vfio/ccw: use struct_size() helper

Prefer struct_size() over open-coded versions.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-

vfio/ccw: use struct_size() helper

Prefer struct_size() over open-coded versions.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/f657276073630e806e69726a40ad1cc85101448a.1684805398.git.gustavoars@kernel.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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vfio/ccw: replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with fl

vfio/ccw: replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct vfio_ccw_parent and refactor the rest of the code
accordingly.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/297
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/3c10549ebe1564eade68a2515bde233527376971.1684805398.git.gustavoars@kernel.org
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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vfio/ccw: remove WARN_ON during shutdown

The logic in vfio_ccw_sch_shutdown() always assumed that the input
subchannel would point to a vfio_ccw_private struct, without checking
that one exists. The

vfio/ccw: remove WARN_ON during shutdown

The logic in vfio_ccw_sch_shutdown() always assumed that the input
subchannel would point to a vfio_ccw_private struct, without checking
that one exists. The blamed commit put in a check for this scenario,
to prevent the possibility of a missing private.

The trouble is that check was put alongside a WARN_ON(), presuming
that such a scenario would be a cause for concern. But this can be
triggered by binding a subchannel to vfio-ccw, and rebooting the
system before starting the mdev (via "mdevctl start" or similar)
or after stopping it. In those cases, shutdown doesn't need to
worry because either the private was never allocated, or it was
cleaned up by vfio_ccw_mdev_remove().

Remove the WARN_ON() piece of this check, since there are plausible
scenarios where private would be NULL in this path.

Fixes: 9e6f07cd1eaa ("vfio/ccw: create a parent struct")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20230210174227.2256424-1-farman@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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vfio/ap/ccw/samples: Fix device_register() unwind path

We always need to call put_device() if device_register() fails.
All vfio drivers calling device_register() include a similar unwind
stack via g

vfio/ap/ccw/samples: Fix device_register() unwind path

We always need to call put_device() if device_register() fails.
All vfio drivers calling device_register() include a similar unwind
stack via gotos, therefore split device_unregister() into its
device_del() and put_device() components in the unwind path, and
add a goto target to handle only the put_device() requirement.

Reported-by: Ruan Jinjie <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/all/20221118032827.3725190-1-ruanjinjie@huawei.com
Fixes: d61fc96f47fd ("sample: vfio mdev display - host device")
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Fixes: a5e6e6505f38 ("sample: vfio bochs vbe display (host device for bochs-drm)")
Fixes: 9e6f07cd1eaa ("vfio/ccw: create a parent struct")
Fixes: 36360658eb5a ("s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem")
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Jason Herne <jjherne@linux.ibm.com>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Link: https://lore.kernel.org/r/166999942139.645727.12439756512449846442.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: replace vfio_init_device with _alloc_

Now that we have a reasonable separation of structs that follow
the subchannel and mdev lifecycles, there's no reason we can't
call the official vfio_

vfio/ccw: replace vfio_init_device with _alloc_

Now that we have a reasonable separation of structs that follow
the subchannel and mdev lifecycles, there's no reason we can't
call the official vfio_alloc_device routine for our private data,
and behave like everyone else.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-7-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: move private to mdev lifecycle

Now that the mdev parent data is split out into its own struct,
it is safe to move the remaining private data to follow the
mdev probe/remove lifecycle. The

vfio/ccw: move private to mdev lifecycle

Now that the mdev parent data is split out into its own struct,
it is safe to move the remaining private data to follow the
mdev probe/remove lifecycle. The mdev parent data will remain
where it is, and follow the subchannel and the css driver
interfaces.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-5-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: move private initialization to callback

There's already a device initialization callback that is used to
initialize the release completion workaround that was introduced
by commit ebb72b76

vfio/ccw: move private initialization to callback

There's already a device initialization callback that is used to
initialize the release completion workaround that was introduced
by commit ebb72b765fb49 ("vfio/ccw: Use the new device life cycle
helpers").

Move the other elements of the vfio_ccw_private struct that
require distinct initialization over to that routine.

With that done, the vfio_ccw_alloc_private routine only does a
kzalloc, so fold it inline.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-4-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: remove private->sch

These places all rely on the ability to jump from a private
struct back to the subchannel struct. Rather than keeping a
copy in our back pocket, let's use the relations

vfio/ccw: remove private->sch

These places all rely on the ability to jump from a private
struct back to the subchannel struct. Rather than keeping a
copy in our back pocket, let's use the relationship provided
by the vfio_device embedded within the private.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-3-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: create a parent struct

Move the stuff associated with the mdev parent (and thus the
subchannel struct) into its own struct, and leave the rest in
the existing private structure.

The subch

vfio/ccw: create a parent struct

Move the stuff associated with the mdev parent (and thus the
subchannel struct) into its own struct, and leave the rest in
the existing private structure.

The subchannel will point to the parent, and the parent will point
to the private, for the areas where one or both are needed. Further
separation of these structs will follow.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/mdev: add mdev available instance checking to the core

Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the

vfio/mdev: add mdev available instance checking to the core

Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_parent. Implement it using correct locking, fixing mdpy.

Drivers just provide the value in the mdev_driver at registration time
and the core code takes care of maintaining it and exposing the value in
sysfs.

[hch: count instances per-parent instead of per-type, use an atomic_t
to avoid taking mdev_list_lock in the show method]

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/mdev: consolidate all the name sysfs into the core code

Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name an

vfio/mdev: consolidate all the name sysfs into the core code

Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name and
provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/mdev: simplify mdev_type handling

Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mde

vfio/mdev: simplify mdev_type handling

Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mdev_type structures in the caller and pass them to
mdev_register_parent.

This allows the caller to use container_of to get at the containing
structure and thus significantly simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure. T

vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure. This
removes the need for a list of parents and the separate mdev_parent
refcount as we can simplify rely on the reference to the parent device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/mdev: make mdev.h standalone includable

Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

S

vfio/mdev: make mdev.h standalone includable

Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Remove FSM Close from remove handlers

Now that neither vfio_ccw_sch_probe() nor vfio_ccw_mdev_probe()
affect the FSM state, it doesn't make sense for their _remove()
counterparts try to re

vfio/ccw: Remove FSM Close from remove handlers

Now that neither vfio_ccw_sch_probe() nor vfio_ccw_mdev_probe()
affect the FSM state, it doesn't make sense for their _remove()
counterparts try to revert things in this way. Since the FSM open
and close are handled alongside MDEV open/close, these are
unnecessary.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220728204914.2420989-3-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Move FSM open/close to MDEV open/close

Part of the confusion that has existed is the FSM lifecycle of
subchannels between the common CSS driver and the vfio-ccw driver.
During configuratio

vfio/ccw: Move FSM open/close to MDEV open/close

Part of the confusion that has existed is the FSM lifecycle of
subchannels between the common CSS driver and the vfio-ccw driver.
During configuration, the FSM state goes from NOT_OPER to STANDBY
to IDLE, but then back to NOT_OPER. For example:

vfio_ccw_sch_probe: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_probe: VFIO_CCW_STATE_STANDBY
vfio_ccw_mdev_probe: VFIO_CCW_STATE_IDLE
vfio_ccw_mdev_remove: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_remove: VFIO_CCW_STATE_NOT_OPER
vfio_ccw_sch_shutdown: VFIO_CCW_STATE_NOT_OPER

Rearrange the open/close events to align with the mdev open/close,
to better manage the memory and state of the devices as time
progresses. Specifically, make mdev_open() perform the FSM open,
and mdev_close() perform the FSM close instead of reset (which is
both close and open).

This makes the NOT_OPER state a dead-end path, indicating the
device is probably not recoverable without fully probing and
re-configuring the device.

This has the nice side-effect of removing a number of special-cases
where the FSM state is managed outside of the FSM itself (such as
the aforementioned mdev_close() routine).

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-12-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Create a CLOSE FSM event

Refactor the vfio_ccw_sch_quiesce() routine to extract the bit that
disables the subchannel and affects the FSM state. Use this to form
the basis of a CLOSE event

vfio/ccw: Create a CLOSE FSM event

Refactor the vfio_ccw_sch_quiesce() routine to extract the bit that
disables the subchannel and affects the FSM state. Use this to form
the basis of a CLOSE event that will mirror the OPEN event, and move
the subchannel back to NOT_OPER state.

A key difference with that mirroring is that while OPEN handles the
transition from NOT_OPER => STANDBY, the later probing of the mdev
handles the transition from STANDBY => IDLE. On the other hand,
the CLOSE event will move from one of the operating states {IDLE,
CP_PROCESSING, CP_PENDING} => NOT_OPER. That is, there is no stop
in a STANDBY state on the deconfigure path.

Add a call to cp_free() in this event, such that it is captured for
the various permutations of this event.

In the unlikely event that cio_disable_subchannel() returns -EBUSY,
the remaining logic of vfio_ccw_sch_quiesce() can still be used.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-10-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Create an OPEN FSM Event

Move the process of enabling a subchannel for use by vfio-ccw
into the FSM, such that it can manage the sequence of lifecycle
events for the device.

That is, if t

vfio/ccw: Create an OPEN FSM Event

Move the process of enabling a subchannel for use by vfio-ccw
into the FSM, such that it can manage the sequence of lifecycle
events for the device.

That is, if the FSM state is NOT_OPER(erational), then do the work
that would enable the subchannel and move the FSM to STANDBY state.
An attempt to perform this event again from any of the other operating
states (IDLE, CP_PROCESSING, CP_PENDING) will convert the device back
to NOT_OPER so the configuration process can be started again.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-9-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Flatten MDEV device (un)register

The vfio_ccw_mdev_(un)reg routines are merely vfio-ccw routines that
pass control to mdev_(un)register_device. Since there's only one
caller of each, let's

vfio/ccw: Flatten MDEV device (un)register

The vfio_ccw_mdev_(un)reg routines are merely vfio-ccw routines that
pass control to mdev_(un)register_device. Since there's only one
caller of each, let's just call the mdev routines directly.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-7-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Do not change FSM state in subchannel event

The routine vfio_ccw_sch_event() is tasked with handling subchannel events,
specifically machine checks, on behalf of vfio-ccw. It correctly cal

vfio/ccw: Do not change FSM state in subchannel event

The routine vfio_ccw_sch_event() is tasked with handling subchannel events,
specifically machine checks, on behalf of vfio-ccw. It correctly calls
cio_update_schib(), and if that fails (meaning the subchannel is gone)
it makes an FSM event call to mark the subchannel Not Operational.

If that worked, however, then it decides that if the FSM state was already
Not Operational (implying the subchannel just came back), then it should
simply change the FSM to partially- or fully-open.

Remove this trickery, since a subchannel returning will require more
probing than simply "oh all is well again" to ensure it works correctly.

Fixes: bbe37e4cb8970 ("vfio: ccw: introduce a finite state machine")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-4-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Fix FSM state if mdev probe fails

The FSM is in STANDBY state when arriving in vfio_ccw_mdev_probe(),
and this routine converts it to IDLE as part of its processing.
The error exit sets it

vfio/ccw: Fix FSM state if mdev probe fails

The FSM is in STANDBY state when arriving in vfio_ccw_mdev_probe(),
and this routine converts it to IDLE as part of its processing.
The error exit sets it to IDLE (again) but clears the private->mdev
pointer.

The FSM should of course be managing the state itself, but the
correct thing for vfio_ccw_mdev_probe() to do would be to put
the state back the way it found it.

The corresponding check of private->mdev in vfio_ccw_sch_io_todo()
can be removed, since the distinction is unnecessary at this point.

Fixes: 3bf1311f351ef ("vfio/ccw: Convert to use vfio_register_emulated_iommu_dev()")
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220707135737.720765-3-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Remove UUID from s390 debug log

As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a p

vfio/ccw: Remove UUID from s390 debug log

As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a pointer to the UUID is stored instead of the UUID
itself, and that memory may have been repurposed if/when the logs are
examined. The result is usually garbage UUID data in the logs, though
there is an outside chance of an oops happening here.

Simply remove the UUID from the traces, as the subchannel number will
provide useful configuration information for problem determination,
and is stored directly into the log instead of a pointer.

As we were the only consumer of mdev_uuid(), remove that too.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Michael Kawano <mkawano@linux.ibm.com>
Fixes: 60e05d1cf0875 ("vfio-ccw: add some logging")
Fixes: b7701dfbf9832 ("vfio-ccw: Register a chp_event callback for vfio-ccw")
[farman: reworded commit message, added Fixes: tags]
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220707135737.720765-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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s390/cio: remove uevent suppress from cio driver

commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")
introduced suppression of uevents for a subchannel until after it is
clear that the

s390/cio: remove uevent suppress from cio driver

commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")
introduced suppression of uevents for a subchannel until after it is
clear that the subchannel would not be unregistered again
immediately. This was done to avoid uevents being generated for I/O
subchannels with no valid device, which can happen on LPAR.

However, this also has some drawbacks: All subchannel drivers need to
manually remove the uevent suppression and generate an ADD uevent as
soon as they are sure that the subchannel will stay around. This misses
out on all uevents that are not the initial ADD uevent that would be
generated while uevents are suppressed; for example, all subchannels
were missing the BIND uevent.

As uevents being generated even for I/O subchannels without an
operational device turned out to be not as bad as missing uevents and
complicating the code flow, let's remove uevent suppression for
subchannels.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
[cohuck@redhat.com: modified changelog]
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: https://lore.kernel.org/r/20211122103756.352463-2-vneethv@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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vfio/ccw: Convert to use vfio_register_emulated_iommu_dev()

This is a more complicated conversion because vfio_ccw is sharing the
vfio_device between both the mdev_device, its vfio_device and the
cs

vfio/ccw: Convert to use vfio_register_emulated_iommu_dev()

This is a more complicated conversion because vfio_ccw is sharing the
vfio_device between both the mdev_device, its vfio_device and the
css_driver.

The mdev is a singleton, and the reason for this sharing is so the extra
css_driver function callbacks to be delivered to the vfio_device
implementation.

This keeps things as they are, with the css_driver allocating the
singleton, not the mdev_driver.

Embed the vfio_device in the vfio_ccw_private and instantiate it as a
vfio_device when the mdev probes. The drvdata of both the css_device and
the mdev_device point at the private, and container_of is used to get it
back from the vfio_device.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v4-cea4f5bd2c00+b52-ccw_mdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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vfio/ccw: Use functions for alloc/free of the vfio_ccw_private

Makes the code easier to understand what is memory lifecycle and what is
other stuff.

Reviewed-by: Eric Farman <farman@linux.ibm.com>

vfio/ccw: Use functions for alloc/free of the vfio_ccw_private

Makes the code easier to understand what is memory lifecycle and what is
other stuff.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-cea4f5bd2c00+b52-ccw_mdev_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

show more ...