diff options
| -rw-r--r-- | hw/s390x/css.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 2c0782cc6a..95962808de 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -290,6 +290,10 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr) ((ccw.cmd_code & 0xf0) != 0)) { return -EINVAL; } + if (!sch->ccw_fmt_1 && (ccw.count == 0) && + (ccw.cmd_code != CCW_CMD_TIC)) { + return -EINVAL; + } if (ccw.flags & CCW_FLAG_SUSPEND) { return -EINPROGRESS; |