[PATCH 8/9] s390x/css: Expand check against no-data-count CCWs

[Eric Farman <farman@linux.ibm.com>]

The channel subsystem will reject channel programs that incorporate
256 CCWs without a data transfer, but the existing check for this
does so against a data address of zero. Expand the check to include
other CCWs that are valid but would transfer no data.

Fixes: e8601dd5d0 ("s390x/css: catch ccw sequence errors")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 hw/s390x/css.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 9da9128d88..c38549c7be 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -1016,7 +1016,9 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
 
     check_len = !((ccw.flags & CCW_FLAG_SLI) && !(ccw.flags & CCW_FLAG_DC));
 
-    if (!ccw.cda) {
+    if (!ccw.cda ||
+        (ccw.flags & CCW_FLAG_SKIP) ||
+        (ccw.cmd_code == CCW_CMD_NOOP)) {
         if (sch->ccw_no_data_cnt == 255) {
             return -EINVAL;
         }
-- 
2.53.0