s390/ap: Fix CCA crypto card behavior within protected execution environment

A crypto card comes in 3 flavors: accelerator, CCA co-processor or
EP11 co-processor. Within a protected execution enviro

s390/ap: Fix CCA crypto card behavior within protected execution environment

A crypto card comes in 3 flavors: accelerator, CCA co-processor or
EP11 co-processor. Within a protected execution environment only the
accelerator and EP11 co-processor is supported. However, it is
possible to set up a KVM guest with a CCA card and run it as a
protected execution guest. There is nothing at the host side which
prevents this. Within such a guest, a CCA card is shown as "illicit"
and you can't do anything with such a crypto card.

Regardless of the unsupported CCA card within a protected execution
guest there are a couple of user space applications which
unconditional try to run crypto requests to the zcrypt device
driver. There was a bug within the AP bus code which allowed such a
request to be forwarded to a CCA card where it is finally
rejected and the driver reacts with -ENODEV but also triggers an AP
bus scan. Together with a retry loop this caused some kind of "hang"
of the KVM guest. On startup it caused timeouts and finally led the
KVM guest startup fail. Fix that by closing the gap and make sure a
CCA card is not usable within a protected execution environment.

Another behavior within an protected execution environment with CCA
cards was that the se_bind and se_associate AP queue sysfs attributes
where shown. The implementation unconditional always added these
attributes. Fix that by checking if the card mode is supported within
a protected execution environment and only if valid, add the attribute
group.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/ap: Fix deadlock caused by recursive lock of the AP bus scan mutex

There is a possibility to deadlock with an recursive
lock of the AP bus scan mutex ap_scan_bus_mutex:

... kernel: =========

s390/ap: Fix deadlock caused by recursive lock of the AP bus scan mutex

There is a possibility to deadlock with an recursive
lock of the AP bus scan mutex ap_scan_bus_mutex:

... kernel: ============================================
... kernel: WARNING: possible recursive locking detected
... kernel: 5.14.0-496.el9.s390x #3 Not tainted
... kernel: --------------------------------------------
... kernel: kworker/12:1/130 is trying to acquire lock:
... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_bus_force_rescan+0x92/0x108
... kernel:
but task is already holding lock:
... kernel: 0000000358bc1510 (ap_scan_bus_mutex){+.+.}-{3:3}, at: ap_scan_bus_wq_callback+0x28/0x60
... kernel:
other info that might help us debug this:
... kernel: Possible unsafe locking scenario:
... kernel: CPU0
... kernel: ----
... kernel: lock(ap_scan_bus_mutex);
... kernel: lock(ap_scan_bus_mutex);
... kernel:
*** DEADLOCK ***

Here is how the callstack looks like:

... [<00000003576fe9ce>] process_one_work+0x2a6/0x748
... [<0000000358150c00>] ap_scan_bus_wq_callback+0x40/0x60 <- mutex locked
... [<00000003581506e2>] ap_scan_bus+0x5a/0x3b0
... [<000000035815037c>] ap_scan_adapter+0x5b4/0x8c0
... [<000000035814fa34>] ap_scan_domains+0x2d4/0x668
... [<0000000357d989b4>] device_add+0x4a4/0x6b8
... [<0000000357d9bb54>] bus_probe_device+0xb4/0xc8
... [<0000000357d9daa8>] __device_attach+0x120/0x1b0
... [<0000000357d9a632>] bus_for_each_drv+0x8a/0xd0
... [<0000000357d9d548>] __device_attach_driver+0xc0/0x140
... [<0000000357d9d3d8>] driver_probe_device+0x40/0xf0
... [<0000000357d9cec2>] really_probe+0xd2/0x460
... [<000000035814d7b0>] ap_device_probe+0x150/0x208
... [<000003ff802a5c46>] zcrypt_cex4_queue_probe+0xb6/0x1c0 [zcrypt_cex4]
... [<000003ff7fb2d36e>] zcrypt_queue_register+0xe6/0x1b0 [zcrypt]
... [<000003ff7fb2c8ac>] zcrypt_rng_device_add+0x94/0xd8 [zcrypt]
... [<0000000357d7bc52>] hwrng_register+0x212/0x228
... [<0000000357d7b8c2>] add_early_randomness+0x102/0x110
... [<000003ff7fb29c94>] zcrypt_rng_data_read+0x94/0xb8 [zcrypt]
... [<0000000358150aca>] ap_bus_force_rescan+0x92/0x108
... [<0000000358177572>] mutex_lock_interruptible_nested+0x32/0x40 <- lock again

Note this only happens when the very first random data providing
crypto card appears via hot plug in the system AND is in disabled
state ("deconfig"). Then the initial pull of random data fails and
a re-scan of the AP bus is triggered while already in the middle
of an AP bus scan caused by the appearing new hardware.

The fix is relatively simple once the scenario us understood:
The AP bus force rescan function will immediately return if there
is currently an AP bus scan running with the very same thread id.

Fixes: eacf5b3651c5 ("s390/ap: introduce mutex to lock the AP bus scan")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

show more ...

s390/ap_bus: Cleanup debug code

The dynamic debugging provides function names on request. So remove
all explicit function strings.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-of

s390/ap_bus: Cleanup debug code

The dynamic debugging provides function names on request. So remove
all explicit function strings.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/ap: Refine AP bus bindings complete processing

With the rework of the AP bus scan and the introduction of
a bindings complete completion also the timing until the
userspace finally receives a A

s390/ap: Refine AP bus bindings complete processing

With the rework of the AP bus scan and the introduction of
a bindings complete completion also the timing until the
userspace finally receives a AP bus binding complete uevent
had increased. Unfortunately this event triggers some important
jobs for preparation of KVM guests, for example the modification
of card/queue masks to reassign AP resources to the alternate
AP queue device driver (vfio_ap) which is the precondition
for building mediated devices which may be a precondition for
starting KVM guests using AP resources.

This small fix now triggers the check for binding complete
each time an AP device driver has registered. With this patch
the bindings complete may be posted up to 30s earlier as there
is no need to wait for the next AP bus scan any more.

Fixes: 778412ab915d ("s390/ap: rearm APQNs bindings complete completion")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: stable@vger.kernel.org
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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driver core: have match() callback in struct bus_type take a const *

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *. This

driver core: have match() callback in struct bus_type take a const *

In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *. This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly. This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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s390/ap: Fix bind complete udev event sent after each AP bus scan

With the mentioned commit (see the fixes tag) on every AP bus scan an
uevent "AP bus change bindings complete" is emitted. Furtherm

s390/ap: Fix bind complete udev event sent after each AP bus scan

With the mentioned commit (see the fixes tag) on every AP bus scan an
uevent "AP bus change bindings complete" is emitted. Furthermore if an AP
device switched from one driver to another, for example by manipulating the
apmask, there was never a "bindings complete" uevent generated.

The "bindings complete" event should be sent once when all AP devices have
been bound to device drivers and again if unbind/bind actions take place
and finally all AP devices are bound again. Therefore implement this.

Fixes: 778412ab915d ("s390/ap: rearm APQNs bindings complete completion")
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/ap: Fix crash in AP internal function modify_bitmap()

A system crash like this

Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
Fault in home space mode while using kernel ASCE.

s390/ap: Fix crash in AP internal function modify_bitmap()

A system crash like this

Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403
Fault in home space mode while using kernel ASCE.
AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d
Oops: 0038 ilc:3 [#1] PREEMPT SMP
Modules linked in: mlx5_ib ...
CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8
Hardware name: IBM 3931 A01 704 (LPAR)
Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3
000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0
000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff
000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8
Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a
0000014b75e7b600: 18b2 lr %r11,%r2
#0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616
>0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13)
0000014b75e7b60c: a7680001 lhi %r6,1
0000014b75e7b610: 187b lr %r7,%r11
0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654
0000014b75e7b616: 18e9 lr %r14,%r9
Call Trace:
[<0000014b75e7b606>] ap_parse_bitmap_str+0x10e/0x1f8
([<0000014b75e7b5dc>] ap_parse_bitmap_str+0xe4/0x1f8)
[<0000014b75e7b758>] apmask_store+0x68/0x140
[<0000014b75679196>] kernfs_fop_write_iter+0x14e/0x1e8
[<0000014b75598524>] vfs_write+0x1b4/0x448
[<0000014b7559894c>] ksys_write+0x74/0x100
[<0000014b7618a440>] __do_syscall+0x268/0x328
[<0000014b761a3558>] system_call+0x70/0x98
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<0000014b75e7b636>] ap_parse_bitmap_str+0x13e/0x1f8
Kernel panic - not syncing: Fatal exception: panic_on_oops

occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value
(like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.

The fix is simple: use unsigned long values for the internal variables. The
correct checks are already in place in the function but a simple int for
the internal variables was used with the possibility to overflow.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/ap: Externalize AP bus specific bitmap reading function

Rename hex2bitmap() to ap_hex2bitmap() and export it for external
use. This function will be used by the implementation of the vfio-ap
ap

s390/ap: Externalize AP bus specific bitmap reading function

Rename hex2bitmap() to ap_hex2bitmap() and export it for external
use. This function will be used by the implementation of the vfio-ap
ap_config sysfs attribute.

Signed-off-by: "Jason J. Herne" <jjherne@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20240415152555.13152-2-jjherne@linux.ibm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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s390/ap: modularize ap bus

There is no hard requirement to have the ap bus statically in the
kernel, so add an option to compile it as module.

Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pa

s390/ap: modularize ap bus

There is no hard requirement to have the ap bus statically in the
kernel, so add an option to compile it as module.

Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/chsc: use notifier for AP configuration changes

The direct dependency of chsc and the AP bus prevents the
modularization of ap bus. Introduce a notifier interface for AP
changes, which decouple

s390/chsc: use notifier for AP configuration changes

The direct dependency of chsc and the AP bus prevents the
modularization of ap bus. Introduce a notifier interface for AP
changes, which decouples the producer of the change events (chsc) from
the consumer (ap_bus).

Remove the ap_cfg_chg() interface and replace it with the notifier
invocation. The ap bus module registers a notification handler, which
triggers the AP bus scan.

Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: swap IRQ and bus/device registration

The IRQ handler may rely on the bus or the root device. Register the
adapter IRQ after setting up the bus and the root device to avoid any
race conditio

s390/ap: swap IRQ and bus/device registration

The IRQ handler may rely on the bus or the root device. Register the
adapter IRQ after setting up the bus and the root device to avoid any
race conditions.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: rework ap initialization

Rework the ap initialization and add missing cleanups to the error path.
Errors during the registration of IRQ handler is now also detected.

Suggested-by: Heiko Ca

s390/ap: rework ap initialization

Rework the ap initialization and add missing cleanups to the error path.
Errors during the registration of IRQ handler is now also detected.

Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: use static qci information

Since qci is available on most of the current machines, move away from
the dynamic buffers for qci information and store it instead in a
statically defined buffer

s390/ap: use static qci information

Since qci is available on most of the current machines, move away from
the dynamic buffers for qci information and store it instead in a
statically defined buffer.

The new flags member in struct ap_config_info is now used as an
indicator, if qci is available in the system (at least one of these
bits is set).

Suggested-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

show more ...

s390/ap: introduce mutex to lock the AP bus scan

Rework the invocations around ap_scan_bus():
- Protect ap_scan_bus() with a mutex to make sure only one
scan at a time is running.
- The workqueue

s390/ap: introduce mutex to lock the AP bus scan

Rework the invocations around ap_scan_bus():
- Protect ap_scan_bus() with a mutex to make sure only one
scan at a time is running.
- The workqueue invocation which is triggered by either the
module init or via AP bus scan timer expiration uses this
mutex and if there is already a scan running, the work
is simple aborted (as the job is done by another task).
- The ap_bus_force_rescan() which is invoked by higher level
layers mostly on failures which indicate a bus scan may
help is reworked to call ap_scan_bus() direct instead of
enqueuing work into a system workqueue and waiting for that
to finish. Of course the mutex is respected and in case of
another task already running a bus scan the shortcut of
waiting for this scan to finish and reusing the scan result
is taken.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/ap: rework ap_scan_bus() to return true on config change

The AP scan bus function now returns true if there have
been any config changes detected. This will become
important in a follow up patc

s390/ap: rework ap_scan_bus() to return true on config change

The AP scan bus function now returns true if there have
been any config changes detected. This will become
important in a follow up patch which will exploit this
hint for further actions. This also required to have
the AP scan bus timer callback reworked as the function
signature has changed to bool ap_scan_bus(void).

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/ap: clarify AP scan bus related functions and variables

This patch tries to clarify the functions and variables
around the AP scan bus job. All these variables and
functions start with ap_scan_

s390/ap: clarify AP scan bus related functions and variables

This patch tries to clarify the functions and variables
around the AP scan bus job. All these variables and
functions start with ap_scan_bus and are declared in
one place now.

No functional changes in this patch - only renaming and
move of code or declarations.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/ap: rearm APQNs bindings complete completion

The APQN bindings complete completion was used to reflect
that 1st the AP bus initial scan is done and 2nd all the
detected APQNs have been bound to

s390/ap: rearm APQNs bindings complete completion

The APQN bindings complete completion was used to reflect
that 1st the AP bus initial scan is done and 2nd all the
detected APQNs have been bound to a device driver.
This was a single-shot action. However, as the AP bus
supports hot-plug it may be that new APQNs appear reflected
as new AP queue and card devices which need to be bound
to appropriate device drivers. So the condition that
all existing AP queue devices are bound to device drivers
may go away for a certain time.

This patch now checks during AP bus scan for maybe new AP
devices appearing and does a re-init of the internal completion
variable. So the AP bus function ap_wait_apqn_bindings_complete()
now may block on this condition variable even later after
initial scan is through when new APQNs appear which need to
get bound.

This patch also moves the check for binding complete invocation
from the probe function to the end of the AP bus scan function.
This change also covers some weird scenarios where during a
card hotplug the binding of the card device was sufficient for
binding complete but the queue devices where still in the
process of being discovered.

As of now this change has no impact on existing code. The
behavior change in the now later bindings complete should not
impact any code (and has been tested so far). The only
exploiter is the zcrypt function zcrypt_wait_api_operational()
which only initial calls ap_wait_apqn_bindings_complete().

However, this new behavior of the AP bus wait for APQNs bindings
complete function will be used in a later patch exploiting
this for the zcrypt API layer.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/ap: explicitly include ultravisor header

The ap_bus is using inline functions of the ultravisor (uv) in-kernel
API. The related header file is implicitly included via several other
headers. Rep

s390/ap: explicitly include ultravisor header

The ap_bus is using inline functions of the ultravisor (uv) in-kernel
API. The related header file is implicitly included via several other
headers. Replace this by an explicit include of the ultravisor header
in the ap_bus file.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/zcrypt: introduce dynamic debugging for AP and zcrypt code

This patch replaces all the s390 debug feature calls with
debug level by dynamic debug calls pr_debug. These calls
are much more flexi

s390/zcrypt: introduce dynamic debugging for AP and zcrypt code

This patch replaces all the s390 debug feature calls with
debug level by dynamic debug calls pr_debug. These calls
are much more flexible and each single invocation can get
enabled/disabled at runtime wheres the s390 debug feature
debug calls have only one knob - enable or disable all in
one bunch. The benefit is especially significant with
high frequency called functions like the AP bus scan. In
most debugging scenarios you don't want and need them, but
sometimes it is crucial to know exactly when and how long
the AP bus scan took.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

show more ...

s390/zcrypt: harmonize debug feature calls and defines

This patch harmonizes the calls and defines around the
s390 debug feature as it is used in the AP bus and
zcrypt device driver code.

More or l

s390/zcrypt: harmonize debug feature calls and defines

This patch harmonizes the calls and defines around the
s390 debug feature as it is used in the AP bus and
zcrypt device driver code.

More or less cleanup and renaming, no functional changes.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/ap: make ap_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the ap_bus_type variable to be a constant structure as well,
placing it into read-only mem

s390/ap: make ap_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the ap_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-5-ac891afc7282@marliere.net
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

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s390/ap: handle outband SE bind state change

This patch addresses some weird scenarios where an outband
manipulation of the SE bind state of a queue assigned and
maybe in use by an SE guest with AP

s390/ap: handle outband SE bind state change

This patch addresses some weird scenarios where an outband
manipulation of the SE bind state of a queue assigned and
maybe in use by an SE guest with AP pass-through support
took place. So for example when the guest has bound and
associated a queue and then this domain has been zeroed on
the service element.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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s390/ap: store TAPQ hwinfo in struct ap_card

As of now the AP card struct held only part of the
queue's hwinfo (that is the GR2 register content returned
with an TAPQ invocation). This patch reworks

s390/ap: store TAPQ hwinfo in struct ap_card

As of now the AP card struct held only part of the
queue's hwinfo (that is the GR2 register content returned
with an TAPQ invocation). This patch reworks struct ap_card
to hold the whole hwinfo now.

As there is a nice bit field union on top of this
ap_tapq_hwinfo struct, all the ugly bit checkings can
now get replaced by simple evaluations of the required
bit field.

Suggested-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

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s390/ap: fix vanishing crypto cards in SE environment

A secure execution (SE, also known as confidential computing)
guest may see asynchronous errors on a crypto firmware queue.
The current implemen

s390/ap: fix vanishing crypto cards in SE environment

A secure execution (SE, also known as confidential computing)
guest may see asynchronous errors on a crypto firmware queue.
The current implementation to gather information about cards
and queues in ap_queue_info() simple returns if an asynchronous
error is hanging on the firmware queue. If such a situation
happened and it was the only queue visible for a crypto card
within an SE guest, then the card vanished from sysfs as
the AP bus scan function refuses to hold a card without any
type information. As lszcrypt evaluates the sysfs such
a card vanished from the lszcrypt card listing and the
user is baffled and has no way to reset and thus clear the
pending asynchronous error.

This patch improves the named function to also evaluate GR2
of the TAPQ in case of asynchronous error pending. If there
is a not-null value stored in, the info is processed now.
In the end, a queue with pending asynchronous error does not
lead to a vanishing card any more.

Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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s390/ap: fix AP bus crash on early config change callback invocation

Fix kernel crash in AP bus code caused by very early invocation of the
config change callback function via SCLP.

After a fresh I

s390/ap: fix AP bus crash on early config change callback invocation

Fix kernel crash in AP bus code caused by very early invocation of the
config change callback function via SCLP.

After a fresh IML of the machine the crypto cards are still offline and
will get switched online only with activation of any LPAR which has the
card in it's configuration. A crypto card coming online is reported
to the LPAR via SCLP and the AP bus offers a callback function to get
this kind of information. However, it may happen that the callback is
invoked before the AP bus init function is complete. As the callback
triggers a synchronous AP bus scan, the scan may already run but some
internal states are not initialized by the AP bus init function resulting
in a crash like this:

[ 11.635859] Unable to handle kernel pointer dereference in virtual kernel address space
[ 11.635861] Failing address: 0000000000000000 TEID: 0000000000000887
[ 11.635862] Fault in home space mode while using kernel ASCE.
[ 11.635864] AS:00000000894c4007 R3:00000001fece8007 S:00000001fece7800 P:000000000000013d
[ 11.635879] Oops: 0004 ilc:1 [#1] SMP
[ 11.635882] Modules linked in:
[ 11.635884] CPU: 5 PID: 42 Comm: kworker/5:0 Not tainted 6.6.0-rc3-00003-g4dbf7cdc6b42 #12
[ 11.635886] Hardware name: IBM 3931 A01 751 (LPAR)
[ 11.635887] Workqueue: events_long ap_scan_bus
[ 11.635891] Krnl PSW : 0704c00180000000 0000000000000000 (0x0)
[ 11.635895] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 11.635897] Krnl GPRS: 0000000001000a00 0000000000000000 0000000000000006 0000000089591940
[ 11.635899] 0000000080000000 0000000000000a00 0000000000000000 0000000000000000
[ 11.635901] 0000000081870c00 0000000089591000 000000008834e4e2 0000000002625a00
[ 11.635903] 0000000081734200 0000038000913c18 000000008834c6d6 0000038000913ac8
[ 11.635906] Krnl Code:>0000000000000000: 0000 illegal
[ 11.635906] 0000000000000002: 0000 illegal
[ 11.635906] 0000000000000004: 0000 illegal
[ 11.635906] 0000000000000006: 0000 illegal
[ 11.635906] 0000000000000008: 0000 illegal
[ 11.635906] 000000000000000a: 0000 illegal
[ 11.635906] 000000000000000c: 0000 illegal
[ 11.635906] 000000000000000e: 0000 illegal
[ 11.635915] Call Trace:
[ 11.635916] [<0000000000000000>] 0x0
[ 11.635918] [<000000008834e4e2>] ap_queue_init_state+0x82/0xb8
[ 11.635921] [<000000008834ba1c>] ap_scan_domains+0x6fc/0x740
[ 11.635923] [<000000008834c092>] ap_scan_adapter+0x632/0x8b0
[ 11.635925] [<000000008834c3e4>] ap_scan_bus+0xd4/0x288
[ 11.635927] [<00000000879a33ba>] process_one_work+0x19a/0x410
[ 11.635930] Discipline DIAG cannot be used without z/VM
[ 11.635930] [<00000000879a3a2c>] worker_thread+0x3fc/0x560
[ 11.635933] [<00000000879aea60>] kthread+0x120/0x128
[ 11.635936] [<000000008792afa4>] __ret_from_fork+0x3c/0x58
[ 11.635938] [<00000000885ebe62>] ret_from_fork+0xa/0x30
[ 11.635942] Last Breaking-Event-Address:
[ 11.635942] [<000000008834c6d4>] ap_wait+0xcc/0x148

This patch improves the ap_bus_force_rescan() function which is
invoked by the config change callback by checking if a first
initial AP bus scan has been done. If not, the force rescan request
is simple ignored. Anyhow it does not make sense to trigger AP bus
re-scans even before the very first bus scan is complete.

Cc: stable@vger.kernel.org
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

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