Historically the uaccess code pre-initializes the result of get_user()
(and now also __get_kernel_nofault()) to zero and uses the result as
input parameter for inline assemblies. This is different to what most,
if not all, other architectures are doing, which set the result to
zero within the exception handler in case of a fault.
Use the new extable mechanism and handle zeroing of the result within
the exception handler in case of a fault.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Commit d768bd892f ("s390: add options to change branch prediction
behaviour for the kernel") introduced .Lsie_exit label - supposedly
to fence off SIE instruction. However, the corresponding address
range length .Lsie_crit_mcck_length was not updated, which led to
BPON code potentionally marked with CIF_MCCK_GUEST flag.
Both .Lsie_exit and .Lsie_crit_mcck_length were removed with commit
0b0ed657fe ("s390: remove critical section cleanup from entry.S"),
but the issue persisted - currently BPOFF and BPENTER macros might
get wrongly considered by the machine check handler as a guest.
Fixes: d768bd892f ("s390: add options to change branch prediction behaviour for the kernel")
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The switch to a keyed guest does not require a classic sske as the other
guest CPUs are not accessing the key before the switch is complete.
By using the NQ SSKE things are faster especially with multiple guests.
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Suggested-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With large and many guest with storage keys it is possible to create
large latencies or stalls during initial key setting:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 18-....: (2099 ticks this GP) idle=54e/1/0x4000000000000002 softirq=35598716/35598716 fqs=998
(t=2100 jiffies g=155867385 q=20879)
Task dump for CPU 18:
CPU 1/KVM R running task 0 1030947 256019 0x06000004
Call Trace:
sched_show_task
rcu_dump_cpu_stacks
rcu_sched_clock_irq
update_process_times
tick_sched_handle
tick_sched_timer
__hrtimer_run_queues
hrtimer_interrupt
do_IRQ
ext_int_handler
ptep_zap_key
The mmap lock is held during the page walking but since this is a
semaphore scheduling is still possible. Same for the kvm srcu.
To minimize overhead do this on every segment table entry or large page.
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20220530092706.11637-2-borntraeger@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add myself to the kernel side of virtio-ccw
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/20220525144028.2714489-2-farman@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Avoid invoking the OOM-killer when allocating the control page. This
is the s390 variant of commit dc5cccacf4 ("kexec: don't invoke
OOM-killer for control page allocation").
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The convention for indentation seems to be a single tab. Help text is
further indented by an additional two whitespaces. Fix the lines that
violate these rules.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Link: https://lore.kernel.org/r/20220525120151.39594-1-juerg.haefliger@canonical.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The convention for indentation seems to be a single tab. Help text is
further indented by an additional two whitespaces. Fix the lines that
violate these rules.
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Link: https://lore.kernel.org/r/20220525120140.39534-1-juerg.haefliger@canonical.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Since commit 1179f170b6 ("s390: fix fpu restore in entry.S"), the
sie_block pointer is located at empty1[1], but in sie_block() it was
taken from empty1[0].
This leads to a random pointer being dereferenced, possibly causing
system crash.
This problem can be observed when running a simple guest with an endless
loop and recording the cpu-clock event:
sudo perf kvm --guestvmlinux=<guestkernel> --guest top -e cpu-clock
With this fix, the correct guest address is shown.
Fixes: 1179f170b6 ("s390: fix fpu restore in entry.S")
Cc: stable@vger.kernel.org
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Use asm offsets method to generate register offsets into pt_regs,
instead of open-coding at several places.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Due to historic reasons the base program check handler calls a
configurable function. Given that there is only the early program
check handler left, simplify the code by directly calling that
function.
The only other user was removed with commit d485235b00 ("s390:
assume diag308 set always works").
Also rename all functions and the asm file to reflect this.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The argument of scatterwalk_unmap() is supposed to be the void* that was
returned by the previous scatterwalk_map() call.
The s390 AES-GCM implementation was instead passing the pointer to the
struct scatter_walk.
This doesn't actually break anything because scatterwalk_unmap() only uses
its argument under CONFIG_HIGHMEM and ARCH_HAS_FLUSH_ON_KUNMAP.
Fixes: bf7fa03870 ("s390/crypto: add s390 platform specific aes gcm support.")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Harald Freudenberger <freude@linux.ibm.com>
Link: https://lore.kernel.org/r/20220517143047.3054498-1-jannh@google.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Get rid of old 31 bit leftovers within ipl code:
- convert everything to pc relative code
- use 64 bit addressing mode as early as possible
- use 64 bit arithmetics wherever possible
This way the code doesn't look as odd as before anymore.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Before version 14.0.0 llvm's integrated assembler fails to handle some
displacement variants:
arch/s390/purgatory/head.S:108:10: error: invalid operand for instruction
lg %r11,kernel_type-.base_crash(%r13)
Instead of working around this and given that this is already fixed
raise the minimum clang version from 13.0.0 to 14.0.0.
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://reviews.llvm.org/D113341
Link: https://lore.kernel.org/r/20220511120532.2228616-9-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Commit ee6d777d3e ("s390/decompressor: support extra debug flags")
added extra debug flags, in particular debug info is created,
depending on config options.
With llvm's IAS this causes this compile warning:
arch/s390/boot/head.S:38:1: warning: DWARF2 only supports one section per compilation unit
.section ".head.text","ax"
^
This is a known problem and was addressed with commit b8a9092330
("Kbuild: do not emit debug info for assembly with LLVM_IAS=1").
Just do the same for s390 to get rid of this warning.
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220511120532.2228616-8-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
For at least the mvc and clc instructions llvm's integrated assembler can
generate incorrect code. In particular this happens with decompressor boot
code. The reason seems to be that relocations for the second displacement
of each instruction are at incorrect locations (-/+: gas vs llvm IAS):
mvc __LC_IO_NEW_PSW(16),.Lnewpsw
results in
4: d2 0f 01 f0 00 00 mvc 496(16,%r0),0
- 8: R_390_12 .head.text+0x10
+ 6: R_390_12 .head.text+0x10
and
clc 0(3,%r4),.L_hdr
results in
258: d5 02 40 00 00 00 clc 0(3,%r4),0
- 25c: R_390_12 .head.text+0x324
+ 25a: R_390_12 .head.text+0x324
Workaround this by writing the code in a different way.
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://github.com/llvm/llvm-project/issues/55411
Link: https://lore.kernel.org/r/20220511120532.2228616-7-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
llvm's integrated assembler cannot handle immediate values which are
calculated with two local labels:
arch/s390/purgatory/head.S:139:11: error: invalid operand for instruction
aghi %r8,-(.base_crash-purgatory_start)
Workaround this by partially rewriting the code.
Link: https://lore.kernel.org/r/20220511120532.2228616-6-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
llvm's integrated assembler cannot handle immediate values which are
calculated with two local labels:
<instantiation>:3:13: error: invalid operand for instruction
clgfi %r14,.Lsie_done - .Lsie_gmap
Workaround this by adding clang specific code which reads the specific
value from memory. Since this code is within the hot paths of the kernel
and adds an additional memory reference, keep the original code, and add
ifdef'ed code.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20220511120532.2228616-5-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
clang fails to handle ".if" statements in inline assembly which are heavily
used in the alternatives code.
To work around this remove this code, and enforce that users of
alternatives must specify original and alternative instruction sequences
which have identical sizes. Add a compile time check with two ".org"
statements similar to arm64.
In result not only clang can handle this, but also quite a lot of code can
be removed.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1356
Link: https://lore.kernel.org/r/20220511120532.2228616-3-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Explicitly provide identical sized original/alternative instruction
sequences. This way there is no need for the s390 specific alternatives
infrastructure to generate padding sequences.
The code which generates such sequences will be removed with a follow on
patch.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220511120532.2228616-2-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Export the extended counter set counters of the IBM z16 via sysfs.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
gcc 12 does not (always) optimize away code that should only be generated
if parameters are constant and within in a certain range. This depends on
various obscure kernel config options, however in particular
PROFILE_ALL_BRANCHES can trigger this compile error:
In function ‘__atomic_add_const’,
inlined from ‘__preempt_count_add.part.0’ at ./arch/s390/include/asm/preempt.h:50:3:
./arch/s390/include/asm/atomic_ops.h:80:9: error: impossible constraint in ‘asm’
80 | asm volatile( \
| ^~~
Workaround this by simply disabling the optimization for
PROFILE_ALL_BRANCHES, since the kernel will be so slow, that this
optimization won't matter at all.
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
clock_delta is declared as unsigned long in various places. However,
the clock sync delta can be negative. This would add a huge positive
offset in clock_sync_global where clock_delta is added to clk.eitod
which is a 72 bit integer. Declare it as signed long to fix this.
Cc: stable@vger.kernel.org
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The size of the TOD offset field in the stp info response is 64 bits.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
PMU device driver perf_pai_crypto supports Processor Activity
Instrumentation (PAI), available with IBM z16:
- maps a full page to lowcore address 0x1500.
- uses CR0 bit 13 to turn PAI crypto counting on and off.
- creates a sample with raw data on each context switch out when
at context switch some mapped counters have a value of nonzero.
This device driver only supports CPU wide context, no task context
is allowed.
Support for counting:
- one or more counters can be specified using
perf stat -e pai_crypto/xxx/
where xxx stands for the counter event name. Multiple invocation
of this command is possible. The counter names are listed in
/sys/devices/pai_crypto/events directory.
- one special counters can be specified using
perf stat -e pai_crypto/CRYPTO_ALL/
which returns the sum of all incremented crypto counters.
- one event pai_crypto/CRYPTO_ALL/ is reserved for sampling.
No multiple invocations are possible. The event collects data at
context switch out and saves them in the ring buffer.
Add qpaci assembly instruction to query supported memory mapped crypto
counters. It returns the number of counters (no holes allowed in that
range).
The PAI crypto counter events are system wide and can not be executed
in parallel. Therefore some restrictions documented in function
paicrypt_busy apply.
In particular event CRYPTO_ALL for sampling must run exclusive.
Only counting events can run in parallel.
PAI crypto counter events can not be created when a CPU hot plug
add is processed. This means a CPU hot plug add does not get
the necessary PAI event to record PAI cryptography counter increments
on the newly added CPU. CPU hot plug remove removes the event and
terminates the counting of PAI counters immediately.
Co-developed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20220504062351.2954280-3-tmricht@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
arch_check_user_regs() is used at the moment to verify that struct pt_regs
contains valid values when entering the kernel from userspace. s390 needs
a place in the generic entry code to modify a cpu data structure when
switching from userspace to kernel mode. As arch_check_user_regs() is
exactly this, rename it to arch_enter_from_user_mode().
When entering the kernel from userspace, arch_check_user_regs() is
used to verify that struct pt_regs contains valid values. Note that
the NMI codepath doesn't call this function. s390 needs a place in the
generic entry code to modify a cpu data structure when switching from
userspace to kernel mode. As arch_check_user_regs() is exactly this,
rename it to arch_enter_from_user_mode().
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220504062351.2954280-2-tmricht@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Remove various declarations from former s390 specific compat system
calls which have been removed with commit fef747bab3 ("s390: use
generic UID16 implementation"). While at it clean up the whole small
header file.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
LLVM's integrated assembler reports the following error when compiling
entry.S:
<instantiation>:38:5: error: unknown token in expression
tm %r8,0x0001 # coming from user space?
The correct instruction would have been tmhh instead of tm.
The current code is doing nothing, since (with gas) it get's
translated to a tm instruction which reads from real address 8, which
again contains always zero, and therefore the conditional code is
never executed.
Note that due to the missing displacement gas translates "%r8" into
"8(%r0)".
Also code inspection reveals that this conditional code is not needed.
Therefore remove it.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Convert parmarea to C, which makes it much easier to initialize it. No need
to keep offsets in assembler code in sync with struct parmarea anymore.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Convert initial lowcore to C and use proper defines and structures to
initialize it. This should make the z/VM ipl procedure a bit less magic.
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The short psw definitions are contained in compat header files, however
short psws are not compat specific. Therefore move the definitions to
ptrace header file. This also gets rid of a compat header include in kvm
code.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Initialize all new psws with disabled wait psws, except for the restart new
psw. This way every unexpected exception, svc, machine check, or interrupt
is handled properly.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The program check handler of the kernel image points to
startup_pgm_check_handler. However an early program check which happens
while loading the kernel image will jump to potentially random code, since
the code of the program check handler is not yet loaded; leading to a
program check loop.
Therefore initialize it to a disabled wait psw and let the startup code set
the proper psw when everything is in memory.
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Move iplstart entry point to 0x200 again, instead of the middle of the ipl
code. This way even the comment describing the ccw program is correct
again.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The final kernel image is created by linking decompressor object files with
a startup archive. The startup archive file however does not contain only
optional code and data which can be discarded if not referenced. It also
contains mandatory object data like head.o which must never be discarded,
even if not referenced.
Move the decompresser code and linker script to the boot directory and get
rid of the startup archive so everything is kept during link time.
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
LLVM's integrated assembler does not like comments within macros:
<instantiation>:3:19: error: too many positional arguments
GR_NUM b2, 1 /* Base register */
^
Remove them, since they are obvious anyway.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Use local labels in .set directives to avoid potential compile errors
with LTO + clang. See commit 334865b291 ("x86/extable: Prefer local
labels in .set directives") for further details.
Since s390 doesn't support LTO currently this doesn't fix a real bug
for now, but helps to avoid problems as soon as required pieces have
been added to llvm.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Use local labels in .set directives to avoid potential compile errors
with LTO + clang. See commit 334865b291 ("x86/extable: Prefer local
labels in .set directives") for further details.
Since s390 doesn't support LTO currently this doesn't fix a real bug
for now, but helps to avoid problems as soon as required pieces have
been added to llvm.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently many console drivers for s390 rely on panic/reboot notifiers
to invoke callbacks on these events. The panic() function disables local
IRQs, secondary CPUs and preemption, so callbacks invoked on panic are
effectively running in atomic context.
Happens that most of these console callbacks from s390 doesn't take the
proper care with regards to atomic context, like taking spinlocks that
might be taken in other function/CPU and hence will cause a lockup
situation.
The goal for this patch is to improve the notifiers reliability, acting
on 4 console drivers, as detailed below:
(1) con3215: changed a regular spinlock to the trylock alternative.
(2) con3270: also changed a regular spinlock to its trylock counterpart,
but here we also have another problem: raw3270_activate_view() takes a
different spinlock. So, we worked a helper to validate if this other lock
is safe to acquire, and if so, raw3270_activate_view() should be safe.
Notice though that there is a functional change here: it's now possible
to continue the notifier code [reaching con3270_wait_write() and
con3270_rebuild_update()] without executing raw3270_activate_view().
(3) sclp: a global lock is used heavily in the functions called from
the notifier, so we added a check here - if the lock is taken already,
we just bail-out, preventing the lockup.
(4) sclp_vt220: same as (3), a lock validation was added to prevent the
potential lockup problem.
Besides (1)-(4), we also removed useless void functions, adding the
code called from the notifier inside its own body, and changed the
priority of such notifiers to execute late, since they are "heavyweight"
for the panic environment, so we aim to reduce risks here.
Changed return values to NOTIFY_DONE as well, the standard one.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Link: https://lore.kernel.org/r/20220427224924.592546-14-gpiccoli@igalia.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
As demonstrated by commit 74bdf7815d ("genirq: Speedup
show_interrupts()"), irq_desc can be accessed safely in RCU read section.
Hence here resorting to rcu read lock to get rid of irq_lock_sparse().
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Link: https://lore.kernel.org/r/20220422100212.22666-1-kernelfans@gmail.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
test_barrier fails on s390 because of the missing KCSAN instrumentation
for several synchronization primitives.
Add it to barriers by defining __mb(), __rmb(), __wmb(), __dma_rmb()
and __dma_wmb(), and letting the common code in asm-generic/barrier.h
do the rest.
Spinlocks require instrumentation only on the unlock path; notify KCSAN
that the CPU cannot move memory accesses outside of the spin lock. In
reality it also cannot move stores inside of it, but this is not
important and can be omitted.
Reported-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently it is not detectable from within Linux when PCI instructions
are retried because of a busy condition. Detecting such conditions and
especially how long they lasted can however be quite useful in problem
determination. This patch enables this by adding an s390dbf error log
when a CC 2 is first encountered as well as after the retried
instruction.
Despite being unlikely it may be possible that these added debug
messages drown out important other messages so allow setting the debug
level in zpci_err_insn*() and set their level to 1 so they can be
filtered out if need be.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently when a PCI instruction returns a non-zero condition code it
can be very hard to tell from the s390dbf logs what kind of instruction
was executed. In case of PCI memory I/O (MIO) instructions it is even
impossible to tell if we attempted a load, store or block store or how
large the access was because only the address is logged.
Improve this by adding an indicator byte for the instruction type to the
error record and also store the length of the access for MIO
instructions where this can not be deduced from the request.
We use the following indicator values:
- 'l': PCI load
- 's': PCI store
- 'b': PCI store block
- 'L': PCI load (MIO)
- 'S': PCI store (MIO)
- 'B': PCI store block (MIO)
- 'M': MPCIFC
- 'R': RPCIT
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Availability events are logged in s390dbf in s390dbf/pci_error/hex_ascii
even though they don't indicate an error condition.
They have also become redundant as commit 6526a597a2 ("s390/pci: add
simpler s390dbf traces for events") added an s390dbf/pci_msg/sprintf log
entry for availability events which contains all non reserved fields of
struct zpci_ccdf_avail. On the other hand the availability entries in
the error log make it easy to miss actual errors and may even overwrite
error entries if the message buffer wraps.
Thus simply remove the availability events from the error log thereby
establishing the rule that any content in s390dbf/pci_error indicates
some kind of error.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
While the zpci_dbg() macro offers a level parameter this is currently
largely unused. The only instance with higher importance than 3 is the
UID checking change debug message which is not actually more important
as the UID uniqueness guarantee is already exposed in sysfs so this
should rather be 3 as well.
On the other hand the "add ..." message which shows what devices are
visible at the lowest level is essential during problem determination.
By setting its level to 1, lowering the debug level can act as a filter
to only show the available functions.
On the error side the default level is set to 6 while all existing
messages are printed at level 0. This is inconsistent and means there is
no room for having messages be invisible on the default level so instead
set the default level to 3 like for errors matching the default for
debug messages.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The vfio_ap module tries to register for the vfio_ap bus - but that's
the interface that it provides itself, so this does not make much sense,
thus let's simply drop this statement now.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Link: https://lore.kernel.org/r/20220413094416.412114-1-thuth@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Randomize the address of vdso if randomize_va_space is enabled.
Note that this keeps the vdso address on the same PMD as the stack
to avoid allocating an extra page table just for vdso.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
