On Wed, 15 May 2019 01:42:48 +0200 Eric Farman <farman@xxxxxxxxxxxxx> wrote: > If the CCW being processed is a No-Operation, then by definition no > data is being transferred. Let's fold those checks into the normal > CCW processors, rather than skipping out early. > > Likewise, if the CCW being processed is a "test" (an invented > definition to simply mean it ends in a zero), let's permit that to go > through to the hardware. There's nothing inherently unique about > those command codes versus one that ends in an eight [1], or any other > otherwise valid command codes that are undefined for the device type > in question. Hm... let's tweak that a bit? It's not that "test" is an invented category; it's just that this has not been a valid command for post-s/370 and therefore should not get any special treatment and just be sent to the hardware? > > [1] POPS states that a x08 is a TIC CCW, and that having any high-order > bits enabled is invalid for format-1 CCWs. For format-0 CCWs, the > high-order bits are ignored. > > Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx> > --- > drivers/s390/cio/vfio_ccw_cp.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-)