I'm currently prototyping hsch()/csch() support for vfio-ccw, and stumbled over this: We currently expect any I/O to be in command-mode, but don't take care to actively reject transport-mode. This is not an issue with QEMU (which rejects transport-mode ORBs before even the css backend gets to it), but better play safe.
Should we want to support transport-mode in the future, we'll probably need to introduce a capability for it that needs to be enabled by user space. [I also still have the doc patch from some time ago queued. Let's see if we'll collect more patches.] Cornelia Huck (1): vfio-ccw: fence off transport mode drivers/s390/cio/vfio_ccw_fsm.c | 5 +++++ 1 file changed, 5 insertions(+) -- 2.13.6