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[PULL,3/4] KVM: s390: document FLIC behavior on unsupported

Message ID 1461156896-27006-4-git-send-email-cornelia.huck@de.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Cornelia Huck April 20, 2016, 12:54 p.m. UTC 
From: Halil Pasic <pasic@linux.vnet.ibm.com>

FLIC behavior deviates from the API documentation in reporting EINVAL
instead of ENXIO for KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR when the group
or attribute is unknown/unsupported. Unfortunately this can not be fixed
for historical reasons. Let us at least have it documented.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 Documentation/virtual/kvm/devices/s390_flic.txt | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt
index e3e314c..646f474 100644
--- a/Documentation/virtual/kvm/devices/s390_flic.txt
+++ b/Documentation/virtual/kvm/devices/s390_flic.txt
@@ -94,3 +94,9 @@  struct kvm_s390_io_adapter_req {
     KVM_S390_IO_ADAPTER_UNMAP
       release a userspace page for the translated address specified in addr
       from the list of mappings
+
+Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR device ioctls executed on
+FLIC with an unknown group or attribute gives the error code EINVAL (instead of
+ENXIO, as specified in the API documentation). It is not possible to conclude
+that a FLIC operation is unavailable based on the error code resulting from a
+usage attempt.