According to the POP a start subchannel instruction (SSCH) returning with
cc 1 implies that the subchannel was status pending when SSCH executed.
Due to a somewhat confusing error handling, where error codes are mapped
to cc value, sane looking error codes result in non AR compliant
behavior.
Let's fix this! Instead of cc 1 we use cc 3 which means device not
operational, and is much closer to the truth in the given cases.
Signed-off-by: Halil Pasic <pa...@linux.vnet.ibm.com>
Acked-by: Pierre Morel<pmo...@linux.vnet.ibm.com>
---
This patch turned out quite controversial. We did not reach a consensus
during the internal review.
The most of the discussion revolved around the ORB flag which
architecturally must be supported, but are currently not supported by
vfio-ccw (not yet, or can't be). The idea showing the most promise for
consensus was to handle this via device status (along the lines better a
strange acting device than a non-conform machine) but since it's a
radical change we decided to first discuss upstream and then do whatever
needs to be done.
---
hw/s390x/css.c | 15 ++++++---------
hw/s390x/s390-ccw.c | 2 +-
2 files changed, 7 insertions(+), 10 deletions(-)
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index a50fb0727e..0822538cde 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -1034,7 +1034,7 @@ static int sch_handle_start_func_passthrough(SubchDev
*sch)
*/
if (!(orb->ctrl0 & ORB_CTRL0_MASK_PFCH) ||
!(orb->ctrl0 & ORB_CTRL0_MASK_C64)) {
- return -EINVAL;
+ return -ENODEV;
}
ret = s390_ccw_cmd_request(orb, s, sch->driver_data);
@@ -1046,16 +1046,13 @@ static int sch_handle_start_func_passthrough(SubchDev
*sch)
break;
case -ENODEV:
break;
+ case -EFAULT:
+ break;
case -EACCES:
/* Let's reflect an inaccessible host device by cc 3. */
- ret = -ENODEV;
- break;
default:
- /*
- * All other return codes will trigger a program check,
- * or set cc to 1.
- */
- break;
+ /* Let's make all other return codes map to cc 3. */
+ ret = -ENODEV;
};
return ret;
@@ -1115,7 +1112,7 @@ static int do_subchannel_work(SubchDev *sch)
if (sch->do_subchannel_work) {
return sch->do_subchannel_work(sch);
} else {
- return -EINVAL;
+ return -ENODEV;
}
}
diff --git a/hw/s390x/s390-ccw.c b/hw/s390x/s390-ccw.c
index 8614dda6f8..2b0741741c 100644
--- a/hw/s390x/s390-ccw.c
+++ b/hw/s390x/s390-ccw.c
@@ -25,7 +25,7 @@ int s390_ccw_cmd_request(ORB *orb, SCSW *scsw, void *data)
if (cdc->handle_request) {
return cdc->handle_request(orb, scsw, data);
} else {
- return -ENOSYS;
+ return -ENODEV;
}
}
--
2.13.5
