vfio/ccw: update sense data if a unit check is pending

Concurrent-sense data is currently not delivered. This patch stores
the concurrent-sense data to the subchannel if a unit check is pending
and the concurrent-sense bit is enabled. Then a TSCH can retreive the
right IRB data back to the guest.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-13-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

hw/vfio/ccw.c

@@ -94,6 +94,7 @@ static void vfio_ccw_io_notifier_handler(void *opaque)
     CcwDevice *ccw_dev = CCW_DEVICE(cdev);
     SubchDev *sch = ccw_dev->sch;
     SCSW *s = &sch->curr_status.scsw;
+    PMCW *p = &sch->curr_status.pmcw;
     IRB irb;
     int size;
 
@@ -143,6 +144,12 @@ static void vfio_ccw_io_notifier_handler(void *opaque)
     /* Update control block via irb. */
     copy_scsw_to_guest(s, &irb.scsw);
 
+    /* If a uint check is pending, copy sense data. */
+    if ((s->dstat & SCSW_DSTAT_UNIT_CHECK) &&
+        (p->chars & PMCW_CHARS_MASK_CSENSE)) {
+        memcpy(sch->sense_data, irb.ecw, sizeof(irb.ecw));
+    }
+
 read_err:
     css_inject_io_interrupt(sch);
 }