diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 248e9d4..390c78f 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -894,6 +894,7 @@
     }
 
     /* Look at the command. */
+    ccw_dstream_init(&sch->cds, &ccw, &(sch->orb));
     switch (ccw.cmd_code) {
     case CCW_CMD_NOOP:
         /* Nothing to do. */
@@ -907,8 +908,8 @@
             }
         }
         len = MIN(ccw.count, sizeof(sch->sense_data));
-        cpu_physical_memory_write(ccw.cda, sch->sense_data, len);
-        sch->curr_status.scsw.count = ccw.count - len;
+        ccw_dstream_write_buf(&sch->cds, sch->sense_data, len);
+        sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
         memset(sch->sense_data, 0, sizeof(sch->sense_data));
         ret = 0;
         break;
@@ -934,8 +935,8 @@
         } else {
             sense_id.reserved = 0;
         }
-        cpu_physical_memory_write(ccw.cda, &sense_id, len);
-        sch->curr_status.scsw.count = ccw.count - len;
+        ccw_dstream_write_buf(&sch->cds, &sense_id, len);
+        sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
         ret = 0;
         break;
     }