hw/scsi-disk.c

   1 /*
   2  * SCSI Device emulation
   3  *
   4  * Copyright (c) 2006 CodeSourcery.
   5  * Based on code by Fabrice Bellard
   6  *
   7  * Written by Paul Brook
   8  *
   9  * This code is licenced under the LGPL.
  10  */
  11
  12 //#define DEBUG_SCSI
  13
  14 #ifdef DEBUG_SCSI
  15 #define DPRINTF(fmt, args...) \
  16 do { printf("scsi-disk: " fmt , ##args); } while (0)
  17 #else
  18 #define DPRINTF(fmt, args...) do {} while(0)
  19 #endif
  20
  21 #define BADF(fmt, args...) \
  22 do { fprintf(stderr, "scsi-disk: " fmt , ##args); } while (0)
  23
  24 #include "vl.h"
  25
  26 #define SENSE_NO_SENSE        0
  27 #define SENSE_NOT_READY       2
  28 #define SENSE_HARDWARE_ERROR  4
  29 #define SENSE_ILLEGAL_REQUEST 5
  30
  31 struct SCSIDevice
  32 {
  33     int command;
  34     uint32_t tag;
  35     BlockDriverState *bdrv;
  36     /* The qemu block layer uses a fixed 512 byte sector size.
  37        This is the number of 512 byte blocks in a single scsi sector.  */
  38     int cluster_size;
  39     /* When transfering data buf_pos and buf_len contain a partially
  40        transferred block of data (or response to a command), and
  41        sector/sector_count identify any remaining sectors.
  42        Both sector and sector_count are in terms of qemu 512 byte blocks.  */
  43     /* ??? We should probably keep track of whether the data trasfer is
  44        a read or a write.  Currently we rely on the host getting it right.  */
  45     int sector;
  46     int sector_count;
  47     int buf_pos;
  48     int buf_len;
  49     int sense;
  50     BlockDriverAIOCB *aiocb;
  51     /* Data still to be transfered after this request completes.  */
  52     uint8_t *aiodata;
  53     uint32_t aiolen;
  54     char buf[512];
  55     /* Completion functions may be called from either scsi_{read,write}_data
  56        or from the AIO completion routines.  */
  57     scsi_completionfn completion;
  58     void *opaque;
  59 };
  60
  61 static void scsi_command_complete(SCSIDevice *s, int sense)
  62 {
  63     s->sense = sense;
  64     s->completion(s->opaque, SCSI_REASON_DONE, sense);
  65 }
  66
  67 static void scsi_transfer_complete(SCSIDevice *s)
  68 {
  69     s->completion(s->opaque, SCSI_REASON_DATA, 0);
  70     s->aiocb = NULL;
  71 }
  72
  73 static void scsi_read_complete(void * opaque, int ret)
  74 {
  75     SCSIDevice *s = (SCSIDevice *)opaque;
  76
  77     if (ret) {
  78         DPRINTF("IO error\n");
  79         scsi_command_complete(s, SENSE_HARDWARE_ERROR);
  80     }
  81
  82     if (s->aiolen) {
  83         /* Read the remaining data.  Full and partial sectors are transferred
  84            separately.  */
  85         scsi_read_data(s, s->aiodata, s->aiolen);
  86     } else {
  87         if (s->buf_len == 0 && s->sector_count == 0)
  88             scsi_command_complete(s, SENSE_NO_SENSE);
  89         else
  90             scsi_transfer_complete(s);
  91     }
  92 }
  93
  94 /* Cancel a pending data transfer.  */
  95 void scsi_cancel_io(SCSIDevice *s)
  96 {
  97     if (!s->aiocb) {
  98         BADF("Cancel with no pending IO\n");
  99         return;
 100     }
 101     bdrv_aio_cancel(s->aiocb);
 102     s->aiocb = NULL;
 103 }
 104
 105 /* Read data from a scsi device.  Returns nonzero on failure.
 106    The transfer may complete asynchronously.  */
 107 int scsi_read_data(SCSIDevice *s, uint8_t *data, uint32_t len)
 108 {
 109     uint32_t n;
 110
 111     DPRINTF("Read %d (%d/%d)\n", len, s->buf_len, s->sector_count);
 112     if (s->buf_len == 0 && s->sector_count == 0)
 113         return 1;
 114
 115     if (s->buf_len) {
 116         n = s->buf_len;
 117         if (n > len)
 118             n = len;
 119         memcpy(data, s->buf + s->buf_pos, n);
 120         s->buf_pos += n;
 121         s->buf_len -= n;
 122         data += n;
 123         len -= n;
 124         if (s->buf_len == 0)
 125             s->buf_pos = 0;
 126     }
 127
 128     n = len / 512;
 129     if (n > s->sector_count)
 130       n = s->sector_count;
 131
 132     if (n != 0) {
 133         s->aiolen = len - n * 512;
 134         s->aiodata = data + n * 512;
 135         s->aiocb = bdrv_aio_read(s->bdrv, s->sector, data, n,
 136                                  scsi_read_complete, s);
 137         if (s->aiocb == NULL)
 138             scsi_command_complete(s, SENSE_HARDWARE_ERROR);
 139         s->sector += n;
 140         s->sector_count -= n;
 141         return 0;
 142     }
 143
 144     if (len && s->sector_count) {
 145         /* TODO: Make this use AIO.  */
 146         bdrv_read(s->bdrv, s->sector, s->buf, 1);
 147         s->sector++;
 148         s->sector_count--;
 149         s->buf_pos = 0;
 150         s->buf_len = 512;
 151         /* Recurse to complete the partial read.  */
 152         return scsi_read_data(s, data, len);
 153     }
 154
 155     if (len != 0)
 156         return 1;
 157
 158     if (s->buf_len == 0 && s->sector_count == 0)
 159         scsi_command_complete(s, SENSE_NO_SENSE);
 160     else
 161         scsi_transfer_complete(s);
 162
 163     return 0;
 164 }
 165
 166 static void scsi_write_complete(void * opaque, int ret)
 167 {
 168     SCSIDevice *s = (SCSIDevice *)opaque;
 169
 170     if (ret) {
 171         fprintf(stderr, "scsi-disc: IO write error\n");
 172         exit(1);
 173     }
 174
 175     if (s->sector_count == 0)
 176         scsi_command_complete(s, SENSE_NO_SENSE);
 177     else
 178         scsi_transfer_complete(s);
 179 }
 180
 181 static uint32_t scsi_write_partial_sector(SCSIDevice *s, uint8_t *data,
 182                                           uint32_t len)
 183 {
 184     int n;
 185
 186     n = 512 - s->buf_len;
 187     if (n > len)
 188         n = len;
 189
 190     memcpy(s->buf + s->buf_len, data, n);
 191     data += n;
 192     s->buf_len += n;
 193     len -= n;
 194     if (s->buf_len == 512) {
 195         /* A full sector has been accumulated. Write it to disk.  */
 196         /* TODO: Make this use async IO.  */
 197         bdrv_write(s->bdrv, s->sector, s->buf, 1);
 198         s->buf_len = 0;
 199         s->sector++;
 200         s->sector_count--;
 201     }
 202     return n;
 203 }
 204
 205 /* Write data to a scsi device.  Returns nonzero on failure.
 206    The transfer may complete asynchronously.  */
 207 int scsi_write_data(SCSIDevice *s, uint8_t *data, uint32_t len)
 208 {
 209     uint32_t n;
 210
 211     DPRINTF("Write %d (%d/%d)\n", len, s->buf_len, s->sector_count);
 212     if (s->buf_pos != 0) {
 213         BADF("Bad state on write\n");
 214         return 1;
 215     }
 216
 217     if (s->sector_count == 0)
 218         return 1;
 219
 220     if (s->buf_len != 0 || len < 512) {
 221         n = scsi_write_partial_sector(s, data, len);
 222         len -= n;
 223         data += n;
 224     }
 225
 226     n = len / 512;
 227     if (n > s->sector_count)
 228         return 1;
 229
 230     if (n != 0) {
 231         s->aiocb = bdrv_aio_write(s->bdrv, s->sector, data, n,
 232                                    scsi_write_complete, s);
 233         if (s->aiocb == NULL)
 234             scsi_command_complete(s, SENSE_HARDWARE_ERROR);
 235         data += n * 512;
 236         len -= n * 512;
 237         s->sector += n;
 238         s->sector_count -= n;
 239     }
 240
 241     if (len) {
 242         if (s->sector_count == 0)
 243             return 1;
 244         /* Complete a partial write.  */
 245         scsi_write_partial_sector(s, data, len);
 246     }
 247     if (n == 0) {
 248         /* Transfer completes immediately.  */
 249         if (s->sector_count == 0)
 250             scsi_command_complete(s, SENSE_NO_SENSE);
 251         else
 252             scsi_transfer_complete(s);
 253     }
 254
 255     return 0;
 256 }
 257
 258 /* Execute a scsi command.  Returns the length of the data expected by the
 259    command.  This will be Positive for data transfers from the device
 260    (eg. disk reads), negative for transfers to the device (eg. disk writes),
 261    and zero if the command does not transfer any data.  */
 262
 263 int32_t scsi_send_command(SCSIDevice *s, uint32_t tag, uint8_t *buf, int lun)
 264 {
 265     int64_t nb_sectors;
 266     uint32_t lba;
 267     uint32_t len;
 268     int cmdlen;
 269     int is_write;
 270
 271     s->command = buf[0];
 272     s->tag = tag;
 273     s->sector_count = 0;
 274     s->buf_pos = 0;
 275     s->buf_len = 0;
 276     is_write = 0;
 277     DPRINTF("Command: 0x%02x", buf[0]);
 278     switch (s->command >> 5) {
 279     case 0:
 280         lba = buf[3] | (buf[2] << 8) | ((buf[1] & 0x1f) << 16);
 281         len = buf[4];
 282         cmdlen = 6;
 283         break;
 284     case 1:
 285     case 2:
 286         lba = buf[5] | (buf[4] << 8) | (buf[3] << 16) | (buf[2] << 24);
 287         len = buf[8] | (buf[7] << 8);
 288         cmdlen = 10;
 289         break;
 290     case 4:
 291         lba = buf[5] | (buf[4] << 8) | (buf[3] << 16) | (buf[2] << 24);
 292         len = buf[13] | (buf[12] << 8) | (buf[11] << 16) | (buf[10] << 24);
 293         cmdlen = 16;
 294         break;
 295     case 5:
 296         lba = buf[5] | (buf[4] << 8) | (buf[3] << 16) | (buf[2] << 24);
 297         len = buf[9] | (buf[8] << 8) | (buf[7] << 16) | (buf[6] << 24);
 298         cmdlen = 12;
 299         break;
 300     default:
 301         BADF("Unsupported command length, command %x\n", s->command);
 302         goto fail;
 303     }
 304 #ifdef DEBUG_SCSI
 305     {
 306         int i;
 307         for (i = 1; i < cmdlen; i++) {
 308             printf(" 0x%02x", buf[i]);
 309         }
 310         printf("\n");
 311     }
 312 #endif
 313     if (lun || buf[1] >> 5) {
 314         /* Only LUN 0 supported.  */
 315         DPRINTF("Unimplemented LUN %d\n", lun ? lun : buf[1] >> 5);
 316         goto fail;
 317     }
 318     switch (s->command) {
 319     case 0x0:
 320         DPRINTF("Test Unit Ready\n");
 321         break;
 322     case 0x03:
 323         DPRINTF("Request Sense (len %d)\n", len);
 324         if (len < 4)
 325             goto fail;
 326         memset(buf, 0, 4);
 327         s->buf[0] = 0xf0;
 328         s->buf[1] = 0;
 329         s->buf[2] = s->sense;
 330         s->buf_len = 4;
 331         break;
 332     case 0x12:
 333         DPRINTF("Inquiry (len %d)\n", len);
 334         if (len < 36) {
 335             BADF("Inquiry buffer too small (%d)\n", len);
 336         }
 337         memset(s->buf, 0, 36);
 338         if (bdrv_get_type_hint(s->bdrv) == BDRV_TYPE_CDROM) {
 339             s->buf[0] = 5;
 340             s->buf[1] = 0x80;
 341             memcpy(&s->buf[16], "QEMU CD-ROM    ", 16);
 342         } else {
 343             s->buf[0] = 0;
 344             memcpy(&s->buf[16], "QEMU HARDDISK  ", 16);
 345         }
 346         memcpy(&s->buf[8], "QEMU   ", 8);
 347         memcpy(&s->buf[32], QEMU_VERSION, 4);
 348         /* Identify device as SCSI-3 rev 1.
 349            Some later commands are also implemented. */
 350         s->buf[2] = 3;
 351         s->buf[3] = 2; /* Format 2 */
 352         s->buf[4] = 32;
 353         s->buf_len = 36;
 354         break;
 355     case 0x16:
 356         DPRINTF("Reserve(6)\n");
 357         if (buf[1] & 1)
 358             goto fail;
 359         break;
 360     case 0x17:
 361         DPRINTF("Release(6)\n");
 362         if (buf[1] & 1)
 363             goto fail;
 364         break;
 365     case 0x1a:
 366     case 0x5a:
 367         {
 368             char *p;
 369             int page;
 370
 371             page = buf[2] & 0x3f;
 372             DPRINTF("Mode Sense (page %d, len %d)\n", page, len);
 373             p = s->buf;
 374             memset(p, 0, 4);
 375             s->buf[1] = 0; /* Default media type.  */
 376             s->buf[3] = 0; /* Block descriptor length.  */
 377             if (bdrv_get_type_hint(s->bdrv) == BDRV_TYPE_CDROM) {
 378                 s->buf[2] = 0x80; /* Readonly.  */
 379             }
 380             p += 4;
 381             if ((page == 8 || page == 0x3f)) {
 382                 /* Caching page.  */
 383                 p[0] = 8;
 384                 p[1] = 0x12;
 385                 p[2] = 4; /* WCE */
 386                 p += 19;
 387             }
 388             if ((page == 0x3f || page == 0x2a)
 389                     && (bdrv_get_type_hint(s->bdrv) == BDRV_TYPE_CDROM)) {
 390                 /* CD Capabilities and Mechanical Status page. */
 391                 p[0] = 0x2a;
 392                 p[1] = 0x14;
 393                 p[2] = 3; // CD-R & CD-RW read
 394                 p[3] = 0; // Writing not supported
 395                 p[4] = 0x7f; /* Audio, composite, digital out,
 396                                          mode 2 form 1&2, multi session */
 397                 p[5] = 0xff; /* CD DA, DA accurate, RW supported,
 398                                          RW corrected, C2 errors, ISRC,
 399                                          UPC, Bar code */
 400                 p[6] = 0x2d | (bdrv_is_locked(s->bdrv)? 2 : 0);
 401                 /* Locking supported, jumper present, eject, tray */
 402                 p[7] = 0; /* no volume & mute control, no
 403                                       changer */
 404                 p[8] = (50 * 176) >> 8; // 50x read speed
 405                 p[9] = (50 * 176) & 0xff;
 406                 p[10] = 0 >> 8; // No volume
 407                 p[11] = 0 & 0xff;
 408                 p[12] = 2048 >> 8; // 2M buffer
 409                 p[13] = 2048 & 0xff;
 410                 p[14] = (16 * 176) >> 8; // 16x read speed current
 411                 p[15] = (16 * 176) & 0xff;
 412                 p[18] = (16 * 176) >> 8; // 16x write speed
 413                 p[19] = (16 * 176) & 0xff;
 414                 p[20] = (16 * 176) >> 8; // 16x write speed current
 415                 p[21] = (16 * 176) & 0xff;
 416                 p += 21;
 417             }
 418             s->buf_len = p - s->buf;
 419             s->buf[0] = s->buf_len - 4;
 420             if (s->buf_len > len)
 421                 s->buf_len = len;
 422         }
 423         break;
 424     case 0x1b:
 425         DPRINTF("Start Stop Unit\n");
 426         break;
 427     case 0x1e:
 428         DPRINTF("Prevent Allow Medium Removal (prevent = %d)\n", buf[4] & 3);
 429         bdrv_set_locked(s->bdrv, buf[4] & 1);
 430         break;
 431     case 0x25:
 432         DPRINTF("Read Capacity\n");
 433         /* The normal LEN field for this command is zero.  */
 434         memset(s->buf, 0, 8);
 435         bdrv_get_geometry(s->bdrv, &nb_sectors);
 436         /* Returned value is the address of the last sector.  */
 437         if (nb_sectors) {
 438             nb_sectors--;
 439             s->buf[0] = (nb_sectors >> 24) & 0xff;
 440             s->buf[1] = (nb_sectors >> 16) & 0xff;
 441             s->buf[2] = (nb_sectors >> 8) & 0xff;
 442             s->buf[3] = nb_sectors & 0xff;
 443             s->buf[4] = 0;
 444             s->buf[5] = 0;
 445             s->buf[6] = s->cluster_size * 2;
 446             s->buf[7] = 0;
 447             s->buf_len = 8;
 448         } else {
 449             scsi_command_complete(s, SENSE_NOT_READY);
 450         }
 451         break;
 452     case 0x08:
 453     case 0x28:
 454         DPRINTF("Read (sector %d, count %d)\n", lba, len);
 455         s->sector = lba * s->cluster_size;
 456         s->sector_count = len * s->cluster_size;
 457         break;
 458     case 0x0a:
 459     case 0x2a:
 460         DPRINTF("Write (sector %d, count %d)\n", lba, len);
 461         s->sector = lba * s->cluster_size;
 462         s->sector_count = len * s->cluster_size;
 463         is_write = 1;
 464         break;
 465     case 0x35:
 466         DPRINTF("Syncronise cache (sector %d, count %d)\n", lba, len);
 467         bdrv_flush(s->bdrv);
 468         break;
 469     case 0x43:
 470         {
 471             int start_track, format, msf, toclen;
 472
 473             msf = buf[1] & 2;
 474             format = buf[2] & 0xf;
 475             start_track = buf[6];
 476             bdrv_get_geometry(s->bdrv, &nb_sectors);
 477             DPRINTF("Read TOC (track %d format %d msf %d)\n", start_track, format, msf >> 1);
 478             switch(format) {
 479             case 0:
 480                 toclen = cdrom_read_toc(nb_sectors, s->buf, msf, start_track);
 481                 break;
 482             case 1:
 483                 /* multi session : only a single session defined */
 484                 toclen = 12;
 485                 memset(s->buf, 0, 12);
 486                 s->buf[1] = 0x0a;
 487                 s->buf[2] = 0x01;
 488                 s->buf[3] = 0x01;
 489                 break;
 490             case 2:
 491                 toclen = cdrom_read_toc_raw(nb_sectors, s->buf, msf, start_track);
 492                 break;
 493             default:
 494                 goto error_cmd;
 495             }
 496             if (toclen > 0) {
 497                 if (len > toclen)
 498                   len = toclen;
 499                 s->buf_len = len;
 500                 break;
 501             }
 502         error_cmd:
 503             DPRINTF("Read TOC error\n");
 504             goto fail;
 505         }
 506     case 0x46:
 507         DPRINTF("Get Configuration (rt %d, maxlen %d)\n", buf[1] & 3, len);
 508         memset(s->buf, 0, 8);
 509         /* ??? This shoud probably return much more information.  For now
 510            just return the basic header indicating the CD-ROM profile.  */
 511         s->buf[7] = 8; // CD-ROM
 512         s->buf_len = 8;
 513         break;
 514     case 0x56:
 515         DPRINTF("Reserve(10)\n");
 516         if (buf[1] & 3)
 517             goto fail;
 518         break;
 519     case 0x57:
 520         DPRINTF("Release(10)\n");
 521         if (buf[1] & 3)
 522             goto fail;
 523         break;
 524     case 0xa0:
 525         DPRINTF("Report LUNs (len %d)\n", len);
 526         if (len < 16)
 527             goto fail;
 528         memset(s->buf, 0, 16);
 529         s->buf[3] = 8;
 530         s->buf_len = 16;
 531         break;
 532     default:
 533         DPRINTF("Unknown SCSI command (%2.2x)\n", buf[0]);
 534     fail:
 535         scsi_command_complete(s, SENSE_ILLEGAL_REQUEST);
 536         return 0;
 537     }
 538     if (s->sector_count == 0 && s->buf_len == 0) {
 539         scsi_command_complete(s, SENSE_NO_SENSE);
 540     }
 541     len = s->sector_count * 512 + s->buf_len;
 542     return is_write ? -len : len;
 543 }
 544
 545 void scsi_disk_destroy(SCSIDevice *s)
 546 {
 547     bdrv_close(s->bdrv);
 548     qemu_free(s);
 549 }
 550
 551 SCSIDevice *scsi_disk_init(BlockDriverState *bdrv,
 552                            scsi_completionfn completion,
 553                            void *opaque)
 554 {
 555     SCSIDevice *s;
 556
 557     s = (SCSIDevice *)qemu_mallocz(sizeof(SCSIDevice));
 558     s->bdrv = bdrv;
 559     s->completion = completion;
 560     s->opaque = opaque;
 561     if (bdrv_get_type_hint(s->bdrv) == BDRV_TYPE_CDROM) {
 562         s->cluster_size = 4;
 563     } else {
 564         s->cluster_size = 1;
 565     }
 566
 567     return s;
 568 }
 569