Re: [PATCH v1 00/18] VFIO ccw/mdev rework

[Yi Liu <yi.l.liu@intel.com>]

Hi Eric,

On 2022/6/3 01:19, Eric Farman wrote:
> Last autumn, Jason Gunthorpe proposed some rework of vfio-ccw [1],
> to better fit with the new mdev API (thank you!). Part of that
> series was pulled for kernel 5.16 [2], but the complexities of
> the remaining patches got them hung up behind other work.
> 
> This series attempts to dust off and complete that, with the
> goal of untangling the lifecycle of a s390 subchannel when
> bound to vfio-ccw instead of the usual io_subchannel driver.
> 
> Patches 1-8 are inspired by and/or split out from that series,
> in order to be consumable on their own (backports, etc.).
> 
> Patches 9-12 handle the goal of making the FSM complete,
> and synchronizing the subchannel's life with that of the mdev.
> (This was the goal of patch 5 of the larger series [3].)
> 
> Patches 13-14 are pulled directly from the earlier series.
> As these patches hit some other of the consumers of vfio,
> those on CC who are unfamiliar with vfio-ccw probably only
> care about these. :)
> 
> Patches 15-18 links the lifecycle of the vfio_ccw_private struct
> with the mdev via a vfio reference. (Patch 17 was also pulled
> directly from the earlier series.)
> 
> In the end, the subchannel probe/remove callbacks from the css
> driver simply register/unregister with vfio-mdev. The communication
> with the subchannel is delayed until the mdev routines, which
> handles all the vfio-related memory and subchannel enablement.
> There's no longer a configuration where the mdev is closed while
> the subchannel remains enabled, since that's weird.
> 
> @Jason: I carried the S-o-b/r-b tags on patches 13, 14, and 17,
> as they were cherry-picked straight from your v3.
> If you'd prefer your S-o-b on others, please let me know.

very nice to see it. do you have a 5.19 based branch including these
changes on github? I'd like to rebase my vfio cdev patches on top of
your changes. :-)

> [1] https://lore.kernel.org/r/0-v3-57c1502c62fd+2190-ccw_mdev_jgg@nvidia.com/
> [2] https://lore.kernel.org/r/0-v4-cea4f5bd2c00+b52-ccw_mdev_jgg@nvidia.com/
> [3] https://lore.kernel.org/r/5-v3-57c1502c62fd+2190-ccw_mdev_jgg@nvidia.com/
> 
> Cc: Kirti Wankhede <kwankhede@nvidia.com>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
> Cc: Zhi Wang <zhi.a.wang@intel.com>
> Cc: intel-gvt-dev@lists.freedesktop.org
> Cc: Tony Krowiak <akrowiak@linux.ibm.com>
> Cc: Jason Herne <jjherne@linux.ibm.com>
> 
> Eric Farman (14):
>    vfio/ccw: Fix FSM state if mdev probe fails
>    vfio/ccw: Ensure mdev->dev is cleared on mdev remove
>    vfio/ccw: Do not change FSM state in subchannel event
>    vfio/ccw: Remove private->mdev
>    vfio/ccw: Pass enum to FSM event jumptable
>    vfio/ccw: Flatten MDEV device (un)register
>    vfio/ccw: Check that private pointer is not NULL
>    vfio/ccw: Create an OPEN FSM Event
>    vfio/ccw: Create a CLOSE FSM event
>    vfio/ccw: Refactor vfio_ccw_mdev_reset
>    vfio/ccw: Move FSM open/close to MDEV open/close
>    vfio/ccw: Manage private with mdev
>    vfio/ccw: Create a get_private routine
>    vfio/ccw: Manage ccw/mdev reference counts
> 
> Jason Gunthorpe (3):
>    vfio/mdev: Consolidate all the device_api sysfs into the core code
>    vfio/mdev: Add mdev available instance checking to the core
>    vfio: Export vfio_device_try_get()
> 
> Michael Kawano (1):
>    vfio/ccw: Remove UUID from s390 debug log
> 
>   .../driver-api/vfio-mediated-device.rst       |   8 +-
>   drivers/gpu/drm/i915/gvt/kvmgt.c              |   9 +-
>   drivers/s390/cio/vfio_ccw_async.c             |   1 -
>   drivers/s390/cio/vfio_ccw_drv.c               | 114 ++++++--------
>   drivers/s390/cio/vfio_ccw_fsm.c               |  91 +++++++++--
>   drivers/s390/cio/vfio_ccw_ops.c               | 145 ++++++------------
>   drivers/s390/cio/vfio_ccw_private.h           |  33 +++-
>   drivers/s390/crypto/vfio_ap_ops.c             |  41 ++---
>   drivers/s390/crypto/vfio_ap_private.h         |   2 -
>   drivers/vfio/mdev/mdev_core.c                 |  13 +-
>   drivers/vfio/mdev/mdev_private.h              |   2 +
>   drivers/vfio/mdev/mdev_sysfs.c                |  64 +++++++-
>   drivers/vfio/vfio.c                           |   3 +-
>   include/linux/mdev.h                          |  13 +-
>   include/linux/vfio.h                          |   1 +
>   samples/vfio-mdev/mbochs.c                    |   9 +-
>   samples/vfio-mdev/mdpy.c                      |  31 +---
>   samples/vfio-mdev/mtty.c                      |  10 +-
>   18 files changed, 300 insertions(+), 290 deletions(-)
> 

-- 
Regards,
Yi Liu