linux-stable.git/arch/s390/kernel/nmi.c, branch linux-rolling-stable Linux kernel stable tree KVM: s390: vsie: Avoid injecting machine check on signal 2026-03-16T15:56:39+00:00 Christian Borntraeger borntraeger@linux.ibm.com 2026-03-16T12:13:17+00:00 ab5119735e984f6b724ef1b699c01479949ed1de The recent XFER_TO_GUEST_WORK change resulted in a situation, where the vsie code would interpret a signal during work as a machine check during SIE as both use the EINTR return code. The exit_reason of the sie64a function has nothing to do with the kvm_run exit_reason. Rename it and define a specific code for machine checks instead of abusing -EINTR. rename exit_reason into sie_return to avoid the naming conflict and change the code flow in vsie.c to have a separate variable for rc and sie_return. Fixes: 2bd1337a1295e ("KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions") Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> 
The recent XFER_TO_GUEST_WORK change resulted in a situation, where the
vsie code would interpret a signal during work as a machine check during
SIE as both use the EINTR return code.
The exit_reason of the sie64a function has nothing to do with the
kvm_run exit_reason. Rename it and define a specific code for machine
checks instead of abusing -EINTR.
rename exit_reason into sie_return to avoid the naming conflict
and change the code flow in vsie.c to have a separate variable for rc
and sie_return.

Fixes: 2bd1337a1295e ("KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions")
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
s390/nmi: Annotate s390_handle_damage() with __noreturn 2025-11-06T13:17:28+00:00 Thorsten Blum thorsten.blum@linux.dev 2025-10-27T08:47:25+00:00 f07ebfa5e48c59c41aea247982184fe956cbb756 s390_handle_damage() ends by calling the non-returning function disabled_wait() and therefore also never returns. Annotate it with the __noreturn compiler attribute to improve compiler optimizations. Remove the unreachable infinite while loop. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
s390_handle_damage() ends by calling the non-returning function
disabled_wait() and therefore also never returns. Annotate it with the
__noreturn compiler attribute to improve compiler optimizations.

Remove the unreachable infinite while loop.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390/nmi: Print additional information 2025-06-26T13:30:51+00:00 Heiko Carstens hca@linux.ibm.com 2025-06-18T15:22:17+00:00 fbb3bdf541e634ce5395cc99f0d4dba15d182b4e In case of an unrecoverable machine check only the machine check interrupt code is printed to the console before the machine is stopped. This makes root cause analysis sometimes hard. Print additional machine check information to make analysis easier. The output now looks like this: Unrecoverable machine check, code: 00400F5F4C3B0000 6.16.0-rc2-11605-g987a9431e53a-dirty HW: IBM 3931 A01 704 (z/VM 7.4.0) PSW: 0706C00180000000 000003FFE0F0462E PFX: 0000000000070000 LBA: 000003FFE0F0462A EDC: 0000000000000000 FSA: 0000000000000000 CRS: 0080000014966A12 0000000087CB41C7 0000000000BFF140 0000000000000000 000000000000FFFF 0000000000BFF140 0000000071000000 0000000087CB41C7 0000000000008000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 00000000024C0007 00000000DB000000 0000000000BFF000 GPRS: FFFFFFFF00000000 000003FFE0F0462E E10EA4F489F897A6 0000000000000000 7FFFFFF2C0413C4C 000003FFE19B7010 0000000000000000 0000000000000000 0000000000000000 00000001F76B3380 000003FFE15D4050 0000000000000005 0000000000000000 0000000000070000 000003FFE0F0586C 0000037FE00B7DA0 System stopped Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> 
In case of an unrecoverable machine check only the machine check interrupt
code is printed to the console before the machine is stopped. This makes
root cause analysis sometimes hard.

Print additional machine check information to make analysis easier.
The output now looks like this:

Unrecoverable machine check, code: 00400F5F4C3B0000
6.16.0-rc2-11605-g987a9431e53a-dirty
HW: IBM 3931 A01 704 (z/VM 7.4.0)
PSW: 0706C00180000000 000003FFE0F0462E PFX: 0000000000070000
LBA: 000003FFE0F0462A EDC: 0000000000000000 FSA: 0000000000000000
CRS:
0080000014966A12 0000000087CB41C7 0000000000BFF140 0000000000000000
000000000000FFFF 0000000000BFF140 0000000071000000 0000000087CB41C7
0000000000008000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 00000000024C0007 00000000DB000000 0000000000BFF000
GPRS:
FFFFFFFF00000000 000003FFE0F0462E E10EA4F489F897A6 0000000000000000
7FFFFFF2C0413C4C 000003FFE19B7010 0000000000000000 0000000000000000
0000000000000000 00000001F76B3380 000003FFE15D4050 0000000000000005
0000000000000000 0000000000070000 000003FFE0F0586C 0000037FE00B7DA0
System stopped

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
s390: Remove unnecessary include <linux/export.h> 2025-06-17T16:18:02+00:00 Heiko Carstens hca@linux.ibm.com 2025-06-12T12:02:59+00:00 0f3760d43da56736dcfc91c04c05fdf2936a158e Remove include <linux/export.h> from all files which do not contain an EXPORT_SYMBOL(). See commit 7d95680d64ac ("scripts/misc-check: check unnecessary #include <linux/export.h> when W=1") for more details. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> 
Remove include <linux/export.h> from all files which do not contain an
EXPORT_SYMBOL().

See commit 7d95680d64ac ("scripts/misc-check: check unnecessary #include
<linux/export.h> when W=1") for more details.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
s390/cpufeature: Convert MACHINE_HAS_GS to cpu_has_gs() 2025-03-04T16:18:04+00:00 Heiko Carstens hca@linux.ibm.com 2025-02-07T14:48:49+00:00 42805261fcea809e1e76243dfc5218f6f12c1614 Convert MACHINE_HAS_... to cpu_has_...() which uses test_facility() instead of testing the machine_flags lowcore member if the feature is present. test_facility() generates better code since it results in a static branch without accessing memory. The branch is patched via alternatives by the decompressor depending on the availability of the required facility. Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
Convert MACHINE_HAS_... to cpu_has_...() which uses test_facility() instead
of testing the machine_flags lowcore member if the feature is present.

test_facility() generates better code since it results in a static branch
without accessing memory. The branch is patched via alternatives by the
decompressor depending on the availability of the required facility.

Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390/nmi: Remove duplicate get_lowcore() calls 2024-06-18T15:01:33+00:00 Sven Schnelle svens@linux.ibm.com 2024-06-10T11:45:28+00:00 d7c3ebc49eb72e9c8142fed49e9c9ec21815810c Assign the output from get_lowcore() to a local variable, so the code is easier to read. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
Assign the output from get_lowcore() to a local variable,
so the code is easier to read.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390: Replace S390_lowcore by get_lowcore() 2024-06-18T15:01:33+00:00 Sven Schnelle svens@linux.ibm.com 2024-06-10T11:45:25+00:00 208da1d5fc3c67d8ae5d34e844fd67cc47a136f0 Replace all S390_lowcore usages in arch/s390/ by get_lowcore(). Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> 
Replace all S390_lowcore usages in arch/s390/ by get_lowcore().

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390/irq,nmi: Include <asm/vtime.h> header directly 2024-04-17T11:37:22+00:00 Alexander Gordeev agordeev@linux.ibm.com 2024-04-10T15:09:47+00:00 036cbbafbd1eb2a7437912c2fe5fdefc9d52c309 update_timer_sys() and update_timer_mcck() are inlines used for CPU time accounting from the interrupt and machine-check handlers. These routines are specific to s390 architecture, but included via <linux/vtime.h> header implicitly. Avoid the extra loop and include <asm/vtime.h> header directly. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/3fb696637c0eb7e9d6ffd6cbf9e647d7c5986b3d.1712760275.git.agordeev@linux.ibm.com 
update_timer_sys() and update_timer_mcck() are inlines used for
CPU time accounting from the interrupt and machine-check handlers.
These routines are specific to s390 architecture, but included
via <linux/vtime.h> header implicitly. Avoid the extra loop and
include <asm/vtime.h> header directly.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/3fb696637c0eb7e9d6ffd6cbf9e647d7c5986b3d.1712760275.git.agordeev@linux.ibm.com
s390/fpu: move, rename, and merge header files 2024-02-16T13:30:14+00:00 Heiko Carstens hca@linux.ibm.com 2024-02-03T10:45:02+00:00 fd2527f20915d041e838b6e4a08122dbc73c7abc Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
Move, rename, and merge the fpu and vx header files. This way fpu header
files have a consistent naming scheme (fpu*.h).

Also get rid of the fpu subdirectory and move header files to asm
directory, so that all fpu and vx header files can be found at the same
location.

Merge internal.h header file into other header files, since the internal
helpers are used at many locations. so those helper functions are really
not internal.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390/nmi: remove register validation code 2024-02-16T13:30:14+00:00 Heiko Carstens hca@linux.ibm.com 2024-02-03T10:44:59+00:00 9e96afab8c0fadafc3fa2dbb2f233a641d7fe229 Remove the historic machine check handler code which validates registers. Registers are automatically validated as part of the machine check handling sequence (see Principles of Operation, Machine-Check Handling chapter, Validation). Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
Remove the historic machine check handler code which validates registers.
Registers are automatically validated as part of the machine check handling
sequence (see Principles of Operation, Machine-Check Handling chapter,
Validation).

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>