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?
> +
> 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?
> + *
> + * Author(s): Farhan Ali <alifm@xxxxxxxxxxxxx>
> + */
(...)
