On 11/19/19 11:52 AM, Cornelia Huck wrote:
> On Fri, 15 Nov 2019 03:56:15 +0100
> Eric Farman <farman@xxxxxxxxxxxxx> wrote:
>
>> From: Farhan Ali <alifm@xxxxxxxxxxxxx>
>>
>> The schib region can be used by userspace to get the SCHIB for the
>> passthrough subchannel. This can be useful to get information such
>> as channel path information via the SCHIB.PMCW.
>>
>> Signed-off-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
>> Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx>
>> ---
>>
>> Notes:
>> 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
>>
>> 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 | 5 ++
>> 7 files changed, 117 insertions(+), 3 deletions(-)
>> create mode 100644 drivers/s390/cio/vfio_ccw_chp.c
>>
>
>> diff --git a/include/uapi/linux/vfio_ccw.h b/include/uapi/linux/vfio_ccw.h
>> index cbecbf0cd54f..7c0a834e5d7a 100644
>> --- a/include/uapi/linux/vfio_ccw.h
>> +++ b/include/uapi/linux/vfio_ccw.h
>> @@ -34,4 +34,9 @@ struct ccw_cmd_region {
>> __u32 ret_code;
>> } __packed;
>>
>
> Let's add a comment:
> - that reading this region triggers a stsch()
> - that this region is guarded by a capability
>
> ?
Agreed, and ditto for patch 6.
>
>> +struct ccw_schib_region {
>> +#define SCHIB_AREA_SIZE 52
>> + __u8 schib_area[SCHIB_AREA_SIZE];
>> +} __packed;
>> +
>> #endif
>
> Seems sane; but I need to continue reading this and the QEMU series to
> see how it is used.
>
> Oh, and please update Documentation/s390/vfio-ccw.rst :)
>
Whoops! Yes, I'll do that here and in patch 6.
