Re: [PATCH v4 6/8] vfio-ccw: Introduce a new CRW region

Cornelia Huck
2020-05-06T13:24:47Z

On Tue, 5 May 2020 14:27:43 +0200
Eric Farman <farman@linux.ibm.com> wrote:

> From: Farhan Ali <alifm@linux.ibm.com>
>
> 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>
> ---
>
> Notes:
> v3->v4:
> - Move crw_trigger and CRW_IRQ from later patch to here [EF]
> - Cleanup descriptions of sizeof CRW region in doc, commentary,
> and commit description [CH]
> - Clear crw when finished [CH]
>
> v2->v3:
> - Remove "if list-empty" check, since there's no list yet [EF]
> - Reduce the CRW region to one fullword, instead of two [CH]
>
> v1->v2:
> - Add new region info to Documentation/s390/vfio-ccw.rst [CH]
> - Add a block comment to struct ccw_crw_region [CH]
>
> v0->v1: [EF]
> - Clean up checkpatch (whitespace) errors
> - Add ret=-ENOMEM in error path for new region
> - Add io_mutex for region read (originally in last patch)
> - Change crw1/crw2 to crw0/crw1
> - Reorder cleanup of regions
>
> Documentation/s390/vfio-ccw.rst | 19 ++++++++++
> drivers/s390/cio/vfio_ccw_chp.c | 55 +++++++++++++++++++++++++++++
> drivers/s390/cio/vfio_ccw_drv.c | 20 +++++++++++
> drivers/s390/cio/vfio_ccw_ops.c | 8 +++++
> drivers/s390/cio/vfio_ccw_private.h | 4 +++
> include/uapi/linux/vfio.h | 2 ++
> include/uapi/linux/vfio_ccw.h | 8 +++++
> 7 files changed, 116 insertions(+)
>

Reviewed-by: Cornelia Huck <cohuck@redhat.com>