scsi: fix parsing of allocation length field

- several MMC commands were parsed wrong by QEMU because their allocation
length/parameter list length is placed in a non-standard position in
the CDB (i.e. it is different from most commands with the same value in
bits 5-7).

- SEND VOLUME TAG length was multiplied by 40 which is not in SMC.  The
parameter list length is between 32 and 40 bytes.  Same for MEDIUM SCAN
(spec found at http://ldkelley.com/SCSI2/SCSI2-16.html but not in any of
the PDFs I have here).

- READ_POSITION (SSC) conflicts with PRE_FETCH (SBC).  READ_POSITION's
transfer length is not hardcoded to 20 in SSC; for PRE_FETCH cmd->xfer
should be 0.  Both fixed.

- FORMAT MEDIUM (the SSC name for FORMAT UNIT) was missing.  The FORMAT
UNIT command is still somewhat broken for block devices because its
parameter list length is not in the CDB.  However it works for CD/DVD
drives, which mandate the length of the payload.

- fixed wrong sign-extensions for 32-bit fields (for the LBA field,
this affects disks >1 TB).

- several other SBC or SSC commands were missing or parsed wrong.

- some commands were not in the list of "write" commands.

Reported-by: Thomas Schmitt <scdbackup@gmx.net>
Tested-by: Thomas Schmitt <scdbackup@gmx.net> (MMC bits only)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 87 insertions, 10 deletions

diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 7efcbd83fc..4d9ff35fd8 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -649,6 +649,31 @@ 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 +691,11 @@ 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:
@@ -683,6 +708,7 @@ static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
     case START_STOP:
     case SET_CAPACITY:
     case WRITE_FILEMARKS:
+    case WRITE_FILEMARKS_16:
     case SPACE:
     case RESERVE:
     case RELEASE:
@@ -691,6 +717,8 @@ 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 +726,11 @@ 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 +744,13 @@ 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 +769,39 @@ 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 +817,10 @@ 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 +836,15 @@ 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 +884,8 @@ 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 +912,7 @@ 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]);