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

Eric Farman
2022-06-02T17:20:09Z

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.

[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(-)

--
2.32.0