linux.git/drivers/s390/crypto, branch v6.7

s390/ap: fix vanishing crypto cards in SE environment

2023-11-05T21:34:57+00:00

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 
Signed-off-by: Harald Freudenberger 
Signed-off-by: Vasily Gorbik

s390/zcrypt: don't report online if card or queue is in check-stop state

2023-11-05T21:34:57+00:00

If a card or a queue is in check-stop state, it can't be used by
applications to perform crypto operations. Applications check the 'online'
sysfs attribute to check if a card or queue is usable.

Report a card or queue as offline in case it is in check-stop state.
Furthermore, don't allow to set a card or queue online, if it is in
check-stop state.

This is similar to when the card or the queue is in deconfigured state,
there it is also reported as being offline, and it can't be set online.

Reviewed-by: Harald Freudenberger 
Signed-off-by: Ingo Franzki 
Signed-off-by: Vasily Gorbik

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

2023-11-05T21:34:57+00:00

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 
Signed-off-by: Harald Freudenberger 
Signed-off-by: Vasily Gorbik

s390/ap: re-enable interrupt for AP queues

2023-11-05T21:34:57+00:00

This patch introduces some code lines which check
for interrupt support enabled on an AP queue after
a reply has been received. This invocation has been
chosen as there is a good chance to have the queue
empty at that time. As the enablement of the irq
imples a state machine change the queue should not
have any pending requests or unreceived replies.

Reviewed-by: Tony Krowiak 
Reviewed-by: Holger Dengler 
Signed-off-by: Harald Freudenberger 
Signed-off-by: Vasily Gorbik

s390/ap: rework to use irq info from ap queue status

2023-11-05T21:34:57+00:00

This patch reworks the irq handling and reporting code
for the AP queue interrupt handling to always use the
irq info from the queue status.

Until now the interrupt status of an AP queue was stored
into a bool variable within the ap_queue struct. This
variable was set on a successful interrupt enablement
and cleared with kicking a reset. However, it may be
that the interrupt state is manipulated outband for
example by a hypervisor. This patch removes this variable
and instead the irq bit from the AP queue status which is
always reflecting the current irq state is used.

Reviewed-by: Tony Krowiak 
Reviewed-by: Holger Dengler 
Signed-off-by: Harald Freudenberger 
Signed-off-by: Vasily Gorbik

s390/ap: show APFS value on error reply 0x8B

2023-10-16T11:04:09+00:00

With Secure Execution the error reply RX 0x8B now carries
an APFS value indicating why the request has been filtered
by a lower layer of the firmware. So display this value
as a warning line in the s390 debug feature trace.

Signed-off-by: Harald Freudenberger 
Reviewed-by: Holger Dengler 
Signed-off-by: Vasily Gorbik

s390/zcrypt: introduce new internal AP queue se_bound attribute

2023-10-16T11:04:09+00:00

This patch introduces a new AP queue internal attribute
se_bound which reflects the bound state of an APQN within
a Secure Execution environment.

With introduction of Secure Execution guests now an
AP firmware queue needs to be bound to the guest before
usage. This patch introduces a new internal attribute
reflecting this bound state and some glue code to handle
this new field during lifetime of an AP queue device.

Together with that now the zcrypt scheduler considers
the state of the AP queues when a message is about to be
distributed among the existing queues. There is a new
function ap_queue_usable() which returns true only when
all conditions for using this AP queue device are fulfilled.
In details this means: the AP queue needs to be configured,
not checkstopped and within an SE environment it needs
to be bound. So the new function gives and indication
if the AP queue device is ready to serve requests or not.

Signed-off-by: Harald Freudenberger 
Reviewed-by: Holger Dengler 
Signed-off-by: Vasily Gorbik

s390/ap: re-init AP queues on config on

2023-10-16T11:04:09+00:00

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: 2d72eaf036d2 ("s390/ap: implement SE AP bind, unbind and associate")
Signed-off-by: Harald Freudenberger 
Reviewed-by: Holger Dengler 
Signed-off-by: Vasily Gorbik

s390/zcrypt: update list of EP11 operation modes

2023-09-19T11:26:55+00:00

Add additional operation mode strings into the EP11 operation mode table.
These strings are returned by sysfs entries /sys/devices/ap/cardxx/op_modes
and /sys/devices/ap/cardxx/xx.yyyy/op_modes.

Signed-off-by: Ingo Franzki 
Reviewed-by: Harald Freudenberger 
Signed-off-by: Vasily Gorbik

Merge tag 's390-6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2023-09-07T17:52:13+00:00

Pull more s390 updates from Heiko Carstens:

 - A couple of virtual vs physical address confusion fixes

 - Rework locking in dcssblk driver to address a lockdep warning

 - Remove support for "noexec" kernel command line option since there is
   no use case where it would make sense

 - Simplify kernel mapping setup and get rid of quite a bit of code

 - Add architecture specific __set_memory_yy() functions which allow us
   to modify kernel mappings. Unlike the set_memory_xx() variants they
   take void pointer start and end parameters, which allows using them
   without the usual casts, and also to use them on areas larger than
   8TB.

   Note that the set_memory_xx() family comes with an int num_pages
   parameter which overflows with 8TB. This could be addressed by
   changing the num_pages parameter to unsigned long, however requires
   to change all architectures, since the module code expects an int
   parameter (see module_set_memory()).

   This was indeed an issue since for debug_pagealloc() we call
   set_memory_4k() on the whole identity mapping. Therefore address this
   for now with the __set_memory_yy() variant, and address common code
   later

 - Use dev_set_name() and also fix memory leak in zcrypt driver error
   handling

 - Remove unused lsi_mask from airq_struct

 - Add warning for invalid kernel mapping requests

* tag 's390-6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vmem: do not silently ignore mapping limit
  s390/zcrypt: utilize dev_set_name() ability to use a formatted string
  s390/zcrypt: don't leak memory if dev_set_name() fails
  s390/mm: fix MAX_DMA_ADDRESS physical vs virtual confusion
  s390/airq: remove lsi_mask from airq_struct
  s390/mm: use __set_memory() variants where useful
  s390/set_memory: add __set_memory() variant
  s390/set_memory: generate all set_memory() functions
  s390/mm: improve description of mapping permissions of prefix pages
  s390/amode31: change type of __samode31, __eamode31, etc
  s390/mm: simplify kernel mapping setup
  s390: remove "noexec" option
  s390/vmem: fix virtual vs physical address confusion
  s390/dcssblk: fix lockdep warning
  s390/monreader: fix virtual vs physical address confusion