Merge remote-tracking branch 'kwolf/block-stable' into staging

5 files changed, 153 insertions, 44 deletions

diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 1fed359ab1..8af1cfdd7e 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -695,12 +695,7 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
     int action, code;
     int max_len;
 
-    if (buf[0] == GPCMD_MODE_SENSE_10) {
-        max_len = ube16_to_cpu(buf + 7);
-    } else {
-        max_len = buf[4];
-    }
-
+    max_len = ube16_to_cpu(buf + 7);
     action = buf[2] >> 6;
     code = buf[2] & 0x3f;
 
@@ -708,7 +703,7 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
     case 0: /* current values */
         switch(code) {
         case MODE_PAGE_R_W_ERROR: /* error recovery */
-            cpu_to_ube16(&buf[0], 16 + 6);
+            cpu_to_ube16(&buf[0], 16 - 2);
             buf[2] = 0x70;
             buf[3] = 0;
             buf[4] = 0;
@@ -727,7 +722,7 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
             ide_atapi_cmd_reply(s, 16, max_len);
             break;
         case MODE_PAGE_AUDIO_CTL:
-            cpu_to_ube16(&buf[0], 24 + 6);
+            cpu_to_ube16(&buf[0], 24 - 2);
             buf[2] = 0x70;
             buf[3] = 0;
             buf[4] = 0;
@@ -746,7 +741,7 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
             ide_atapi_cmd_reply(s, 24, max_len);
             break;
         case MODE_PAGE_CAPABILITIES:
-            cpu_to_ube16(&buf[0], 28 + 6);
+            cpu_to_ube16(&buf[0], 30 - 2);
             buf[2] = 0x70;
             buf[3] = 0;
             buf[4] = 0;
@@ -755,7 +750,7 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
             buf[7] = 0;
 
             buf[8] = MODE_PAGE_CAPABILITIES;
-            buf[9] = 28 - 10;
+            buf[9] = 30 - 10;
             buf[10] = 0x3b; /* read CDR/CDRW/DVDROM/DVDR/DVDRAM */
             buf[11] = 0x00;
 
@@ -777,7 +772,9 @@ static void cmd_mode_sense(IDEState *s, uint8_t *buf)
             buf[25] = 0;
             buf[26] = 0;
             buf[27] = 0;
-            ide_atapi_cmd_reply(s, 28, max_len);
+            buf[28] = 0;
+            buf[29] = 0;
+            ide_atapi_cmd_reply(s, 30, max_len);
             break;
         default:
             goto error_cmd;
@@ -1043,7 +1040,6 @@ static const struct {
     [ 0x00 ] = { cmd_test_unit_ready,               CHECK_READY },
     [ 0x03 ] = { cmd_request_sense,                 ALLOW_UA },
     [ 0x12 ] = { cmd_inquiry,                       ALLOW_UA },
-    [ 0x1a ] = { cmd_mode_sense, /* (6) */          0 },
     [ 0x1b ] = { cmd_start_stop_unit,               0 }, /* [1] */
     [ 0x1e ] = { cmd_prevent_allow_medium_removal,  0 },
     [ 0x25 ] = { cmd_read_cdvd_capacity,            CHECK_READY },
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index e6ebbd594e..3a2a7bb72c 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -9,8 +9,6 @@
 static char *scsibus_get_fw_dev_path(DeviceState *dev);
 static int scsi_req_parse(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf);
 static void scsi_req_dequeue(SCSIRequest *req);
-static int scsi_build_sense(uint8_t *in_buf, int in_len,
-                            uint8_t *buf, int len, bool fixed);
 
 static struct BusInfo scsi_bus_info = {
     .name  = "SCSI",
@@ -502,7 +500,7 @@ SCSIRequest *scsi_req_new(SCSIDevice *d, uint32_t tag, uint32_t lun,
                                  hba_private);
         } else if (lun != d->lun ||
             buf[0] == REPORT_LUNS ||
-            buf[0] == REQUEST_SENSE) {
+            (buf[0] == REQUEST_SENSE && (d->sense_len || cmd.xfer < 4))) {
             req = scsi_req_alloc(&reqops_target_command, d, tag, lun,
                                  hba_private);
         } else {
@@ -649,6 +647,31 @@ static void scsi_req_dequeue(SCSIRequest *req)
     }
 }
 
+static int scsi_get_performance_length(int num_desc, int type, int data_type)
+{
+    /* MMC-6, paragraph 6.7.  */
+    switch (type) {
+    case 0:
+        if ((data_type & 3) == 0) {
+            /* Each descriptor is as in Table 295 - Nominal performance.  */
+            return 16 * num_desc + 8;
+        } else {
+            /* Each descriptor is as in Table 296 - Exceptions.  */
+            return 6 * num_desc + 8;
+        }
+    case 1:
+    case 4:
+    case 5:
+        return 8 * num_desc + 8;
+    case 2:
+        return 2048 * num_desc + 8;
+    case 3:
+        return 16 * num_desc + 8;
+    default:
+        return 8;
+    }
+}
+
 static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
 {
     switch (buf[0] >> 5) {
@@ -666,11 +689,11 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
         cmd->len = 10;
         break;
     case 4:
-        cmd->xfer = ldl_be_p(&buf[10]);
+        cmd->xfer = ldl_be_p(&buf[10]) & 0xffffffffULL;
         cmd->len = 16;
         break;
     case 5:
-        cmd->xfer = ldl_be_p(&buf[6]);
+        cmd->xfer = ldl_be_p(&buf[6]) & 0xffffffffULL;
         cmd->len = 12;
         break;
     default:
@@ -681,8 +704,9 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case TEST_UNIT_READY:
     case REWIND:
     case START_STOP:
-    case SEEK_6:
+    case SET_CAPACITY:
     case WRITE_FILEMARKS:
+    case WRITE_FILEMARKS_16:
     case SPACE:
     case RESERVE:
     case RELEASE:
@@ -691,6 +715,8 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case VERIFY_10:
     case SEEK_10:
     case SYNCHRONIZE_CACHE:
+    case SYNCHRONIZE_CACHE_16:
+    case LOCATE_16:
     case LOCK_UNLOCK_CACHE:
     case LOAD_UNLOAD:
     case SET_CD_SPEED:
@@ -698,6 +724,11 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case WRITE_LONG_10:
     case MOVE_MEDIUM:
     case UPDATE_BLOCK:
+    case RESERVE_TRACK:
+    case SET_READ_AHEAD:
+    case PRE_FETCH:
+    case PRE_FETCH_16:
+    case ALLOW_OVERWRITE:
         cmd->xfer = 0;
         break;
     case MODE_SENSE:
@@ -711,14 +742,13 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case READ_BLOCK_LIMITS:
         cmd->xfer = 6;
         break;
-    case READ_POSITION:
-        cmd->xfer = 20;
-        break;
     case SEND_VOLUME_TAG:
-        cmd->xfer *= 40;
-        break;
-    case MEDIUM_SCAN:
-        cmd->xfer *= 8;
+        /* GPCMD_SET_STREAMING from multimedia commands.  */
+        if (dev->type == TYPE_ROM) {
+            cmd->xfer = buf[10] | (buf[9] << 8);
+        } else {
+            cmd->xfer = buf[9] | (buf[8] << 8);
+        }
         break;
     case WRITE_10:
     case WRITE_VERIFY_10:
@@ -737,9 +767,39 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case READ_16:
         cmd->xfer *= dev->blocksize;
         break;
+    case FORMAT_UNIT:
+        /* MMC mandates the parameter list to be 12-bytes long.  Parameters
+         * for block devices are restricted to the header right now.  */
+        if (dev->type == TYPE_ROM && (buf[1] & 16)) {
+            cmd->xfer = 12;
+        } else {
+            cmd->xfer = (buf[1] & 16) == 0 ? 0 : (buf[1] & 32 ? 8 : 4);
+        }
+        break;
     case INQUIRY:
+    case RECEIVE_DIAGNOSTIC:
+    case SEND_DIAGNOSTIC:
         cmd->xfer = buf[4] | (buf[3] << 8);
         break;
+    case READ_CD:
+    case READ_BUFFER:
+    case WRITE_BUFFER:
+    case SEND_CUE_SHEET:
+        cmd->xfer = buf[8] | (buf[7] << 8) | (buf[6] << 16);
+        break;
+    case PERSISTENT_RESERVE_OUT:
+        cmd->xfer = ldl_be_p(&buf[5]) & 0xffffffffULL;
+        break;
+    case ERASE_12:
+        if (dev->type == TYPE_ROM) {
+            /* MMC command GET PERFORMANCE.  */
+            cmd->xfer = scsi_get_performance_length(buf[9] | (buf[8] << 8),
+                                                    buf[10], buf[1] & 0x1f);
+        }
+        break;
+    case MECHANISM_STATUS:
+    case READ_DVD_STRUCTURE:
+    case SEND_DVD_STRUCTURE:
     case MAINTENANCE_OUT:
     case MAINTENANCE_IN:
         if (dev->type == TYPE_ROM) {
@@ -755,6 +815,10 @@ static int scsi_req_stream_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *bu
 {
     switch (buf[0]) {
     /* stream commands */
+    case ERASE_12:
+    case ERASE_16:
+        cmd->xfer = 0;
+        break;
     case READ_6:
     case READ_REVERSE:
     case RECOVER_BUFFERED_DATA:
@@ -770,6 +834,15 @@ static int scsi_req_stream_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *bu
         cmd->len = 6;
         cmd->xfer = 0;
         break;
+    case SPACE_16:
+        cmd->xfer = buf[13] | (buf[12] << 8);
+        break;
+    case READ_POSITION:
+        cmd->xfer = buf[8] | (buf[7] << 8);
+        break;
+    case FORMAT_UNIT:
+        cmd->xfer = buf[4] | (buf[3] << 8);
+        break;
     /* generic commands */
     default:
         return scsi_req_length(cmd, dev, buf);
@@ -809,6 +882,8 @@ static void scsi_cmd_xfer_mode(SCSICommand *cmd)
     case SEARCH_LOW_12:
     case MEDIUM_SCAN:
     case SEND_VOLUME_TAG:
+    case SEND_CUE_SHEET:
+    case SEND_DVD_STRUCTURE:
     case PERSISTENT_RESERVE_OUT:
     case MAINTENANCE_OUT:
         cmd->mode = SCSI_XFER_TO_DEV;
@@ -835,7 +910,7 @@ static uint64_t scsi_cmd_lba(SCSICommand *cmd)
     case 1:
     case 2:
     case 5:
-        lba = ldl_be_p(&buf[2]);
+        lba = ldl_be_p(&buf[2]) & 0xffffffffULL;
         break;
     case 4:
         lba = ldq_be_p(&buf[2]);
@@ -1036,7 +1111,7 @@ static const char *scsi_command_name(uint8_t cmd)
         [ REASSIGN_BLOCKS          ] = "REASSIGN_BLOCKS",
         [ READ_6                   ] = "READ_6",
         [ WRITE_6                  ] = "WRITE_6",
-        [ SEEK_6                   ] = "SEEK_6",
+        [ SET_CAPACITY             ] = "SET_CAPACITY",
         [ READ_REVERSE             ] = "READ_REVERSE",
         [ WRITE_FILEMARKS          ] = "WRITE_FILEMARKS",
         [ SPACE                    ] = "SPACE",
@@ -1064,7 +1139,7 @@ static const char *scsi_command_name(uint8_t cmd)
         [ SEARCH_EQUAL             ] = "SEARCH_EQUAL",
         [ SEARCH_LOW               ] = "SEARCH_LOW",
         [ SET_LIMITS               ] = "SET_LIMITS",
-        [ PRE_FETCH                ] = "PRE_FETCH",
+        [ PRE_FETCH                ] = "PRE_FETCH/READ_POSITION",
         /* READ_POSITION and PRE_FETCH use the same operation code */
         [ SYNCHRONIZE_CACHE        ] = "SYNCHRONIZE_CACHE",
         [ LOCK_UNLOCK_CACHE        ] = "LOCK_UNLOCK_CACHE",
@@ -1101,9 +1176,11 @@ static const char *scsi_command_name(uint8_t cmd)
         [ WRITE_16                 ] = "WRITE_16",
         [ WRITE_VERIFY_16          ] = "WRITE_VERIFY_16",
         [ VERIFY_16                ] = "VERIFY_16",
-        [ SYNCHRONIZE_CACHE_16     ] = "SYNCHRONIZE_CACHE_16",
+        [ PRE_FETCH_16             ] = "PRE_FETCH_16",
+        [ SYNCHRONIZE_CACHE_16     ] = "SPACE_16/SYNCHRONIZE_CACHE_16",
+        /* SPACE_16 and SYNCHRONIZE_CACHE_16 use the same operation code */
         [ LOCATE_16                ] = "LOCATE_16",
-        [ WRITE_SAME_16            ] = "WRITE_SAME_16",
+        [ WRITE_SAME_16            ] = "ERASE_16/WRITE_SAME_16",
         /* ERASE_16 and WRITE_SAME_16 use the same operation code */
         [ SERVICE_ACTION_IN_16     ] = "SERVICE_ACTION_IN_16",
         [ WRITE_LONG_16            ] = "WRITE_LONG_16",
@@ -1113,6 +1190,8 @@ static const char *scsi_command_name(uint8_t cmd)
         [ LOAD_UNLOAD              ] = "LOAD_UNLOAD",
         [ READ_12                  ] = "READ_12",
         [ WRITE_12                 ] = "WRITE_12",
+        [ ERASE_12                 ] = "ERASE_12/GET_PERFORMANCE",
+        /* ERASE_12 and GET_PERFORMANCE use the same operation code */
         [ SERVICE_ACTION_IN_12     ] = "SERVICE_ACTION_IN_12",
         [ WRITE_VERIFY_12          ] = "WRITE_VERIFY_12",
         [ VERIFY_12                ] = "VERIFY_12",
@@ -1120,9 +1199,18 @@ static const char *scsi_command_name(uint8_t cmd)
         [ SEARCH_EQUAL_12          ] = "SEARCH_EQUAL_12",
         [ SEARCH_LOW_12            ] = "SEARCH_LOW_12",
         [ READ_ELEMENT_STATUS      ] = "READ_ELEMENT_STATUS",
-        [ SEND_VOLUME_TAG          ] = "SEND_VOLUME_TAG",
+        [ SEND_VOLUME_TAG          ] = "SEND_VOLUME_TAG/SET_STREAMING",
+        /* SEND_VOLUME_TAG and SET_STREAMING use the same operation code */
+        [ READ_CD                  ] = "READ_CD",
         [ READ_DEFECT_DATA_12      ] = "READ_DEFECT_DATA_12",
+        [ READ_DVD_STRUCTURE       ] = "READ_DVD_STRUCTURE",
+        [ RESERVE_TRACK            ] = "RESERVE_TRACK",
+        [ SEND_CUE_SHEET           ] = "SEND_CUE_SHEET",
+        [ SEND_DVD_STRUCTURE       ] = "SEND_DVD_STRUCTURE",
         [ SET_CD_SPEED             ] = "SET_CD_SPEED",
+        [ SET_READ_AHEAD           ] = "SET_READ_AHEAD",
+        [ ALLOW_OVERWRITE          ] = "ALLOW_OVERWRITE",
+        [ MECHANISM_STATUS         ] = "MECHANISM_STATUS",
     };
 
     if (cmd >= ARRAY_SIZE(names) || names[cmd] == NULL)
@@ -1279,7 +1367,7 @@ static char *scsibus_get_fw_dev_path(DeviceState *dev)
     SCSIDevice *d = DO_UPCAST(SCSIDevice, qdev, dev);
     char path[100];
 
-    snprintf(path, sizeof(path), "%s@%d:%d:%d", qdev_fw_name(dev),
+    snprintf(path, sizeof(path), "%s@%d,%d,%d", qdev_fw_name(dev),
              d->channel, d->id, d->lun);
 
     return strdup(path);
diff --git a/hw/scsi-defs.h b/hw/scsi-defs.h
index d0a467aab7..354ed7b55b 100644
--- a/hw/scsi-defs.h
+++ b/hw/scsi-defs.h
@@ -32,7 +32,7 @@
 #define REASSIGN_BLOCKS       0x07
 #define READ_6                0x08
 #define WRITE_6               0x0a
-#define SEEK_6                0x0b
+#define SET_CAPACITY          0x0b
 #define READ_REVERSE          0x0f
 #define WRITE_FILEMARKS       0x10
 #define SPACE                 0x11
@@ -81,14 +81,17 @@
 #define GET_EVENT_STATUS_NOTIFICATION 0x4a
 #define LOG_SELECT            0x4c
 #define LOG_SENSE             0x4d
+#define RESERVE_TRACK         0x53
 #define MODE_SELECT_10        0x55
 #define RESERVE_10            0x56
 #define RELEASE_10            0x57
 #define MODE_SENSE_10         0x5a
+#define SEND_CUE_SHEET        0x5d
 #define PERSISTENT_RESERVE_IN 0x5e
 #define PERSISTENT_RESERVE_OUT 0x5f
 #define VARLENGTH_CDB         0x7f
 #define WRITE_FILEMARKS_16    0x80
+#define ALLOW_OVERWRITE       0x82
 #define EXTENDED_COPY         0x83
 #define ATA_PASSTHROUGH       0x85
 #define ACCESS_CONTROL_IN     0x86
@@ -98,6 +101,8 @@
 #define WRITE_16              0x8a
 #define WRITE_VERIFY_16       0x8e
 #define VERIFY_16             0x8f
+#define PRE_FETCH_16          0x90
+#define SPACE_16              0x91
 #define SYNCHRONIZE_CACHE_16  0x91
 #define LOCATE_16             0x92
 #define WRITE_SAME_16         0x93
@@ -110,9 +115,11 @@
 #define MAINTENANCE_OUT       0xa4
 #define MOVE_MEDIUM           0xa5
 #define LOAD_UNLOAD           0xa6
+#define SET_READ_AHEAD        0xa7
 #define READ_12               0xa8
 #define WRITE_12              0xaa
 #define SERVICE_ACTION_IN_12  0xab
+#define ERASE_12              0xac
 #define READ_DVD_STRUCTURE    0xad
 #define WRITE_VERIFY_12       0xae
 #define VERIFY_12             0xaf
@@ -125,6 +132,7 @@
 #define SET_CD_SPEED          0xbb
 #define MECHANISM_STATUS      0xbd
 #define READ_CD               0xbe
+#define SEND_DVD_STRUCTURE    0xbf
 
 /*
  * SERVICE ACTION IN subcodes
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 62f538f4f8..673948c51f 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -797,7 +797,7 @@ static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
             break;
         }
         /* if a geometry hint is available, use it */
-        bdrv_get_geometry_hint(bdrv, &cylinders, &heads, &secs);
+        bdrv_guess_geometry(bdrv, &cylinders, &heads, &secs);
         p[2] = (cylinders >> 16) & 0xff;
         p[3] = (cylinders >> 8) & 0xff;
         p[4] = cylinders & 0xff;
@@ -831,7 +831,7 @@ static int mode_sense_page(SCSIDiskState *s, int page, uint8_t **p_outbuf,
         p[2] = 5000 >> 8;
         p[3] = 5000 & 0xff;
         /* if a geometry hint is available, use it */
-        bdrv_get_geometry_hint(bdrv, &cylinders, &heads, &secs);
+        bdrv_guess_geometry(bdrv, &cylinders, &heads, &secs);
         p[4] = heads & 0xff;
         p[5] = secs & 0xff;
         p[6] = s->qdev.blocksize >> 8;
@@ -956,8 +956,9 @@ static int scsi_disk_emulate_mode_sense(SCSIDiskReq *r, uint8_t *outbuf)
         p += 8;
     }
 
+    /* MMC prescribes that CD/DVD drives have no block descriptors.  */
     bdrv_get_geometry(s->qdev.conf.bs, &nb_sectors);
-    if (!dbd && nb_sectors) {
+    if (!dbd && s->qdev.type == TYPE_DISK && nb_sectors) {
         if (r->req.cmd.buf[0] == MODE_SENSE) {
             outbuf[3] = 8; /* Block descriptor length  */
         } else { /* MODE_SENSE_10 */
@@ -1178,6 +1179,11 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r)
         outbuf[7] = 0;
         buflen = 8;
         break;
+    case REQUEST_SENSE:
+        /* Just return "NO SENSE".  */
+        buflen = scsi_build_sense(NULL, 0, outbuf, r->buflen,
+                                  (req->cmd.buf[1] & 1) == 0);
+        break;
     case MECHANISM_STATUS:
         buflen = scsi_emulate_mechanism_status(s, outbuf);
         if (buflen < 0) {
@@ -1312,6 +1318,7 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
     case GET_EVENT_STATUS_NOTIFICATION:
     case MECHANISM_STATUS:
     case SERVICE_ACTION_IN_16:
+    case REQUEST_SENSE:
     case VERIFY_10:
         rc = scsi_disk_emulate_command(r);
         if (rc < 0) {
@@ -1374,10 +1381,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
             goto fail;
         }
         break;
-    case SEEK_6:
     case SEEK_10:
-        DPRINTF("Seek(%d) (sector %" PRId64 ")\n", command == SEEK_6 ? 6 : 10,
-                r->req.cmd.lba);
+        DPRINTF("Seek(10) (sector %" PRId64 ")\n", r->req.cmd.lba);
         if (r->req.cmd.lba > s->qdev.max_lba) {
             goto illegal_lba;
         }
@@ -1408,8 +1413,6 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
         }
 
         break;
-    case REQUEST_SENSE:
-        abort();
     default:
         DPRINTF("Unknown SCSI command (%2.2x)\n", buf[0]);
         scsi_check_condition(r, SENSE_CODE(INVALID_OPCODE));
@@ -1553,7 +1556,7 @@ static int scsi_initfn(SCSIDevice *dev)
     bdrv_set_buffer_alignment(s->qdev.conf.bs, s->qdev.blocksize);
 
     bdrv_iostatus_enable(s->qdev.conf.bs);
-    add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, ",0");
+    add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, NULL);
     return 0;
 }
 
@@ -1700,8 +1703,20 @@ static SCSIRequest *scsi_block_new_request(SCSIDevice *d, uint32_t tag,
     case WRITE_VERIFY_10:
     case WRITE_VERIFY_12:
     case WRITE_VERIFY_16:
-        return scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun,
-                              hba_private);
+        /* 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_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 scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun,
+                                  hba_private);
+        }
     }
 
     return scsi_req_alloc(&scsi_generic_req_ops, &s->qdev, tag, lun,
diff --git a/hw/scsi.h b/hw/scsi.h
index ff8fdd0962..61c64d5c72 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -179,6 +179,8 @@ extern const struct SCSISense sense_code_DEVICE_INTERNAL_RESET;
 #define SENSE_CODE(x) sense_code_ ## x
 
 int scsi_sense_valid(SCSISense sense);
+int scsi_build_sense(uint8_t *in_buf, int in_len,
+                     uint8_t *buf, int len, bool fixed);
 
 SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops, SCSIDevice *d,
                             uint32_t tag, uint32_t lun, void *hba_private);