On Fri, 17 Apr 2020 12:33:18 -0400 Eric Farman <farman@xxxxxxxxxxxxx> wrote: > On 4/7/20 7:16 AM, Cornelia Huck wrote: > > Interacting with the I/O and the async regions can yield a number > > of errors, which had been undocumented so far. These are part of > > the api, so remedy that. > > (Makes a note to myself, to do the same for the schib/crw regions we're > adding for channel path handling.) Yes, please :) I plan to merge this today, so you can add a patch on top. > > > > > Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx> > > --- > > Documentation/s390/vfio-ccw.rst | 54 ++++++++++++++++++++++++++++++++- > > 1 file changed, 53 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst > > index fca9c4f5bd9c..4538215a362c 100644 > > --- a/Documentation/s390/vfio-ccw.rst > > +++ b/Documentation/s390/vfio-ccw.rst > > @@ -210,7 +210,36 @@ Subchannel. > > > > irb_area stores the I/O result. > > > > -ret_code stores a return code for each access of the region. > > +ret_code stores a return code for each access of the region. The following > > +values may occur: > > + > > +``0`` > > + The operation was successful. > > + > > +``-EOPNOTSUPP`` > > + The orb specified transport mode or an unidentified IDAW format, did not > > + specify prefetch mode, or the scsw specified a function other than the 'did not specify prefetch mode' needs to be dropped now, will do so before queuing. > > + start function. > > + > > +``-EIO`` > > + A request was issued while the device was not in a state ready to accept > > + requests, or an internal error occurred. > > + > > +``-EBUSY`` > > + The subchannel was status pending or busy, or a request is already active. > > + > > +``-EAGAIN`` > > + A request was being processed, and the caller should retry. > > + > > +``-EACCES`` > > + The channel path(s) used for the I/O were found to be not operational. > > + > > +``-ENODEV`` > > + The device was found to be not operational. > > + > > +``-EINVAL`` > > + The orb specified a chain longer than 255 ccws, or an internal error > > + occurred. > > > > This region is always available. > > Maybe move this little line up between the struct layout and "While > starting an I/O request, orb_area ..." instead of being lost way down here? Good idea, that also would match the documentation for the async region. > > But other than that suggestion, everything looks fine. > > Reviewed-by: Eric Farman <farman@xxxxxxxxxxxxx> Thanks! > > > > > @@ -231,6 +260,29 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD. > > > > Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region. > > > > +command specifies the command to be issued; ret_code stores a return code > > +for each access of the region. The following values may occur: > > + > > +``0`` > > + The operation was successful. > > + > > +``-ENODEV`` > > + The device was found to be not operational. > > + > > +``-EINVAL`` > > + A command other than halt or clear was specified. > > + > > +``-EIO`` > > + A request was issued while the device was not in a state ready to accept > > + requests. > > + > > +``-EAGAIN`` > > + A request was being processed, and the caller should retry. > > + > > +``-EBUSY`` > > + The subchannel was status pending or busy while processing a halt request. > > + > > + > > vfio-ccw operation details > > -------------------------- > > > > >
