unsigned int num, struct sdebug_dev_info * devip);
 static int resp_report_luns(struct scsi_cmnd * SCpnt,
                            struct sdebug_dev_info * devip);
+static int resp_xdwriteread(struct scsi_cmnd *scp, unsigned long long lba,
+                           unsigned int num, struct sdebug_dev_info *devip);
 static int fill_from_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                                 int arr_len);
 static int fetch_to_dev_buffer(struct scsi_cmnd * scp, unsigned char * arr,
                break;
        case WRITE_10:
        case READ_10:
+       case XDWRITEREAD_10:
                *lba = cmd[5] + (cmd[4] << 8) + (cmd[3] << 16) + (cmd[2] << 24);
                *num = cmd[8] + (cmd[7] << 8);
                break;
        case WRITE_BUFFER:
                errsts = check_readiness(SCpnt, 1, devip);
                break;
+       case XDWRITEREAD_10:
+               if (!scsi_bidi_cmnd(SCpnt)) {
+                       mk_sense_buffer(devip, ILLEGAL_REQUEST,
+                                       INVALID_FIELD_IN_CDB, 0);
+                       errsts = check_condition_result;
+                       break;
+               }
+
+               errsts = check_readiness(SCpnt, 0, devip);
+               if (errsts)
+                       break;
+               if (scsi_debug_fake_rw)
+                       break;
+               get_data_transfer_info(cmd, &lba, &num);
+               errsts = resp_read(SCpnt, lba, num, devip);
+               if (errsts)
+                       break;
+               errsts = resp_write(SCpnt, lba, num, devip);
+               if (errsts)
+                       break;
+               errsts = resp_xdwriteread(SCpnt, lba, num, devip);
+               break;
        default:
                if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
                        printk(KERN_INFO "scsi_debug: Opcode: 0x%x not "
                                    min((int)alloc_len, SDEBUG_RLUN_ARR_SZ));
 }
 
+static int resp_xdwriteread(struct scsi_cmnd *scp, unsigned long long lba,
+                           unsigned int num, struct sdebug_dev_info *devip)
+{
+       int i, j, ret = -1;
+       unsigned char *kaddr, *buf;
+       unsigned int offset;
+       struct scatterlist *sg;
+       struct scsi_data_buffer *sdb = scsi_in(scp);
+
+       /* better not to use temporary buffer. */
+       buf = kmalloc(scsi_bufflen(scp), GFP_ATOMIC);
+       if (!buf)
+               return ret;
+
+       offset = 0;
+       scsi_for_each_sg(scp, sg, scsi_sg_count(scp), i) {
+               kaddr = (unsigned char *)kmap_atomic(sg_page(sg), KM_USER0);
+               if (!kaddr)
+                       goto out;
+
+               memcpy(buf + offset, kaddr + sg->offset, sg->length);
+               offset += sg->length;
+               kunmap_atomic(kaddr, KM_USER0);
+       }
+
+       offset = 0;
+       for_each_sg(sdb->table.sgl, sg, sdb->table.nents, i) {
+               kaddr = (unsigned char *)kmap_atomic(sg_page(sg), KM_USER0);
+               if (!kaddr)
+                       goto out;
+
+               for (j = 0; j < sg->length; j++)
+                       *(kaddr + sg->offset + j) ^= *(buf + offset + j);
+
+               offset += sg->length;
+               kunmap_atomic(kaddr, KM_USER0);
+       }
+       ret = 0;
+out:
+       kfree(buf);
+
+       return ret;
+}
+
 /* When timer goes off this function is called. */
 static void timer_intr_handler(unsigned long indx)
 {
        if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
                printk(KERN_INFO "scsi_debug: slave_alloc <%u %u %u %u>\n",
                       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
+       set_bit(QUEUE_FLAG_BIDI, &sdp->request_queue->queue_flags);
        return 0;
 }