Commit Graph

4268 Commits

Author SHA1 Message Date
Claudio Imbrenda
c98175b791 KVM: s390: Add gmap_helper_set_unused()
Add gmap_helper_set_unused() to mark userspace ptes as unused.

Core mm code will use that information to discard unused pages instead
of attempting to swap them.

Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Tested-by: Nico Boehr <nrb@linux.ibm.com>
Acked-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-04 17:00:08 +01:00
Claudio Imbrenda
4dadf64d9b s390: Move sske_frame() to a header
Move the sske_frame() function to asm/pgtable.h, so it can be used in
other modules too.

Opportunistically convert the .insn opcode specification to the
appropriate mnemonic.

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-04 17:00:08 +01:00
Claudio Imbrenda
013bf0f57e KVM: s390: Add P bit in table entry bitfields, move union vaddress
Add P bit in hardware definition of region 3 and segment table entries.

Move union vaddress from kvm/gaccess.c to asm/dat_bits.h

Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-04 17:00:08 +01:00
Claudio Imbrenda
05664e0021 KVM: s390: Refactor pgste lock and unlock functions
Move the pgste lock and unlock functions back into mm/pgtable.c and
duplicate them in mm/gmap_helpers.c to avoid function name collisions
later on.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-04 17:00:08 +01:00
Jan Höppner
effcf3df28 s390/tape: Remove tape load display support
The LOAD_DISPLAY (LDD) X'9F' is still accepted by the Virtual Tape
Server (VTS) but does not perform any action.

Remove all functions and definitions related to this command.

The tape_34xx_ioctl() function is also removed as it was mainly used to
handle additional ioctl functionality. LOAD_DISPLAY was the only left
case. All other ioctls are handled in tapechar_ioctl().

With LOAD_DISPLAY, the remaining definitions in asm/tape390.h are gone.
Delete the file.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-04 08:31:29 +01:00
Jan Höppner
c03b6ef74c s390/tape: Remove support for 3590/3592 models
Physical 3590/3592 tape models are not supported anymore for a very long
time. The Virtual Tape Server (VTS) emulates and presents only 3490E
models to the host. This is the only supported model and storage server.

Remove the entire code base for 3590/3592 models as it can be considered
dead code for quite some time already.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-04 08:31:29 +01:00
Yury Norov
269586d689 kernel.h: include linux/instruction_pointer.h explicitly
In preparation for decoupling linux/instruction_pointer.h and
linux/kernel.h, include instruction_pointer.h explicitly where needed.

Link: https://lkml.kernel.org/r/20260116042510.241009-5-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Aaron Tomlin <atomlin@atomlin.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31 16:16:05 -08:00
Harald Freudenberger
2dfca61119 s390/pkey: Support new xflag PKEY_XFLAG_NOCLEARKEY
Introduce a new xflag PKEY_XFLAG_NOCLEARKEY which when given refuses
the conversion of "clear key tokens" to protected key material.

Some algorithms (PAES, PHMAC) have the need to construct "clear key
tokens" to be used during selftest. But in general these algorithms
should only support clear key material for testing purpose. So now the
algorithm implementation can signal via xflag PKEY_XFLAG_NOCLEARKEY
that a conversion of clear key material to protected key is not
acceptable and thus the pkey layer (usually one of the handler
modules) refuses clear key material with -EINVAL.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-01-31 10:52:30 +08:00
Gerd Bayer
0d453ba040 s390/Kconfig: Define non-zero ILLEGAL_POINTER_VALUE
Define CONFIG_ILLEGAL_POINTER_VALUE to the eye-catching non-zero value
of 0xdead000000000000, consistent with other architectures. Assert at
compile-time that the poison pointers that include/linux/poison.h
defines based on this illegal pointer are beyond the largest useful
virtual addresses. Also, assert at compile-time that the range of poison
pointers per include/linux/poison.h (currently a range of less than
0x10000 addresses) does not overlap with the range used for address
handles for s390's non-MIO PCI instructions.

This enables s390 to track the DMA mappings by the network stack's
page_pool that was introduced with [0]. Other functional changes are not
intended.

Other archictectures have introduced this for various other reasons with
commit 5c178472af ("riscv: define ILLEGAL_POINTER_VALUE for 64bit")
commit f6853eb561 ("powerpc/64: Define ILLEGAL_POINTER_VALUE for 64-bit")
commit bf0c4e0473 ("arm64: kconfig: Move LIST_POISON to a safe value")
commit a29815a333 ("core, x86: make LIST_POISON less deadly")

[0] https://lore.kernel.org/all/20250409-page-pool-track-dma-v9-0-6a9ef2e0cba8@redhat.com/

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:21:20 +01:00
Heiko Carstens
9f9d68c308 s390/bug: Prevent tail-call optimization
For the exception based __WARN_trap() implementation it is technically not
necessary to prevent tail-call optimization, however it may be confusing to
see warning messages like:

WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x2c/0x50, CPU#0: swapper/0/0

together with a disassembly of a different function caused by tail-call
optimization for the __WARN_trap() call. Prevent that by adding an empty
asm statement. This generates slightly worse code, but should hopefully
avoid confusion.

With this the output looks like:

WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x2c/0x50, CPU#0: swapper/0/0
...
Krnl PSW : 0704c00180000000 000003ffe0119788 (foobar+0x38/0x50)
...
Krnl Code: 000003ffe0119776: e3e0f0980024        stg     %r14,152(%r15)
           000003ffe011977c: c02000b8992a        larl    %r2,000003ffe182c9d0
          *000003ffe0119782: c0e5007270b7        brasl   %r14,000003ffe0f678f0
          >000003ffe0119788: ebeff0a00004        lmg     %r14,%r15,160(%r15)
           000003ffe011978e: 07fe                bcr     15,%r14
           000003ffe0119790: 47000700            bc      0,1792
           000003ffe0119794: 0707                bcr     0,%r7
           000003ffe0119796: 0707                bcr     0,%r7
Call Trace:
 [<000003ffe0119788>] foobar+0x38/0x50
 [<000003ffe185bc2e>] arch_cpu_finalize_init+0x26/0x60
 [<000003ffe185654c>] start_kernel+0x53c/0x5d8
 [<000003ffe010002e>] startup_continue+0x2e/0x40

A better solution would be to replace or patch the branch instruction to
__WARN_trap() with the monitor call instruction, similar to what is done
for x86 [1]. However s390 does not support static_cond_calls(). Therefore
use the simple approach for the time being.

[1] commit 860238af7a ("x86_64/bug: Inline the UD1")

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:16 +01:00
Heiko Carstens
940cfea427 s390/bug: Implement WARN_ONCE()
This is the s390 variant of commit 11bb4944f0 ("x86/bug: Implement
WARN_ONCE()").

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:16 +01:00
Heiko Carstens
04dabb4261 s390/bug: Implement __WARN_printf()
This is the s390 variant of commit 5b472b6e5b ("x86_64/bug: Implement
__WARN_printf()"). See the x86 commit for the general idea; there are only
implementation details which are different.

With the new exception based __WARN_printf() implementation the generated
code for a simple WARN() is simplified.

For example:

void foo(int a) { WARN(a, "bar"); }

Before this change the generated code looks like this:

0000000000000210 <foo>:
 210:   c0 04 00 00 00 00       jgnop   210 <foo>
 216:   ec 26 00 06 00 7c       cgijne  %r2,0,222 <foo+0x12>
 21c:   c0 f4 00 00 00 00       jg      21c <foo+0xc>
                        21e: R_390_PC32DBL      __s390_indirect_jump_r14+0x2
 222:   eb ef f0 88 00 24       stmg    %r14,%r15,136(%r15)
 228:   b9 04 00 ef             lgr     %r14,%r15
 22c:   e3 f0 ff e8 ff 71       lay     %r15,-24(%r15)
 232:   e3 e0 f0 98 00 24       stg     %r14,152(%r15)
 238:   c0 20 00 00 00 00       larl    %r2,238 <foo+0x28>
                        23a: R_390_PC32DBL      .LC48+0x2
 23e:   c0 e5 00 00 00 00       brasl   %r14,23e <foo+0x2e>
                        240: R_390_PLT32DBL     __warn_printk+0x2
 244:   af 00 00 00             mc      0,0
 248:   eb ef f0 a0 00 04       lmg     %r14,%r15,160(%r15)
 24e:   c0 f4 00 00 00 00       jg      24e <foo+0x3e>
                        250: R_390_PC32DBL      __s390_indirect_jump_r14+0x2

With this change the generated code looks like this:

0000000000000210 <foo>:
 210:   c0 04 00 00 00 00       jgnop   210 <foo>
 216:   ec 26 00 06 00 7c       cgijne  %r2,0,222 <foo+0x12>
 21c:   c0 f4 00 00 00 00       jg      21c <foo+0xc>
                        21e: R_390_PC32DBL      __s390_indirect_jump_r14+0x2
 222:   c0 20 00 00 00 00       larl    %r2,222 <foobar+0x12>
                        224: R_390_PC32DBL      __bug_table+0x2
 228:   c0 f4 00 00 00 00       jg      228 <foobar+0x18>
                        22a: R_390_PLT32DBL     __WARN_trap+0x2

Downside is that the call trace now starts at __WARN_trap():

------------[ cut here ]------------
bar
WARNING: arch/s390/kernel/setup.c:1017 at 0x0, CPU#0: swapper/0/0
...
Krnl PSW : 0704c00180000000 000003ffe0f6a3b4 (__WARN_trap+0x4/0x10)
...
Krnl Code: 000003ffe0f6a3ac: 0707                bcr     0,%r7
           000003ffe0f6a3ae: 0707                bcr     0,%r7
          *000003ffe0f6a3b0: af000001            mc      1,0
          >000003ffe0f6a3b4: 07fe                bcr     15,%r14
           000003ffe0f6a3b6: 47000700            bc      0,1792
           000003ffe0f6a3ba: 0707                bcr     0,%r7
           000003ffe0f6a3bc: 0707                bcr     0,%r7
           000003ffe0f6a3be: 0707                bcr     0,%r7
Call Trace:
 [<000003ffe0f6a3b4>] __WARN_trap+0x4/0x10
([<000003ffe185a54c>] start_kernel+0x53c/0x5d8)
 [<000003ffe010002e>] startup_continue+0x2e/0x40

Which isn't too helpful. This can be addressed by just skipping __WARN_trap(),
which will be addressed in a later patch.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:16 +01:00
Heiko Carstens
ee44f4e7eb s390/traps: Copy monitor code to pt_regs
In case of a monitor call program check the CPU stores the monitor code to
lowcore. Let the program check handler copy it to the pt_regs structure so
it can be used by the monitor call exception handler.

Instead of increasing the pt_regs size add a union which contains both
orig_gpr2 and monitor_code, since orig_gpr2 is not used in case of a
program check.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:16 +01:00
Heiko Carstens
8cbfd13601 s390/bug: Introduce and use monitor code macro
The first operand address of the monitor call (mc) instruction is the
monitor code. Currently the monitor code is ignored, but this will
change. Therefore add and use MONCODE_BUG instead of a hardcoded zero.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:16 +01:00
Heiko Carstens
2b71b8ab97 s390/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED
This is just the s390 variant of commit 4f1b701f24 ("x86/bug: Use
BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED").

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:15 +01:00
Heiko Carstens
e3abd056ff s390/bug: Convert to inline assembly with input operands
Rewrite the bug inline assembly so it uses input operands again instead of
pure macro replacements. This more or less reverts the conversion done when
'cond_str' support was added [1].

Reason for this is that the upcoming __WARN_printf() implementation
requires an inline assembly with an output operand. At the same time input
strings (format specifier and condition string) may contain the special '%'
character. As soon as an inline assembly is specified to have input/output
operands the '%' has a special meaning: e.g. converting the existing

 #define __BUG_FLAGS(cond_str, flags) \
   asm_inline volatile(__stringify(ASM_BUG_FLAGS(cond_str, flags)));

to

 #define __BUG_FLAGS(cond_str, flags) \
   asm_inline volatile(__stringify(ASM_BUG_FLAGS(cond_str, flags))::);

will result in a compile error as soon as 'cond_str' contains a '%'
character:

net/core/neighbour.c: In function ‘neigh_table_init’:
././include/linux/compiler_types.h:546:20: error: invalid 'asm': invalid %-code
...
net/core/neighbour.c:1838:17: note: in expansion of macro ‘WARN_ON’
 1838 |                 WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
      |                 ^~~~~~~

Convert the code, use immediate operands, and also add comments similar to
x86 which are emitted to the generated assembly file, which makes debugging
much easier.

Note: since gcc-8 does not support strings as immediate input operands,
guard the new implementation with CC_HAS_ASM_IMMEDIATE_STRINGS and fallback
to the generic non-exception based warning implementation for incompatible
compilers.

[1] 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-27 12:16:15 +01:00
Wei Yang
f9b74c13b7 mm/mmu_gather: remove @delay_remap of __tlb_remove_page_size()
__tlb_remove_page_size() is only used in tlb_remove_page_size() with
@delay_remap set to false and it is passed directly to
__tlb_remove_folio_pages_size().

Remove @delay_remap of __tlb_remove_page_size() and call
__tlb_remove_folio_pages_size() with false @delay_remap.

Link: https://lkml.kernel.org/r/20251231030026.15938-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:54 -08:00
David Hildenbrand
8e38607aa4 treewide: provide a generic clear_user_page() variant
Patch series "mm: folio_zero_user: clear page ranges", v11.

This series adds clearing of contiguous page ranges for hugepages.

The series improves on the current discontiguous clearing approach in two
ways:

  - clear pages in a contiguous fashion.
  - use batched clearing via clear_pages() wherever exposed.

The first is useful because it allows us to make much better use of
hardware prefetchers.

The second, enables advertising the real extent to the processor.  Where
specific instructions support it (ex.  string instructions on x86; "mops"
on arm64 etc), a processor can optimize based on this because, instead of
seeing a sequence of 8-byte stores, or a sequence of 4KB pages, it sees a
larger unit being operated on.

For instance, AMD Zen uarchs (for extents larger than LLC-size) switch to
a mode where they start eliding cacheline allocation.  This is helpful not
just because it results in higher bandwidth, but also because now the
cache is not evicting useful cachelines and replacing them with zeroes.

Demand faulting a 64GB region shows performance improvement:

 $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5

                       baseline              +series
                   (GBps +- %stdev)      (GBps +- %stdev)

   pg-sz=2MB       11.76 +- 1.10%        25.34 +- 1.18% [*]   +115.47%  	preempt=*

   pg-sz=1GB       24.85 +- 2.41%        39.22 +- 2.32%       + 57.82%  	preempt=none|voluntary
   pg-sz=1GB         (similar)           52.73 +- 0.20% [#]   +112.19%  	preempt=full|lazy

 [*] This improvement is because switching to sequential clearing
  allows the hardware prefetchers to do a much better job.

 [#] For pg-sz=1GB a large part of the improvement is because of the
  cacheline elision mentioned above. preempt=full|lazy improves upon
  that because, not needing explicit invocations of cond_resched() to
  ensure reasonable preemption latency, it can clear the full extent
  as a single unit. In comparison the maximum extent used for
  preempt=none|voluntary is PROCESS_PAGES_NON_PREEMPT_BATCH (32MB).

  When provided the full extent the processor forgoes allocating
  cachelines on this path almost entirely.

  (The hope is that eventually, in the fullness of time, the lazy
   preemption model will be able to do the same job that none or
   voluntary models are used for, allowing us to do away with
   cond_resched().)

Raghavendra also tested previous version of the series on AMD Genoa and
sees similar improvement [1] with preempt=lazy.

  $ perf bench mem map -p $page-size -f populate -s 64GB -l 10

                    base               patched              change
   pg-sz=2MB       12.731939 GB/sec    26.304263 GB/sec     106.6%
   pg-sz=1GB       26.232423 GB/sec    61.174836 GB/sec     133.2%


This patch (of 8):

Let's drop all variants that effectively map to clear_page() and provide
it in a generic variant instead.

We'll use the macro clear_user_page to indicate whether an architecture
provides it's own variant.

Also, clear_user_page() is only called from the generic variant of
clear_user_highpage(), so define it only if the architecture does not
provide a clear_user_highpage().  And, for simplicity define it in
linux/highmem.h.

Note that for parisc, clear_page() and clear_user_page() map to
clear_page_asm(), so we can just get rid of the custom clear_user_page()
implementation.  There is a clear_user_page_asm() function on parisc, that
seems to be unused.  Not sure what's up with that.

Link: https://lkml.kernel.org/r/20260107072009.1615991-1-ankur.a.arora@oracle.com
Link: https://lkml.kernel.org/r/20260107072009.1615991-2-ankur.a.arora@oracle.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Co-developed-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:39 -08:00
Heiko Carstens
48b4790f05 s390/preempt: Optimize __preempt_count_dec_and_test()
Provide an inline assembly using alternatives to avoid the need of a
base register due to relocatable lowcore when adding or subtracting
small constants from preempt_count.

Main user is preempt_enable(), which subtracts one from preempt_count
and tests if the result is zero.

With this the generated code changes from

  1000b8:       a7 19 00 00             lghi    %r1,0
  1000bc:       eb ff 13 a8 00 6e       alsi    936(%r1),-1
  1000c2:       a7 54 00 05             jnhe    1000cc <__rcu_read_unlock+0x14>

to something like this:

  1000b8:       eb ff 03 a8 00 6e       alsi    936,-1
  1000be:       a7 54 00 05             jnhe    1000c8 <__rcu_read_unlock+0x10>

Kernel image size is reduced by 45kb (bloat-o-meter -t, defconfig, gcc15).

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-17 15:52:49 +01:00
Heiko Carstens
05405b8fd2 s390/asm: Let __HAVE_ASM_FLAG_OUTPUTS__ define 1
With the empty define __is_enabled(__HAVE_ASM_FLAG_OUTPUTS__)
evaluates to false. Therefore let __HAVE_ASM_FLAG_OUTPUTS__ define 1
if it is defined.

This allows to make use of __is_defined(__HAVE_ASM_FLAG_OUTPUTS__)
like expected.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-17 15:52:49 +01:00
Heiko Carstens
23ba7d3163 s390/preempt: Optimize __preemp_count_add()/__preempt_count_sub()
Provide an inline assembly using alternatives to avoid the need of a
base register due to relocatable lowcore when adding or subtracting
small constants from preempt_count.

Main user is preempt_disable(), which subtracts one from
preempt_count. With this the generated code changes from

  10012c:       a7 b9 00 00             lghi    %r11,0
  100130:       eb 01 b3 a8 00 6a       asi     936(%r11),1

to something like this:

 10012c:        eb 01 03 a8 00 6a       asi     936,1

Kernel image size is reduced by 13kb (bloat-o-meter -t, defconfig, gcc15).

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-17 15:52:49 +01:00
Heiko Carstens
6cce3609a1 s390/preempt: Optimize preempt_count()
Provide an inline assembly using alternatives to avoid the need of
a base register when reading preempt_count() from lowcore. Use the
LLGT instruction, which reads only the least significant 31 bits of
preempt_count. This masks out the encoded PREEMPT_NEED_RESCHED bit.

Generated code is changed from

000000000046e5d0 <vfree>:
  46e5d0:       c0 04 00 00 00 00       jgnop   46e5d0 <vfree>
  46e5d6:       a7 39 00 00             lghi    %r3,0
  46e5da:       58 10 33 a8             l       %r1,936(%r3)
  46e5de:       c0 1b 00 ff ff 00       nilf    %r1,16776960
  46e5e4:       a7 74 00 11             jne     46e606 <vfree+0x36>

to something like this:

000000000046e5d0 <vfree>:
  46e5d0:       c0 04 00 00 00 00       jgnop   46e5d0 <vfree>
  46e5d6:       e3 10 03 a8 00 17       llgt    %r1,936
  46e5dc:       ec 41 28 b7 00 55       risbgz  %r4,%r1,40,55
  46e5e2:       a7 74 00 0f             jne     46e600 <vfree+0x30>

Overall savings are only 82 bytes according to bloat-o-meter. This
is because of different inlining decisions, and there aren't many
preempt_count() users in the kernel.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-17 15:52:49 +01:00
Julia Lawall
12ea976f95 s390/ap: Fix typo in function name reference
Add missing s into ap_intructions_available.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Jimmy Brisson <jbrisson@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-01-02 13:23:48 +01:00
Jens Remus
afa8fa52a4 s390/ptrace: Convert function macros to inline functions
Convert the function macros user_mode(), instruction_pointer(), and
user_stack_pointer() to inline functions, to align their definition
with x86 and arm64.

Use const qualifier on struct pt_regs pointer parameters to prevent
compiler warnings:

arch/s390/kernel/stacktrace.c: In function ‘arch_stack_walk_user_common’:
arch/s390/kernel/stacktrace.c:114:34: warning: passing argument 1 of
‘instruction_pointer’ discards ‘const’ qualifier from pointer target
type [-Wdiscarded-qualifiers]
...
arch/s390/kernel/stacktrace.c:117:48: warning: passing argument 1 of
‘user_stack_pointer’ discards ‘const’ qualifier from pointer target
type [-Wdiscarded-qualifiers]
...

While at it add const qualifier to all struct pt_regs pointer parameters
that are accessed read-only and use __always_inline instead of inline to
harmonize the helper functions.

[hca@linux.ibm.com: Use psw_bits() helper]

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-22 12:11:31 +01:00
Sven Schnelle
b1aa01d312 s390/ipl: Clear SBP flag when bootprog is set
With z16 a new flag 'search boot program' was introduced for
list-directed IPL (SCSI, NVMe, ECKD DASD). If this flag is set,
e.g. via selecting the "Automatic" value for the "Boot program
selector" control on an HMC load panel, it is copied to the reipl
structure from the initial ipl structure. When a user now sets a
boot prog via sysfs, the flag is not cleared and the bootloader
will again automatically select the boot program, ignoring user
configuration.

To avoid that, clear the SBP flag when a bootprog sysfs file is
written.

Cc: stable@vger.kernel.org
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-14 11:03:57 +01:00
Heiko Carstens
70075e3d0c s390/bug: Add missing alignment
All objects are supposed to have a minimal alignment of two, since a
couple of instructions only work with even addresses. Add the missing
align statement for the file string.

Fixes: 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-08 15:42:41 +01:00
Heiko Carstens
1a82d430c5 s390/bug: Add missing CONFIG_BUG ifdef again
Fallback to generic BUG implementation in case CONFIG_BUG is disabled.
This restores the old behaviour before 'cond_str' support was added.

It probably doesn't matter, since nobody should disable CONFIG_BUG, but at
least this is consistent to before.

Fixes: 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-08 15:42:36 +01:00
Tobias Schumacher
f770950a47 s390/pci: Migrate s390 IRQ logic to IRQ domain API
s390 is one of the last architectures using the legacy API for setup and
teardown of PCI MSI IRQs. Migrate the s390 IRQ allocation and teardown
to the MSI parent domain API. For details, see:

https://lore.kernel.org/lkml/20221111120501.026511281@linutronix.de

In detail, create an MSI parent domain for each PCI domain. When a PCI
device sets up MSI or MSI-X IRQs, the library creates a per-device IRQ
domain for this device, which is used by the device for allocating and
freeing IRQs.

The per-device domain delegates this allocation and freeing to the
parent-domain. In the end, the corresponding callbacks of the parent
domain are responsible for allocating and freeing the IRQs.

The allocation is split into two parts:
- zpci_msi_prepare() is called once for each device and allocates the
  required resources. On s390, each PCI function has its own airq
  vector and a summary bit, which must be configured once per function.
  This is done in prepare().
- zpci_msi_alloc() can be called multiple times for allocating one or
  more MSI/MSI-X IRQs. This creates a mapping between the virtual IRQ
  number in the kernel and the hardware IRQ number.

Freeing is split into two counterparts:
- zpci_msi_free() reverts the effects of zpci_msi_alloc() and
- zpci_msi_teardown() reverts the effects of zpci_msi_prepare(). This is
  called once when all IRQs are freed before a device is removed.

Since the parent domain in the end allocates the IRQs, the hwirq
encoding must be unambiguous for all IRQs of all devices. This is
achieved by encoding the hwirq using the devfn and the MSI index.

Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Tobias Schumacher <ts@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:23 +01:00
Vasily Gorbik
6a35d02fec s390/vmem: Support 2G page splitting for KASAN shadow freeing
Export split_pud_page() so it can be used from the vmem code and teach
modify_pud_table() to split PUD-sized mappings when only a subrange
needs to be removed.

If the range to be removed covers a full PUD-sized mapping, keep the
existing behavior: clear the PUD entry and free the backing large page
(for non-direct mappings). Otherwise, split the PUD-mapped page into
PMD mappings and let the walker handle the smaller ranges.

This is needed for KASAN early shadow removal support: memory hotplug
freeing the KASAN early shadow is the only expected caller that will
try to free 2G PUD-mapped regions of non-direct mappings.

Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-12-07 16:15:19 +01:00
Linus Torvalds
51d90a15fe ARM:
- Support for userspace handling of synchronous external aborts (SEAs),
   allowing the VMM to potentially handle the abort in a non-fatal
   manner.
 
 - Large rework of the VGIC's list register handling with the goal of
   supporting more active/pending IRQs than available list registers in
   hardware. In addition, the VGIC now supports EOImode==1 style
   deactivations for IRQs which may occur on a separate vCPU than the
   one that acked the IRQ.
 
 - Support for FEAT_XNX (user / privileged execute permissions) and
   FEAT_HAF (hardware update to the Access Flag) in the software page
   table walkers and shadow MMU.
 
 - Allow page table destruction to reschedule, fixing long need_resched
   latencies observed when destroying a large VM.
 
 - Minor fixes to KVM and selftests
 
 Loongarch:
 
 - Get VM PMU capability from HW GCFG register.
 
 - Add AVEC basic support.
 
 - Use 64-bit register definition for EIOINTC.
 
 - Add KVM timer test cases for tools/selftests.
 
 RISC/V:
 
 - SBI message passing (MPXY) support for KVM guest
 
 - Give a new, more specific error subcode for the case when in-kernel
   AIA virtualization fails to allocate IMSIC VS-file
 
 - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
   in small chunks
 
 - Fix guest page fault within HLV* instructions
 
 - Flush VS-stage TLB after VCPU migration for Andes cores
 
 s390:
 
 - Always allocate ESCA (Extended System Control Area), instead of
   starting with the basic SCA and converting to ESCA with the
   addition of the 65th vCPU.  The price is increased number of
   exits (and worse performance) on z10 and earlier processor;
   ESCA was introduced by z114/z196 in 2010.
 
 - VIRT_XFER_TO_GUEST_WORK support
 
 - Operation exception forwarding support
 
 - Cleanups
 
 x86:
 
 - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO SPTE
   caching is disabled, as there can't be any relevant SPTEs to zap.
 
 - Relocate a misplaced export.
 
 - Fix an async #PF bug where KVM would clear the completion queue when the
   guest transitioned in and out of paging mode, e.g. when handling an SMI and
   then returning to paged mode via RSM.
 
 - Leave KVM's user-return notifier registered even when disabling
   virtualization, as long as kvm.ko is loaded.  On reboot/shutdown, keeping
   the notifier registered is ok; the kernel does not use the MSRs and the
   callback will run cleanly and restore host MSRs if the CPU manages to
   return to userspace before the system goes down.
 
 - Use the checked version of {get,put}_user().
 
 - Fix a long-lurking bug where KVM's lack of catch-up logic for periodic APIC
   timers can result in a hard lockup in the host.
 
 - Revert the periodic kvmclock sync logic now that KVM doesn't use a
   clocksource that's subject to NTP corrections.
 
 - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the latter
   behind CONFIG_CPU_MITIGATIONS.
 
 - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast path;
   the only reason they were handled in the fast path was to paper of a bug
   in the core #MC code, and that has long since been fixed.
 
 - Add emulator support for AVX MOV instructions, to play nice with emulated
   devices whose guest drivers like to access PCI BARs with large multi-byte
   instructions.
 
 x86 (AMD):
 
 - Fix a few missing "VMCB dirty" bugs.
 
 - Fix the worst of KVM's lack of EFER.LMSLE emulation.
 
 - Add AVIC support for addressing 4k vCPUs in x2AVIC mode.
 
 - Fix incorrect handling of selective CR0 writes when checking intercepts
   during emulation of L2 instructions.
 
 - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32] on
   VMRUN and #VMEXIT.
 
 - Fix a bug where KVM corrupt the guest code stream when re-injecting a soft
   interrupt if the guest patched the underlying code after the VM-Exit, e.g.
   when Linux patches code with a temporary INT3.
 
 - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits to
   userspace, and extend KVM "support" to all policy bits that don't require
   any actual support from KVM.
 
 x86 (Intel):
 
 - Use the root role from kvm_mmu_page to construct EPTPs instead of the
   current vCPU state, partly as worthwhile cleanup, but mostly to pave the
   way for tracking per-root TLB flushes, and elide EPT flushes on pCPU
   migration if the root is clean from a previous flush.
 
 - Add a few missing nested consistency checks.
 
 - Rip out support for doing "early" consistency checks via hardware as the
   functionality hasn't been used in years and is no longer useful in general;
   replace it with an off-by-default module param to WARN if hardware fails
   a check that KVM does not perform.
 
 - Fix a currently-benign bug where KVM would drop the guest's SPEC_CTRL[63:32]
   on VM-Enter.
 
 - Misc cleanups.
 
 - Overhaul the TDX code to address systemic races where KVM (acting on behalf
   of userspace) could inadvertantly trigger lock contention in the TDX-Module;
   KVM was either working around these in weird, ugly ways, or was simply
   oblivious to them (though even Yan's devilish selftests could only break
   individual VMs, not the host kernel)
 
 - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a TDX vCPU,
   if creating said vCPU failed partway through.
 
 - Fix a few sparse warnings (bad annotation, 0 != NULL).
 
 - Use struct_size() to simplify copying TDX capabilities to userspace.
 
 - Fix a bug where TDX would effectively corrupt user-return MSR values if the
   TDX Module rejects VP.ENTER and thus doesn't clobber host MSRs as expected.
 
 Selftests:
 
 - Fix a math goof in mmu_stress_test when running on a single-CPU system/VM.
 
 - Forcefully override ARCH from x86_64 to x86 to play nice with specifying
   ARCH=x86_64 on the command line.
 
 - Extend a bunch of nested VMX to validate nested SVM as well.
 
 - Add support for LA57 in the core VM_MODE_xxx macro, and add a test to
   verify KVM can save/restore nested VMX state when L1 is using 5-level
   paging, but L2 is not.
 
 - Clean up the guest paging code in anticipation of sharing the core logic for
   nested EPT and nested NPT.
 
 guest_memfd:
 
 - Add NUMA mempolicy support for guest_memfd, and clean up a variety of
   rough edges in guest_memfd along the way.
 
 - Define a CLASS to automatically handle get+put when grabbing a guest_memfd
   from a memslot to make it harder to leak references.
 
 - Enhance KVM selftests to make it easer to develop and debug selftests like
   those added for guest_memfd NUMA support, e.g. where test and/or KVM bugs
   often result in hard-to-debug SIGBUS errors.
 
 - Misc cleanups.
 
 Generic:
 
 - Use the recently-added WQ_PERCPU when creating the per-CPU workqueue for
   irqfd cleanup.
 
 - Fix a goof in the dirty ring documentation.
 
 - Fix choice of target for directed yield across different calls to
   kvm_vcpu_on_spin(); the function was always starting from the first
   vCPU instead of continuing the round-robin search.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "ARM:

   - Support for userspace handling of synchronous external aborts
     (SEAs), allowing the VMM to potentially handle the abort in a
     non-fatal manner

   - Large rework of the VGIC's list register handling with the goal of
     supporting more active/pending IRQs than available list registers
     in hardware. In addition, the VGIC now supports EOImode==1 style
     deactivations for IRQs which may occur on a separate vCPU than the
     one that acked the IRQ

   - Support for FEAT_XNX (user / privileged execute permissions) and
     FEAT_HAF (hardware update to the Access Flag) in the software page
     table walkers and shadow MMU

   - Allow page table destruction to reschedule, fixing long
     need_resched latencies observed when destroying a large VM

   - Minor fixes to KVM and selftests

  Loongarch:

   - Get VM PMU capability from HW GCFG register

   - Add AVEC basic support

   - Use 64-bit register definition for EIOINTC

   - Add KVM timer test cases for tools/selftests

  RISC/V:

   - SBI message passing (MPXY) support for KVM guest

   - Give a new, more specific error subcode for the case when in-kernel
     AIA virtualization fails to allocate IMSIC VS-file

   - Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
     in small chunks

   - Fix guest page fault within HLV* instructions

   - Flush VS-stage TLB after VCPU migration for Andes cores

  s390:

   - Always allocate ESCA (Extended System Control Area), instead of
     starting with the basic SCA and converting to ESCA with the
     addition of the 65th vCPU. The price is increased number of exits
     (and worse performance) on z10 and earlier processor; ESCA was
     introduced by z114/z196 in 2010

   - VIRT_XFER_TO_GUEST_WORK support

   - Operation exception forwarding support

   - Cleanups

  x86:

   - Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO
     SPTE caching is disabled, as there can't be any relevant SPTEs to
     zap

   - Relocate a misplaced export

   - Fix an async #PF bug where KVM would clear the completion queue
     when the guest transitioned in and out of paging mode, e.g. when
     handling an SMI and then returning to paged mode via RSM

   - Leave KVM's user-return notifier registered even when disabling
     virtualization, as long as kvm.ko is loaded. On reboot/shutdown,
     keeping the notifier registered is ok; the kernel does not use the
     MSRs and the callback will run cleanly and restore host MSRs if the
     CPU manages to return to userspace before the system goes down

   - Use the checked version of {get,put}_user()

   - Fix a long-lurking bug where KVM's lack of catch-up logic for
     periodic APIC timers can result in a hard lockup in the host

   - Revert the periodic kvmclock sync logic now that KVM doesn't use a
     clocksource that's subject to NTP corrections

   - Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the
     latter behind CONFIG_CPU_MITIGATIONS

   - Context switch XCR0, XSS, and PKRU outside of the entry/exit fast
     path; the only reason they were handled in the fast path was to
     paper of a bug in the core #MC code, and that has long since been
     fixed

   - Add emulator support for AVX MOV instructions, to play nice with
     emulated devices whose guest drivers like to access PCI BARs with
     large multi-byte instructions

  x86 (AMD):

   - Fix a few missing "VMCB dirty" bugs

   - Fix the worst of KVM's lack of EFER.LMSLE emulation

   - Add AVIC support for addressing 4k vCPUs in x2AVIC mode

   - Fix incorrect handling of selective CR0 writes when checking
     intercepts during emulation of L2 instructions

   - Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32]
     on VMRUN and #VMEXIT

   - Fix a bug where KVM corrupt the guest code stream when re-injecting
     a soft interrupt if the guest patched the underlying code after the
     VM-Exit, e.g. when Linux patches code with a temporary INT3

   - Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits
     to userspace, and extend KVM "support" to all policy bits that
     don't require any actual support from KVM

  x86 (Intel):

   - Use the root role from kvm_mmu_page to construct EPTPs instead of
     the current vCPU state, partly as worthwhile cleanup, but mostly to
     pave the way for tracking per-root TLB flushes, and elide EPT
     flushes on pCPU migration if the root is clean from a previous
     flush

   - Add a few missing nested consistency checks

   - Rip out support for doing "early" consistency checks via hardware
     as the functionality hasn't been used in years and is no longer
     useful in general; replace it with an off-by-default module param
     to WARN if hardware fails a check that KVM does not perform

   - Fix a currently-benign bug where KVM would drop the guest's
     SPEC_CTRL[63:32] on VM-Enter

   - Misc cleanups

   - Overhaul the TDX code to address systemic races where KVM (acting
     on behalf of userspace) could inadvertantly trigger lock contention
     in the TDX-Module; KVM was either working around these in weird,
     ugly ways, or was simply oblivious to them (though even Yan's
     devilish selftests could only break individual VMs, not the host
     kernel)

   - Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a
     TDX vCPU, if creating said vCPU failed partway through

   - Fix a few sparse warnings (bad annotation, 0 != NULL)

   - Use struct_size() to simplify copying TDX capabilities to userspace

   - Fix a bug where TDX would effectively corrupt user-return MSR
     values if the TDX Module rejects VP.ENTER and thus doesn't clobber
     host MSRs as expected

  Selftests:

   - Fix a math goof in mmu_stress_test when running on a single-CPU
     system/VM

   - Forcefully override ARCH from x86_64 to x86 to play nice with
     specifying ARCH=x86_64 on the command line

   - Extend a bunch of nested VMX to validate nested SVM as well

   - Add support for LA57 in the core VM_MODE_xxx macro, and add a test
     to verify KVM can save/restore nested VMX state when L1 is using
     5-level paging, but L2 is not

   - Clean up the guest paging code in anticipation of sharing the core
     logic for nested EPT and nested NPT

  guest_memfd:

   - Add NUMA mempolicy support for guest_memfd, and clean up a variety
     of rough edges in guest_memfd along the way

   - Define a CLASS to automatically handle get+put when grabbing a
     guest_memfd from a memslot to make it harder to leak references

   - Enhance KVM selftests to make it easer to develop and debug
     selftests like those added for guest_memfd NUMA support, e.g. where
     test and/or KVM bugs often result in hard-to-debug SIGBUS errors

   - Misc cleanups

  Generic:

   - Use the recently-added WQ_PERCPU when creating the per-CPU
     workqueue for irqfd cleanup

   - Fix a goof in the dirty ring documentation

   - Fix choice of target for directed yield across different calls to
     kvm_vcpu_on_spin(); the function was always starting from the first
     vCPU instead of continuing the round-robin search"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits)
  KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
  KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
  KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}
  KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected"
  KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot()
  KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
  KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
  KVM: arm64: selftests: Add test for AT emulation
  KVM: arm64: nv: Expose hardware access flag management to NV guests
  KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW
  KVM: arm64: Implement HW access flag management in stage-1 SW PTW
  KVM: arm64: Propagate PTW errors up to AT emulation
  KVM: arm64: Add helper for swapping guest descriptor
  KVM: arm64: nv: Use pgtable definitions in stage-2 walk
  KVM: arm64: Handle endianness in read helper for emulated PTW
  KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW
  KVM: arm64: Call helper for reading descriptors directly
  KVM: arm64: nv: Advertise support for FEAT_XNX
  KVM: arm64: Teach ptdump about FEAT_XNX permissions
  KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
  ...
2025-12-05 17:01:20 -08:00
Linus Torvalds
2547f79b0b s390 updates for 6.19 merge window
- Provide a new interface for dynamic configuration and deconfiguration of
   hotplug memory, allowing with and without memmap_on_memory support. This
   makes the way memory hotplug is handled on s390 much more similar to
   other architectures
 
 - Remove compat support. There shouldn't be any compat user space around
   anymore, therefore get rid of a lot of code which also doesn't need to be
   tested anymore
 
 - Add stackprotector support. GCC 16 will get new compiler options, which
   allow to generate code required for kernel stackprotector support
 
 - Merge pai_crypto and pai_ext PMU drivers into a new driver. This removes
   a lot of duplicated code. The new driver is also extendable and allows
   to support new PMUs
 
 - Add driver override support for AP queues
 
 - Rework and extend zcrypt and AP trace events to allow for tracing of
   crypto requests
 
 - Support block sizes larger than 65535 bytes for CCW tape devices
 
 - Since the rework of the virtual kernel address space the module area and
   the kernel image are within the same 4GB area. This eliminates the need
   of weak per cpu variables. Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
 
 - Various other small improvements and fixes
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Merge tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Provide a new interface for dynamic configuration and deconfiguration
   of hotplug memory, allowing with and without memmap_on_memory
   support. This makes the way memory hotplug is handled on s390 much
   more similar to other architectures

 - Remove compat support. There shouldn't be any compat user space
   around anymore, therefore get rid of a lot of code which also doesn't
   need to be tested anymore

 - Add stackprotector support. GCC 16 will get new compiler options,
   which allow to generate code required for kernel stackprotector
   support

 - Merge pai_crypto and pai_ext PMU drivers into a new driver. This
   removes a lot of duplicated code. The new driver is also extendable
   and allows to support new PMUs

 - Add driver override support for AP queues

 - Rework and extend zcrypt and AP trace events to allow for tracing of
   crypto requests

 - Support block sizes larger than 65535 bytes for CCW tape devices

 - Since the rework of the virtual kernel address space the module area
   and the kernel image are within the same 4GB area. This eliminates
   the need of weak per cpu variables. Get rid of
   ARCH_MODULE_NEEDS_WEAK_PER_CPU

 - Various other small improvements and fixes

* tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (92 commits)
  watchdog: diag288_wdt: Remove KMSG_COMPONENT macro
  s390/entry: Use lay instead of aghik
  s390/vdso: Get rid of -m64 flag handling
  s390/vdso: Rename vdso64 to vdso
  s390: Rename head64.S to head.S
  s390/vdso: Use common STABS_DEBUG and DWARF_DEBUG macros
  s390: Add stackprotector support
  s390/modules: Simplify module_finalize() slightly
  s390: Remove KMSG_COMPONENT macro
  s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
  s390/ap: Restrict driver_override versus apmask and aqmask use
  s390/ap: Rename mutex ap_perms_mutex to ap_attr_mutex
  s390/ap: Support driver_override for AP queue devices
  s390/ap: Use all-bits-one apmask/aqmask for vfio in_use() checks
  s390/debug: Update description of resize operation
  s390/syscalls: Switch to generic system call table generation
  s390/syscalls: Remove system call table pointer from thread_struct
  s390/uapi: Remove 31 bit support from uapi header files
  s390: Remove compat support
  tools: Remove s390 compat support
  ...
2025-12-02 16:37:00 -08:00
Paolo Bonzini
e0c26d47de - SCA rework
- VIRT_XFER_TO_GUEST_WORK support
 - Operation exception forwarding support
 - Cleanups
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Merge tag 'kvm-s390-next-6.19-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

- SCA rework
- VIRT_XFER_TO_GUEST_WORK support
- Operation exception forwarding support
- Cleanups
2025-12-02 18:58:47 +01:00
Linus Torvalds
1dce50698a Scoped user mode access and related changes:
- Implement the missing u64 user access function on ARM when
    CONFIG_CPU_SPECTRE=n. This makes it possible to access a 64bit value in
    generic code with [unsafe_]get_user(). All other architectures and ARM
    variants provide the relevant accessors already.
 
  - Ensure that ASM GOTO jump label usage in the user mode access helpers
    always goes through a local C scope label indirection inside the
    helpers. This is required because compilers are not supporting that a
    ASM GOTO target leaves a auto cleanup scope. GCC silently fails to emit
    the cleanup invocation and CLANG fails the build.
 
    This provides generic wrapper macros and the conversion of affected
    architecture code to use them.
 
  - Scoped user mode access with auto cleanup
 
    Access to user mode memory can be required in hot code paths, but if it
    has to be done with user controlled pointers, the access is shielded
    with a speculation barrier, so that the CPU cannot speculate around the
    address range check. Those speculation barriers impact performance quite
    significantly. This can be avoided by "masking" the provided pointer so
    it is guaranteed to be in the valid user memory access range and
    otherwise to point to a guaranteed unpopulated address space. This has
    to be done without branches so it creates an address dependency for the
    access, which the CPU cannot speculate ahead.
 
    This results in repeating and error prone programming patterns:
 
      	    if (can_do_masked_user_access())
                     from = masked_user_read_access_begin((from));
             else if (!user_read_access_begin(from, sizeof(*from)))
                     return -EFAULT;
             unsafe_get_user(val, from, Efault);
             user_read_access_end();
             return 0;
       Efault:
             user_read_access_end();
             return -EFAULT;
 
     which can be replaced with scopes and automatic cleanup:
 
             scoped_user_read_access(from, Efault)
                     unsafe_get_user(val, from, Efault);
             return 0;
        Efault:
             return -EFAULT;
 
  - Convert code which implements the above pattern over to
    scope_user.*.access(). This also corrects a couple of imbalanced
    masked_*_begin() instances which are harmless on most architectures, but
    prevent PowerPC from implementing the masking optimization.
 
  - Add a missing speculation barrier in copy_from_user_iter()
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Merge tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scoped user access updates from Thomas Gleixner:
 "Scoped user mode access and related changes:

   - Implement the missing u64 user access function on ARM when
     CONFIG_CPU_SPECTRE=n.

     This makes it possible to access a 64bit value in generic code with
     [unsafe_]get_user(). All other architectures and ARM variants
     provide the relevant accessors already.

   - Ensure that ASM GOTO jump label usage in the user mode access
     helpers always goes through a local C scope label indirection
     inside the helpers.

     This is required because compilers are not supporting that a ASM
     GOTO target leaves a auto cleanup scope. GCC silently fails to emit
     the cleanup invocation and CLANG fails the build.

     [ Editor's note: gcc-16 will have fixed the code generation issue
       in commit f68fe3ddda4 ("eh: Invoke cleanups/destructors in asm
       goto jumps [PR122835]"). But we obviously have to deal with clang
       and older versions of gcc, so.. - Linus ]

     This provides generic wrapper macros and the conversion of affected
     architecture code to use them.

   - Scoped user mode access with auto cleanup

     Access to user mode memory can be required in hot code paths, but
     if it has to be done with user controlled pointers, the access is
     shielded with a speculation barrier, so that the CPU cannot
     speculate around the address range check. Those speculation
     barriers impact performance quite significantly.

     This cost can be avoided by "masking" the provided pointer so it is
     guaranteed to be in the valid user memory access range and
     otherwise to point to a guaranteed unpopulated address space. This
     has to be done without branches so it creates an address dependency
     for the access, which the CPU cannot speculate ahead.

     This results in repeating and error prone programming patterns:

       	    if (can_do_masked_user_access())
                      from = masked_user_read_access_begin((from));
              else if (!user_read_access_begin(from, sizeof(*from)))
                      return -EFAULT;
              unsafe_get_user(val, from, Efault);
              user_read_access_end();
              return 0;
        Efault:
              user_read_access_end();
              return -EFAULT;

      which can be replaced with scopes and automatic cleanup:

              scoped_user_read_access(from, Efault)
                      unsafe_get_user(val, from, Efault);
              return 0;
         Efault:
              return -EFAULT;

   - Convert code which implements the above pattern over to
     scope_user.*.access(). This also corrects a couple of imbalanced
     masked_*_begin() instances which are harmless on most
     architectures, but prevent PowerPC from implementing the masking
     optimization.

   - Add a missing speculation barrier in copy_from_user_iter()"

* tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/strn*,uaccess: Use masked_user_{read/write}_access_begin when required
  scm: Convert put_cmsg() to scoped user access
  iov_iter: Add missing speculation barrier to copy_from_user_iter()
  iov_iter: Convert copy_from_user_iter() to masked user access
  select: Convert to scoped user access
  x86/futex: Convert to scoped user access
  futex: Convert to get/put_user_inline()
  uaccess: Provide put/get_user_inline()
  uaccess: Provide scoped user access regions
  arm64: uaccess: Use unsafe wrappers for ASM GOTO
  s390/uaccess: Use unsafe wrappers for ASM GOTO
  riscv/uaccess: Use unsafe wrappers for ASM GOTO
  powerpc/uaccess: Use unsafe wrappers for ASM GOTO
  x86/uaccess: Use unsafe wrappers for ASM GOTO
  uaccess: Provide ASM GOTO safe wrappers for unsafe_*_user()
  ARM: uaccess: Implement missing __get_user_asm_dword()
2025-12-02 08:01:39 -08:00
Linus Torvalds
4a26e7032d Core kernel bug handling infrastructure changes for v6.19:
- Improve WARN(), which has vararg printf like arguments,
     to work with the x86 #UD based WARN-optimizing infrastructure
     by hiding the format in the bug_table and replacing this
     first argument with the address of the bug-table entry,
     while making the actual function that's called a UD1 instruction.
     (Peter Zijlstra)
 
   - Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch
     (Ingo Molnar, s390 support by Heiko Carstens)
 
 Fixes and cleanups:
 
   - bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)
 
   - <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
     (Peter Zijlstra)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull bug handling infrastructure updates from Ingo Molnar:
 "Core updates:

   - Improve WARN(), which has vararg printf like arguments, to work
     with the x86 #UD based WARN-optimizing infrastructure by hiding the
     format in the bug_table and replacing this first argument with the
     address of the bug-table entry, while making the actual function
     that's called a UD1 instruction (Peter Zijlstra)

   - Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch (Ingo
     Molnar, s390 support by Heiko Carstens)

  Fixes and cleanups:

   - bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens)

   - <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS (Peter
     Zijlstra)"

* tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86/bugs: Make i386 use GENERIC_BUG_RELATIVE_POINTERS
  x86/bug: Fix BUG_FORMAT vs KASLR
  x86_64/bug: Inline the UD1
  x86/bug: Implement WARN_ONCE()
  x86_64/bug: Implement __WARN_printf()
  x86/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED
  x86/bug: Add BUG_FORMAT basics
  bug: Allow architectures to provide __WARN_printf()
  bug: Implement WARN_ON() using __WARN_FLAGS()
  bug: Add report_bug_entry()
  bug: Add BUG_FORMAT_ARGS infrastructure
  bug: Clean up CONFIG_GENERIC_BUG_RELATIVE_POINTERS
  bug: Add BUG_FORMAT infrastructure
  x86: Rework __bug_table helpers
  bugs/s390: Remove private WARN_ON() implementation
  bugs/core: Reorganize fields in the first line of WARNING output, add ->comm[] output
  bugs/sh: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/parisc: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/riscv: Concatenate 'cond_str' with '__FILE__' in __BUG_FLAGS(), to extend WARN_ON/BUG_ON output
  bugs/riscv: Pass in 'cond_str' to __BUG_FLAGS()
  ...
2025-12-01 21:33:01 -08:00
Linus Torvalds
63e6995005 objtool updates for v6.19:
- klp-build livepatch module generation (Josh Poimboeuf)
 
    Introduce new objtool features and a klp-build
    script to generate livepatch modules using a
    source .patch as input.
 
    This builds on concepts from the longstanding out-of-tree
    kpatch project which began in 2012 and has been used for
    many years to generate livepatch modules for production kernels.
    However, this is a complete rewrite which incorporates
    hard-earned lessons from 12+ years of maintaining kpatch.
 
    Key improvements compared to kpatch-build:
 
     - Integrated with objtool: Leverages objtool's existing control-flow
       graph analysis to help detect changed functions.
 
     - Works on vmlinux.o: Supports late-linked objects, making it
       compatible with LTO, IBT, and similar.
 
     - Simplified code base: ~3k fewer lines of code.
 
     - Upstream: No more out-of-tree #ifdef hacks, far less cruft.
 
     - Cleaner internals: Vastly simplified logic for symbol/section/reloc
       inclusion and special section extraction.
 
     - Robust __LINE__ macro handling: Avoids false positive binary diffs
       caused by the __LINE__ macro by introducing a fix-patch-lines script
       which injects #line directives into the source .patch to preserve
       the original line numbers at compile time.
 
  - Disassemble code with libopcodes instead of running objdump
    (Alexandre Chartre)
 
  - Disassemble support (-d option to objtool) by Alexandre Chartre,
    which supports the decoding of various Linux kernel code generation
    specials such as alternatives:
 
       17ef:  sched_balance_find_dst_group+0x62f                 mov    0x34(%r9),%edx
       17f3:  sched_balance_find_dst_group+0x633               | <alternative.17f3>             | X86_FEATURE_POPCNT
       17f3:  sched_balance_find_dst_group+0x633               | call   0x17f8 <__sw_hweight64> | popcnt %rdi,%rax
       17f8:  sched_balance_find_dst_group+0x638                 cmp    %eax,%edx
 
    ... jump table alternatives:
 
       1895:  sched_use_asym_prio+0x5                            test   $0x8,%ch
       1898:  sched_use_asym_prio+0x8                            je     0x18a9 <sched_use_asym_prio+0x19>
       189a:  sched_use_asym_prio+0xa                          | <jump_table.189a>                        | JUMP
       189a:  sched_use_asym_prio+0xa                          | jmp    0x18ae <sched_use_asym_prio+0x1e> | nop2
       189c:  sched_use_asym_prio+0xc                            mov    $0x1,%eax
       18a1:  sched_use_asym_prio+0x11                           and    $0x80,%ecx
 
    ... exception table alternatives:
 
     native_read_msr:
       5b80:  native_read_msr+0x0                                                     mov    %edi,%ecx
       5b82:  native_read_msr+0x2                                                   | <ex_table.5b82> | EXCEPTION
       5b82:  native_read_msr+0x2                                                   | rdmsr           | resume at 0x5b84 <native_read_msr+0x4>
       5b84:  native_read_msr+0x4                                                     shl    $0x20,%rdx
 
    .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT
         example in sched_balance_find_dst_group() above):
 
       2faaf:  start_thread_common.constprop.0+0x1f                                    jne    0x2fba4 <start_thread_common.constprop.0+0x114>
       2fab5:  start_thread_common.constprop.0+0x25                                  | <alternative.2fab5>                  | X86_FEATURE_ALWAYS                                  | X86_BUG_NULL_SEG
       2fab5:  start_thread_common.constprop.0+0x25                                  | jmp    0x2faba <.altinstr_aux+0x2f4> | jmp    0x4b0 <start_thread_common.constprop.0+0x3f> | nop5
       2faba:  start_thread_common.constprop.0+0x2a                                    mov    $0x2b,%eax
 
    ... NOP sequence shortening:
 
       1048e2:  snapshot_write_finalize+0xc2                                            je     0x104917 <snapshot_write_finalize+0xf7>
       1048e4:  snapshot_write_finalize+0xc4                                            nop6
       1048ea:  snapshot_write_finalize+0xca                                            nop11
       1048f5:  snapshot_write_finalize+0xd5                                            nop11
       104900:  snapshot_write_finalize+0xe0                                            mov    %rax,%rcx
       104903:  snapshot_write_finalize+0xe3                                            mov    0x10(%rdx),%rax
 
    ... and much more.
 
  - Function validation tracing support (Alexandre Chartre)
 
  - Various -ffunction-sections fixes (Josh Poimboeuf)
 
  - Clang AutoFDO (Automated Feedback-Directed Optimizations) support (Josh Poimboeuf)
 
  - Misc fixes and cleanups (Borislav Petkov, Chen Ni,
    Dylan Hatch, Ingo Molnar, John Wang, Josh Poimboeuf,
    Pankaj Raghav, Peter Zijlstra, Thorsten Blum)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - klp-build livepatch module generation (Josh Poimboeuf)

   Introduce new objtool features and a klp-build script to generate
   livepatch modules using a source .patch as input.

   This builds on concepts from the longstanding out-of-tree kpatch
   project which began in 2012 and has been used for many years to
   generate livepatch modules for production kernels. However, this is a
   complete rewrite which incorporates hard-earned lessons from 12+
   years of maintaining kpatch.

   Key improvements compared to kpatch-build:

    - Integrated with objtool: Leverages objtool's existing control-flow
      graph analysis to help detect changed functions.

    - Works on vmlinux.o: Supports late-linked objects, making it
      compatible with LTO, IBT, and similar.

    - Simplified code base: ~3k fewer lines of code.

    - Upstream: No more out-of-tree #ifdef hacks, far less cruft.

    - Cleaner internals: Vastly simplified logic for
      symbol/section/reloc inclusion and special section extraction.

    - Robust __LINE__ macro handling: Avoids false positive binary diffs
      caused by the __LINE__ macro by introducing a fix-patch-lines
      script which injects #line directives into the source .patch to
      preserve the original line numbers at compile time.

 - Disassemble code with libopcodes instead of running objdump
   (Alexandre Chartre)

 - Disassemble support (-d option to objtool) by Alexandre Chartre,
   which supports the decoding of various Linux kernel code generation
   specials such as alternatives:

      17ef:  sched_balance_find_dst_group+0x62f                 mov    0x34(%r9),%edx
      17f3:  sched_balance_find_dst_group+0x633               | <alternative.17f3>             | X86_FEATURE_POPCNT
      17f3:  sched_balance_find_dst_group+0x633               | call   0x17f8 <__sw_hweight64> | popcnt %rdi,%rax
      17f8:  sched_balance_find_dst_group+0x638                 cmp    %eax,%edx

   ... jump table alternatives:

      1895:  sched_use_asym_prio+0x5                            test   $0x8,%ch
      1898:  sched_use_asym_prio+0x8                            je     0x18a9 <sched_use_asym_prio+0x19>
      189a:  sched_use_asym_prio+0xa                          | <jump_table.189a>                        | JUMP
      189a:  sched_use_asym_prio+0xa                          | jmp    0x18ae <sched_use_asym_prio+0x1e> | nop2
      189c:  sched_use_asym_prio+0xc                            mov    $0x1,%eax
      18a1:  sched_use_asym_prio+0x11                           and    $0x80,%ecx

   ... exception table alternatives:

    native_read_msr:
      5b80:  native_read_msr+0x0                                                     mov    %edi,%ecx
      5b82:  native_read_msr+0x2                                                   | <ex_table.5b82> | EXCEPTION
      5b82:  native_read_msr+0x2                                                   | rdmsr           | resume at 0x5b84 <native_read_msr+0x4>
      5b84:  native_read_msr+0x4                                                     shl    $0x20,%rdx

   .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT
        example in sched_balance_find_dst_group() above):

      2faaf:  start_thread_common.constprop.0+0x1f                                    jne    0x2fba4 <start_thread_common.constprop.0+0x114>
      2fab5:  start_thread_common.constprop.0+0x25                                  | <alternative.2fab5>                  | X86_FEATURE_ALWAYS                                  | X86_BUG_NULL_SEG
      2fab5:  start_thread_common.constprop.0+0x25                                  | jmp    0x2faba <.altinstr_aux+0x2f4> | jmp    0x4b0 <start_thread_common.constprop.0+0x3f> | nop5
      2faba:  start_thread_common.constprop.0+0x2a                                    mov    $0x2b,%eax

   ... NOP sequence shortening:

      1048e2:  snapshot_write_finalize+0xc2                                            je     0x104917 <snapshot_write_finalize+0xf7>
      1048e4:  snapshot_write_finalize+0xc4                                            nop6
      1048ea:  snapshot_write_finalize+0xca                                            nop11
      1048f5:  snapshot_write_finalize+0xd5                                            nop11
      104900:  snapshot_write_finalize+0xe0                                            mov    %rax,%rcx
      104903:  snapshot_write_finalize+0xe3                                            mov    0x10(%rdx),%rax

   ... and much more.

 - Function validation tracing support (Alexandre Chartre)

 - Various -ffunction-sections fixes (Josh Poimboeuf)

 - Clang AutoFDO (Automated Feedback-Directed Optimizations) support
   (Josh Poimboeuf)

 - Misc fixes and cleanups (Borislav Petkov, Chen Ni, Dylan Hatch, Ingo
   Molnar, John Wang, Josh Poimboeuf, Pankaj Raghav, Peter Zijlstra,
   Thorsten Blum)

* tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  objtool: Fix segfault on unknown alternatives
  objtool: Build with disassembly can fail when including bdf.h
  objtool: Trim trailing NOPs in alternative
  objtool: Add wide output for disassembly
  objtool: Compact output for alternatives with one instruction
  objtool: Improve naming of group alternatives
  objtool: Add Function to get the name of a CPU feature
  objtool: Provide access to feature and flags of group alternatives
  objtool: Fix address references in alternatives
  objtool: Disassemble jump table alternatives
  objtool: Disassemble exception table alternatives
  objtool: Print addresses with alternative instructions
  objtool: Disassemble group alternatives
  objtool: Print headers for alternatives
  objtool: Preserve alternatives order
  objtool: Add the --disas=<function-pattern> action
  objtool: Do not validate IBT for .return_sites and .call_sites
  objtool: Improve tracing of alternative instructions
  objtool: Add functions to better name alternatives
  objtool: Identify the different types of alternatives
  ...
2025-12-01 20:18:59 -08:00
Heiko Carstens
d0139059e3 KVM: s390: Enable and disable interrupts in entry code
Move enabling and disabling of interrupts around the SIE instruction to
entry code. Enabling interrupts only after the __TI_sie flag has been set
guarantees that the SIE instruction is not executed if an interrupt happens
between enabling interrupts and the execution of the SIE instruction.
Interrupt handlers and machine check handler forward the PSW to the
sie_exit label in such cases.

This is a prerequisite for VIRT_XFER_TO_GUEST_WORK to prevent that guest
context is entered when e.g. a scheduler IPI, indicating that a reschedule
is required, happens right before the SIE instruction, which could lead to
long delays.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-27 15:39:46 +01:00
Andrew Donnellan
c067847c52 KVM: s390: Add signal_exits counter
Add a signal_exits counter for s390, as exists on arm64, loongarch, mips,
powerpc, riscv and x86.

This is used by kvm_handle_signal_exit(), which we will use when we
later enable CONFIG_VIRT_XFER_TO_GUEST_WORK.

Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-27 15:39:46 +01:00
Heiko Carstens
c0087d807a s390/vdso: Rename vdso64 to vdso
Since compat is gone there is only a 64 bit vdso left.
Remove the superfluous "64" suffix everywhere.

Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-25 15:28:07 +01:00
Heiko Carstens
f5730d44e0 s390: Add stackprotector support
Stackprotector support was previously unavailable on s390 because by
default compilers generate code which is not suitable for the kernel:
the canary value is accessed via thread local storage, where the address
of thread local storage is within access registers 0 and 1.

Using those registers also for the kernel would come with a significant
performance impact and more complicated kernel entry/exit code, since
access registers contents would have to be exchanged on every kernel entry
and exit.

With the upcoming gcc 16 release new compiler options will become available
which allow to generate code suitable for the kernel. [1]

Compiler option -mstack-protector-guard=global instructs gcc to generate
stackprotector code that refers to a global stackprotector canary value via
symbol __stack_chk_guard. Access to this value is guaranteed to occur via
larl and lgrl instructions.

Furthermore, compiler option -mstack-protector-guard-record generates a
section containing all code addresses that reference the canary value.

To allow for per task canary values the instructions which load the address
of __stack_chk_guard are patched so they access a lowcore field instead: a
per task canary value is available within the task_struct of each task, and
is written to the per-cpu lowcore location on each context switch.

Also add sanity checks and debugging option to be consistent with other
kernel code patching mechanisms.

Full debugging output can be enabled with the following kernel command line
options:

debug_stackprotector
bootdebug
ignore_loglevel
earlyprintk
dyndbg="file stackprotector.c +p"

Example debug output:

stackprot: 0000021e402d4eda: c010005a9ae3 -> c01f00070240

where "<insn address>: <old insn> -> <new insn>".

[1] gcc commit 0cd1f03939d5 ("s390: Support global stack protector")

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:21 +01:00
Heiko Carstens
e950d1f84d s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU
Since the rework of the kernel virtual address space [1] the module area
and the kernel image are within the same 4GB area. Therefore there is no
need for the weak per cpu workaround for modules anymore. Remove it.

[1] commit c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-24 11:45:20 +01:00
Peter Zijlstra
2ace527183 Merge branch 'objtool/core'
Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-11-21 11:21:20 +01:00
Janosch Frank
8e8678e740 KVM: s390: Add capability that forwards operation exceptions
Setting KVM_CAP_S390_USER_OPEREXEC will forward all operation
exceptions to user space. This also includes the 0x0000 instructions
managed by KVM_CAP_S390_USER_INSTR0. It's helpful if user space wants
to emulate instructions which do not (yet) have an opcode.

While we're at it refine the documentation for
KVM_CAP_S390_USER_INSTR0.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-11-21 10:26:03 +01:00
Heiko Carstens
4ac286c4a8 s390/syscalls: Switch to generic system call table generation
The s390 syscall.tbl format differs slightly from most others, and
therefore requires an s390 specific system call table generation
script.

With compat support gone use the opportunity to switch to generic
system call table generation. The abi for all 64 bit system calls is
now common, since there is no need to specify if system call entry
points are only for 64 bit anymore.

Furthermore create the system call table in C instead of assembler
code in order to get type checking for all system call functions
contained within the table.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:39 +01:00
Heiko Carstens
f4e1f1b137 s390/syscalls: Remove system call table pointer from thread_struct
With compat support gone there is only one system call table
left. Therefore remove the sys_call_table pointer from
thread_struct and use the sys_call_table directly.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:39 +01:00
Heiko Carstens
3db5cf9354 s390/uapi: Remove 31 bit support from uapi header files
Since the kernel does not support running 31 bit / compat binaries
anymore, remove also the corresponding 31 bit support from uapi header
files.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:38 +01:00
Heiko Carstens
8e0b986c59 s390: Remove compat support
There shouldn't be any 31 bit code around anymore that matters.
Remove the compat layer support required to run 31 bit code.

Reason for removal is code simplification and reduced test effort.

Note that this comes without any deprecation warnings added to config
options, or kernel messages, since most likely those would be ignored
anyway.

If it turns out there is still a reason to keep the compat layer this
can be reverted at any time in the future.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:38 +01:00
Heiko Carstens
7afb095df3 s390/syscalls: Add pt_regs parameter to SYSCALL_DEFINE0() syscall wrapper
All system call wrappers should match the sys_call_ptr_t type. This is not
the case for system calls without parameters. Add the missing pt_regs
parameter there too.

Note: this is currently not a problem, since the parameter is unused.
However it prevents to create a correctly typed system call table in
C. With the current assembler implementation this works because of
missing type checking.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:38 +01:00
Heiko Carstens
8c633c78c2 s390/ptrace: Rename psw_t32 to psw32_t
Use a standard "_t" suffix for psw_t32 and rename it to psw32_t.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-17 11:10:37 +01:00
Heiko Carstens
31475b8811 s390/mm: Fix __ptep_rdp() inline assembly
When a zero ASCE is passed to the __ptep_rdp() inline assembly, the
generated instruction should have the R3 field of the instruction set to
zero. However the inline assembly is written incorrectly: for such cases a
zero is loaded into a register allocated by the compiler and this register
is then used by the instruction.

This means that selected TLB entries may not be flushed since the specified
ASCE does not match the one which was used when the selected TLB entries
were created.

Fix this by removing the asce and opt parameters of __ptep_rdp(), since
all callers always pass zero, and use a hard-coded register zero for
the R3 field.

Fixes: 0807b85652 ("s390/mm: add support for RDP (Reset DAT-Protection)")
Cc: stable@vger.kernel.org
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 15:58:20 +01:00
Heiko Carstens
52a1f73d17 s390/fault: Print unmodified PSW address on protection exception
In case of a kernel crash caused by a protection exception, print the
unmodified PSW address as reported by the CPU. The protection exception
handler modifies the PSW address in order to keep fault handling easy,
however that leads to misleading call traces.

Therefore restore the original PSW address before printing it.

Before this change the output in case of a protection exception looks like
this:

 Oops: 0004 ilc:2 [#1]SMP
 Krnl PSW : 0704c00180000000 000003ffe0b40d78 (sysrq_handle_crash+0x28/0x40)
            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
...
 Krnl Code: 000003ffe0b40d66: e3e0f0980024        stg     %r14,152(%r15)
            000003ffe0b40d6c: c010fffffff2        larl    %r1,000003ffe0b40d50
           #000003ffe0b40d72: c0200046b6bc        larl    %r2,000003ffe1417aea
           >000003ffe0b40d78: 92021000            mvi     0(%r1),2
            000003ffe0b40d7c: c0e5ffae03d6        brasl   %r14,000003ffe0101528

With this change it looks like this:

 Oops: 0004 ilc:2 [#1]SMP
 Krnl PSW : 0704c00180000000 000003ffe0b40dfc (sysrq_handle_crash+0x2c/0x40)
            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
...
 Krnl Code: 000003ffe0b40dec: c010fffffff2        larl    %r1,000003ffe0b40dd0
            000003ffe0b40df2: c0200046b67c        larl    %r2,000003ffe1417aea
           *000003ffe0b40df8: 92021000            mvi     0(%r1),2
           >000003ffe0b40dfc: c0e5ffae03b6        brasl   %r14,000003ffe0101568
            000003ffe0b40e02: 0707                bcr     0,%r7

Note that with this change the PSW address points to the instruction behind
the instruction which caused the exception like it is expected for
protection exceptions.

This also replaces the '#' marker in the disassembly with '*', which allows
to distinguish between new and old behavior.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 11:34:28 +01:00
Heiko Carstens
37450e0994 s390/processor: Add __forward_psw() helper
Similar to __rewind_psw() add the counter part __forward_psw(). This
helps to make code more readable if a PSW address has to be forwarded,
since it is more natural to write

addr = __forward_psw(psw, ilen);

instead of

addr = __rewind_psw(psw, -ilen);

This renames also the ilc parameter of __rewind_psw() to ilen, since
the parameter reflects an instruction length, and not an instruction
length code. Also change the type of ilen from unsigned long to long
so it reflects that lengths can be negative or positive.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 11:34:28 +01:00
Aleksei Nikiforov
14e4e4175b s390/fpu: Fix false-positive kmsan report in fpu_vstl()
A false-positive kmsan report is detected when running ping command.

An inline assembly instruction 'vstl' can write varied amount of bytes
depending on value of 'index' argument. If 'index' > 0, 'vstl' writes
at least 2 bytes.

clang generates kmsan write helper call depending on inline assembly
constraints. Constraints are evaluated compile-time, but value of
'index' argument is known only at runtime.

clang currently generates call to __msan_instrument_asm_store with 1 byte
as size. Manually call kmsan function to indicate correct amount of bytes
written and fix false-positive report.

This change fixes following kmsan reports:

[   36.563119] =====================================================
[   36.563594] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70
[   36.563852]  virtqueue_add+0x35c6/0x7c70
[   36.564016]  virtqueue_add_outbuf+0xa0/0xb0
[   36.564266]  start_xmit+0x288c/0x4a20
[   36.564460]  dev_hard_start_xmit+0x302/0x900
[   36.564649]  sch_direct_xmit+0x340/0xea0
[   36.564894]  __dev_queue_xmit+0x2e94/0x59b0
[   36.565058]  neigh_resolve_output+0x936/0xb40
[   36.565278]  __neigh_update+0x2f66/0x3a60
[   36.565499]  neigh_update+0x52/0x60
[   36.565683]  arp_process+0x1588/0x2de0
[   36.565916]  NF_HOOK+0x1da/0x240
[   36.566087]  arp_rcv+0x3e4/0x6e0
[   36.566306]  __netif_receive_skb_list_core+0x1374/0x15a0
[   36.566527]  netif_receive_skb_list_internal+0x1116/0x17d0
[   36.566710]  napi_complete_done+0x376/0x740
[   36.566918]  virtnet_poll+0x1bae/0x2910
[   36.567130]  __napi_poll+0xf4/0x830
[   36.567294]  net_rx_action+0x97c/0x1ed0
[   36.567556]  handle_softirqs+0x306/0xe10
[   36.567731]  irq_exit_rcu+0x14c/0x2e0
[   36.567910]  do_io_irq+0xd4/0x120
[   36.568139]  io_int_handler+0xc2/0xe8
[   36.568299]  arch_cpu_idle+0xb0/0xc0
[   36.568540]  arch_cpu_idle+0x76/0xc0
[   36.568726]  default_idle_call+0x40/0x70
[   36.568953]  do_idle+0x1d6/0x390
[   36.569486]  cpu_startup_entry+0x9a/0xb0
[   36.569745]  rest_init+0x1ea/0x290
[   36.570029]  start_kernel+0x95e/0xb90
[   36.570348]  startup_continue+0x2e/0x40
[   36.570703]
[   36.570798] Uninit was created at:
[   36.571002]  kmem_cache_alloc_node_noprof+0x9e8/0x10e0
[   36.571261]  kmalloc_reserve+0x12a/0x470
[   36.571553]  __alloc_skb+0x310/0x860
[   36.571844]  __ip_append_data+0x483e/0x6a30
[   36.572170]  ip_append_data+0x11c/0x1e0
[   36.572477]  raw_sendmsg+0x1c8c/0x2180
[   36.572818]  inet_sendmsg+0xe6/0x190
[   36.573142]  __sys_sendto+0x55e/0x8e0
[   36.573392]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   36.573571]  __do_syscall+0x12e/0x240
[   36.573823]  system_call+0x6e/0x90
[   36.573976]
[   36.574017] Byte 35 of 98 is uninitialized
[   36.574082] Memory access of size 98 starts at 0000000007aa0012
[   36.574218]
[   36.574325] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G    B            N  6.17.0-dirty #16 NONE
[   36.574541] Tainted: [B]=BAD_PAGE, [N]=TEST
[   36.574617] Hardware name: IBM 3931 A01 703 (KVM/Linux)
[   36.574755] =====================================================

[   63.532541] =====================================================
[   63.533639] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70
[   63.533989]  virtqueue_add+0x35c6/0x7c70
[   63.534940]  virtqueue_add_outbuf+0xa0/0xb0
[   63.535861]  start_xmit+0x288c/0x4a20
[   63.536708]  dev_hard_start_xmit+0x302/0x900
[   63.537020]  sch_direct_xmit+0x340/0xea0
[   63.537997]  __dev_queue_xmit+0x2e94/0x59b0
[   63.538819]  neigh_resolve_output+0x936/0xb40
[   63.539793]  ip_finish_output2+0x1ee2/0x2200
[   63.540784]  __ip_finish_output+0x272/0x7a0
[   63.541765]  ip_finish_output+0x4e/0x5e0
[   63.542791]  ip_output+0x166/0x410
[   63.543771]  ip_push_pending_frames+0x1a2/0x470
[   63.544753]  raw_sendmsg+0x1f06/0x2180
[   63.545033]  inet_sendmsg+0xe6/0x190
[   63.546006]  __sys_sendto+0x55e/0x8e0
[   63.546859]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   63.547730]  __do_syscall+0x12e/0x240
[   63.548019]  system_call+0x6e/0x90
[   63.548989]
[   63.549779] Uninit was created at:
[   63.550691]  kmem_cache_alloc_node_noprof+0x9e8/0x10e0
[   63.550975]  kmalloc_reserve+0x12a/0x470
[   63.551969]  __alloc_skb+0x310/0x860
[   63.552949]  __ip_append_data+0x483e/0x6a30
[   63.553902]  ip_append_data+0x11c/0x1e0
[   63.554912]  raw_sendmsg+0x1c8c/0x2180
[   63.556719]  inet_sendmsg+0xe6/0x190
[   63.557534]  __sys_sendto+0x55e/0x8e0
[   63.557875]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   63.558869]  __do_syscall+0x12e/0x240
[   63.559832]  system_call+0x6e/0x90
[   63.560780]
[   63.560972] Byte 35 of 98 is uninitialized
[   63.561741] Memory access of size 98 starts at 0000000005704312
[   63.561950]
[   63.562824] CPU: 3 UID: 0 PID: 192 Comm: ping Tainted: G    B            N  6.17.0-dirty #16 NONE
[   63.563868] Tainted: [B]=BAD_PAGE, [N]=TEST
[   63.564751] Hardware name: IBM 3931 A01 703 (KVM/Linux)
[   63.564986] =====================================================

Fixes: dcd3e1de9d ("s390/checksum: provide csum_partial_copy_nocheck()")
Signed-off-by: Aleksei Nikiforov <aleksei.nikiforov@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 11:34:27 +01:00
Heiko Carstens
02310adcc6 s390/mm: Remove unused flush_tlb()
flush_tlb() exists for historic reasons and was never used. Remove it.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 11:34:27 +01:00
Thomas Richter
413957980a s390/pai_crypto: Introduce generic event init using pai_pmu[]
To support one common PAI PMU device driver which handles
both PMUs pai_crypto and pai_ext, use a common naming scheme
for structures and variables suitable for both device drivers.

Rework PAI crypto event initialization. Add a common
function for event initialization. It uses the PAI characteristics
stored in the pai_pmu table instead of hardcoded values.
Enlarge pai_event_valid() to check all event validation aspects.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-14 11:30:05 +01:00
Ingo Molnar
d851f2b2b2 Linux 6.18-rc5
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Merge tag 'v6.18-rc5' into objtool/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-11-13 07:58:43 +01:00
Thorsten Blum
eb3a9b405b s390/smp: Mark pcpu_delegate() and smp_call_ipl_cpu() as __noreturn
pcpu_delegate() never returns to its caller. If the target CPU is the
current CPU, it calls __pcpu_delegate(), whose delegate function is not
supposed to return. In any case, even if __pcpu_delegate() unexpectedly
returns, pcpu_delegate() sends SIGP_STOP to the current CPU and waits
in an infinite loop. Annotate pcpu_delegate() with the __noreturn
attribute to improve compiler optimizations.

Also annotate smp_call_ipl_cpu() accordingly since it always calls
pcpu_delegate().

[hca: Merge two patches from Thorsten Blum]

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-06 14:17:28 +01:00
Heiko Carstens
547e9feb0e Merge branch 'dat-enhancement-1'
Heiko Carstens says:

====================

Add the Dat-Enhancement facility 1 to the list of facilities which are
required to start the kernel. The facility provides the CSPG and IDTE
instructions. In particular the CSPG instruction can be used to replace a
valid page table entry with a different page table entry, which also
differs in the page frame real address.

Without the CSPG instruction it is possible to use the CSP instruction to
change valid page table entries, however it only allows to change the lower
or higher 32 bits of such entries, which means it cannot be used to change
the page frame real address of valid page table entries.

Given that there is code around (e.g. HugeTLB vmemmap optimization) which
requires to change valid page table entries of the kernel mapping, without
the detour over an invalid page table entry, make the CSPG instruction
unconditionally available.

The Dat-Enhancement facility 1 is available since z990, which is older than
the currently supported minimum architecture (z10). Therefore adding this
the architecture level set shouldn't cause any problems.

====================

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-06 14:14:00 +01:00
Heiko Carstens
68807a894f s390/mm: Replace the CSP instruction with CSPG
The CSPG instruction is part of the Dat-Enhancement facility 1, which
is always available. Given that it can be used everywhere where also
the CSP instruction can be used, replace CSP with CSPG everywhere.

This allows to remove the csp() inline assembly. Also remove the
unused gmap_pmdp_csp() function.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-06 14:12:31 +01:00
Heiko Carstens
220d8e10d6 s390/mm: Remove cpu_has_idte()
Remove cpu_has_idte(). The IDTE instruction is part of the
Dat-Enhancement facility 1, which is always available.
Therefore remove the helper and now superfluous code.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-11-06 14:12:31 +01:00
Thomas Gleixner
43cc54d8db s390/uaccess: Use unsafe wrappers for ASM GOTO
ASM GOTO is miscompiled by GCC when it is used inside a auto cleanup scope:

bool foo(u32 __user *p, u32 val)
{
	scoped_guard(pagefault)
		unsafe_put_user(val, p, efault);
	return true;
efault:
	return false;
}

It ends up leaking the pagefault disable counter in the fault path. clang
at least fails the build.

S390 is not affected for unsafe_*_user() as it uses its own local label
already, but __get/put_kernel_nofault() lack that.

Rename them to arch_*_kernel_nofault() which makes the generic uaccess
header wrap it with a local label that makes both compilers emit correct
code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://patch.msgid.link/20251027083745.483079889@linutronix.de
2025-11-03 15:26:10 +01:00
Jens Remus
f25d952ab6 s390/ptrace: Explicitly include <linux/typecheck.h>
The psw_bits() macro makes use of typecheck() without that typecheck.h
is included. Add the missing include to avoid potential future compile
problems.

[hca@linux.ibm.com: change commit message]

Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-24 15:25:56 +02:00
Farhan Ali
b45873c3f0 s390/pci: Restore IRQ unconditionally for the zPCI device
Commit c1e18c17bd ("s390/pci: add zpci_set_irq()/zpci_clear_irq()"),
introduced the zpci_set_irq() and zpci_clear_irq(), to be used while
resetting a zPCI device.

Commit da995d538d ("s390/pci: implement reset_slot for hotplug
slot"), mentions zpci_clear_irq() being called in the path for
zpci_hot_reset_device().  But that is not the case anymore and these
functions are not called outside of this file. Instead
zpci_hot_reset_device() relies on zpci_disable_device() also clearing
the IRQs, but misses to reset the zdev->irqs_registered flag.

However after a CLP disable/enable reset, the device's IRQ are
unregistered, but the flag zdev->irq_registered does not get cleared. It
creates an inconsistent state and so arch_restore_msi_irqs() doesn't
correctly restore the device's IRQ. This becomes a problem when a PCI
driver tries to restore the state of the device through
pci_restore_state(). Restore IRQ unconditionally for the device and remove
the irq_registered flag as its redundant.

Fixes: c1e18c17bd ("s390/pci: add zpci_set_irq()/zpci_clear_irq()")
Cc: stable@vger.kernnel.org
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-24 15:25:43 +02:00
Harald Freudenberger
9c11918040 s390/ap: Introduce new AP nqap and dqap trace events
Introduce two new AP bus related tracepoint events:
- There is a tracepoint s390_ap_nqap event immediately after a request
  has been pushed into the AP firmware queue with the NQAP AP command.
- The other tracepoint s390_ap_dqap event fires immediately after a
  reply has been pulled out of the AP firmware queue via DQAP AP
  command.
Both events are triggered unconditional and may need filtering.
Filtering can be done based on the status value which is part of
the nqap and dqap trace. So for example a
  echo "!(status & 0x00ff0000)" >.../s390_ap_dqap/filter
filters out all trace events which have a response_code != 0
leaving just the successful nqap and dqap invocations.

The idea of these two trace events focuses on performance to measure
the runtime of a crypto request/reply as close as possible at the
firmware level. In combination with the two zcrypt tracepoints (see
the zcrypt.h trace event definition file) this gives measurement data
about the runtime of a request/reply within the zcrpyt and AP bus
layer. However, with having the status of these AP commands in hand
also other usage may be possible.

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>
2025-10-21 11:09:21 +02:00
Harald Freudenberger
7f124d78d4 s390/ap: Extend struct ap_queue_status with some convenience fields
Sometimes there is a different view of the AP status word
needed. So here is slight rework of the struct ap_queue_status
to open up the possibility to have different ways of accessing
the AP status bits and fields.

The new struct ap_queue_status

struct ap_queue_status {
	union {
		unsigned int value			: 32;
		struct {
			unsigned int status_bits	: 8;
			unsigned int rc			: 8;
			unsigned int			: 16;
		};
		struct {
			unsigned int queue_empty	: 1;
			unsigned int replies_waiting	: 1;
			unsigned int queue_full		: 1;
			unsigned int			: 3;
			unsigned int async		: 1;
			unsigned int irq_enabled	: 1;
			unsigned int response_code	: 8;
			unsigned int			: 16;
		};
	};
};

comprises the old struct ap_queue_status but extends it
to have this also accessible as an unsigned int required
for example for a simple print or trace of the whole value.

Note that this rework is fully backward compatible to the
existing code exploiting the struct ap_queue_status.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-21 11:09:21 +02:00
Harald Freudenberger
507cff242a s390/zcrypt: Rework zcrypt request and reply trace event definition
This is a slight rework of the s390_zcrypt_req and s390_zcrypt_rep
trace event:
- the psmid has been added to the s390_zcrypt_rep
- "dev" renamed to "card"
- "domain" renamed to "dom"
The motivation of these changes is to make these traces more
aligned to new upcoming traces for AP bus related trace events.
Additionally the psmid is needed to match the reply (and thus
indirect the request) to AP bus related trace events where only
the psmid is unique identifying AP messages.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-21 11:09:21 +02:00
Jan Höppner
574817d6c0 s390/tape: Introduce idal buffer array
The tape device driver uses a single idal_buffer for I/O. While the
buffer itself can be arbitrary big, the limit for data transfer for a
single Channel-Command Word is at 65535 bytes (64K-1) since the count
field specifying the amount of data designated by the CCW is a 16-bit
unsigned value.

Provide functionality that allocates an array of multiple IDAL buffer
with the limitation mentioned above in mind.
A call to idal_buffer_array_alloc() allocates an array with a certain
amount of IDAL buffers which is determined based on the total size of
@size. Each individual buffer is limited to a size of CCW_MAX_BYTE_COUNT
(65535 bytes).

Add helper functions that determine the size (# of elements) and the
total data size covered by the array as well.

Current users of the single IDAL buffer are adapted to use the new
functions with one buffer to allocate.

The single IDAL buffer is removed from the tape_char_data struct.

Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-21 10:25:55 +02:00
Christoph Schlameuss
14542a0a54 KVM: S390: Remove sca_lock
Since we are no longer switching from a BSCA to a ESCA we can completely
get rid of the sca_lock. The write lock was only taken for that
conversion.

After removal of the lock some local code cleanups are possible.

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Suggested-by: Janosch Frank <frankja@linux.ibm.com>
[frankja@linux.ibm.com: Added suggested-by tag as discussed on list]
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-20 08:47:58 +00:00
Christoph Schlameuss
e72753ed12 KVM: s390: Use ESCA instead of BSCA at VM init
All modern IBM Z and Linux One machines do offer support for the
Extended System Control Area (ESCA). The ESCA is available since the
z114/z196 released in 2010.
KVM needs to allocate and manage the SCA for guest VMs. Prior to this
change the SCA was setup as Basic SCA only supporting a maximum of 64
vCPUs when initializing the VM. With addition of the 65th vCPU the SCA
was needed to be converted to a ESCA.

Instead of allocating a BSCA and upgrading it for PV or when adding the
65th cpu we can always allocate the ESCA directly upon VM creation
simplifying the code in multiple places as well as completely removing
the need to convert an existing SCA.

In cases where the ESCA is not supported (z10 and earlier) the use of
the SCA entries and with that SIGP interpretation are disabled for VMs.
This increases the number of exits from the VM in multiprocessor
scenarios and thus decreases performance.
The same is true for VSIE where SIGP is currently disabled and thus no
SCA entries are used.

The only downside of the change is that we will always allocate 4 pages
for a 248 cpu ESCA instead of a single page for the BSCA per VM.
In return we can delete a bunch of checks and special handling depending
on the SCA type as well as the whole BSCA to ESCA conversion.

With that behavior change we are no longer referencing a bsca_block in
kvm->arch.sca. This will always be esca_block instead.
By specifying the type of the sca as esca_block we can simplify access
to the sca and get rid of some helpers while making the code clearer.

KVM_MAX_VCPUS is also moved to kvm_host_types to allow using this in
future type definitions.

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2025-10-20 08:47:43 +00:00
Josh Poimboeuf
68e71067ec s390/vmlinux.lds.S: Prevent thunk functions from getting placed with normal text
The s390 indirect thunks are placed in the .text.__s390_indirect_jump_*
sections.

Certain config options which enable -ffunction-sections have a custom
version of the TEXT_TEXT macro:

  .text.[0-9a-zA-Z_]*

That unintentionally matches the thunk sections, causing them to get
grouped with normal text rather than being handled by their intended
rule later in the script:

  *(.text.*_indirect_*)

Fix that by adding another period to the thunk section names, following
the kernel's general convention for distinguishing code-generated text
sections from compiler-generated ones.

Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2025-10-14 14:45:21 -07:00
Linus Torvalds
9361cace0d more s390 updates for 6.18 merge window
- Compile the decompressor with -Wno-pointer-sign flag to avoid
   a clang warning
 
 - Fix incomplete conversion to flag output macros in __xsch(),
   to avoid always zero return value instead of the expected
   condition code
 
 - Remove superfluous newlines from inline assemblies to improve
   compiler inlining decisions
 
 - Expose firmware provided UID Checking state in sysfs regardless
   of the device presence or state
 
 - CIO does not unregister subchannels when the attached device is
   invalid or unavailable. Update the purge function to remove I/O
   subchannels if the device number is found on cio_ignore list
 
 - Consolidate PAI crypto allocation and cleanup paths
 
 - The uv_get_secret_metadata() function has been removed some few
   months ago, remove also the function mention it in a comment
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Merge tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Alexander Gordeev:

 - Compile the decompressor with -Wno-pointer-sign flag to avoid a clang
   warning

 - Fix incomplete conversion to flag output macros in __xsch(), to avoid
   always zero return value instead of the expected condition code

 - Remove superfluous newlines from inline assemblies to improve
   compiler inlining decisions

 - Expose firmware provided UID Checking state in sysfs regardless of
   the device presence or state

 - CIO does not unregister subchannels when the attached device is
   invalid or unavailable. Update the purge function to remove I/O
   subchannels if the device number is found on cio_ignore list

 - Consolidate PAI crypto allocation and cleanup paths

 - The uv_get_secret_metadata() function has been removed some few
   months ago, remove also the function mention it in a comment

* tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/uv: Fix comment of uv_find_secret() function
  s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths
  s390/cio: Update purge function to unregister the unused subchannels
  s390/pci: Expose firmware provided UID Checking state in sysfs
  s390: Remove superfluous newlines from inline assemblies
  s390/cio/ioasm: Fix __xsch() condition code handling
  s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR
2025-10-09 10:51:43 -07:00
Linus Torvalds
256e341706 Generic:
* Rework almost all of KVM's exports to expose symbols only to KVM's x86
   vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko.
 
 x86:
 
 * Rework almost all of KVM x86's exports to expose symbols only to KVM's
   vendor modules, i.e. to kvm-{amd,intel}.ko.
 
 * Add support for virtualizing Control-flow Enforcement Technology (CET) on
   Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks).
   It's worth noting that while SHSTK and IBT can be enabled separately in CPUID,
   it is not really possible to virtualize them separately.  Therefore, Intel
   processors will really allow both SHSTK and IBT under the hood if either is
   made visible in the guest's CPUID.  The alternative would be to intercept
   XSAVES/XRSTORS, which is not feasible for performance reasons.
 
 * Fix a variety of fuzzing WARNs all caused by checking L1 intercepts when
   completing userspace I/O.  KVM has already committed to allowing L2 to
   to perform I/O at that point.
 
 * Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is
   supposed to exist for v2 PMUs.
 
 * Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs.
 
 * Add support for the immediate forms of RDMSR and WRMSRNS, sans full
   emulator support (KVM should never need to emulate the MSRs outside of
   forced emulation and other contrived testing scenarios).
 
 * Clean up the MSR APIs in preparation for CET and FRED virtualization, as
   well as mediated vPMU support.
 
 * Clean up a pile of PMU code in anticipation of adding support for mediated
   vPMUs.
 
 * Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI vmexits
   needed to faithfully emulate an I/O APIC for such guests.
 
 * Many cleanups and minor fixes.
 
 * Recover possible NX huge pages within the TDP MMU under read lock to
   reduce guest jitter when restoring NX huge pages.
 
 * Return -EAGAIN during prefault if userspace concurrently deletes/moves the
   relevant memslot, to fix an issue where prefaulting could deadlock with the
   memslot update.
 
 x86 (AMD):
 
 * Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported.
 
 * Require a minimum GHCB version of 2 when starting SEV-SNP guests via
   KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors
   instead of latent guest failures.
 
 * Add support for SEV-SNP's CipherText Hiding, an opt-in feature that prevents
   unauthorized CPU accesses from reading the ciphertext of SNP guest private
   memory, e.g. to attempt an offline attack.  This feature splits the shared
   SEV-ES/SEV-SNP ASID space into separate ranges for SEV-ES and SEV-SNP guests,
   therefore a new module parameter is needed to control the number of ASIDs
   that can be used for VMs with CipherText Hiding vs. how many can be used to
   run SEV-ES guests.
 
 * Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted
   host from tampering with the guest's TSC frequency, while still allowing the
   the VMM to configure the guest's TSC frequency prior to launch.
 
 * Validate the XCR0 provided by the guest (via the GHCB) to avoid bugs
   resulting from bogus XCR0 values.
 
 * Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to
   avoid leaving behind stale state (thankfully not consumed in KVM).
 
 * Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE
   instead of subtly relying on guest_memfd to deal with them.
 
 * Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's
   desired TSC_AUX, to fix a bug where KVM was keeping a different vCPU's
   TSC_AUX in the host MSR until return to userspace.
 
 KVM (Intel):
 
 * Preparation for FRED support.
 
 * Don't retry in TDX's anti-zero-step mitigation if the target memslot is
   invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar
   to the aforementioned prefaulting case.
 
 * Misc bugfixes and minor cleanups.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull x86 kvm updates from Paolo Bonzini:
 "Generic:

   - Rework almost all of KVM's exports to expose symbols only to KVM's
     x86 vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko

  x86:

   - Rework almost all of KVM x86's exports to expose symbols only to
     KVM's vendor modules, i.e. to kvm-{amd,intel}.ko

   - Add support for virtualizing Control-flow Enforcement Technology
     (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD
     (Shadow Stacks).

     It is worth noting that while SHSTK and IBT can be enabled
     separately in CPUID, it is not really possible to virtualize them
     separately. Therefore, Intel processors will really allow both
     SHSTK and IBT under the hood if either is made visible in the
     guest's CPUID. The alternative would be to intercept
     XSAVES/XRSTORS, which is not feasible for performance reasons

   - Fix a variety of fuzzing WARNs all caused by checking L1 intercepts
     when completing userspace I/O. KVM has already committed to
     allowing L2 to to perform I/O at that point

   - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the
     MSR is supposed to exist for v2 PMUs

   - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs

   - Add support for the immediate forms of RDMSR and WRMSRNS, sans full
     emulator support (KVM should never need to emulate the MSRs outside
     of forced emulation and other contrived testing scenarios)

   - Clean up the MSR APIs in preparation for CET and FRED
     virtualization, as well as mediated vPMU support

   - Clean up a pile of PMU code in anticipation of adding support for
     mediated vPMUs

   - Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI
     vmexits needed to faithfully emulate an I/O APIC for such guests

   - Many cleanups and minor fixes

   - Recover possible NX huge pages within the TDP MMU under read lock
     to reduce guest jitter when restoring NX huge pages

   - Return -EAGAIN during prefault if userspace concurrently
     deletes/moves the relevant memslot, to fix an issue where
     prefaulting could deadlock with the memslot update

  x86 (AMD):

   - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is
     supported

   - Require a minimum GHCB version of 2 when starting SEV-SNP guests
     via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate
     errors instead of latent guest failures

   - Add support for SEV-SNP's CipherText Hiding, an opt-in feature that
     prevents unauthorized CPU accesses from reading the ciphertext of
     SNP guest private memory, e.g. to attempt an offline attack. This
     feature splits the shared SEV-ES/SEV-SNP ASID space into separate
     ranges for SEV-ES and SEV-SNP guests, therefore a new module
     parameter is needed to control the number of ASIDs that can be used
     for VMs with CipherText Hiding vs. how many can be used to run
     SEV-ES guests

   - Add support for Secure TSC for SEV-SNP guests, which prevents the
     untrusted host from tampering with the guest's TSC frequency, while
     still allowing the the VMM to configure the guest's TSC frequency
     prior to launch

   - Validate the XCR0 provided by the guest (via the GHCB) to avoid
     bugs resulting from bogus XCR0 values

   - Save an SEV guest's policy if and only if LAUNCH_START fully
     succeeds to avoid leaving behind stale state (thankfully not
     consumed in KVM)

   - Explicitly reject non-positive effective lengths during SNP's
     LAUNCH_UPDATE instead of subtly relying on guest_memfd to deal with
     them

   - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the
     host's desired TSC_AUX, to fix a bug where KVM was keeping a
     different vCPU's TSC_AUX in the host MSR until return to userspace

  KVM (Intel):

   - Preparation for FRED support

   - Don't retry in TDX's anti-zero-step mitigation if the target
     memslot is invalid, i.e. is being deleted or moved, to fix a
     deadlock scenario similar to the aforementioned prefaulting case

   - Misc bugfixes and minor cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits)
  KVM: x86: Export KVM-internal symbols for sub-modules only
  KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks
  KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.c
  KVM: Export KVM-internal symbols for sub-modules only
  KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent
  KVM: VMX: Make CR4.CET a guest owned bit
  KVM: selftests: Verify MSRs are (not) in save/restore list when (un)supported
  KVM: selftests: Add coverage for KVM-defined registers in MSRs test
  KVM: selftests: Add KVM_{G,S}ET_ONE_REG coverage to MSRs test
  KVM: selftests: Extend MSRs test to validate vCPUs without supported features
  KVM: selftests: Add support for MSR_IA32_{S,U}_CET to MSRs test
  KVM: selftests: Add an MSR test to exercise guest/host and read/write
  KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors
  KVM: x86: Define Control Protection Exception (#CP) vector
  KVM: x86: Add human friendly formatting for #XM, and #VE
  KVM: SVM: Enable shadow stack virtualization for SVM
  KVM: SEV: Synchronize MSR_IA32_XSS from the GHCB when it's valid
  KVM: SVM: Pass through shadow stack MSRs as appropriate
  KVM: SVM: Update dump_vmcb with shadow stack save area additions
  KVM: nSVM: Save/load CET Shadow Stack state to/from vmcb12/vmcb02
  ...
2025-10-06 12:37:34 -07:00
Ramesh Errabolu
b043a81ce3 s390/pci: Expose firmware provided UID Checking state in sysfs
The sysfs file /sys/bus/pci/devices/<device_id>/uid_is_unique provides
the UID Checking state as a per device attribute, highlighting its
effect of providing the guarantee that a device's UID is unique.
As a device attribute, this parameter is however unavailable if no
device is configured.

Expose the UID Checking state as:
  - A platform-level parameter
  - Available regardless of device presence or state

Signed-off-by: Ramesh Errabolu <ramesh@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2025-10-04 18:40:42 +02:00
Linus Torvalds
f3826aa996 guest_memfd:
* Add support for host userspace mapping of guest_memfd-backed memory for VM
   types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE (which isn't
   precisely the same thing as CoCo VMs, since x86's SEV-MEM and SEV-ES have
   no way to detect private vs. shared).
 
   This lays the groundwork for removal of guest memory from the kernel direct
   map, as well as for limited mmap() for guest_memfd-backed memory.
 
   For more information see:
   * a6ad54137a ("Merge branch 'guest-memfd-mmap' into HEAD", 2025-08-27)
   * https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding
     (guest_memfd in Firecracker)
   * https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/
     (direct map removal)
   * https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/
     (mmap support)
 
 ARM:
 
 * Add support for FF-A 1.2 as the secure memory conduit for pKVM,
   allowing more registers to be used as part of the message payload.
 
 * Change the way pKVM allocates its VM handles, making sure that the
   privileged hypervisor is never tricked into using uninitialised
   data.
 
 * Speed up MMIO range registration by avoiding unnecessary RCU
   synchronisation, which results in VMs starting much quicker.
 
 * Add the dump of the instruction stream when panic-ing in the EL2
   payload, just like the rest of the kernel has always done. This will
   hopefully help debugging non-VHE setups.
 
 * Add 52bit PA support to the stage-1 page-table walker, and make use
   of it to populate the fault level reported to the guest on failing
   to translate a stage-1 walk.
 
 * Add NV support to the GICv3-on-GICv5 emulation code, ensuring
   feature parity for guests, irrespective of the host platform.
 
 * Fix some really ugly architecture problems when dealing with debug
   in a nested VM. This has some bad performance impacts, but is at
   least correct.
 
 * Add enough infrastructure to be able to disable EL2 features and
   give effective values to the EL2 control registers. This then allows
   a bunch of features to be turned off, which helps cross-host
   migration.
 
 * Large rework of the selftest infrastructure to allow most tests to
   transparently run at EL2. This is the first step towards enabling
   NV testing.
 
 * Various fixes and improvements all over the map, including one BE
   fix, just in time for the removal of the feature.
 
 LoongArch:
 
 * Detect page table walk feature on new hardware
 
 * Add sign extension with kernel MMIO/IOCSR emulation
 
 * Improve in-kernel IPI emulation
 
 * Improve in-kernel PCH-PIC emulation
 
 * Move kvm_iocsr tracepoint out of generic code
 
 RISC-V:
 
 * Added SBI FWFT extension for Guest/VM with misaligned delegation and
   pointer masking PMLEN features
 
 * Added ONE_REG interface for SBI FWFT extension
 
 * Added Zicbop and bfloat16 extensions for Guest/VM
 
 * Enabled more common KVM selftests for RISC-V
 
 * Added SBI v3.0 PMU enhancements in KVM and perf driver
 
 s390:
 
 * Improve interrupt cpu for wakeup, in particular the heuristic to decide
   which vCPU to deliver a floating interrupt to.
 
 * Clear the PTE when discarding a swapped page because of CMMA; this
   bug was introduced in 6.16 when refactoring gmap code.
 
 x86 selftests:
 
 * Add #DE coverage in the fastops test (the only exception that's guest-
   triggerable in fastop-emulated instructions).
 
 * Fix PMU selftests errors encountered on Granite Rapids (GNR), Sierra
   Forest (SRF) and Clearwater Forest (CWF).
 
 * Minor cleanups and improvements
 
 x86 (guest side):
 
 * For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when
   overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping
   could map devices as WB and prevent the device drivers from mapping their
   devices with UC/UC-.
 
 * Make kvm_async_pf_task_wake() a local static helper and remove its
   export.
 
 * Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU
   bindings even when PV_UNHALT is unsupported.
 
 Generic:
 
 * Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as __GFP_NOWARN is
   now included in GFP_NOWAIT.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "This excludes the bulk of the x86 changes, which I will send
  separately. They have two not complex but relatively unusual conflicts
  so I will wait for other dust to settle.

  guest_memfd:

   - Add support for host userspace mapping of guest_memfd-backed memory
     for VM types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE
     (which isn't precisely the same thing as CoCo VMs, since x86's
     SEV-MEM and SEV-ES have no way to detect private vs. shared).

     This lays the groundwork for removal of guest memory from the
     kernel direct map, as well as for limited mmap() for
     guest_memfd-backed memory.

     For more information see:
       - commit a6ad54137a ("Merge branch 'guest-memfd-mmap' into HEAD")
       - guest_memfd in Firecracker:
           https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding
       - direct map removal:
           https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/
       - mmap support:
           https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/

  ARM:

   - Add support for FF-A 1.2 as the secure memory conduit for pKVM,
     allowing more registers to be used as part of the message payload.

   - Change the way pKVM allocates its VM handles, making sure that the
     privileged hypervisor is never tricked into using uninitialised
     data.

   - Speed up MMIO range registration by avoiding unnecessary RCU
     synchronisation, which results in VMs starting much quicker.

   - Add the dump of the instruction stream when panic-ing in the EL2
     payload, just like the rest of the kernel has always done. This
     will hopefully help debugging non-VHE setups.

   - Add 52bit PA support to the stage-1 page-table walker, and make use
     of it to populate the fault level reported to the guest on failing
     to translate a stage-1 walk.

   - Add NV support to the GICv3-on-GICv5 emulation code, ensuring
     feature parity for guests, irrespective of the host platform.

   - Fix some really ugly architecture problems when dealing with debug
     in a nested VM. This has some bad performance impacts, but is at
     least correct.

   - Add enough infrastructure to be able to disable EL2 features and
     give effective values to the EL2 control registers. This then
     allows a bunch of features to be turned off, which helps cross-host
     migration.

   - Large rework of the selftest infrastructure to allow most tests to
     transparently run at EL2. This is the first step towards enabling
     NV testing.

   - Various fixes and improvements all over the map, including one BE
     fix, just in time for the removal of the feature.

  LoongArch:

   - Detect page table walk feature on new hardware

   - Add sign extension with kernel MMIO/IOCSR emulation

   - Improve in-kernel IPI emulation

   - Improve in-kernel PCH-PIC emulation

   - Move kvm_iocsr tracepoint out of generic code

  RISC-V:

   - Added SBI FWFT extension for Guest/VM with misaligned delegation
     and pointer masking PMLEN features

   - Added ONE_REG interface for SBI FWFT extension

   - Added Zicbop and bfloat16 extensions for Guest/VM

   - Enabled more common KVM selftests for RISC-V

   - Added SBI v3.0 PMU enhancements in KVM and perf driver

  s390:

   - Improve interrupt cpu for wakeup, in particular the heuristic to
     decide which vCPU to deliver a floating interrupt to.

   - Clear the PTE when discarding a swapped page because of CMMA; this
     bug was introduced in 6.16 when refactoring gmap code.

  x86 selftests:

   - Add #DE coverage in the fastops test (the only exception that's
     guest- triggerable in fastop-emulated instructions).

   - Fix PMU selftests errors encountered on Granite Rapids (GNR),
     Sierra Forest (SRF) and Clearwater Forest (CWF).

   - Minor cleanups and improvements

  x86 (guest side):

   - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when
     overriding guest MTRR for TDX/SNP to fix an issue where ACPI
     auto-mapping could map devices as WB and prevent the device drivers
     from mapping their devices with UC/UC-.

   - Make kvm_async_pf_task_wake() a local static helper and remove its
     export.

   - Use native qspinlocks when running in a VM with dedicated
     vCPU=>pCPU bindings even when PV_UNHALT is unsupported.

  Generic:

   - Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as
     __GFP_NOWARN is now included in GFP_NOWAIT.

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits)
  KVM: s390: Fix to clear PTE when discarding a swapped page
  KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs
  KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs
  KVM: arm64: selftests: Cope with arch silliness in EL2 selftest
  KVM: arm64: selftests: Add basic test for running in VHE EL2
  KVM: arm64: selftests: Enable EL2 by default
  KVM: arm64: selftests: Initialize HCR_EL2
  KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters
  KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2
  KVM: arm64: selftests: Select SMCCC conduit based on current EL
  KVM: arm64: selftests: Provide helper for getting default vCPU target
  KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts
  KVM: arm64: selftests: Create a VGICv3 for 'default' VMs
  KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation
  KVM: arm64: selftests: Add helper to check for VGICv3 support
  KVM: arm64: selftests: Initialize VGICv3 only once
  KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code
  KVM: selftests: Add ex_str() to print human friendly name of exception vectors
  selftests/kvm: remove stale TODO in xapic_state_test
  KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount
  ...
2025-10-04 08:52:16 -07:00
Linus Torvalds
8804d970fa Summary of significant series in this pull request:
- The 3 patch series "mm, swap: improve cluster scan strategy" from
   Kairui Song improves performance and reduces the failure rate of swap
   cluster allocation.
 
 - The 4 patch series "support large align and nid in Rust allocators"
   from Vitaly Wool permits Rust allocators to set NUMA node and large
   alignment when perforning slub and vmalloc reallocs.
 
 - The 2 patch series "mm/damon/vaddr: support stat-purpose DAMOS" from
   Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets
   for virtual address spaces for ops-level DAMOS filters.
 
 - The 3 patch series "execute PROCMAP_QUERY ioctl under per-vma lock"
   from Suren Baghdasaryan reduces mmap_lock contention during reads of
   /proc/pid/maps.
 
 - The 2 patch series "mm/mincore: minor clean up for swap cache
   checking" from Kairui Song performs some cleanup in the swap code.
 
 - The 11 patch series "mm: vm_normal_page*() improvements" from David
   Hildenbrand provides code cleanup in the pagemap code.
 
 - The 5 patch series "add persistent huge zero folio support" from
   Pankaj Raghav provides a block layer speedup by optionalls making the
   huge_zero_pagepersistent, instead of releasing it when its refcount
   falls to zero.
 
 - The 3 patch series "kho: fixes and cleanups" from Mike Rapoport adds a
   few touchups to the recently added Kexec Handover feature.
 
 - The 10 patch series "mm: make mm->flags a bitmap and 64-bit on all
   arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap.  To
   end the constant struggle with space shortage on 32-bit conflicting with
   64-bit's needs.
 
 - The 2 patch series "mm/swapfile.c and swap.h cleanup" from Chris Li
   cleans up some swap code.
 
 - The 7 patch series "selftests/mm: Fix false positives and skip
   unsupported tests" from Donet Tom fixes a few things in our selftests
   code.
 
 - The 7 patch series "prctl: extend PR_SET_THP_DISABLE to only provide
   THPs when advised" from David Hildenbrand "allows individual processes
   to opt-out of THP=always into THP=madvise, without affecting other
   workloads on the system".
 
   It's a long story - the [1/N] changelog spells out the considerations.
 
 - The 11 patch series "Add and use memdesc_flags_t" from Matthew Wilcox
   gets us started on the memdesc project.  Please see
   https://kernelnewbies.org/MatthewWilcox/Memdescs and
   https://blogs.oracle.com/linux/post/introducing-memdesc.
 
 - The 3 patch series "Tiny optimization for large read operations" from
   Chi Zhiling improves the efficiency of the pagecache read path.
 
 - The 5 patch series "Better split_huge_page_test result check" from Zi
   Yan improves our folio splitting selftest code.
 
 - The 2 patch series "test that rmap behaves as expected" from Wei Yang
   adds some rmap selftests.
 
 - The 3 patch series "remove write_cache_pages()" from Christoph Hellwig
   removes that function and converts its two remaining callers.
 
 - The 2 patch series "selftests/mm: uffd-stress fixes" from Dev Jain
   fixes some UFFD selftests issues.
 
 - The 3 patch series "introduce kernel file mapped folios" from Boris
   Burkov introduces the concept of "kernel file pages".  Using these
   permits btrfs to account its metadata pages to the root cgroup, rather
   than to the cgroups of random inappropriate tasks.
 
 - The 2 patch series "mm/pageblock: improve readability of some
   pageblock handling" from Wei Yang provides some readability improvements
   to the page allocator code.
 
 - The 11 patch series "mm/damon: support ARM32 with LPAE" from SeongJae
   Park teaches DAMON to understand arm32 highmem.
 
 - The 4 patch series "tools: testing: Use existing atomic.h for
   vma/maple tests" from Brendan Jackman performs some code cleanups and
   deduplication under tools/testing/.
 
 - The 2 patch series "maple_tree: Fix testing for 32bit compiles" from
   Liam Howlett fixes a couple of 32-bit issues in
   tools/testing/radix-tree.c.
 
 - The 2 patch series "kasan: unify kasan_enabled() and remove
   arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN
   arch-specific initialization code into a common arch-neutral
   implementation.
 
 - The 3 patch series "mm: remove zpool" from Johannes Weiner removes
   zspool - an indirection layer which now only redirects to a single thing
   (zsmalloc).
 
 - The 2 patch series "mm: task_stack: Stack handling cleanups" from
   Pasha Tatashin makes a couple of cleanups in the fork code.
 
 - The 37 patch series "mm: remove nth_page()" from David Hildenbrand
   makes rather a lot of adjustments at various nth_page() callsites,
   eventually permitting the removal of that undesirable helper function.
 
 - The 2 patch series "introduce kasan.write_only option in hw-tags" from
   Yeoreum Yun creates a KASAN read-only mode for ARM, using that
   architecture's memory tagging feature.  It is felt that a read-only mode
   KASAN is suitable for use in production systems rather than debug-only.
 
 - The 3 patch series "mm: hugetlb: cleanup hugetlb folio allocation"
   from Kefeng Wang does some tidying in the hugetlb folio allocation code.
 
 - The 12 patch series "mm: establish const-correctness for pointer
   parameters" from Max Kellermann makes quite a number of the MM API
   functions more accurate about the constness of their arguments.  This
   was getting in the way of subsystems (in this case CEPH) when they
   attempt to improving their own const/non-const accuracy.
 
 - The 7 patch series "Cleanup free_pages() misuse" from Vishal Moola
   fixes a number of code sites which were confused over when to use
   free_pages() vs __free_pages().
 
 - The 3 patch series "Add Rust abstraction for Maple Trees" from Alice
   Ryhl makes the mapletree code accessible to Rust.  Required by nouveau
   and by its forthcoming successor: the new Rust Nova driver.
 
 - The 2 patch series "selftests/mm: split_huge_page_test:
   split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and
   some cleanups to the thp selftesting code.
 
 - The 14 patch series "mm, swap: introduce swap table as swap cache
   (phase I)" from Chris Li and Kairui Song is the first step along the
   path to implementing "swap tables" - a new approach to swap allocation
   and state tracking which is expected to yield speed and space
   improvements.  This patchset itself yields a 5-20% performance benefit
   in some situations.
 
 - The 3 patch series "Some ptdesc cleanups" from Matthew Wilcox utilizes
   the new memdesc layer to clean up the ptdesc code a little.
 
 - The 3 patch series "Fix va_high_addr_switch.sh test failure" from
   Chunyu Hu fixes some issues in our 5-level pagetable selftesting code.
 
 - The 2 patch series "Minor fixes for memory allocation profiling" from
   Suren Baghdasaryan addresses a couple of minor issues in relatively new
   memory allocation profiling feature.
 
 - The 3 patch series "Small cleanups" from Matthew Wilcox has a few
   cleanups in preparation for more memdesc work.
 
 - The 2 patch series "mm/damon: add addr_unit for DAMON_LRU_SORT and
   DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in
   furtherance of supporting arm highmem.
 
 - The 2 patch series "selftests/mm: Add -Wunreachable-code and fix
   warnings" from Muhammad Anjum adds that compiler check to selftests code
   and fixes the fallout, by removing dead code.
 
 - The 10 patch series "Improvements to Victim Process Thawing and OOM
   Reaper Traversal Order" from zhongjinji makes a number of improvements
   in the OOM killer: mainly thawing a more appropriate group of victim
   threads so they can release resources.
 
 - The 5 patch series "mm/damon: misc fixups and improvements for 6.18"
   from SeongJae Park is a bunch of small and unrelated fixups for DAMON.
 
 - The 7 patch series "mm/damon: define and use DAMON initialization
   check function" from SeongJae Park implement reliability and
   maintainability improvements to a recently-added bug fix.
 
 - The 2 patch series "mm/damon/stat: expose auto-tuned intervals and
   non-idle ages" from SeongJae Park provides additional transparency to
   userspace clients of the DAMON_STAT information.
 
 - The 2 patch series "Expand scope of khugepaged anonymous collapse"
   from Dev Jain removes some constraints on khubepaged's collapsing of
   anon VMAs.  It also increases the success rate of MADV_COLLAPSE against
   an anon vma.
 
 - The 2 patch series "mm: do not assume file == vma->vm_file in
   compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards
   removal of file_operations.mmap().  This patchset concentrates upon
   clearing up the treatment of stacked filesystems.
 
 - The 6 patch series "mm: Improve mlock tracking for large folios" from
   Kiryl Shutsemau provides some fixes and improvements to mlock's tracking
   of large folios.  /proc/meminfo's "Mlocked" field became more accurate.
 
 - The 2 patch series "mm/ksm: Fix incorrect accounting of KSM counters
   during fork" from Donet Tom fixes several user-visible KSM stats
   inaccuracies across forks and adds selftest code to verify these
   counters.
 
 - The 2 patch series "mm_slot: fix the usage of mm_slot_entry" from Wei
   Yang addresses some potential but presently benign issues in KSM's
   mm_slot handling.
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Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm, swap: improve cluster scan strategy" from Kairui Song improves
   performance and reduces the failure rate of swap cluster allocation

 - "support large align and nid in Rust allocators" from Vitaly Wool
   permits Rust allocators to set NUMA node and large alignment when
   perforning slub and vmalloc reallocs

 - "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend
   DAMOS_STAT's handling of the DAMON operations sets for virtual
   address spaces for ops-level DAMOS filters

 - "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren
   Baghdasaryan reduces mmap_lock contention during reads of
   /proc/pid/maps

 - "mm/mincore: minor clean up for swap cache checking" from Kairui Song
   performs some cleanup in the swap code

 - "mm: vm_normal_page*() improvements" from David Hildenbrand provides
   code cleanup in the pagemap code

 - "add persistent huge zero folio support" from Pankaj Raghav provides
   a block layer speedup by optionalls making the
   huge_zero_pagepersistent, instead of releasing it when its refcount
   falls to zero

 - "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to
   the recently added Kexec Handover feature

 - "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo
   Stoakes turns mm_struct.flags into a bitmap. To end the constant
   struggle with space shortage on 32-bit conflicting with 64-bit's
   needs

 - "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap
   code

 - "selftests/mm: Fix false positives and skip unsupported tests" from
   Donet Tom fixes a few things in our selftests code

 - "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised"
   from David Hildenbrand "allows individual processes to opt-out of
   THP=always into THP=madvise, without affecting other workloads on the
   system".

   It's a long story - the [1/N] changelog spells out the considerations

 - "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on
   the memdesc project. Please see

      https://kernelnewbies.org/MatthewWilcox/Memdescs and
      https://blogs.oracle.com/linux/post/introducing-memdesc

 - "Tiny optimization for large read operations" from Chi Zhiling
   improves the efficiency of the pagecache read path

 - "Better split_huge_page_test result check" from Zi Yan improves our
   folio splitting selftest code

 - "test that rmap behaves as expected" from Wei Yang adds some rmap
   selftests

 - "remove write_cache_pages()" from Christoph Hellwig removes that
   function and converts its two remaining callers

 - "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD
   selftests issues

 - "introduce kernel file mapped folios" from Boris Burkov introduces
   the concept of "kernel file pages". Using these permits btrfs to
   account its metadata pages to the root cgroup, rather than to the
   cgroups of random inappropriate tasks

 - "mm/pageblock: improve readability of some pageblock handling" from
   Wei Yang provides some readability improvements to the page allocator
   code

 - "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON
   to understand arm32 highmem

 - "tools: testing: Use existing atomic.h for vma/maple tests" from
   Brendan Jackman performs some code cleanups and deduplication under
   tools/testing/

 - "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes
   a couple of 32-bit issues in tools/testing/radix-tree.c

 - "kasan: unify kasan_enabled() and remove arch-specific
   implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific
   initialization code into a common arch-neutral implementation

 - "mm: remove zpool" from Johannes Weiner removes zspool - an
   indirection layer which now only redirects to a single thing
   (zsmalloc)

 - "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a
   couple of cleanups in the fork code

 - "mm: remove nth_page()" from David Hildenbrand makes rather a lot of
   adjustments at various nth_page() callsites, eventually permitting
   the removal of that undesirable helper function

 - "introduce kasan.write_only option in hw-tags" from Yeoreum Yun
   creates a KASAN read-only mode for ARM, using that architecture's
   memory tagging feature. It is felt that a read-only mode KASAN is
   suitable for use in production systems rather than debug-only

 - "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does
   some tidying in the hugetlb folio allocation code

 - "mm: establish const-correctness for pointer parameters" from Max
   Kellermann makes quite a number of the MM API functions more accurate
   about the constness of their arguments. This was getting in the way
   of subsystems (in this case CEPH) when they attempt to improving
   their own const/non-const accuracy

 - "Cleanup free_pages() misuse" from Vishal Moola fixes a number of
   code sites which were confused over when to use free_pages() vs
   __free_pages()

 - "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the
   mapletree code accessible to Rust. Required by nouveau and by its
   forthcoming successor: the new Rust Nova driver

 - "selftests/mm: split_huge_page_test: split_pte_mapped_thp
   improvements" from David Hildenbrand adds a fix and some cleanups to
   the thp selftesting code

 - "mm, swap: introduce swap table as swap cache (phase I)" from Chris
   Li and Kairui Song is the first step along the path to implementing
   "swap tables" - a new approach to swap allocation and state tracking
   which is expected to yield speed and space improvements. This
   patchset itself yields a 5-20% performance benefit in some situations

 - "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc
   layer to clean up the ptdesc code a little

 - "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some
   issues in our 5-level pagetable selftesting code

 - "Minor fixes for memory allocation profiling" from Suren Baghdasaryan
   addresses a couple of minor issues in relatively new memory
   allocation profiling feature

 - "Small cleanups" from Matthew Wilcox has a few cleanups in
   preparation for more memdesc work

 - "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from
   Quanmin Yan makes some changes to DAMON in furtherance of supporting
   arm highmem

 - "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad
   Anjum adds that compiler check to selftests code and fixes the
   fallout, by removing dead code

 - "Improvements to Victim Process Thawing and OOM Reaper Traversal
   Order" from zhongjinji makes a number of improvements in the OOM
   killer: mainly thawing a more appropriate group of victim threads so
   they can release resources

 - "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park
   is a bunch of small and unrelated fixups for DAMON

 - "mm/damon: define and use DAMON initialization check function" from
   SeongJae Park implement reliability and maintainability improvements
   to a recently-added bug fix

 - "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from
   SeongJae Park provides additional transparency to userspace clients
   of the DAMON_STAT information

 - "Expand scope of khugepaged anonymous collapse" from Dev Jain removes
   some constraints on khubepaged's collapsing of anon VMAs. It also
   increases the success rate of MADV_COLLAPSE against an anon vma

 - "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()"
   from Lorenzo Stoakes moves us further towards removal of
   file_operations.mmap(). This patchset concentrates upon clearing up
   the treatment of stacked filesystems

 - "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau
   provides some fixes and improvements to mlock's tracking of large
   folios. /proc/meminfo's "Mlocked" field became more accurate

 - "mm/ksm: Fix incorrect accounting of KSM counters during fork" from
   Donet Tom fixes several user-visible KSM stats inaccuracies across
   forks and adds selftest code to verify these counters

 - "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses
   some potential but presently benign issues in KSM's mm_slot handling

* tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits)
  mm: swap: check for stable address space before operating on the VMA
  mm: convert folio_page() back to a macro
  mm/khugepaged: use start_addr/addr for improved readability
  hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list
  alloc_tag: fix boot failure due to NULL pointer dereference
  mm: silence data-race in update_hiwater_rss
  mm/memory-failure: don't select MEMORY_ISOLATION
  mm/khugepaged: remove definition of struct khugepaged_mm_slot
  mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
  hugetlb: increase number of reserving hugepages via cmdline
  selftests/mm: add fork inheritance test for ksm_merging_pages counter
  mm/ksm: fix incorrect KSM counter handling in mm_struct during fork
  drivers/base/node: fix double free in register_one_node()
  mm: remove PMD alignment constraint in execmem_vmalloc()
  mm/memory_hotplug: fix typo 'esecially' -> 'especially'
  mm/rmap: improve mlock tracking for large folios
  mm/filemap: map entire large folio faultaround
  mm/fault: try to map the entire file folio in finish_fault()
  mm/rmap: mlock large folios in try_to_unmap_one()
  mm/rmap: fix a mlock race condition in folio_referenced_one()
  ...
2025-10-02 18:18:33 -07:00
Linus Torvalds
7601d18be0 A set of changes to consolidate the generic TIF bits accross architectures
All architectures define the same set of generic TIF bits. This makes it
 pointlessly hard to add a new generic TIF bit or to change an existing one.
 
 Provide a generic variant and convert the architectures which utilize the
 generic entry code over to use it. The TIF space is divided into 16 generic
 bits and 16 architecture specific bits, which turned out to provide enough
 space on both sides.
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Merge tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull TIF bit unification updates from Thomas Gleixner:
 "A set of changes to consolidate the generic TIF (thread info flag)
  bits accross architectures.

  All architectures define the same set of generic TIF bits. This makes
  it pointlessly hard to add a new generic TIF bit or to change an
  existing one.

  Provide a generic variant and convert the architectures which utilize
  the generic entry code over to use it. The TIF space is divided into
  16 generic bits and 16 architecture specific bits, which turned out to
  provide enough space on both sides"

* tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  LoongArch: Fix bitflag conflict for TIF_FIXADE
  riscv: Use generic TIF bits
  loongarch: Use generic TIF bits
  s390/entry: Remove unused TIF flags
  s390: Use generic TIF bits
  x86: Use generic TIF bits
  asm-generic: Provide generic TIF infrastructure
2025-09-30 14:36:20 -07:00
Sean Christopherson
15463eece9 KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent
Use kvm_is_gpa_in_memslot() to check the validity of the notification
indicator byte address instead of open coding equivalent logic in the VFIO
AP driver.

Opportunistically use a dedicated wrapper that exists and is exported
expressly for the VFIO AP module.  kvm_is_gpa_in_memslot() is generally
unsuitable for use outside of KVM; other drivers typically shouldn't rely
on KVM's memslots, and using the API requires kvm->srcu (or slots_lock) to
be held for the entire duration of the usage, e.g. to avoid TOCTOU bugs.
handle_pqap() is a bit of a special case, as it's explicitly invoked from
KVM with kvm->srcu already held, and the VFIO AP driver is in many ways an
extension of KVM that happens to live in a separate module.

Providing a dedicated API for the VFIO AP driver will allow restricting
the vast majority of generic KVM's exports to KVM submodules (e.g. to x86's
kvm-{amd,intel}.ko vendor mdoules).

No functional change intended.

Acked-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Link: https://lore.kernel.org/r/20250919003303.1355064-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30 13:38:06 -04:00
Paolo Bonzini
6a13749717 LoongArch KVM changes for v6.18
1. Add PTW feature detection on new hardware.
 2. Add sign extension with kernel MMIO/IOCSR emulation.
 3. Improve in-kernel IPI emulation.
 4. Improve in-kernel PCH-PIC emulation.
 5. Move kvm_iocsr tracepoint out of generic code.
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Merge tag 'loongarch-kvm-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

LoongArch KVM changes for v6.18

1. Add PTW feature detection on new hardware.
2. Add sign extension with kernel MMIO/IOCSR emulation.
3. Improve in-kernel IPI emulation.
4. Improve in-kernel PCH-PIC emulation.
5. Move kvm_iocsr tracepoint out of generic code.
2025-09-30 13:23:44 -04:00
Paolo Bonzini
68f6051098 KVM: s390: A bugfix and a performance improvement
* Improve interrupt cpu for wakeup, change the heuristic to decide wich
   vCPU to deliver a floating interrupt to.
 * Clear the pte when discarding a swapped page because of CMMA; this
   bug was introduced in 6.16 when refactoring gmap code.
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Merge tag 'kvm-s390-next-6.18-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: A bugfix and a performance improvement

* Improve interrupt cpu for wakeup, change the heuristic to decide wich
  vCPU to deliver a floating interrupt to.
* Clear the pte when discarding a swapped page because of CMMA; this
  bug was introduced in 6.16 when refactoring gmap code.
2025-09-30 13:09:20 -04:00
Gautam Gala
5deafa27d9 KVM: s390: Fix to clear PTE when discarding a swapped page
KVM run fails when guests with 'cmm' cpu feature and host are
under memory pressure and use swap heavily. This is because
npages becomes ENOMEN (out of memory) in hva_to_pfn_slow()
which inturn propagates as EFAULT to qemu. Clearing the page
table entry when discarding an address that maps to a swap
entry resolves the issue.

Fixes: 200197908d ("KVM: s390: Refactor and split some gmap helpers")
Cc: stable@vger.kernel.org
Suggested-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Gautam Gala <ggala@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-09-30 15:58:30 +02:00
Linus Torvalds
9cc220a422 s390 updates for 6.18 merge window
- Refactor SCLP memory hotplug code
 
 - Introduce common boot_panic() decompressor helper macro and
   use it to get rid of nearly few identical implementations
 
 - Take into account additional key generation flags and forward
   it to the ep11 implementation. With that allow users to modify
   the key generation process, e.g. provide valid combinations of
   XCP_BLOB_* flags
 
 - Replace kmalloc() + copy_from_user() with memdup_user_nul()
   in s390 debug facility and HMC driver
 
 - Add DAX support for DCSS memory block devices
 
 - Make the compiler statement attribute "assume" available with
   a new __assume macro
 
 - Rework ffs() and fls() family bitops functions, including
   source code improvements and generated code optimizations.
   Use the newly introduced __assume macro for that
 
 - Enable additional network features in default configurations
 
 - Use __GFP_ACCOUNT flag for user page table allocations to add
   missing kmemcg accounting
 
 - Add WQ_PERCPU flag to explicitly request the use of the per-CPU
   workqueue for 3590 tape driver
 
 - Switch power reading to the per-CPU and the Hiperdispatch to the
   default workqueue
 
 - Add memory allocation profiling hooks to allow better profiling
   data and the /proc/allocinfo output similar to other architectures
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Merge tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Refactor SCLP memory hotplug code

 - Introduce common boot_panic() decompressor helper macro and use it to
   get rid of nearly few identical implementations

 - Take into account additional key generation flags and forward it to
   the ep11 implementation. With that allow users to modify the key
   generation process, e.g. provide valid combinations of XCP_BLOB_*
   flags

 - Replace kmalloc() + copy_from_user() with memdup_user_nul() in s390
   debug facility and HMC driver

 - Add DAX support for DCSS memory block devices

 - Make the compiler statement attribute "assume" available with a new
   __assume macro

 - Rework ffs() and fls() family bitops functions, including source code
   improvements and generated code optimizations. Use the newly
   introduced __assume macro for that

 - Enable additional network features in default configurations

 - Use __GFP_ACCOUNT flag for user page table allocations to add missing
   kmemcg accounting

 - Add WQ_PERCPU flag to explicitly request the use of the per-CPU
   workqueue for 3590 tape driver

 - Switch power reading to the per-CPU and the Hiperdispatch to the
   default workqueue

 - Add memory allocation profiling hooks to allow better profiling data
   and the /proc/allocinfo output similar to other architectures

* tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits)
  s390/mm: Add memory allocation profiling hooks
  s390: Replace use of system_wq with system_dfl_wq
  s390/diag324: Replace use of system_wq with system_percpu_wq
  s390/tape: Add WQ_PERCPU to alloc_workqueue users
  s390/bitops: Switch to generic ffs() if supported by compiler
  s390/bitops: Switch to generic fls(), fls64(), etc.
  s390/mm: Use __GFP_ACCOUNT for user page table allocations
  s390/configs: Enable additional network features
  s390/bitops: Cleanup __flogr()
  s390/bitops: Use __assume() for __flogr() inline assembly return value
  compiler_types: Add __assume macro
  s390/bitops: Limit return value range of __flogr()
  s390/dcssblk: Add DAX support
  s390/hmcdrv: Replace kmalloc() + copy_from_user() with memdup_user_nul()
  s390/debug: Replace kmalloc() + copy_from_user() with memdup_user_nul()
  s390/pkey: Forward keygenflags to ep11_unwrapkey
  s390/boot: Add common boot_panic() code
  s390/bitops: Optimize inlining
  s390/bitops: Slightly optimize ffs() and fls64()
  s390/sclp: Move memory hotplug code for better modularity
  ...
2025-09-29 19:14:25 -07:00
Linus Torvalds
8c1ed30218 ffs-const update for v6.18-rc1
- PCI: Fix theoretical underflow in use of ffs().
 
 - Universally apply __attribute_const__ to all architecture's ffs()-family
   of functions.
 
 - Add KUnit tests for ffs() behavior and const-ness.
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Merge tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull ffs const-attribute cleanups from Kees Cook:
 "While working on various hardening refactoring a while back we
  encountered inconsistencies in the application of __attribute_const__
  on the ffs() family of functions.

  This series fixes this across all archs and adds KUnit tests.

  Notably, this found a theoretical underflow in PCI (also fixed here)
  and uncovered an inefficiency in ARC (fixed in the ARC arch PR). I
  kept the series separate from the general hardening PR since it is a
  stand-alone "topic".

   - PCI: Fix theoretical underflow in use of ffs().

   - Universally apply __attribute_const__ to all architecture's
     ffs()-family of functions.

   - Add KUnit tests for ffs() behavior and const-ness"

* tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  KUnit: ffs: Validate all the __attribute_const__ annotations
  sparc: Add __attribute_const__ to ffs()-family implementations
  xtensa: Add __attribute_const__ to ffs()-family implementations
  s390: Add __attribute_const__ to ffs()-family implementations
  parisc: Add __attribute_const__ to ffs()-family implementations
  mips: Add __attribute_const__ to ffs()-family implementations
  m68k: Add __attribute_const__ to ffs()-family implementations
  openrisc: Add __attribute_const__ to ffs()-family implementations
  riscv: Add __attribute_const__ to ffs()-family implementations
  hexagon: Add __attribute_const__ to ffs()-family implementations
  alpha: Add __attribute_const__ to ffs()-family implementations
  sh: Add __attribute_const__ to ffs()-family implementations
  powerpc: Add __attribute_const__ to ffs()-family implementations
  x86: Add __attribute_const__ to ffs()-family implementations
  csky: Add __attribute_const__ to ffs()-family implementations
  bitops: Add __attribute_const__ to generic ffs()-family implementations
  KUnit: Introduce ffs()-family tests
  PCI: Test for bit underflow in pcie_set_readrq()
2025-09-29 16:31:35 -07:00
Heiko Carstens
4335edb713 s390: Remove superfluous newlines from inline assemblies
Remove superfluous newlines from inline assemblies. Compilers use the
number of lines of inline assemblies as heuristic for the complexity
and inline decisions. Therefore inline assemblies should only contain
as many lines as required.

A lot of inline assemblies contain a superfluous newline for the last
line. Remove such newlines to improve compiler inlining decisions.

Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-29 13:52:08 +02:00
Heiko Carstens
088bb10e37 s390/mm: Add memory allocation profiling hooks
Similar to common code changes [1] add alloc_hook() wrappers to page table
allocation functions to allow for memory allocation profiling.

If CONFIG_MEM_ALLOC_PROFILING is enabled call sites of page table
allocations are accounted, instead of e.g. only crst_table_alloc() and
page_table_alloc(). This allows for slightly better profiling data, and the
output of /proc/allocinfo is similar to other architectures.

Without alloc_hook() wrappers the output of /proc/allocinfo looks like
this:

    17096704     4174 mm/memory.c:1061 func:folio_prealloc
    17809408     4348 mm/memory.c:1063 func:folio_prealloc
           0        0 mm/memory.c:4422 func:alloc_swap_folio
           0        0 mm/memory.c:4286 func:__alloc_swap_folio
           0        0 mm/memory.c:4971 func:alloc_anon_folio
         ...
     1589248       97 arch/s390/mm/pgalloc.c:25 func:crst_table_alloc
           0        0 arch/s390/mm/pgalloc.c:124 func:page_table_alloc_pgste
     4280320     1045 arch/s390/mm/pgalloc.c:149 func:page_table_alloc

With alloc_hook() wrappers:

     1097728      268 mm/memory.c:5147 func:__do_fault
    20119552     4912 mm/memory.c:1061 func:folio_prealloc
    17534976     4281 mm/memory.c:1063 func:folio_prealloc
           0        0 mm/memory.c:4422 func:alloc_swap_folio
           0        0 mm/memory.c:4286 func:__alloc_swap_folio
      786432      192 mm/memory.c:452 func:__pte_alloc
      405504       99 mm/memory.c:464 func:__pte_alloc_kernel
     1880064      459 mm/memory.c:5525 func:do_fault_around
           0        0 mm/memory.c:6403 func:__p4d_alloc
           0        0 mm/memory.c:6426 func:__pud_alloc
     1064960       65 mm/memory.c:6450 func:__pmd_alloc
           0        0 mm/memory.c:4971 func:alloc_anon_folio
           0        0 mm/memory.c:5233 func:do_set_pmd

[1] commit 2c321f3f70 ("mm: change inlined allocation helpers to account at the call site")

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-25 14:28:58 +02:00
Heiko Carstens
6c4e0cb3d8 s390/bitops: Switch to generic ffs() if supported by compiler
Use generic ffs() / __builtin_ffs() if supported by the compiler. GCC 16
will have support for __builtin_ffs().
See gcc commit f50cff9766c5 ("s390: Implement clz and ctz for SI mode").

In the distant future when GCC 16 becomes the minimum supported version,
this allows to get rid of the flogr inline assembly.

Kernel image size is reduced by ~500 bytes (gcc 16 beta + defconfig).

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>
2025-09-24 16:24:18 +02:00
Heiko Carstens
7b80a23c0e s390/bitops: Switch to generic fls(), fls64(), etc.
Switch to generic fls(), fls64(), etc. which are implemented with
__builtin_ctzl(), __builtin_clzl().
Those builtins are available for all supported compilers.

Kernel image size is reduced by ~10kb (gcc 15.1.0 + defconfig).

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>
2025-09-24 16:24:17 +02:00
Heiko Carstens
f46ccdb87a s390/bitops: Cleanup __flogr()
The flogr() inline assembly has no side effects and generates the same
output if the input does not change. Therefore remove the volatile
qualifier to allow the compiler to optimize the inline assembly away,
if possible.

Also remove the superfluous '\n' which makes the inline assembly appear
larger than it is according to compiler heuristics (number of lines).

Furthermore change the return type of flogr() to unsigned long and add the
const attribute to the function.

This reduces the kernel image size by 994 bytes (defconfig, gcc 15.2.0).

Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18 14:06:41 +02:00
Heiko Carstens
7916160395 s390/bitops: Use __assume() for __flogr() inline assembly return value
Use __assume() to tell compilers that the output operand of the __flogr()
inline assembly contains a value in the range of 0..64. This allows to
optimize the logical AND operation away.

This reduces the kernel image size by 2804 bytes (defconfig, gcc 15.2.0).

Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18 14:06:40 +02:00
Heiko Carstens
a9f859b516 s390/bitops: Limit return value range of __flogr()
With the recent ffs() and ffs64() optimization a logical AND operation was
removed, which allowed the compiler to tell the return value range of both
functions. This may lead to compile warnings as reported by the kernel test
robot:

   drivers/infiniband/hw/mlx5/mr.c: In function 'mlx5r_cache_create_ent_locked':
>> drivers/infiniband/hw/mlx5/mr.c:840:31: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=]
     840 |         sprintf(ent->name, "%d", order);
         |                               ^
   In function 'mlx5_mkey_cache_debugfs_add_ent',
       inlined from 'mlx5r_cache_create_ent_locked' at drivers/infiniband/hw/mlx5/mr.c:930:3:
   drivers/infiniband/hw/mlx5/mr.c:840:9: note: 'sprintf' output between 2 and 5 bytes into a destination of size 4
     840 |         sprintf(ent->name, "%d", order);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Add the AND operation again to address the warning.

From a correctness point of view the AND operation is not necessary,
however there is no other way to tell the compiler that the returned
value of the flogr inline assembly is in the range of 0..64.

This increases the kernel image size by 566 bytes (defconfig, gcc 15.2.0).

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508211859.UoYsJbLN-lkp@intel.com/
Fixes: de88e74889 ("s390/bitops: Slightly optimize ffs() and fls64()")
Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18 14:06:40 +02:00
Sven Schnelle
c7ac5a089d s390/entry: Remove unused TIF flags
The conversion of s390 to generic entry missed to remove the
TIF_SYSCALL*/TIF_SECCOMP flags. Remove them as they are unused now.

Fixes: 56e62a7370 ("s390: convert to generic entry")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
2025-09-17 08:14:04 +02:00
Thomas Gleixner
06e5b72858 s390: Use generic TIF bits
No point in defining generic items and the upcoming RSEQ optimizations are
only available with this _and_ the generic entry infrastructure, which is
already used by s390. So no further action required here.

This leaves a comment about the AUDIT/TRACE/SECCOMP bits which are handled
by SYSCALL_WORK in the generic code, so they seem redundant, but that's a
problem for the s390 wizards to think about.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
2025-09-17 08:14:04 +02:00
Matthew Wilcox (Oracle)
53fbef56e0 mm: introduce memdesc_flags_t
Patch series "Add and use memdesc_flags_t".

At some point struct page will be separated from struct slab and struct
folio.  This is a step towards that by introducing a type for the 'flags'
word of all three structures.  This gives us a certain amount of type
safety by establishing that some of these unsigned longs are different
from other unsigned longs in that they contain things like node ID,
section number and zone number in the upper bits.  That lets us have
functions that can be easily called by anyone who has a slab, folio or
page (but not easily by anyone else) to get the node or zone.

There's going to be some unusual merge problems with this as some odd bits
of the kernel decide they want to print out the flags value or something
similar by writing page->flags and now they'll need to write page->flags.f
instead.  That's most of the churn here.  Maybe we should be removing
these things from the debug output?


This patch (of 11):

Wrap the unsigned long flags in a typedef.  In upcoming patches, this will
provide a strong hint that you can't just pass a random unsigned long to
functions which take this as an argument.

[willy@infradead.org: s/flags/flags.f/ in several architectures]
  Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org
[nicola.vetrini@gmail.com: mips: fix compilation error]
  Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/
  Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com
Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13 16:55:07 -07:00
Kees Cook
b77fee88bf s390: Add __attribute_const__ to ffs()-family implementations
While tracking down a problem where constant expressions used by
BUILD_BUG_ON() suddenly stopped working[1], we found that an added static
initializer was convincing the compiler that it couldn't track the state
of the prior statically initialized value. Tracing this down found that
ffs() was used in the initializer macro, but since it wasn't marked with
__attribute__const__, the compiler had to assume the function might
change variable states as a side-effect (which is not true for ffs(),
which provides deterministic math results).

Add missing __attribute_const__ annotations to S390's implementations of
ffs(), __ffs(), fls(), and __fls() functions. These are pure mathematical
functions that always return the same result for the same input with no
side effects, making them eligible for compiler optimization.

Build tested ARCH=s390 defconfig with GCC s390x-linux-gnu 14.2.0.

Link: https://github.com/KSPP/linux/issues/364 [1]
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250804164417.1612371-14-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-08 14:58:52 -07:00
Christian Borntraeger
352ccf890a KVM: s390: improve interrupt cpu for wakeup
Turns out that picking an idle CPU for floating interrupts has some
negative side effects. The guest will keep the IO workload on its CPU
and rather use an IPI from the interrupt CPU instead of moving workload.
For example a guest with 2 vCPUs and 1 fio process might run that fio on
vcpu1. If after diag500 both vCPUs are idle then vcpu0 is woken up. The
guest will then do an IPI from vcpu0 to vcpu1.

So lets change the heuristics and prefer the last CPU that went to
sleep. This one is likely still in halt polling and can be woken up
quickly.

This patch shows significant improvements in terms of bandwidth or
cpu consumption for fio and uperf workloads and seems to be a net
win.

Link: https://lore.kernel.org/linux-s390/20250904113927.119306-1-borntraeger@linux.ibm.com/
Reviewed-by: Christoph Schlameuß <schlameuss@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2025-09-08 11:12:39 +02:00
Niklas Schnelle
9ffaf52290 iommu/s390: Make attach succeed when the device was surprise removed
When a PCI device is removed with surprise hotplug, there may still be
attempts to attach the device to the default domain as part of tear down
via (__iommu_release_dma_ownership()), or because the removal happens
during probe (__iommu_probe_device()). In both cases zpci_register_ioat()
fails with a cc value indicating that the device handle is invalid. This
is because the device is no longer part of the instance as far as the
hypervisor is concerned.

Currently this leads to an error return and s390_iommu_attach_device()
fails. This triggers the WARN_ON() in __iommu_group_set_domain_nofail()
because attaching to the default domain must never fail.

With the device fenced by the hypervisor no DMAs to or from memory are
possible and the IOMMU translations have no effect. Proceed as if the
registration was successful and let the hotplug event handling clean up
the device.

This is similar to how devices in the error state are handled since
commit 59bbf59679 ("iommu/s390: Make attach succeed even if the device
is in error state") except that for removal the domain will not be
registered later. This approach was also previously discussed at the
link.

Handle both cases, error state and removal, in a helper which checks if
the error needs to be propagated or ignored. Avoid magic number
condition codes by using the pre-existing, but never used, defines for
PCI load/store condition codes and rename them to reflect that they
apply to all PCI instructions.

Cc: stable@vger.kernel.org # v6.2
Link: https://lore.kernel.org/linux-iommu/20240808194155.GD1985367@ziepe.ca/
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Link: https://lore.kernel.org/r/20250904-iommu_succeed_attach_removed-v1-1-e7f333d2f80f@linux.ibm.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-09-05 15:11:09 +02:00
Juergen Christ
669bc57e70 s390/bitops: Optimize inlining
GCC inlining heuristics prevent code growth due to inlining into cold
paths.  This causes GCC to emit a partially specialized version of
__flogr for non-constant input for all occurrences on cold paths.
This happens since the overhead seen during inlining includes setting
up a union register_pair, calling flogr, and extracting and casting
the result.  This overhead is not removed until the function is
lowered into RTL.  But this happens after inlining.

For -ftrivial-var-auto-init=zero builds, an additional initialization
of the union register_pair adds another statement to be inlinined.
This is unneeded since the even register is initialized anyway and the
odd register is not an input register.  It is only marked as such
since the whole pair has to be marked as a read/write output register.
Mark the union register_pair as uninitialized to get rid of this
statement.  This, however, does not change the code since the
initialization happens when part of the register pair is written.
Nevertheless, GCC function size approximation during inlining is
reduced by one statement.

Force inlining of flogr and also flatten some other functions that
should be leaf functions but are called in cold context, like, e.g.,
__init functions.

Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-08-20 16:38:24 +02:00
Heiko Carstens
de88e74889 s390/bitops: Slightly optimize ffs() and fls64()
Use a simpler algorithm to calculate the result of ffs() and fls64().
This generates slightly better code and increases readability.

Kernel image size is reduced by ~3kb (gcc 15.1.0 + defconfig).

Suggested-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-08-20 16:38:23 +02:00
Linus Torvalds
bec077162b more s390 updates for 6.17 merge window
- Support MMIO read/write tracing
 
 - Enable THP swapping and THP migration
 
 - Unmask SLCF bit ("stateless command filtering") introduced with
   CEX8 cards, so that user space applications like lszcrypt could
   evaluate and list this feature
 
 - Fix the value of high_memory variable, so it considers possible
   tailing offline memory blocks
 
 - Make vmem_pte_alloc() consistent and always allocate memory of
   PAGE_SIZE for page tables. This ensures a page table occupies
   the whole page, as the rest of the code assumes
 
 - Fix kernel image end address in the decompressor debug output
 
 - Fix a typo in debug_sprintf_format_fn() comment
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Merge tag 's390-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Alexander Gordeev:

 - Support MMIO read/write tracing

 - Enable THP swapping and THP migration

 - Unmask SLCF bit ("stateless command filtering") introduced with CEX8
   cards, so that user space applications like lszcrypt could evaluate
   and list this feature

 - Fix the value of high_memory variable, so it considers possible
   tailing offline memory blocks

 - Make vmem_pte_alloc() consistent and always allocate memory of
   PAGE_SIZE for page tables. This ensures a page table occupies the
   whole page, as the rest of the code assumes

 - Fix kernel image end address in the decompressor debug output

 - Fix a typo in debug_sprintf_format_fn() comment

* tag 's390-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/debug: Fix typo in debug_sprintf_format_fn() comment
  s390/boot: Fix startup debugging log
  s390/mm: Allocate page table with PAGE_SIZE granularity
  s390/mm: Enable THP_SWAP and THP_MIGRATION
  s390: Support CONFIG_TRACE_MMIO_ACCESS
  s390/mm: Set high_memory at the end of the identity mapping
  s390/ap: Unmask SLCF bit in card and queue ap functions sysfs
2025-08-08 06:56:55 +03:00
Ingo Molnar
a53d0cf7f1 Merge commit 'linus' into core/bugs, to resolve conflicts
Resolve conflicts with this commit that was developed in parallel
during the merge window:

 8c8efa93db ("x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust")

 Conflicts:
	arch/riscv/include/asm/bug.h
	arch/x86/include/asm/bug.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-08-05 11:15:34 +02:00
Linus Torvalds
beace86e61 Summary of significant series in this pull request:
- The 4 patch series "mm: ksm: prevent KSM from breaking merging of new
   VMAs" from Lorenzo Stoakes addresses an issue with KSM's
   PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for
   merging with existing adjacent VMAs.
 
 - The 4 patch series "mm/damon: introduce DAMON_STAT for simple and
   practical access monitoring" from SeongJae Park adds a new kernel module
   which simplifies the setup and usage of DAMON in production
   environments.
 
 - The 6 patch series "stop passing a writeback_control to swap/shmem
   writeout" from Christoph Hellwig is a cleanup to the writeback code
   which removes a couple of pointers from struct writeback_control.
 
 - The 7 patch series "drivers/base/node.c: optimization and cleanups"
   from Donet Tom contains largely uncorrelated cleanups to the NUMA node
   setup and management code.
 
 - The 4 patch series "mm: userfaultfd: assorted fixes and cleanups" from
   Tal Zussman does some maintenance work on the userfaultfd code.
 
 - The 5 patch series "Readahead tweaks for larger folios" from Ryan
   Roberts implements some tuneups for pagecache readahead when it is
   reading into order>0 folios.
 
 - The 4 patch series "selftests/mm: Tweaks to the cow test" from Mark
   Brown provides some cleanups and consistency improvements to the
   selftests code.
 
 - The 4 patch series "Optimize mremap() for large folios" from Dev Jain
   does that.  A 37% reduction in execution time was measured in a
   memset+mremap+munmap microbenchmark.
 
 - The 5 patch series "Remove zero_user()" from Matthew Wilcox expunges
   zero_user() in favor of the more modern memzero_page().
 
 - The 3 patch series "mm/huge_memory: vmf_insert_folio_*() and
   vmf_insert_pfn_pud() fixes" from David Hildenbrand addresses some warts
   which David noticed in the huge page code.  These were not known to be
   causing any issues at this time.
 
 - The 3 patch series "mm/damon: use alloc_migrate_target() for
   DAMOS_MIGRATE_{HOT,COLD" from SeongJae Park provides some cleanup and
   consolidation work in DAMON.
 
 - The 3 patch series "use vm_flags_t consistently" from Lorenzo Stoakes
   uses vm_flags_t in places where we were inappropriately using other
   types.
 
 - The 3 patch series "mm/memfd: Reserve hugetlb folios before
   allocation" from Vivek Kasireddy increases the reliability of large page
   allocation in the memfd code.
 
 - The 14 patch series "mm: Remove pXX_devmap page table bit and pfn_t
   type" from Alistair Popple removes several now-unneeded PFN_* flags.
 
 - The 5 patch series "mm/damon: decouple sysfs from core" from SeongJae
   Park implememnts some cleanup and maintainability work in the DAMON
   sysfs layer.
 
 - The 5 patch series "madvise cleanup" from Lorenzo Stoakes does quite a
   lot of cleanup/maintenance work in the madvise() code.
 
 - The 4 patch series "madvise anon_name cleanups" from Vlastimil Babka
   provides additional cleanups on top or Lorenzo's effort.
 
 - The 11 patch series "Implement numa node notifier" from Oscar Salvador
   creates a standalone notifier for NUMA node memory state changes.
   Previously these were lumped under the more general memory on/offline
   notifier.
 
 - The 6 patch series "Make MIGRATE_ISOLATE a standalone bit" from Zi Yan
   cleans up the pageblock isolation code and fixes a potential issue which
   doesn't seem to cause any problems in practice.
 
 - The 5 patch series "selftests/damon: add python and drgn based DAMON
   sysfs functionality tests" from SeongJae Park adds additional drgn- and
   python-based DAMON selftests which are more comprehensive than the
   existing selftest suite.
 
 - The 5 patch series "Misc rework on hugetlb faulting path" from Oscar
   Salvador fixes a rather obscure deadlock in the hugetlb fault code and
   follows that fix with a series of cleanups.
 
 - The 3 patch series "cma: factor out allocation logic from
   __cma_declare_contiguous_nid" from Mike Rapoport rationalizes and cleans
   up the highmem-specific code in the CMA allocator.
 
 - The 28 patch series "mm/migration: rework movable_ops page migration
   (part 1)" from David Hildenbrand provides cleanups and
   future-preparedness to the migration code.
 
 - The 2 patch series "mm/damon: add trace events for auto-tuned
   monitoring intervals and DAMOS quota" from SeongJae Park adds some
   tracepoints to some DAMON auto-tuning code.
 
 - The 6 patch series "mm/damon: fix misc bugs in DAMON modules" from
   SeongJae Park does that.
 
 - The 6 patch series "mm/damon: misc cleanups" from SeongJae Park also
   does what it claims.
 
 - The 4 patch series "mm: folio_pte_batch() improvements" from David
   Hildenbrand cleans up the large folio PTE batching code.
 
 - The 13 patch series "mm/damon/vaddr: Allow interleaving in
   migrate_{hot,cold} actions" from SeongJae Park facilitates dynamic
   alteration of DAMON's inter-node allocation policy.
 
 - The 3 patch series "Remove unmap_and_put_page()" from Vishal Moola
   provides a couple of page->folio conversions.
 
 - The 4 patch series "mm: per-node proactive reclaim" from Davidlohr
   Bueso implements a per-node control of proactive reclaim - beyond the
   current memcg-based implementation.
 
 - The 14 patch series "mm/damon: remove damon_callback" from SeongJae
   Park replaces the damon_callback interface with a more general and
   powerful damon_call()+damos_walk() interface.
 
 - The 10 patch series "mm/mremap: permit mremap() move of multiple VMAs"
   from Lorenzo Stoakes implements a number of mremap cleanups (of course)
   in preparation for adding new mremap() functionality: newly permit the
   remapping of multiple VMAs when the user is specifying MREMAP_FIXED.  It
   still excludes some specialized situations where this cannot be
   performed reliably.
 
 - The 3 patch series "drop hugetlb_free_pgd_range()" from Anthony Yznaga
   switches some sparc hugetlb code over to the generic version and removes
   the thus-unneeded hugetlb_free_pgd_range().
 
 - The 4 patch series "mm/damon/sysfs: support periodic and automated
   stats update" from SeongJae Park augments the present
   userspace-requested update of DAMON sysfs monitoring files.  Automatic
   update is now provided, along with a tunable to control the update
   interval.
 
 - The 4 patch series "Some randome fixes and cleanups to swapfile" from
   Kemeng Shi does what is claims.
 
 - The 4 patch series "mm: introduce snapshot_page" from Luiz Capitulino
   and David Hildenbrand provides (and uses) a means by which debug-style
   functions can grab a copy of a pageframe and inspect it locklessly
   without tripping over the races inherent in operating on the live
   pageframe directly.
 
 - The 6 patch series "use per-vma locks for /proc/pid/maps reads" from
   Suren Baghdasaryan addresses the large contention issues which can be
   triggered by reads from that procfs file.  Latencies are reduced by more
   than half in some situations.  The series also introduces several new
   selftests for the /proc/pid/maps interface.
 
 - The 6 patch series "__folio_split() clean up" from Zi Yan cleans up
   __folio_split()!
 
 - The 7 patch series "Optimize mprotect() for large folios" from Dev
   Jain provides some quite large (>3x) speedups to mprotect() when dealing
   with large folios.
 
 - The 2 patch series "selftests/mm: reuse FORCE_READ to replace "asm
   volatile("" : "+r" (XXX));" and some cleanup" from wang lian does some
   cleanup work in the selftests code.
 
 - The 3 patch series "tools/testing: expand mremap testing" from Lorenzo
   Stoakes extends the mremap() selftest in several ways, including adding
   more checking of Lorenzo's recently added "permit mremap() move of
   multiple VMAs" feature.
 
 - The 22 patch series "selftests/damon/sysfs.py: test all parameters"
   from SeongJae Park extends the DAMON sysfs interface selftest so that it
   tests all possible user-requested parameters.  Rather than the present
   minimal subset.
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Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "As usual, many cleanups. The below blurbiage describes 42 patchsets.
  21 of those are partially or fully cleanup work. "cleans up",
  "cleanup", "maintainability", "rationalizes", etc.

  I never knew the MM code was so dirty.

  "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes)
     addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly
     mapped VMAs were not eligible for merging with existing adjacent
     VMAs.

  "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park)
     adds a new kernel module which simplifies the setup and usage of
     DAMON in production environments.

  "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig)
     is a cleanup to the writeback code which removes a couple of
     pointers from struct writeback_control.

  "drivers/base/node.c: optimization and cleanups" (Donet Tom)
     contains largely uncorrelated cleanups to the NUMA node setup and
     management code.

  "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman)
     does some maintenance work on the userfaultfd code.

  "Readahead tweaks for larger folios" (Ryan Roberts)
     implements some tuneups for pagecache readahead when it is reading
     into order>0 folios.

  "selftests/mm: Tweaks to the cow test" (Mark Brown)
     provides some cleanups and consistency improvements to the
     selftests code.

  "Optimize mremap() for large folios" (Dev Jain)
     does that. A 37% reduction in execution time was measured in a
     memset+mremap+munmap microbenchmark.

  "Remove zero_user()" (Matthew Wilcox)
     expunges zero_user() in favor of the more modern memzero_page().

  "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand)
     addresses some warts which David noticed in the huge page code.
     These were not known to be causing any issues at this time.

  "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park)
     provides some cleanup and consolidation work in DAMON.

  "use vm_flags_t consistently" (Lorenzo Stoakes)
     uses vm_flags_t in places where we were inappropriately using other
     types.

  "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy)
     increases the reliability of large page allocation in the memfd
     code.

  "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple)
     removes several now-unneeded PFN_* flags.

  "mm/damon: decouple sysfs from core" (SeongJae Park)
     implememnts some cleanup and maintainability work in the DAMON
     sysfs layer.

  "madvise cleanup" (Lorenzo Stoakes)
     does quite a lot of cleanup/maintenance work in the madvise() code.

  "madvise anon_name cleanups" (Vlastimil Babka)
     provides additional cleanups on top or Lorenzo's effort.

  "Implement numa node notifier" (Oscar Salvador)
     creates a standalone notifier for NUMA node memory state changes.
     Previously these were lumped under the more general memory
     on/offline notifier.

  "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan)
     cleans up the pageblock isolation code and fixes a potential issue
     which doesn't seem to cause any problems in practice.

  "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park)
     adds additional drgn- and python-based DAMON selftests which are
     more comprehensive than the existing selftest suite.

  "Misc rework on hugetlb faulting path" (Oscar Salvador)
     fixes a rather obscure deadlock in the hugetlb fault code and
     follows that fix with a series of cleanups.

  "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport)
     rationalizes and cleans up the highmem-specific code in the CMA
     allocator.

  "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand)
     provides cleanups and future-preparedness to the migration code.

  "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park)
     adds some tracepoints to some DAMON auto-tuning code.

  "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park)
     does that.

  "mm/damon: misc cleanups" (SeongJae Park)
     also does what it claims.

  "mm: folio_pte_batch() improvements" (David Hildenbrand)
     cleans up the large folio PTE batching code.

  "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park)
     facilitates dynamic alteration of DAMON's inter-node allocation
     policy.

  "Remove unmap_and_put_page()" (Vishal Moola)
     provides a couple of page->folio conversions.

  "mm: per-node proactive reclaim" (Davidlohr Bueso)
     implements a per-node control of proactive reclaim - beyond the
     current memcg-based implementation.

  "mm/damon: remove damon_callback" (SeongJae Park)
     replaces the damon_callback interface with a more general and
     powerful damon_call()+damos_walk() interface.

  "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes)
     implements a number of mremap cleanups (of course) in preparation
     for adding new mremap() functionality: newly permit the remapping
     of multiple VMAs when the user is specifying MREMAP_FIXED. It still
     excludes some specialized situations where this cannot be performed
     reliably.

  "drop hugetlb_free_pgd_range()" (Anthony Yznaga)
     switches some sparc hugetlb code over to the generic version and
     removes the thus-unneeded hugetlb_free_pgd_range().

  "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park)
     augments the present userspace-requested update of DAMON sysfs
     monitoring files. Automatic update is now provided, along with a
     tunable to control the update interval.

  "Some randome fixes and cleanups to swapfile" (Kemeng Shi)
     does what is claims.

  "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand)
     provides (and uses) a means by which debug-style functions can grab
     a copy of a pageframe and inspect it locklessly without tripping
     over the races inherent in operating on the live pageframe
     directly.

  "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan)
     addresses the large contention issues which can be triggered by
     reads from that procfs file. Latencies are reduced by more than
     half in some situations. The series also introduces several new
     selftests for the /proc/pid/maps interface.

  "__folio_split() clean up" (Zi Yan)
     cleans up __folio_split()!

  "Optimize mprotect() for large folios" (Dev Jain)
     provides some quite large (>3x) speedups to mprotect() when dealing
     with large folios.

  "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian)
     does some cleanup work in the selftests code.

  "tools/testing: expand mremap testing" (Lorenzo Stoakes)
     extends the mremap() selftest in several ways, including adding
     more checking of Lorenzo's recently added "permit mremap() move of
     multiple VMAs" feature.

  "selftests/damon/sysfs.py: test all parameters" (SeongJae Park)
     extends the DAMON sysfs interface selftest so that it tests all
     possible user-requested parameters. Rather than the present minimal
     subset"

* tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits)
  MAINTAINERS: add missing headers to mempory policy & migration section
  MAINTAINERS: add missing file to cgroup section
  MAINTAINERS: add MM MISC section, add missing files to MISC and CORE
  MAINTAINERS: add missing zsmalloc file
  MAINTAINERS: add missing files to page alloc section
  MAINTAINERS: add missing shrinker files
  MAINTAINERS: move memremap.[ch] to hotplug section
  MAINTAINERS: add missing mm_slot.h file THP section
  MAINTAINERS: add missing interval_tree.c to memory mapping section
  MAINTAINERS: add missing percpu-internal.h file to per-cpu section
  mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info()
  selftests/damon: introduce _common.sh to host shared function
  selftests/damon/sysfs.py: test runtime reduction of DAMON parameters
  selftests/damon/sysfs.py: test non-default parameters runtime commit
  selftests/damon/sysfs.py: generalize DAMON context commit assertion
  selftests/damon/sysfs.py: generalize monitoring attributes commit assertion
  selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion
  selftests/damon/sysfs.py: test DAMOS filters commitment
  selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion
  selftests/damon/sysfs.py: test DAMOS destinations commitment
  ...
2025-07-31 14:57:54 -07:00
Gerald Schaefer
10dd5a0009 s390/mm: Enable THP_SWAP and THP_MIGRATION
After hugetlbfs PTE_MARKER support for s390 introduced region-third and
segment table swap entries, it is now possible to also enable THP_SWAP
and THP_MIGRATION for s390.

s390 has different layout for PTE and region / segment table entries
(RSTE). This is also true for swap entries, and their swap type and offset
encoding. For hugetlbfs PTE_MARKER support, s390 has internal
__swp_type_rste() and __swp_offset_rste() helpers to correctly handle RSTE
swap entries.

But common swap code does not know about this difference, and only uses
__swp_type(), __swp_offset() and __swp_entry() helpers for conversion
between arch-dependent and arch-independent representation of swp_entry_t
for all pagetable levels. On s390, those helpers only work for PTE swap
entries.

Therefore, implement __pmd_to_swp_entry() to build a fake PTE swap entry
and return the arch-dependent representation of that. Correspondingly,
implement __swp_entry_to_pmd() to convert that into a proper PMD swap
entry again. With this, the arch-dependent swp_entry_t representation will
always look like a PTE swap entry in common code.

This is somewhat similar to fake PTEs in hugetlbfs code for s390, but only
requires conversion of the swap type and offset, and not all the possible
PTE bits.

For PMD swap entry SOFT_DIRTY handling, use the same helpers as for normal
PMDs. Similar to PTEs, the SOFT_DIRTY bit location is the same for swap
and normal entries.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-07-31 18:59:26 +02:00