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
?
> +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 :)
