This region provides a mechanism to pass a Channel Report Word
that affect vfio-ccw devices, and needs to be passed to the guest
for its awareness and/or processing.
The base driver (see crw_collect_info()) provides space for two
CRWs, as a subchannel event may have two CRWs chained together
(one for the ssid, one for the subchannel). As vfio-ccw will
deal with everything at the subchannel level, provide space
for a single CRW to be transferred in one shot.
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-7-farman@linux.ibm.com>
[CH: added padding to ccw_crw_region]
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
The schib region can be used by userspace to get the subchannel-
information block (SCHIB) for the passthrough subchannel.
This can be useful to get information such as channel path
information via the SCHIB.PMCW fields.
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20200407111605.1795-1-cohuck@redhat.com>
Remove the explicit prefetch check when using vfio-ccw devices.
This check does not trigger in practice as all Linux channel programs
are intended to use prefetch.
It is expected that all ORBs issued by Linux will request prefetch.
Although non-prefetching ORBs are not rejected, they will prefetch
nonetheless. A warning is issued up to once per 5 seconds when a
forced prefetch occurs.
A non-prefetch ORB does not necessarily result in an error, however
frequent encounters with non-prefetch ORBs indicate that channel
programs are being executed in a way that is inconsistent with what
the guest is requesting. While there is currently no known case of an
error caused by forced prefetch, it is possible in theory that forced
prefetch could result in an error if applied to a channel program that
is dependent on non-prefetch.
Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20200506212440.31323-2-jrossi@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
*Really* mark the literal block as such.
Fixes: 127e621740 ("vfio-ccw: Update documentation for csch/hsch")
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.
Move them to their right place.
Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
We now support CLEAR SUBCHANNEL and HALT SUBCHANNEL
via ccw_cmd_region.
Fixes: d5afd5d135 ("vfio-ccw: add handling for async channel instructions")
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <7d977612c3f3152ffb950d77ae11b4b25c1e20c4.1562854091.git.alifm@linux.ibm.com>
[CH: properly mark region as literal block]
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Convert all text files with s390 documentation to ReST format.
Tried to preserve as much as possible the original document
format. Still, some of the files required some work in order
for it to be visible on both plain text and after converted
to html.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Farhan Ali