scsi-bus: correct responses for INQUIRY and REQUEST SENSE

According to SPC-3 INQUIRY and REQUEST SENSE should return GOOD
even on unsupported LUNS.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Message-Id: <1503049022-14749-1-git-send-email-hare@suse.de>
Reported-by: Laszlo Ersek <lersek@redhat.com>
Fixes: ded6ddc5a7
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>

hw/scsi/scsi-bus.c

@@ -516,8 +516,10 @@ static size_t scsi_sense_len(SCSIRequest *req)
 static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
 {
     SCSITargetReq *r = DO_UPCAST(SCSITargetReq, req, req);
+    int fixed_sense = (req->cmd.buf[1] & 1) == 0;
 
-    if (req->lun != 0) {
+    if (req->lun != 0 &&
+        buf[0] != INQUIRY && buf[0] != REQUEST_SENSE) {
         scsi_req_build_sense(req, SENSE_CODE(LUN_NOT_SUPPORTED));
         scsi_req_complete(req, CHECK_CONDITION);
         return 0;
@@ -535,9 +537,28 @@ static int32_t scsi_target_send_command(SCSIRequest *req, uint8_t *buf)
         break;
     case REQUEST_SENSE:
         scsi_target_alloc_buf(&r->req, scsi_sense_len(req));
-        r->len = scsi_device_get_sense(r->req.dev, r->buf,
-                                       MIN(req->cmd.xfer, r->buf_len),
-                                       (req->cmd.buf[1] & 1) == 0);
+        if (req->lun != 0) {
+            const struct SCSISense sense = SENSE_CODE(LUN_NOT_SUPPORTED);
+
+            if (fixed_sense) {
+                r->buf[0] = 0x70;
+                r->buf[2] = sense.key;
+                r->buf[10] = 10;
+                r->buf[12] = sense.asc;
+                r->buf[13] = sense.ascq;
+                r->len = MIN(req->cmd.xfer, SCSI_SENSE_LEN);
+            } else {
+                r->buf[0] = 0x72;
+                r->buf[1] = sense.key;
+                r->buf[2] = sense.asc;
+                r->buf[3] = sense.ascq;
+                r->len = 8;
+            }
+        } else {
+            r->len = scsi_device_get_sense(r->req.dev, r->buf,
+                                           MIN(req->cmd.xfer, r->buf_len),
+                                           fixed_sense);
+        }
         if (r->req.dev->sense_is_ua) {
             scsi_device_unit_attention_reported(req->dev);
             r->req.dev->sense_len = 0;