Re: [PATCH v9 00/10] s390/vfio_ccw fixes

[Matthew Rosato]

On 7/27/26 11:30 PM, Eric Farman wrote:
> This series addresses some pre-existing issues found in the
> s390 vfio_ccw (DASD passthrough) driver.
> 
> Patches 1-6 are identical to v6/v7/v8
> Patches 7-10 have minor changes compared to v7/v8
> 
> v1: https://lore.kernel.org/r/20260714232208.1683788-1-farman@xxxxxxxxxxxxx/
> v2: https://lore.kernel.org/r/20260720201931.976660-1-farman@xxxxxxxxxxxxx/
> v3: https://lore.kernel.org/r/20260723174751.1180334-1-farman@xxxxxxxxxxxxx/
> v4: https://lore.kernel.org/r/20260725152705.3958100-1-farman@xxxxxxxxxxxxx/
> v5: https://lore.kernel.org/r/20260726040129.2946151-1-farman@xxxxxxxxxxxxx/
> v6: https://lore.kernel.org/r/20260726172153.1818056-1-farman@xxxxxxxxxxxxx/
> v7: https://lore.kernel.org/r/20260727192230.2715207-1-farman@xxxxxxxxxxxxx/
> v8: https://lore.kernel.org/r/20260728013509.1551753-1-farman@xxxxxxxxxxxxx/
> v8->v9:
>  - [MR] Added r-b (thank you!)
>  - [MR] Commit/comment message improvements
>  - [MR/sashiko] Re-add workqueue cleanup to vfio_ccw_mdev_release_dev, in the
>    form of a flush_work() call

Thanks Eric.

I think at this point the big issues are resolved, and this already is a
significant improvement overall.

We've also identified a few things (here and off-list) that would be
reasonable tackled as follow-ons, such as a well-defined lock hierarchy
and identifying reasonable places to add lockdep assertions.

Thanks,
Matt

> 
> Eric Farman (10):
>   s390/vfio_ccw: free all memory if cp_init() fails
>   s390/vfio_ccw: limit the number of channel program segments
>   s390/vfio_ccw: fix out of bounds check on CCW array
>   s390/vfio_ccw: ensure first IDAW remains constant
>   s390/vfio_ccw: calculate idal length based on idaw type
>   s390/vfio_ccw: ensure index for read/write regions are within range
>   s390/vfio_ccw: cancel existing workqueues
>   s390/vfio_ccw: move cp cleanup out of not operational
>   s390/vfio_ccw: selectively expand io_mutex
>   s390/vfio_ccw: implement a crw lock
> 
>  drivers/s390/cio/vfio_ccw_async.c   | 16 +++++++
>  drivers/s390/cio/vfio_ccw_chp.c     | 31 ++++++++++--
>  drivers/s390/cio/vfio_ccw_cp.c      | 74 +++++++++++++++++++++--------
>  drivers/s390/cio/vfio_ccw_cp.h      | 10 ++++
>  drivers/s390/cio/vfio_ccw_drv.c     | 21 +++++++-
>  drivers/s390/cio/vfio_ccw_fsm.c     |  8 +++-
>  drivers/s390/cio/vfio_ccw_ops.c     | 39 +++++++++++++--
>  drivers/s390/cio/vfio_ccw_private.h | 10 +++-
>  8 files changed, 176 insertions(+), 33 deletions(-)
>