On 2/14/20 7:32 AM, Cornelia Huck wrote:
> On Thu, 6 Feb 2020 22:38:20 +0100
> Eric Farman <farman@xxxxxxxxxxxxx> wrote:
>
>> From: Farhan Ali <alifm@xxxxxxxxxxxxx>
>>
>> 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@xxxxxxxxxxxxx>
>> Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
>> ---
>>
>> Notes:
>> v1->v2:
>> - Add new region info to Documentation/s390/vfio-ccw.rst [CH]
>> - Add a block comment to struct ccw_schib_region [CH]
>>
>> v0->v1: [EF]
>> - Clean up checkpatch (#include, whitespace) errors
>> - Remove unnecessary includes from vfio_ccw_chp.c
>> - Add ret=-ENOMEM in error path for new region
>> - Add call to vfio_ccw_unregister_dev_regions() during error exit
>> path of vfio_ccw_mdev_open()
>> - New info on the module prologue
>> - Reorder cleanup of regions
>>
>> Documentation/s390/vfio-ccw.rst | 16 +++++-
>> drivers/s390/cio/Makefile | 2 +-
>> drivers/s390/cio/vfio_ccw_chp.c | 75 +++++++++++++++++++++++++++++
>> drivers/s390/cio/vfio_ccw_drv.c | 20 ++++++++
>> drivers/s390/cio/vfio_ccw_ops.c | 14 +++++-
>> drivers/s390/cio/vfio_ccw_private.h | 3 ++
>> include/uapi/linux/vfio.h | 1 +
>> include/uapi/linux/vfio_ccw.h | 10 ++++
>> 8 files changed, 137 insertions(+), 4 deletions(-)
>> create mode 100644 drivers/s390/cio/vfio_ccw_chp.c
>>
>> diff --git a/Documentation/s390/vfio-ccw.rst b/Documentation/s390/vfio-ccw.rst
>> index fca9c4f5bd9c..b805dc995fc8 100644
>> --- a/Documentation/s390/vfio-ccw.rst
>> +++ b/Documentation/s390/vfio-ccw.rst
>> @@ -231,6 +231,19 @@ This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD.
>>
>> Currently, CLEAR SUBCHANNEL and HALT SUBCHANNEL use this region.
>>
>> +vfio-ccw schib region
>> +---------------------
>> +
>> +The vfio-ccw schib region is used to return Subchannel-Information
>> +Block (SCHIB) data to userspace::
>> +
>> + struct ccw_schib_region {
>> + #define SCHIB_AREA_SIZE 52
>> + __u8 schib_area[SCHIB_AREA_SIZE];
>> + } __packed;
>> +
>> +This region is exposed via region type VFIO_REGION_SUBTYPE_CCW_SCHIB.
>
> Also mention that reading this triggers a stsch() updating the schib?
Yeah, I tucked that in the uapi header, but it should be mentioned here too.
>
>> +
>> vfio-ccw operation details
>> --------------------------
>>
>
> (...)
>
>> diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c
>> new file mode 100644
>> index 000000000000..826d08379fe3
>> --- /dev/null
>> +++ b/drivers/s390/cio/vfio_ccw_chp.c
>> @@ -0,0 +1,75 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Channel path related status regions for vfio_ccw
>> + *
>> + * Copyright IBM Corp. 2019
>
> Should the year be updated?
Probably. :)
>
>> + *
>> + * Author(s): Farhan Ali <alifm@xxxxxxxxxxxxx>
>> + */
>
> (...)
>
