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221 commits

Author SHA1 Message Date
Harald Freudenberger
306d6bda8f 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: 778412ab91 ("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>
2024-05-16 10:17:11 +02:00
Harald Freudenberger
d4f9d5a99a 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>
2024-05-16 10:17:11 +02:00
Jason J. Herne
6e6973948c 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>
2024-04-22 12:49:17 +02:00
Holger Dengler
123760841a 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>
2024-04-09 17:29:56 +02:00
Holger Dengler
2a483d333f 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>
2024-04-09 17:29:55 +02:00
Holger Dengler
3c7a377324 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>
2024-04-09 17:29:55 +02:00
Holger Dengler
170660ccf8 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>
2024-04-09 17:29:55 +02:00
Holger Dengler
8dec9cb9f5 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>
2024-04-09 17:29:55 +02:00
Harald Freudenberger
eacf5b3651 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>
2024-03-07 14:41:14 +01:00
Harald Freudenberger
b5caf05ee8 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>
2024-03-07 14:41:14 +01:00
Harald Freudenberger
99b3126e46 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>
2024-03-07 14:41:14 +01:00
Harald Freudenberger
778412ab91 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>
2024-03-07 14:41:14 +01:00
Holger Dengler
d065bdb4d1 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>
2024-02-20 14:37:31 +01:00
Harald Freudenberger
08b2c3706d 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>
2024-02-16 14:30:12 +01:00
Harald Freudenberger
88e4c0da9b 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>
2024-02-16 14:30:12 +01:00
Ricardo B. Marliere
5b43178754 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>
2024-02-09 13:58:16 +01:00
Harald Freudenberger
207022d39d 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>
2023-11-30 16:24:23 +01:00
Harald Freudenberger
d4c53ae8e4 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>
2023-11-30 16:24:23 +01:00
Harald Freudenberger
5cf1a563a3 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>
2023-11-05 22:34:57 +01:00
Harald Freudenberger
e14aec2302 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>
2023-11-05 22:34:57 +01:00
Harald Freudenberger
32d1d9204f s390/ap: re-init AP queues on config on
On a state toggle from config off to config on and on the
state toggle from checkstop to not checkstop the queue's
internal states was set but the state machine was not
nudged. This did not care as on the first enqueue of a
request the state machine kick ran.

However, within an Secure Execution guest a queue is
only chosen by the scheduler when it has been bound.
But to bind a queue, it needs to run through the initial
states (reset, enable interrupts, ...). So this is like
a chicken-and-egg problem and the result was in fact
that a queue was unusable after a config off/on toggle.

With some slight rework of the handling of these states
now the new function _ap_queue_init_state() is called
which is the core of the ap_queue_init_state() function
but without locking handling. This has the benefit that
it can be called on all the places where a (re-)init
of the AP queue's state machine is needed.

Fixes: 2d72eaf036 ("s390/ap: implement SE AP bind, unbind and associate")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2023-10-16 13:04:09 +02:00
Holger Dengler
386cb81e4b s390/zcrypt_ep11misc: support API ordinal 6 with empty pin-blob
Secure execution guest environments require an empty pinblob in all
key generation and unwrap requests. Empty pinblobs are only available
in EP11 API ordinal 6 or higher.

Add an empty pinblob to key generation and unwrap requests, if the AP
secure binding facility is available. In all other cases, stay with
the empty pin tag (no pinblob) and the current API ordinals.

The EP11 API ordinal also needs to be considered when the pkey module
tries to figure out the list of eligible cards for key operations
with protected keys in secure execution environment.

These changes are transparent to userspace but required for running
an secure execution guest with handling key generate and key derive
(e.g. secure key to protected key) correct. Especially using EP11
secure keys with the kernel dm-crypt layer requires this patch.

Co-developed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-08-18 15:07:57 +02:00
Harald Freudenberger
5ac8c72462 s390/zcrypt: remove CEX2 and CEX3 device drivers
Remove the legacy device driver code for CEX2 and CEX3 cards.

The last machines which are able to handle CEX2 crypto cards
are z10 EC first available 2008 and z10 BC first available 2009.
The last machines able to handle a CEX3 crypto card are
z196 first available 2010 and z114 first available 2011.

Please note that this does not imply to drop CEX2 and CEX3
support in general. With older kernels on hardware up to the
aforementioned machine models these crypto cards will get
support by IBM.

The removal of the CEX2 and CEX3 device drivers code opens up
some simplifications, for example support for crypto cards
without rng support can be removed also.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-24 12:12:22 +02:00
Heiko Carstens
cada938a01 s390: fix various typos
Fix various typos found with codespell.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2023-07-03 11:19:42 +02:00
Linus Torvalds
10de638d8e s390 updates for the 6.4 merge window
- Add support for stackleak feature. Also allow specifying
   architecture-specific stackleak poison function to enable faster
   implementation. On s390, the mvc-based implementation helps decrease
   typical overhead from a factor of 3 to just 25%
 
 - Convert all assembler files to use SYM* style macros, deprecating the
   ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS
 
 - Improve KASLR to also randomize module and special amode31 code
   base load addresses
 
 - Rework decompressor memory tracking to support memory holes and improve
   error handling
 
 - Add support for protected virtualization AP binding
 
 - Add support for set_direct_map() calls
 
 - Implement set_memory_rox() and noexec module_alloc()
 
 - Remove obsolete overriding of mem*() functions for KASAN
 
 - Rework kexec/kdump to avoid using nodat_stack to call purgatory
 
 - Convert the rest of the s390 code to use flexible-array member instead
   of a zero-length array
 
 - Clean up uaccess inline asm
 
 - Enable ARCH_HAS_MEMBARRIER_SYNC_CORE
 
 - Convert to using CONFIG_FUNCTION_ALIGNMENT and enable
   DEBUG_FORCE_FUNCTION_ALIGN_64B
 
 - Resolve last_break in userspace fault reports
 
 - Simplify one-level sysctl registration
 
 - Clean up branch prediction handling
 
 - Rework CPU counter facility to retrieve available counter sets just
   once
 
 - Other various small fixes and improvements all over the code
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Merge tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for stackleak feature. Also allow specifying
   architecture-specific stackleak poison function to enable faster
   implementation. On s390, the mvc-based implementation helps decrease
   typical overhead from a factor of 3 to just 25%

 - Convert all assembler files to use SYM* style macros, deprecating the
   ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS

 - Improve KASLR to also randomize module and special amode31 code base
   load addresses

 - Rework decompressor memory tracking to support memory holes and
   improve error handling

 - Add support for protected virtualization AP binding

 - Add support for set_direct_map() calls

 - Implement set_memory_rox() and noexec module_alloc()

 - Remove obsolete overriding of mem*() functions for KASAN

 - Rework kexec/kdump to avoid using nodat_stack to call purgatory

 - Convert the rest of the s390 code to use flexible-array member
   instead of a zero-length array

 - Clean up uaccess inline asm

 - Enable ARCH_HAS_MEMBARRIER_SYNC_CORE

 - Convert to using CONFIG_FUNCTION_ALIGNMENT and enable
   DEBUG_FORCE_FUNCTION_ALIGN_64B

 - Resolve last_break in userspace fault reports

 - Simplify one-level sysctl registration

 - Clean up branch prediction handling

 - Rework CPU counter facility to retrieve available counter sets just
   once

 - Other various small fixes and improvements all over the code

* tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (118 commits)
  s390/stackleak: provide fast __stackleak_poison() implementation
  stackleak: allow to specify arch specific stackleak poison function
  s390: select ARCH_USE_SYM_ANNOTATIONS
  s390/mm: use VM_FLUSH_RESET_PERMS in module_alloc()
  s390: wire up memfd_secret system call
  s390/mm: enable ARCH_HAS_SET_DIRECT_MAP
  s390/mm: use BIT macro to generate SET_MEMORY bit masks
  s390/relocate_kernel: adjust indentation
  s390/relocate_kernel: use SYM* macros instead of ENTRY(), etc.
  s390/entry: use SYM* macros instead of ENTRY(), etc.
  s390/purgatory: use SYM* macros instead of ENTRY(), etc.
  s390/kprobes: use SYM* macros instead of ENTRY(), etc.
  s390/reipl: use SYM* macros instead of ENTRY(), etc.
  s390/head64: use SYM* macros instead of ENTRY(), etc.
  s390/earlypgm: use SYM* macros instead of ENTRY(), etc.
  s390/mcount: use SYM* macros instead of ENTRY(), etc.
  s390/crc32le: use SYM* macros instead of ENTRY(), etc.
  s390/crc32be: use SYM* macros instead of ENTRY(), etc.
  s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc.
  s390/amode31: use SYM* macros instead of ENTRY(), etc.
  ...
2023-04-30 11:43:31 -07:00
Greg Kroah-Hartman
75cff725d9 driver core: bus: mark the struct bus_type for sysfs callbacks as constant
struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
bus_type to be moved to read-only memory.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ben Widawsky <bwidawsk@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hu Haowen <src.res@email.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Acked-by: Ilya Dryomov <idryomov@gmail.com> # rbd
Acked-by: Ira Weiny <ira.weiny@intel.com> # cxl
Reviewed-by: Alex Shi <alexs@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>	# pci
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi
Link: https://lore.kernel.org/r/20230313182918.1312597-23-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-23 13:20:40 +01:00
Harald Freudenberger
038c5bedbc s390/ap: add ap status asynch error support
Review and extend the low level AP code to be able to
deal with asynchronous reported errors on APQNs.

The hypervisor and the SE guest may be confronted with
an asynchronously reported error at return of an AP
instruction. So all places where AP instructions are
called need review and may eventually need extensions.
However, not all places need rework. As together with
the AP status and the enabled asynch bit there is always
a response code set. The asynch error reporting comes
with new response codes which may be simple handled in
the default case of a switch statement.

The idea behind this patch is to report asynch errors
as -EPERM (read this as "Operation not permitted") which
reflects the fact that only a rapq (with F bit enabled)
is a valid AP instruction when an asynch error is flagged.

The AP queue state machine functions return
AP_SM_WAIT_NONE when a asynch error is detected to reflect
the fact, that the state machine can't do anything with
such an error as long as the queue is reset.

Unfortunately the ap bus scan function needed some
update as the ap_queue_info() now needs to return
3 states: 1 if an APQN exists and info is available,
-1 if it is assumed an APQN does not exist and the new
return value 0 without any info values filled. This 0
returncode is handled as "there is an APQN but we currently
don't know any more hw info about this, so please use
your previous info and try again later".

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>
2023-03-20 11:12:49 +01:00
Harald Freudenberger
263c8454db s390/ap: introduce low frequency polling possibility
For some events the ap bus needs to poll. For example
when an AP queue is reset until the reset is through.
Also when no interrupt support is available (e.g. zVM)
there is a need to poll until all requests have been
processed and all replies have been delivered.

Polling is done with a high resolution timer by default
run with a rate of 4kHz (LPAR) or 666Hz (zVM guest).

For some events (wait for reset complete, wait for irq
enabled complete) this is a much too high poll rate
which triggers a lot of TAPQ invocations.

This patch introduces the possibility for the state
machine functions to return a new wait enum
AP_SM_WAIT_LOW_TIMEOUT which gives a hint to the
ap_wait() function to eventually set up the timer
with a more relaxed timeout value of 25Hz.

This patch also includes a slight rework of the sysfs
functions parsing the timer related stuff: Use of
kstrtobool and kstrtoul instead of sscanf.

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>
2023-03-20 11:12:49 +01:00
Harald Freudenberger
088174960e s390/ap: filter ap card functions, new queue functions attribute
With SE SB (Secure Binding) some currently unused and thus always
zero bits in the TAPQ GR2 result are now used to show the binding
state of a queue. So to check if a card has changed the comparing
base is exactly this GR2 value shown as 'ap_function' in sysfs
(/sys/devices/ap/cardxx/ap_functions). Now there is some queue
specific info in this info and so a new mask TAPQ_CARD_FUNC_CMP_MASK
is used to filter out only the relevant bits for card compare.

For the same reason now the function bits (including exactly this
bind/associate information) need to be exposed to user space now.
So tools like lszcrypt can evaluate binding/association state on a
queue base. So here comes a new sysfs attribute

  /sys/devices/ap/cardxx/xx.yyyy/ap_functions

This sysfs attribute is similar to the already existing
ap_functions attribute at ap card level. It shows the
upper 32 bits of GR2 from an invocation of TAPQ for this
AP queue.

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>
2023-03-20 11:12:48 +01:00
Harald Freudenberger
211c06d845 s390/ap: make tapq gr2 response a struct
This patch introduces a new struct ap_tapq_gr2 which covers
the response in GR2 on TAPQ invocation. This makes it much
easier and less error-prone for the calling functions to
access the right field without shifting and masking.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:12:48 +01:00
Harald Freudenberger
d7b1813af6 s390/ap: introduce new AP bus sysfs attribute features
Introduce a new AP bus sysfs attribute /sys/bus/ap/features
which shows the features from the QCI information.
Currently these feature bits are evaluated:

- QCI S bit is shown as 'APSC'
- QCI N bit is shown as 'APXA'
- QCI C bit is shown as 'QACT'
- QCI R bit is shown as 'RC8A'
- QCI B bit is shown as 'APSB'

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:12:48 +01:00
Harald Freudenberger
f604704021 s390/ap: exploit new B bit from QCI config info
This patch introduces an update to the ap_config_info
struct which is filled with the QCI subfunction. There
is a new bit apsb (short 'B') showing if the AP secure
bind facility is available. The patch also includes a
simple function ap_sb_available() wrapping this bit test.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:12:48 +01:00
Harald Freudenberger
964d581daf s390/zcrypt: replace scnprintf with sysfs_emit
Replace scnprintf() with sysfs_emit() and friends
where possible.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-03-20 11:12:48 +01:00
Greg Kroah-Hartman
2a81ada32f driver core: make struct bus_type.uevent() take a const *
The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-27 13:45:52 +01:00
Wei Yongjun
9ac74f0666 s390/ap: fix memory leak in ap_init_qci_info()
If kzalloc() for 'ap_qci_info_old' failed, 'ap_qci_info' shold be
freed before return. Otherwise it is a memory leak.

Link: https://lore.kernel.org/r/20221114110830.542246-1-weiyongjun@huaweicloud.com
Fixes: 283915850a ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-11-23 16:26:21 +01:00
Harald Freudenberger
0fef40be5d s390/ap: fix crash on older machines based on QCI info missing
On older z series machines (z12 and older) there is no QCI info
available. The AP code took care of this and the AP bus scan then
switched to simple probing via TAPQ.

With commit
283915850a ("s390/ap: notify drivers on config changed and scan complete callbacks")
some code was introduced which silently assumed that the QCI info is
always available. However, with KVM simulating an older machine (z12)
the result was a kernel crash. Funnily the same crash does not happen
on LPAR - maybe because NULL is a valid pointer and reading some data
from address 0 also works fine.

This fix now improves the code to be aware that the QCI instruction
may not be available on older machines and thus the two pointers to
QCI info structs may simple be NULL.

However, on a machine not providing the QCI info the two callbacks to
the zcrypt device drivers on_config_changed() and on_scan_complete()
provide parameters which are pointers to a QCI info struct.
These both callbacks are NOT served if there is no QCI info available.
The only consumer of these callbacks is the vfio device driver. This
driver only supports CEX4 and higher. All physical machines which are
able to provide CEX4 cards have QCI support available. So there is
no sense in for example fill the QCI info struct by hand with looping
over cards and queues and TAPQ each APQN.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 283915850a ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-08-15 17:19:52 +02:00
Linus Torvalds
24cb958695 s390 updates for 5.20 merge window
- Rework copy_oldmem_page() callback to take an iov_iter.
   This includes few prerequisite updates and fixes to the
   oldmem reading code.
 
 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities,
   but also allows CPU facilities.
 
 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.
 
 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.
 
 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto test.
 
 - Fix incorrect recovery of kretprobe modified return address in stacktrace.
 
 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.
 
 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as well
   as to implement more of the AP architecture.
 
 - Minor boot code cleanups.
 
 - Grammar and typo fixes to hmcdrv and tape drivers.
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Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

   This includes a few prerequisite updates and fixes to the oldmem
   reading code.

 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities, but
   also allows CPU facilities.

 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.

 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.

 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
   test.

 - Fix incorrect recovery of kretprobe modified return address in
   stacktrace.

 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.

 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as
   well as to implement more of the AP architecture.

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  Revert "s390/smp: enforce lowcore protection on CPU restart"
  Revert "s390/smp: rework absolute lowcore access"
  Revert "s390/smp,ptdump: add absolute lowcore markers"
  s390/unwind: fix fgraph return address recovery
  s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
  s390: add ELF note type for encrypted CPU state of a PV VCPU
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/setup: rearrange absolute lowcore initialization
  s390/boot: cleanup adjust_to_uv_max() function
  s390/smp: enforce lowcore protection on CPU restart
  s390/tape: fix comment typo
  s390/hmcdrv: fix Kconfig "its" grammar
  s390/docs: fix warnings for vfio_ap driver doc
  s390/docs: fix warnings for vfio_ap driver lock usage doc
  s390/crash: support multi-segment iterators
  s390/crash: use static swap buffer for copy_to_user_real()
  s390/crash: move copy_to_user_real() to crash_dump.c
  s390/zcore: fix race when reading from hardware system area
  s390/crash: fix incorrect number of bytes to copy to user space
  ...
2022-08-06 17:05:21 -07:00
Paolo Bonzini
63f4b21041 Merge remote-tracking branch 'kvm/next' into kvm-next-5.20
KVM/s390, KVM/x86 and common infrastructure changes for 5.20

x86:

* Permit guests to ignore single-bit ECC errors

* Fix races in gfn->pfn cache refresh; do not pin pages tracked by the cache

* Intel IPI virtualization

* Allow getting/setting pending triple fault with KVM_GET/SET_VCPU_EVENTS

* PEBS virtualization

* Simplify PMU emulation by just using PERF_TYPE_RAW events

* More accurate event reinjection on SVM (avoid retrying instructions)

* Allow getting/setting the state of the speaker port data bit

* Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls are inconsistent

* "Notify" VM exit (detect microarchitectural hangs) for Intel

* Cleanups for MCE MSR emulation

s390:

* add an interface to provide a hypervisor dump for secure guests

* improve selftests to use TAP interface

* enable interpretive execution of zPCI instructions (for PCI passthrough)

* First part of deferred teardown

* CPU Topology

* PV attestation

* Minor fixes

Generic:

* new selftests API using struct kvm_vcpu instead of a (vm, id) tuple

x86:

* Use try_cmpxchg64 instead of cmpxchg64

* Bugfixes

* Ignore benign host accesses to PMU MSRs when PMU is disabled

* Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior

* x86/MMU: Allow NX huge pages to be disabled on a per-vm basis

* Port eager page splitting to shadow MMU as well

* Enable CMCI capability by default and handle injected UCNA errors

* Expose pid of vcpu threads in debugfs

* x2AVIC support for AMD

* cleanup PIO emulation

* Fixes for LLDT/LTR emulation

* Don't require refcounted "struct page" to create huge SPTEs

x86 cleanups:

* Use separate namespaces for guest PTEs and shadow PTEs bitmasks

* PIO emulation

* Reorganize rmap API, mostly around rmap destruction

* Do not workaround very old KVM bugs for L0 that runs with nesting enabled

* new selftests API for CPUID
2022-08-01 03:21:00 -04:00
Tony Krowiak
3f85d1df26 s390/vfio-ap: implement in-use callback for vfio_ap driver
Let's implement the callback to indicate when an APQN
is in use by the vfio_ap device driver. The callback is
invoked whenever a change to the apmask or aqmask would
result in one or more queue devices being removed from the driver. The
vfio_ap device driver will indicate a resource is in use
if the APQN of any of the queue devices to be removed are assigned to
any of the matrix mdevs under the driver's control.

There is potential for a deadlock condition between the
matrix_dev->guests_lock used to lock the guest during assignment of
adapters and domains and the ap_perms_mutex locked by the AP bus when
changes are made to the sysfs apmask/aqmask attributes.

The AP Perms lock controls access to the objects that store the adapter
numbers (ap_perms) and domain numbers (aq_perms) for the sysfs
/sys/bus/ap/apmask and /sys/bus/ap/aqmask attributes. These attributes
identify which queues are reserved for the zcrypt default device drivers.
Before allowing a bit to be removed from either mask, the AP bus must check
with the vfio_ap device driver to verify that none of the queues are
assigned to any of its mediated devices.

The apmask/aqmask attributes can be written or read at any time from
userspace, so care must be taken to prevent a deadlock with asynchronous
operations that might be taking place in the vfio_ap device driver. For
example, consider the following:

1. A system administrator assigns an adapter to a mediated device under the
   control of the vfio_ap device driver. The driver will need to first take
   the matrix_dev->guests_lock to potentially hot plug the adapter into
   the KVM guest.
2. At the same time, a system administrator sets a bit in the sysfs
   /sys/bus/ap/ap_mask attribute. To complete the operation, the AP bus
   must:
   a. Take the ap_perms_mutex lock to update the object storing the values
      for the /sys/bus/ap/ap_mask attribute.
   b. Call the vfio_ap device driver's in-use callback to verify that the
      queues now being reserved for the default zcrypt drivers are not
      assigned to a mediated device owned by the vfio_ap device driver. To
      do the verification, the in-use callback function takes the
      matrix_dev->guests_lock, but has to wait because it is already held
      by the operation in 1 above.
3. The vfio_ap device driver calls an AP bus function to verify that the
   new queues resulting from the assignment of the adapter in step 1 are
   not reserved for the default zcrypt device driver. This AP bus function
   tries to take the ap_perms_mutex lock but gets stuck waiting for the
   waiting for the lock due to step 2a above.

Consequently, we have the following deadlock situation:

matrix_dev->guests_lock locked (1)
ap_perms_mutex lock locked (2a)
Waiting for matrix_dev->gusts_lock (2b) which is currently held (1)
Waiting for ap_perms_mutex lock (3) which is currently held (2a)

To prevent this deadlock scenario, the function called in step 3 will no
longer take the ap_perms_mutex lock and require the caller to take the
lock. The lock will be the first taken by the adapter/domain assignment
functions in the vfio_ap device driver to maintain the proper locking
order.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-19 16:18:11 +02:00
Tony Krowiak
2f23256c0e s390/ap: fix error handling in __verify_queue_reservations()
The AP bus's __verify_queue_reservations function increments the ref count
for the device driver passed in as a parameter, but fails to decrement it
before returning control to the caller. This will prevents any subsequent
removal of the module.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reported-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Fixes: 4f8206b882 ("s390/ap: driver callback to indicate resource in use")
Link: https://lore.kernel.org/r/20220706222619.602094-1-akrowiak@linux.ibm.com
Cc: stable@vger.kernel.org
[agordeev@linux.ibm.com fixed description, added Fixes and Link]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-15 07:07:36 +02:00
Matthew Rosato
d2197485a1 s390/airq: pass more TPI info to airq handlers
A subsequent patch will introduce an airq handler that requires additional
TPI information beyond directed vs floating, so pass the entire tpi_info
structure via the handler.  Only pci actually uses this information today,
for the other airq handlers this is effectively a no-op.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-6-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2022-07-11 09:54:10 +02:00
Harald Freudenberger
2004b57cde s390/zcrypt: code cleanup
This patch tries to fix as much as possible of the
checkpatch.pl --strict findings:
  CHECK: Logical continuations should be on the previous line
  CHECK: No space is necessary after a cast
  CHECK: Alignment should match open parenthesis
  CHECK: 'useable' may be misspelled - perhaps 'usable'?
  WARNING: Possible repeated word: 'is'
  CHECK: spaces preferred around that '*' (ctx:VxV)
  CHECK: Comparison to NULL could be written "!msg"
  CHECK: Prefer kzalloc(sizeof(*zc)...) over kzalloc(sizeof(struct...)...)
  CHECK: Unnecessary parentheses around resp_type->work
  CHECK: Avoid CamelCase: <xcRB>

There is no functional change comming with this patch, only
code cleanup, renaming, whitespaces, indenting, ... but no
semantic change in any way. Also the API (zcrypt and pkey
header file) is semantically unchanged.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-25 13:54:14 +02:00
Harald Freudenberger
d9b38e9d0f s390/ap: uevent on apmask/aqpmask change
This patch introduces user space notifications for changes
on the apmask or aqmask attributes. So it could be possible
to write a udev rule to load/unload the vfio_ap kernel module
based on changes of these masks.

On chance of the apmask or aqmask an AP change event will
be produced with an uevent environment variable showing
the new APMASK or AQMASK mask.

So a change on the apmask triggers an uvevent like this:

  KERNEL[490.160396] change   /devices/ap (ap)
  ACTION=change
  DEVPATH=/devices/ap
  SUBSYSTEM=ap
  APMASK=0xffffffdfffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  SEQNUM=13367

and a change on the aqmask looks like this:

  KERNEL[283.217642] change   /devices/ap (ap)
  ACTION=change
  DEVPATH=/devices/ap
  SUBSYSTEM=ap
  AQMASK=0xfbffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
  SEQNUM=13348

Only real changes to the masks are processed - the old and
new masks are compared and no action is done if the values
are equal (and thus no uevent). The emit of the uevent is
the very last action done when a mask change is processed.
However, there is no guarantee that all unbind/bind actions
caused by the apmask/aqmask changes are completed when the
apmask/aqmask change uevent is received in userspace.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-04-25 13:54:13 +02:00
Harald Freudenberger
a7e701dba1 s390/zcrypt: handle checkstopped cards with new state
A crypto card may be in checkstopped state. With this
patch this is handled as a new state in the ap card and
ap queue structs. There is also a new card sysfs attribute

  /sys/devices/ap/cardxx/chkstop

and a new queue sysfs attribute

  /sys/devices/ap/cardxx/xx.yyyy/chkstop

displaying the checkstop state of the card or queue. Please
note that the queue's checkstop state is only a copy of the
card's checkstop state but makes maintenance much easier.

The checkstop state expressed here is the result of an
RC 0x04 (CHECKSTOP) during an AP command, mostly the
PQAP(TAPQ) command which is 'testing' the queue.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Harald Freudenberger
985214af93 s390/zcrypt: CEX8S exploitation support
This patch adds CEX8 exploitation support for the AP bus code,
the zcrypt device driver zoo and the vfio device driver.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00
Harald Freudenberger
8944d05f9b s390/ap: enable sysfs attribute scans to force AP bus rescan
This patch switches the sysfs attribute /sys/bus/ap/scans
from read-only to read-write. If there is something written
to this attribute, an AP bus rescan is forced. If an AP
bus scan is triggered this way a debug feature entry line
reports this in /sys/kernel/debug/s390dbf/ap/sprintf.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jakob Naucke <naucke@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-01 21:05:10 +01:00
Tony Krowiak
283915850a s390/ap: notify drivers on config changed and scan complete callbacks
This patch introduces an extension to the ap bus to notify device drivers
when the host AP configuration changes - i.e., adapters, domains or
control domains are added or removed. When an adapter or domain is added to
the host's AP configuration, the AP bus will create the associated queue
devices in the linux sysfs device model. Each new type 10 (i.e., CEX4) or
newer queue device with an APQN that is not reserved for the default device
driver will get bound to the vfio_ap device driver. Likewise, whan an
adapter or domain is removed from the host's AP configuration, the AP bus
will remove the associated queue devices from the sysfs device model. Each
of the queues that is bound to the vfio_ap device driver will get unbound.

With the introduction of hot plug support, binding or unbinding of a
queue device will result in plugging or unplugging one or more queues from
a guest that is using the queue. If there are multiple changes to the
host's AP configuration, it could result in the probe and remove callbacks
getting invoked multiple times. Each time queues are plugged into or
unplugged from a guest, the guest's VCPUs must be taken out of SIE.
If this occurs multiple times due to changes in the host's AP
configuration, that can have an undesirable negative affect on the guest's
performance.

To alleviate this problem, this patch introduces two new callbacks: one to
notify the vfio_ap device driver when the AP bus scan routine detects a
change to the host's AP configuration; and, one to notify the driver when
the AP bus is done scanning. This will allow the vfio_ap driver to do
bulk processing of all affected adapters, domains and control domains for
affected guests rather than plugging or unplugging them one at a time when
the probe or remove callback is invoked. The two new callbacks are:

void (*on_config_changed)(struct ap_config_info *new_config_info,
                          struct ap_config_info *old_config_info);

This callback is invoked at the start of the AP bus scan
function when it determines that the host AP configuration information
has changed since the previous scan. This is done by storing
an old and current QCI info struct and comparing them. If there is any
difference, the callback is invoked.

void (*on_scan_complete)(struct ap_config_info *new_config_info,
                         struct ap_config_info *old_config_info);

The on_scan_complete callback is invoked after the ap bus scan is
completed if the host AP configuration data has changed.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-01 21:05:10 +01:00
Tony Krowiak
4f8206b882 s390/ap: driver callback to indicate resource in use
Introduces a new driver callback to prevent a root user from re-assigning
the APQN of a queue that is in use by a non-default host device driver to
a default host device driver and vice versa. The callback will be invoked
whenever a change to the AP bus's sysfs apmask or aqmask attributes would
result in one or more APQNs being re-assigned. If the callback responds
in the affirmative for any driver queried, the change to the apmask or
aqmask will be rejected with a device busy error.

For this patch, only non-default drivers will be queried. Currently,
there is only one non-default driver, the vfio_ap device driver. The
vfio_ap device driver facilitates pass-through of an AP queue to a
guest. The idea here is that a guest may be administered by a different
sysadmin than the host and we don't want AP resources to unexpectedly
disappear from a guest's AP configuration (i.e., adapters and domains
assigned to the matrix mdev). This will enforce the proper procedure for
removing AP resources intended for guest usage which is to
first unassign them from the matrix mdev, then unbind them from the
vfio_ap device driver.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-01 21:05:09 +01:00
Harald Freudenberger
132c1e74aa s390/ap: function rework based on compiler warning
Slight rework of function __ap_revise_reserved()
because of unused variable warning when build with W=1.
This patch introduces an additional debug feature warning
message when device_reprobe() returns with failure.
However, the return value of __ap_revise_reserved()
is still hard coded to 0 as this is a callback function
to be used together with bus_for_each_dev() and thus
the return value indicates to go on with the
bus_for_each_dev() loop and not apport on a failure
of something within this function.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-26 15:21:30 +02:00
Harald Freudenberger
d098272565 s390/ap: new module option ap.useirq
This patch introduces a new AP module option to be able to
control if the ap bus code is using interrupts or not.
By default if the interrupt support is available it is used.
This option makes it possible to disable interrupt use even
when interrupt support is available.

It should be obvious that this option can't magically enable
interrupt support when the hardware or hypervisor layer does
not support AP interrupts.

On the kernel command line use ap.useirq=0 or ap.useirq=1
to disable or enable (that's the default) interrupt use.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-10-26 15:21:29 +02:00