xe) == 0xe ? "And Verify " : "",
                r->req.cmd.lba, len);
        if (r->req.cmd.buf[1] & 0xe0) {
            goto illegal_request;
        }
        if (!check_lba_range(s, r->req.cmd.lba, len)) {
            goto illegal_lba;
        }
        r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
        r->sector_count = len * (s->qdev.blocksize / 512);
        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;
    }
    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 * 512;
    } else {
        return r->sector_count * 512;
    }
}

static void scsi_disk_reset(DeviceState *dev)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev.qdev, dev);
    uint64_t nb_sectors;

    scsi_device_purge_requests(&s->qdev, SENSE_CODE(RESET));

    blk_get_geometry(s->qdev.conf.blk, &nb_sectors);
    nb_sectors /= s->qdev.blocksize / 512;
    if (nb_sectors) {
        nb_sectors--;
    }
    s->qdev.max_lba = nb_sectors;
    /* reset tray statuses */
    s->tray_locked = 0;
    s->tray_open = 0;
}

static void scsi_disk_resize_cb(void *opaque)
{
    SCSIDiskState *s = opaque;

    /* SPC lists this sense code as available only for
     * direct-access devices.
     */
    if (s->qdev.type == TYPE_DISK) {
        scsi_device_report_change(&s->qdev, SENSE_CODE(CAPACITY_CHANGED));
    }
}

static void scsi_cd_change_media_cb(void *opaque, bool load)
{
    SCSIDiskState *s = opaque;

    /*
     * When a CD gets changed, we have to report an ejected state and
     * then a loaded state to guests so that they detect tray
     * open/close and media change events.  Guests that do not use
     * GET_EVENT_STATUS_NOTIFICATION to detect such tray open/close
     * states rely on this behavior.
     *
     * media_changed governs the state machine used for unit attention
     * report.  media_event is used by GET EVENT STATUS NOTIFICATION.
     */
    s->media_changed = load;
    s->tray_open = !load;
    scsi_device_set_ua(&s->qdev, SENSE_CODE(UNIT_ATTENTION_NO_MEDIUM));
    s->media_event = true;
    s->eject_request = false;
}

static void scsi_cd_eject_request_cb(void *opaque, bool force)
{
    SCSIDiskState *s = opaque;

    s->eject_request = true;
    if (force) {
        s->tray_locked = false;
    }
}

static bool scsi_cd_is_tray_open(void *opaque)
{
    return ((SCSIDiskState *)opaque)->tray_open;
}

static bool scsi_cd_is_medium_locked(void *opaque)
{
    return ((SCSIDiskState *)opaque)->tray_locked;
}

static const BlockDevOps scsi_disk_removable_block_ops = {
    .change_media_cb = scsi_cd_change_media_cb,
    .eject_request_cb = scsi_cd_eject_request_cb,
    .is_tray_open = scsi_cd_is_tray_open,
    .is_medium_locked = scsi_cd_is_medium_locked,

    .resize_cb = scsi_disk_resize_cb,
};

static const BlockDevOps scsi_disk_block_ops = {
    .resize_cb = scsi_disk_resize_cb,
};

static void scsi_disk_unit_attention_reported(SCSIDevice *dev)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
    if (s->media_changed) {
        s->media_changed = false;
        scsi_device_set_ua(&s->qdev, SENSE_CODE(MEDIUM_CHANGED));
    }
}

static void scsi_realize(SCSIDevice *dev, Error **errp)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
    Error *err = NULL;

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

    if (!(s->features & (1 << SCSI_DISK_F_REMOVABLE)) &&
        !blk_is_inserted(s->qdev.conf.blk)) {
        error_setg(errp, "Device needs media, but drive is empty");
        return;
    }

    blkconf_serial(&s->qdev.conf, &s->serial);
    blkconf_blocksizes(&s->qdev.conf);
    if (dev->type == TYPE_DISK) {
        blkconf_geometry(&dev->conf, NULL, 65535, 255, 255, &err);
        if (err) {
            error_propagate(errp, err);
            return;
        }
    }

    if (s->qdev.conf.discard_granularity == -1) {
        s->qdev.conf.discard_granularity =
            MAX(s->qdev.conf.logical_block_size, DEFAULT_DISCARD_GRANULARITY);
    }

    if (!s->version) {
        s->version = g_strdup(qemu_hw_version());
    }
    if (!s->vendor) {
        s->vendor = g_strdup("QEMU");
    }

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

    if ((s->features & (1 << SCSI_DISK_F_REMOVABLE)) &&
            !(s->features & (1 << SCSI_DISK_F_NO_REMOVABLE_DEVOPS))) {
        blk_set_dev_ops(s->qdev.conf.blk, &scsi_disk_removable_block_ops, s);
    } else {
        blk_set_dev_ops(s->qdev.conf.blk, &scsi_disk_block_ops, s);
    }
    blk_set_guest_block_size(s->qdev.conf.blk, s->qdev.blocksize);

    blk_iostatus_enable(s->qdev.conf.blk);
}

static void scsi_hd_realize(SCSIDevice *dev, Error **errp)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
    /* can happen for devices without drive. The error message for missing
     * backend will be issued in scsi_realize
     */
    if (s->qdev.conf.blk) {
        blkconf_blocksizes(&s->qdev.conf);
    }
    s->qdev.blocksize = s->qdev.conf.logical_block_size;
    s->qdev.type = TYPE_DISK;
    if (!s->product) {
        s->product = g_strdup("QEMU HARDDISK");
    }
    scsi_realize(&s->qdev, errp);
}

static void scsi_cd_realize(SCSIDevice *dev, Error **errp)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
    s->qdev.blocksize = 2048;
    s->qdev.type = TYPE_ROM;
    s->features |= 1 << SCSI_DISK_F_REMOVABLE;
    if (!s->product) {
        s->product = g_strdup("QEMU CD-ROM");
    }
    scsi_realize(&s->qdev, errp);
}

static void scsi_disk_realize(SCSIDevice *dev, Error **errp)
{
    DriveInfo *dinfo;
    Error *local_err = NULL;

    if (!dev->conf.blk) {
        scsi_realize(dev, &local_err);
        assert(local_err);
        error_propagate(errp, local_err);
        return;
    }

    dinfo = blk_legacy_dinfo(dev->conf.blk);
    if (dinfo && dinfo->media_cd) {
        scsi_cd_realize(dev, errp);
    } else {
        scsi_hd_realize(dev, errp);
    }
}

static const SCSIReqOps scsi_disk_emulate_reqops = {
    .size         = sizeof(SCSIDiskReq),
    .free_req     = scsi_free_request,
    .send_command = scsi_disk_emulate_command,
    .read_data    = scsi_disk_emulate_read_data,
    .write_data   = scsi_disk_emulate_write_data,
    .get_buf      = scsi_get_buf,
};

static const SCSIReqOps scsi_disk_dma_reqops = {
    .size         = sizeof(SCSIDiskReq),
    .free_req     = scsi_free_request,
    .send_command = scsi_disk_dma_command,
    .read_data    = scsi_read_data,
    .write_data   = scsi_write_data,
    .get_buf      = scsi_get_buf,
    .load_request = scsi_disk_load_request,
    .save_request = scsi_disk_save_request,
};

static const SCSIReqOps *const scsi_disk_reqops_dispatch[256] = {
    [TEST_UNIT_READY]                 = &scsi_disk_emulate_reqops,
    [INQUIRY]                         = &scsi_disk_emulate_reqops,
    [MODE_SENSE]                      = &scsi_disk_emulate_reqops,
    [MODE_SENSE_10]                   = &scsi_disk_emulate_reqops,
    [START_STOP]                      = &scsi_disk_emulate_reqops,
    [ALLOW_MEDIUM_REMOVAL]            = &scsi_disk_emulate_reqops,
    [READ_CAPACITY_10]                = &scsi_disk_emulate_reqops,
    [READ_TOC]                        = &scsi_disk_emulate_reqops,
    [READ_DVD_STRUCTURE]              = &scsi_disk_emulate_reqops,
    [READ_DISC_INFORMATION]           = &scsi_disk_emulate_reqops,
    [GET_CONFIGURATION]               = &scsi_disk_emulate_reqops,
    [GET_EVENT_STATUS_NOTIFICATION]   = &scsi_disk_emulate_reqops,
    [MECHANISM_STATUS]                = &scsi_disk_emulate_reqops,
    [SERVICE_ACTION_IN_16]            = &scsi_disk_emulate_reqops,
    [REQUEST_SENSE]                   = &scsi_disk_emulate_reqops,
    [SYNCHRONIZE_CACHE]               = &scsi_disk_emulate_reqops,
    [SEEK_10]                         = &scsi_disk_emulate_reqops,
    [MODE_SELECT]                     = &scsi_disk_emulate_reqops,
    [MODE_SELECT_10]                  = &scsi_disk_emulate_reqops,
    [UNMAP]                           = &scsi_disk_emulate_reqops,
    [WRITE_SAME_10]                   = &scsi_disk_emulate_reqops,
    [WRITE_SAME_16]                   = &scsi_disk_emulate_reqops,
    [VERIFY_10]                       = &scsi_disk_emulate_reqops,
    [VERIFY_12]                       = &scsi_disk_emulate_reqops,
    [VERIFY_16]                       = &scsi_disk_emulate_reqops,

    [READ_6]                          = &scsi_disk_dma_reqops,
    [READ_10]                         = &scsi_disk_dma_reqops,
    [READ_12]                         = &scsi_disk_dma_reqops,
    [READ_16]                         = &scsi_disk_dma_reqops,
    [WRITE_6]                         = &scsi_disk_dma_reqops,
    [WRITE_10]                        = &scsi_disk_dma_reqops,
    [WRITE_12]                        = &scsi_disk_dma_reqops,
    [WRITE_16]                        = &scsi_disk_dma_reqops,
    [WRITE_VERIFY_10]                 = &scsi_disk_dma_reqops,
    [WRITE_VERIFY_12]                 = &scsi_disk_dma_reqops,
    [WRITE_VERIFY_16]                 = &scsi_disk_dma_reqops,
};

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

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

#ifdef DEBUG_SCSI
    DPRINTF("Command: lun=%d tag=0x%x data=0x%02x", lun, tag, buf[0]);
    {
        int i;
        for (i = 1; i < scsi_cdb_length(buf); i++) {
            printf(" 0x%02x", buf[i]);
        }
        printf("\n");
    }
#endif

    return req;
}

#ifdef __linux__
static int get_device_type(SCSIDiskState *s)
{
    uint8_t cmd[16];
    uint8_t buf[36];
    uint8_t sensebuf[8];
    sg_io_hdr_t io_header;
    int ret;

    memset(cmd, 0, sizeof(cmd));
    memset(buf, 0, sizeof(buf));
    cmd[0] = INQUIRY;
    cmd[4] = sizeof(buf);

    memset(&io_header, 0, sizeof(io_header));
    io_header.interface_id = 'S';
    io_header.dxfer_direction = SG_DXFER_FROM_DEV;
    io_header.dxfer_len = sizeof(buf);
    io_header.dxferp = buf;
    io_header.cmdp = cmd;
    io_header.cmd_len = sizeof(cmd);
    io_header.mx_sb_len = sizeof(sensebuf);
    io_header.sbp = sensebuf;
    io_header.timeout = 6000; /* XXX */

    ret = blk_ioctl(s->qdev.conf.blk, SG_IO, &io_header);
    if (ret < 0 || io_header.driver_status || io_header.host_status) {
        return -1;
    }
    s->qdev.type = buf[0];
    if (buf[1] & 0x80) {
        s->features |= 1 << SCSI_DISK_F_REMOVABLE;
    }
    return 0;
}

static void scsi_block_realize(SCSIDevice *dev, Error **errp)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
    int sg_version;
    int rc;

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

    /* check we are using a driver managing SG_IO (version 3 and after) */
    rc = blk_ioctl(s->qdev.conf.blk, SG_GET_VERSION_NUM, &sg_version);
    if (rc < 0) {
        error_setg(errp, "cannot get SG_IO version number: %s.  "
                     "Is this a SCSI device?",
                     strerror(-rc));
        return;
    }
    if (sg_version < 30000) {
        error_setg(errp, "scsi generic interface too old");
        return;
    }

    /* get device type from INQUIRY data */
    rc = get_device_type(s);
    if (rc < 0) {
        error_setg(errp, "INQUIRY failed");
        return;
    }

    /* Make a guess for the block size, we'll fix it when the guest sends.
     * READ CAPACITY.  If they don't, they likely would assume these sizes
     * anyway. (TODO: check in /sys).
     */
    if (s->qdev.type == TYPE_ROM || s->qdev.type == TYPE_WORM) {
        s->qdev.blocksize = 2048;
    } else {
        s->qdev.blocksize = 512;
    }

    /* Makes the scsi-block device not removable by using HMP and QMP eject
     * command.
     */
    s->features |= (1 << SCSI_DISK_F_NO_REMOVABLE_DEVOPS);

    scsi_realize(&s->qdev, errp);
    scsi_generic_read_device_identification(&s->qdev);
}

static bool scsi_block_is_passthrough(SCSIDiskState *s, uint8_t *buf)
{
    switch (buf[0]) {
    case READ_6:
    case READ_10:
    case READ_12:
    case READ_16:
    case VERIFY_10:
    case VERIFY_12:
    case VERIFY_16:
    case WRITE_6:
    case WRITE_10:
    case WRITE_12:
    case WRITE_16:
    case WRITE_VERIFY_10:
    case WRITE_VERIFY_12:
    case WRITE_VERIFY_16:
        /* If we are not using O_DIRECT, we might read stale data from the
         * host cache if writes were made using other commands than these
         * ones (such as WRITE SAME or EXTENDED COPY, etc.).  So, without
         * O_DIRECT everything must go through SG_IO.
         */
        if (!(blk_get_flags(s->qdev.conf.blk) & BDRV_O_NOCACHE)) {
            break;
        }

        /* MMC writing cannot be done via pread/pwrite, because it sometimes
         * involves writing beyond the maximum LBA or to negative LBA (lead-in).
         * And once you do these writes, reading from the block device is
         * unreliable, too.  It is even possible that reads deliver random data
         * from the host page cache (this is probably a Linux bug).
         *
         * We might use scsi_disk_dma_reqops as long as no writing commands are
         * seen, but performance usually isn't paramount on optical media.  So,
         * just make scsi-block operate the same as scsi-generic for them.
         */
        if (s->qdev.type != TYPE_ROM) {
            return false;
        }
        break;

    default:
        break;
    }

    return true;
}


static SCSIRequest *scsi_block_new_request(SCSIDevice *d, uint32_t tag,
                                           uint32_t lun, uint8_t *buf,
                                           void *hba_private)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);

    if (scsi_block_is_passthrough(s, buf)) {
        return scsi_req_alloc(&scsi_generic_req_ops, &s->qdev, tag, lun,
                              hba_private);
    } else {
        return scsi_req_alloc(&scsi_disk_dma_reqops, &s->qdev, tag, lun,
                              hba_private);
    }
}

static int scsi_block_parse_cdb(SCSIDevice *d, SCSICommand *cmd,
                                  uint8_t *buf, void *hba_private)
{
    SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);

    if (scsi_block_is_passthrough(s, buf)) {
        return scsi_bus_parse_cdb(&s->qdev, cmd, buf, hba_private);
    } else {
        return scsi_req_parse_cdb(&s->qdev, cmd, buf);
    }
}

#endif

#define DEFINE_SCSI_DISK_PROPERTIES()                                \
    DEFINE_BLOCK_PROPERTIES(SCSIDiskState, qdev.conf),               \
    DEFINE_PROP_STRING("ver", SCSIDiskState, version),               \
    DEFINE_PROP_STRING("serial", SCSIDiskState, serial),             \
    DEFINE_PROP_STRING("vendor", SCSIDiskState, vendor),             \
    DEFINE_PROP_STRING("product", SCSIDiskState, product)

static Property scsi_hd_properties[] = {
    DEFINE_SCSI_DISK_PROPERTIES(),
    DEFINE_PROP_BIT("removable", SCSIDiskState, features,
                    SCSI_DISK_F_REMOVABLE, false),
    DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
                    SCSI_DISK_F_DPOFUA, false),
    DEFINE_PROP_UINT64("wwn", SCSIDiskState, qdev.wwn, 0),
    DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, qdev.port_wwn, 0),
    DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
    DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
                       DEFAULT_MAX_UNMAP_SIZE),
    DEFINE_PROP_UINT64("max_io_size", SCSIDiskState, max_io_size,
                       DEFAULT_MAX_IO_SIZE),
    DEFINE_BLOCK_CHS_PROPERTIES(SCSIDiskState, qdev.conf),
    DEFINE_PROP_END_OF_LIST(),
};

static const VMStateDescription vmstate_scsi_disk_state = {
    .name = "scsi-disk",
    .version_id = 1,
    .minimum_version_id = 1,
    .fields = (VMStateField[]) {
        VMSTATE_SCSI_DEVICE(qdev, SCSIDiskState),
        VMSTATE_BOOL(media_changed, SCSIDiskState),
        VMSTATE_BOOL(media_event, SCSIDiskState),
        VMSTATE_BOOL(eject_request, SCSIDiskState),
        VMSTATE_BOOL(tray_open, SCSIDiskState),
        VMSTATE_BOOL(tray_locked, SCSIDiskState),
        VMSTATE_END_OF_LIST()
    }
};

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

    sc->realize      = scsi_hd_realize;
    sc->alloc_req    = scsi_new_request;
    sc->unit_attention_reported = scsi_disk_unit_attention_reported;
    dc->fw_name = "disk";
    dc->desc = "virtual SCSI disk";
    dc->reset = scsi_disk_reset;
    dc->props = scsi_hd_properties;
    dc->vmsd  = &vmstate_scsi_disk_state;
}

static const TypeInfo scsi_hd_info = {
    .name          = "scsi-hd",
    .parent        = TYPE_SCSI_DEVICE,
    .instance_size = sizeof(SCSIDiskState),
    .class_init    = scsi_hd_class_initfn,
};

static Property scsi_cd_properties[] = {
    DEFINE_SCSI_DISK_PROPERTIES(),
    DEFINE_PROP_UINT64("wwn", SCSIDiskState, qdev.wwn, 0),
    DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, qdev.port_wwn, 0),
    DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
    DEFINE_PROP_UINT64("max_io_size", SCSIDiskState, max_io_size,
                       DEFAULT_MAX_IO_SIZE),
    DEFINE_PROP_END_OF_LIST(),
};

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

    sc->realize      = scsi_cd_realize;
    sc->alloc_req    = scsi_new_request;
    sc->unit_attention_reported = scsi_disk_unit_attention_reported;
    dc->fw_name = "disk";
    dc->desc = "virtual SCSI CD-ROM";
    dc->reset = scsi_disk_reset;
    dc->props = scsi_cd_properties;
    dc->vmsd  = &vmstate_scsi_disk_state;
}

static const TypeInfo scsi_cd_info = {
    .name          = "scsi-cd",
    .parent        = TYPE_SCSI_DEVICE,
    .instance_size = sizeof(SCSIDiskState),
    .class_init    = scsi_cd_class_initfn,
};

#ifdef __linux__
static Property scsi_block_properties[] = {
    DEFINE_PROP_DRIVE("drive", SCSIDiskState, qdev.conf.blk),
    DEFINE_PROP_END_OF_LIST(),
};

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

    sc->realize      = scsi_block_realize;
    sc->alloc_req    = scsi_block_new_request;
    sc->parse_cdb    = scsi_block_parse_cdb;
    dc->fw_name = "disk";
    dc->desc = "SCSI block device passthrough";
    dc->reset = scsi_disk_reset;
    dc->props = scsi_block_properties;
    dc->vmsd  = &vmstate_scsi_disk_state;
}

static const TypeInfo scsi_block_info = {
    .name          = "scsi-block",
    .parent        = TYPE_SCSI_DEVICE,
    .instance_size = sizeof(SCSIDiskState),
    .class_init    = scsi_block_class_initfn,
};
#endif

static Property scsi_disk_properties[] = {
    DEFINE_SCSI_DISK_PROPERTIES(),
    DEFINE_PROP_BIT("removable", SCSIDiskState, features,
                    SCSI_DISK_F_REMOVABLE, false),
    DEFINE_PROP_BIT("dpofua", SCSIDiskState, features,
                    SCSI_DISK_F_DPOFUA, false),
    DEFINE_PROP_UINT64("wwn", SCSIDiskState, qdev.wwn, 0),
    DEFINE_PROP_UINT64("port_wwn", SCSIDiskState, qdev.port_wwn, 0),
    DEFINE_PROP_UINT16("port_index", SCSIDiskState, port_index, 0),
    DEFINE_PROP_UINT64("max_unmap_size", SCSIDiskState, max_unmap_size,
                       DEFAULT_MAX_UNMAP_SIZE),
    DEFINE_PROP_UINT64("max_io_size", SCSIDiskState, max_io_size,
                       DEFAULT_MAX_IO_SIZE),
    DEFINE_PROP_END_OF_LIST(),
};

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

    sc->realize      = scsi_disk_realize;
    sc->alloc_req    = scsi_new_request;
    sc->unit_attention_reported = scsi_disk_unit_attention_reported;
    dc->fw_name = "disk";
    dc->desc = "virtual SCSI disk or CD-ROM (legacy)";
    dc->reset = scsi_disk_reset;
    dc->props = scsi_disk_properties;
    dc->vmsd  = &vmstate_scsi_disk_state;
}

static const TypeInfo scsi_disk_info = {
    .name          = "scsi-disk",
    .parent        = TYPE_SCSI_DEVICE,
    .instance_size = sizeof(SCSIDiskState),
    .class_init    = scsi_disk_class_initfn,
};

static void scsi_disk_register_types(void)
{
    type_register_static(&scsi_hd_info);
    type_register_static(&scsi_cd_info);
#ifdef __linux__
    type_register_static(&scsi_block_info);
#endif
    type_register_static(&scsi_disk_info);
}

type_init(scsi_disk_register_types)