scsi: Update sense code handling

The SCSI spec has a quite detailed list of sense codes available.
It even mandates the use of specific ones for some failure cases.
The current implementation just has one type of generic error
which is actually a violation of the spec in certain cases.
This patch introduces various predefined sense codes to have the
sense code reporting more in line with the spec.

On top of Hannes's patch I fixed the reply to REQUEST SENSE commands
with DESC=0 and a small (<18) length.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 39 insertions, 43 deletions

diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 08633db..63aa8f1 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -49,10 +49,6 @@ do { fprintf(stderr, "scsi-disk: " fmt , ## __VA_ARGS__); } while (0)
 
 typedef struct SCSIDiskState SCSIDiskState;
 
-typedef struct SCSISense {
-    uint8_t key;
-} SCSISense;
-
 typedef struct SCSIDiskReq {
     SCSIRequest req;
     /* ??? We should probably keep track of whether the data transfer is
@@ -111,24 +107,19 @@ static void scsi_disk_clear_sense(SCSIDiskState *s)
     memset(&s->sense, 0, sizeof(s->sense));
 }
 
-static void scsi_disk_set_sense(SCSIDiskState *s, uint8_t key)
-{
-    s->sense.key = key;
-}
-
-static void scsi_req_set_status(SCSIDiskReq *r, int status, int sense_code)
+static void scsi_req_set_status(SCSIDiskReq *r, int status, SCSISense sense)
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
 
     r->req.status = status;
-    scsi_disk_set_sense(s, sense_code);
+    s->sense = sense;
 }
 
 /* Helper function for command completion.  */
-static void scsi_command_complete(SCSIDiskReq *r, int status, int sense)
+static void scsi_command_complete(SCSIDiskReq *r, int status, SCSISense sense)
 {
-    DPRINTF("Command complete tag=0x%x status=%d sense=%d\n",
-            r->req.tag, status, sense);
+    DPRINTF("Command complete tag=0x%x status=%d sense=%d/%d/%d\n",
+            r->req.tag, status, sense.key, sense.asc, sense.ascq);
     scsi_req_set_status(r, status, sense);
     scsi_req_complete(&r->req);
 }
@@ -182,7 +173,7 @@ static void scsi_read_data(SCSIRequest *req)
     }
     DPRINTF("Read sector_count=%d\n", r->sector_count);
     if (r->sector_count == 0) {
-        scsi_command_complete(r, GOOD, NO_SENSE);
+        scsi_command_complete(r, GOOD, SENSE_CODE(NO_SENSE));
         return;
     }
 
@@ -225,8 +216,13 @@ static int scsi_handle_rw_error(SCSIDiskReq *r, int error, int type)
         if (type == SCSI_REQ_STATUS_RETRY_READ) {
             scsi_req_data(&r->req, 0);
         }
-        scsi_command_complete(r, CHECK_CONDITION,
-                HARDWARE_ERROR);
+        if (error == ENOMEM) {
+            scsi_command_complete(r, CHECK_CONDITION,
+                                  SENSE_CODE(TARGET_FAILURE));
+        } else {
+            scsi_command_complete(r, CHECK_CONDITION,
+                                  SENSE_CODE(IO_ERROR));
+        }
         bdrv_mon_event(s->bs, BDRV_ACTION_REPORT, is_read);
     }
 
@@ -251,7 +247,7 @@ static void scsi_write_complete(void * opaque, int ret)
     r->sector += n;
     r->sector_count -= n;
     if (r->sector_count == 0) {
-        scsi_command_complete(r, GOOD, NO_SENSE);
+        scsi_command_complete(r, GOOD, SENSE_CODE(NO_SENSE));
     } else {
         len = r->sector_count * 512;
         if (len > SCSI_DMA_BUF_SIZE) {
@@ -278,7 +274,7 @@ static int scsi_write_data(SCSIRequest *req)
         r->req.aiocb = bdrv_aio_writev(s->bs, r->sector, &r->qiov, n,
                                    scsi_write_complete, r);
         if (r->req.aiocb == NULL) {
-            scsi_write_complete(r, -EIO);
+            scsi_write_complete(r, -ENOMEM);
         }
     } else {
         /* Invoke completion routine to fetch data from host.  */
@@ -316,7 +312,7 @@ static void scsi_dma_restart_bh(void *opaque)
             case SCSI_REQ_STATUS_RETRY_FLUSH:
                 ret = scsi_disk_emulate_command(r, r->iov.iov_base);
                 if (ret == 0) {
-                    scsi_command_complete(r, GOOD, NO_SENSE);
+                    scsi_command_complete(r, GOOD, SENSE_CODE(NO_SENSE));
                 }
             }
         }
@@ -815,19 +811,8 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
     case REQUEST_SENSE:
         if (req->cmd.xfer < 4)
             goto illegal_request;
-        memset(outbuf, 0, 4);
-        buflen = 4;
-        if (s->sense.key == NOT_READY && req->cmd.xfer >= 18) {
-            memset(outbuf, 0, 18);
-            buflen = 18;
-            outbuf[7] = 10;
-            /* asc 0x3a, ascq 0: Medium not present */
-            outbuf[12] = 0x3a;
-            outbuf[13] = 0;
-        }
-        outbuf[0] = 0xf0;
-        outbuf[1] = 0;
-        outbuf[2] = s->sense.key;
+        buflen = scsi_build_sense(s->sense, outbuf, req->cmd.xfer,
+                                  req->cmd.xfer > 13);
         scsi_disk_clear_sense(s);
         break;
     case INQUIRY:
@@ -965,17 +950,22 @@ static int scsi_disk_emulate_command(SCSIDiskReq *r, uint8_t *outbuf)
         }
         break;
     default:
-        goto illegal_request;
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(INVALID_OPCODE));
+        return -1;
     }
-    scsi_req_set_status(r, GOOD, NO_SENSE);
+    scsi_req_set_status(r, GOOD, SENSE_CODE(NO_SENSE));
     return buflen;
 
 not_ready:
-    scsi_command_complete(r, CHECK_CONDITION, NOT_READY);
+    if (!bdrv_is_inserted(s->bs)) {
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(NO_MEDIUM));
+    } else {
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(LUN_NOT_READY));
+    }
     return -1;
 
 illegal_request:
-    scsi_command_complete(r, CHECK_CONDITION, ILLEGAL_REQUEST);
+    scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(INVALID_FIELD));
     return -1;
 }
 
@@ -1002,7 +992,8 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
 
     if (scsi_req_parse(&r->req, buf) != 0) {
         BADF("Unsupported command length, command %x\n", command);
-        goto fail;
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(INVALID_OPCODE));
+        return 0;
     }
 #ifdef DEBUG_SCSI
     {
@@ -1017,8 +1008,11 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
     if (req->lun || buf[1] >> 5) {
         /* Only LUN 0 supported.  */
         DPRINTF("Unimplemented LUN %d\n", req->lun ? req->lun : buf[1] >> 5);
-        if (command != REQUEST_SENSE && command != INQUIRY)
-            goto fail;
+        if (command != REQUEST_SENSE && command != INQUIRY) {
+            scsi_command_complete(r, CHECK_CONDITION,
+                                  SENSE_CODE(LUN_NOT_SUPPORTED));
+            return 0;
+        }
     }
     switch (command) {
     case TEST_UNIT_READY:
@@ -1126,15 +1120,17 @@ static int32_t scsi_send_command(SCSIRequest *req, uint8_t *buf)
         break;
     default:
         DPRINTF("Unknown SCSI command (%2.2x)\n", buf[0]);
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(INVALID_OPCODE));
+        return 0;
     fail:
-        scsi_command_complete(r, CHECK_CONDITION, ILLEGAL_REQUEST);
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(INVALID_FIELD));
         return 0;
     illegal_lba:
-        scsi_command_complete(r, CHECK_CONDITION, HARDWARE_ERROR);
+        scsi_command_complete(r, CHECK_CONDITION, SENSE_CODE(LBA_OUT_OF_RANGE));
         return 0;
     }
     if (r->sector_count == 0 && r->iov.iov_len == 0) {
-        scsi_command_complete(r, GOOD, NO_SENSE);
+        scsi_command_complete(r, GOOD, SENSE_CODE(NO_SENSE));
     }
     len = r->sector_count * 512 + r->iov.iov_len;
     if (is_write) {