Commit Graph

5234 Commits

Author SHA1 Message Date
David Carlier
b7403afb7a arm64: errata: match the target implementation CPU's own MIDR
__is_affected_midr_range() is handed the MIDR and REVIDR of one target
implementation CPU, but tests the erratum's range with is_midr_in_range(),
which re-scans all of target_impl_cpus[] and ignores the @midr argument.
The range test is thus constant across the per-CPU loop in
is_affected_midr_range() and only answers "is any target CPU in range".

Since just the fixed_revs REVIDR check uses the iteration's own registers,
an out-of-range target CPU can decide whether a MIDR_FIXED() exemption
applies. A VM then enables a workaround whose only in-range CPU is fixed
silicon, e.g. erratum 2658417 on a Cortex-A510 r1p1 with REVIDR_EL1[25]
set.

Factor the range test into __is_midr_in_range(), which takes an explicit
MIDR, and use it in __is_affected_midr_range().

Fixes: 86edf6bdcf ("smccc/kvm_guest: Enable errata based on implementation CPUs")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-18 11:24:16 +00:00
Yureka Lilian
baaa9b126b arm64: Add override for WFxT
Add an override for WFxT support within ID_AA64ISAR2_EL1 to allow
it to be disabled using the new arm64.nowfxt command line parameter.

This accompanies the idle=nop param introduced in a previous patch
series [1] in dealing with misbehaving WFI and WFIT instructions on
Apple Silicon SoCs, and eases debugging of other quirky WFxT
implementations.

Link[1]: https://lore.kernel.org/all/20260804-arm64-idle-param-v3-1-d10f8159062b@cyberchaos.dev/
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Yureka Lilian <yureka@cyberchaos.dev>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-18 11:17:02 +00:00
Catalin Marinas
fdb9ebc7fb arm64: mte: Fix PTRACE_{PEEK,POKE}MTETAGS error documentation
PTRACE_{PEEK,POKE}MTETAGS return -EIO rather than -EOPNOTSUPP (as
documented) when no tags are copied from/to a mapping without PROT_MTE.
This has been the behaviour since the interface was introduced, though
the original intent was to distinguish between address not being
accessible and mapped as untagged.

Update the documentation to match the implementation (de-facto ABI).
Since -EOPNOTSUPP was never returned, change the error assignment to
-EIO as well to avoid confusion.

Fixes: df9d7a22dd ("arm64: mte: Add Memory Tagging Extension documentation")
Fixes: 18ddbaa02b ("arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support")
Reported-by: Yury Khrustalev <yury.khrustalev@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-11 12:50:02 +00:00
Breno Leitao
e4a6f57d22 arm64: hibernate: clone only the linear map that exists at runtime
This is similar to commit 1537e55728 ("arm64: trans_pgd: clone only
the linear map that exists at runtime"), but in a different place.

swsusp_arch_resume() clones the kernel linear map with
trans_pgd_create_copy(..., PAGE_OFFSET, PAGE_END). PAGE_OFFSET comes
from the compile-time VA_BITS, so a CONFIG_ARM64_VA_BITS_52 kernel
booting on hardware without LPA2 -- vabits_actual is 48 and the fifth
level is folded -- hands the walk a 3.9PB window while its linear map
only spans the top 128TB.

On a VA_BITS_52 4k kernel with CONFIG_KASAN_GENERIC in a 4GB VM, I see:

  swapper/0: page allocation failure: order:0, mode:0x920(GFP_ATOMIC|__GFP_ZERO)
   hibernate_page_alloc+0x10/0x1c
   swsusp_arch_resume+0x70/0x320
   hibernation_restore+0xa4/0x138
   software_resume+0x15c/0x270
  PM: hibernation: Failed to load image, recovering.
  PM: hibernation: resume failed (-12)

Fix it by copying the linear map that is the actual one, not the
compiled one.

Fixes: a6bbf5d4d9 ("arm64: mm: Add definitions to support 5 levels of paging")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-11 12:14:43 +00:00
Bradley Morgan
955d86e5f3 arm64: hibernate: pass HVC_SET_VECTORS args to the resume hvc
swsusp_arch_suspend_exit() reinstalls the restored kernel's hyp stub
vectors with an hvc, but never passes the arguments. x0 is not set to
HVC_SET_VECTORS and x1 is not set to the vector address, so the stub
dispatch falls through and returns without writing vbar_el2. EL2 is
left pointing at the trans_pgd copy of the vectors, a page that
swsusp_free() releases right after resume.

Set the arguments up the same way __hyp_set_vectors() does.

Without this fix, Vladimir was able to trigger a hang when resuming from
hibernation with CONFIG_PAGE_POISONING=y and page_poison=on.

Fixes: 788bfdd974 ("arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors")
Cc: stable@vger.kernel.org
Signed-off-by: Bradley Morgan <include@grrlz.net>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-09 12:51:20 +00:00
Fuad Tabba
5445d64199 arm64: Don't read GMID_EL1 when MTE is disabled
__cpuinfo_store_cpu() gates the GMID_EL1 read on the raw
ID_AA64PFR1_EL1, so it reads the register even when the kernel has
disabled MTE (CONFIG_ARM64_MTE=n or arm64.nomte). KVM sets HCR_EL2.TID5
in that case, and pKVM injects an UNDEF the host cannot handle:

  Internal error: Oops - Undefined instruction: 0000000002000000 [#1]  SMP
  pc : __cpuinfo_store_cpu+0xf4/0x264
  Kernel panic - not syncing: Attempted to kill the idle task!

Only pKVM reaches it, and only after a CPU is offlined and brought back
online: its CPU_ON relay sets the host HCR before the CPU enters EL1,
while plain nVHE sets it at CPUHP_AP_KVM_ONLINE.

Gate the read on the CPU's own ID_AA64PFR1_EL1 with the command-line
override applied, and on CONFIG_ARM64_MTE, which no register reflects.
The boot CPU stores its registers before init_cpu_features() strips an
unsafe override, so clamp against the hardware value here too.

Fixes: f35abcbb8a ("KVM: arm64: Trap MTE access and discovery when MTE is disabled")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-03 13:03:23 +00:00
Khushit Shah
5541432e09 arm64: errata: pass REVIDR when matching target implementation CPUs
When target implementation CPUs are provided, is_affected_midr_range()
accidentally passed the MIDR as both arguments to __is_affected_midr_range(),
so the REVIDR mask check operated on the wrong register.

Pass REVIDR as intended.

Fixes: 86edf6bdcf ("smccc/kvm_guest: Enable errata based on implementation CPUs")
Cc: stable@vger.kernel.org
Signed-off-by: Khushit Shah <khushit.shah@nutanix.com>
Reviewed-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Shameer Kolothum <skolothumtho@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-03 13:02:01 +00:00
Breno Leitao
1537e55728 arm64: trans_pgd: clone only the linear map that exists at runtime
kexec_file_load() fails on arm64 if we have CONFIG_ARM64_VA_BITS_52 but
it runs on a !FEAT_LPA2 host (such as my loving Grace machine).

That is because trans_pgd_create_copy() uses the compile time
PAGE_OFFSET (VA 52) instead of the actual VA size (48 -- due to the lack
of LPA2). With the fifth level folded, pgd_none() is always false, so
the walk cannot skip the 15 extra PGDIR_SIZE slots, and they all alias
back to the same table: the whole kernel page table gets cloned 16
times, KASAN shadow included. Without KASAN it does not blow up, it just
wastes ~RAM/32 in page tables.

Fix it by copying the linear map that is the actual one, not the
compiled one.

Fixes: a6bbf5d4d9 ("arm64: mm: Add definitions to support 5 levels of paging")
Signed-off-by: Breno Leitao <leitao@debian.org>
Tested-by: Yury Smirnov <yurymonzon@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-09-03 13:01:15 +00:00
Linus Torvalds
9d607ae0f7 arm64 fixes for -rc1
- Fix address handling of final memory region in ptdump
 
 - Fix emulation of decrementing load/store multiple from 32-bit task
 
 - Fix SCTLR context-switching for store-only MTE mode
 
 - Fix numerous issues in MTE selftests
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "A mixture of ptdump, compat and MTE fixes that came in during the
  merge window:

   - Fix address handling of final memory region in ptdump

   - Fix emulation of decrementing load/store multiple from 32-bit task

   - Fix SCTLR context-switching for store-only MTE mode

   - Fix numerous issues in MTE selftests"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  selftests/arm64: Add MTE test config fragment
  selftests/arm64: Fix MTE prctl TAP plan
  selftests/arm64: Treat KSM merge_across_nodes as optional
  selftests/arm64: Print missing MTE TAP headers
  arm64: compat: Fix decrementing LDM/STM alignment emulation
  arm64: process: Fix context switching MTE store-only tag check
  KVM: arm64: ptdump: Flush the last region
  arm64: ptdump: Make note_page_flush() range aware
2026-08-28 09:02:04 -07:00
Karl Mehltretter
f5b8b9037d arm64: compat: Fix decrementing LDM/STM alignment emulation
The compat alignment emulator inherited unsigned long data addresses from
the 32-bit ARM implementation.

In do_alignment_ldmstm(), nr_regs is an unsigned int holding the transfer
size. The function uses the same address addition for both transfer
directions, negating nr_regs first for a decrementing LDM or STM. The
32-bit negation wraps before the addition, so the handler adds nearly
4 GiB instead of subtracting the transfer size.
The resulting address lies outside the compat task's address space, so
decrementing LDM/STM emulation fails, while incrementing forms work.

For example, a backwards-moving copy routine using decrementing LDM/STM can
take an alignment fault when called with unaligned pointers. The compat
handler should emulate the transfer, but this bug instead causes SIGBUS.

The offset negated in do_alignment_finish_ldst() is offset_union.un, which
is already unsigned long and does not have this width mismatch.

Make nr_regs unsigned long so its negation and the address arithmetic
use the same width.

Fixes: 3fc24ef32d ("arm64: compat: Implement misalignment fixups for multiword loads")
Cc: stable@vger.kernel.org
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-27 14:16:04 +00:00
Linus Torvalds
7bb6284aa7 Arm:
* Add support for 'slot' based PMU events, paired with new UAPI that
   compels the user to select a specific PMU implementation
 
 * Lazy save/restore of vCPU state for pKVM, along with various fixes
   and cleanups to the management of vCPU state between the untrusted
   host and pKVM hypervisor
 
 * Disable traps of EL1 registers for nested hypervisors when FEAT_NV2p1
   is present, guaranteeing that EL2-specific register bits are stateful
   in the EL1 counterpart
 
 * Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the scope
   of those instructions remains 'in host' (i.e. L1 kernel/userspace)
 
 * Pile of fixes for the management of the VNCR pseudo-TLB, such as
   under-invalidations and races with concurrent TLBIs on other vCPUs
 
 * Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
   runtime-patched constant, allowing the same data to be shared with
   pKVM prior to dropping host privileges
 
 * Considerable pile of LLM-assisted fixes around the shop but mostly in
   the VGIC, our in-kernel generator of bugs (and sometimes interrupts)
 
 LoongArch:
 
 * Advertise already-supported capabilities.
 
 * Some bug fixes about timer and MMIO.
 
 * Some hardening about interrupt injection.
 
 * Replace kvm_err() with kvm_pr_unimpl().
 
 * Add FPU/LSX/LASX test cases for selftests.
 
 RISC-V:
 
 * Svadu/Zicfiss/Zicfilp FWFT support for Guest
 
 * Use try_cmpxchg for IMSIC MRIF RMW
 
 * More arch-specific tracepoints in KVM RISC-V
 
 * Eager page splitting when enabling dirty logging
 
 * Optimize hfence request handling for SMP Guests
 
 * Improve dirty log clearing by skipping zero bits in mask
 
 * Guard HFENCE range loops against overflow
 
 * CPU PM notifiers in KVM RISC-V for non-retentive idle states
 
 * Fix kernel-mode vector context save/restore for Guest
 
 s390:
 
 * Fixes for vfio-ap
 
 * Fixes for the gmap rework
 
 * Fixes for vsie
 
 * AI triggered fixes all over
 
 * diag9c tracing
 
 * code move preparation for the additional arm64 support
 
 * enable CONTEXT_ANALYSIS
 
 x86:
 
 * Perform spring cleaning on x86.{c,h} and asm/kvm_host.h, by adding regs.c
   (the kvm_cache_regs.h => regs.h is already applied) and msrs.{c,h}, and moving
   relevant code out of x86.c.
 
 * Split kvm_mmu in three parts, respectively to describe the format of page
   tables, walking the guest page tables and building the page tables.  Always
   use the same page table walker kvm->arch.gva_walk as the entry point to
   convert a guest's virtual address, where the previous code used two
   different kvm_mmu structs depending on whether the walk included nested
   EPT/NPT or not.  Make page fault vmexits reuse the permission checking
   machinery that is used for guest page faults.  This is both a cleanup
   and a baby step towards supporting XS/XU memory permissions.
 
 * Document some of the "fun" gotchas with the APIC base when creating IRQCHIPs
   on x86.
 
 * Remove a defunct masterclock update from kvm_xen_shared_info_init().  It
   could result in incorrect kvmclock due to triggering an unnecessary
   switch to/from masterclock mode.
 
 * Skip Xen runstate time updates if time has effectively gone backwards, so
   that the guest doesn't report 100% steal time for a very, very long time.
 
 * Drop KVM's runtime updates of the Xen PV timing CPUID leaf, as KVM was
   updating the wrong sub-leaf, and upstream KVM will soon provide all the
   information needed by userspace to populate the CPUID field itself.
 
 * Fix a bug where KVM would walk a newly created rmap without holding the rmap
   lock (or mmu_lock) during aging.
 
 * Fix a bug where aging TDP MMU SPTEs could clobber FROZEN SPTEs.
 
 * Fix a variety of #DB priority bugs.
 
 * Fix a class of races related to enabling Hyper-V emulation on a vCPU after
   the vCPU is visible to the rest of KVM.
 
 * Use static calls for nested virtualization ops.
 
 * Move more KVM-internal code out of x86's kvm_host.h.
 
 * Enumerate support for a variety of Zhaoxin instructions that don't require
   explicit virtualization.
 
 * Fix missing EFER validation bugs, including in the KVM_SET_SREGS* path.
 
 * Harden kvm_vcpu_map() against double-mapping and thus leaking references.
 
 * Misc fixes and cleanups, e.g. for largely benign syzkaller splats.
 
 x86 (Intel):
 
 * Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used for IPI
   virtualization when the vCPU is freed, to fix a use-after-free where hardware
   will write to a freed vCPU's PID.
 
 * Service local TLB flushes on a failed nested VM-Enter to fix a bug where KVM
   could miss a TLB on a future, successful VM-Enter with the same L2 VPID.
 
 * Cap the maximum value shoved into the VMX Preemption Timer to workaround an
   erratum that affects all existing Intel CPUs that support CPUID 0x15.
 
 * Fix VPID virtualization bugs where KVM would fail to flush hardware TLBs.
 
 * Harden the TDX "populate" ioctls against bad input, and to prepare
   for supporting in-place private<=>shared conversion.
 
 x86 (AMD):
 
 * Forcefully invalidate SNP VMSA pages if their backing guest_memfd page is
   zapped/invalidated, e.g. due to a PUNCH_HOLE in response to a Page-State
   Change request.
 
 * Remove a dying VM from the GA Log notifier list before the VM is actually
   destroyed, to fix a potential use-after-free.
 
 * While FOLL_WRITE was needed in the past to trigger CoW unsharing, nowadays
   FOLL_LONGTERM does that already even without FOLL_WRITE, and in fact,
   get_user_pages() actually disallows FOLL_WRITE together with FOLL_LONGTERM.
   So don't pass FOLL_WRITE when registering encrypted memory regions, i.e. when
   pinning SEV/SEV-ES guest memory, to fix a regression with file-backed memory
   introduced by KVM's (correct) usage of long-term pins.
 
   (This was reviewed by mm maintainers; for more information, see commit
   ee1a586dd1).
 
 * Allocate full pages for SEV/SEV-ES {DE,EN}CRYPT ops on SNP-enabled hosts to
   fix a data corruption issue due to the PSP driver assigning to-be-written
   pages to firmware (as required by the SNP specs).
 
 * Unconditionally intercept ICBEP so that KVM generates the correct guest RIP
   when handling an ICEBP-induced TASK_SWITCH #VMEXIT.
 
 * Harden the SNP "populate" ioctls against bad input, and to prepare
   for supporting in-place private<=>shared conversion.
 
 Generic:
 
 * Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's debugfs.
 
 * Add a per-VM bitmap to track which vCPU IDs have been "claimed" but for
   which the vCPU isn't yet online, and use the bitmap to reject duplicate IDs
   before calling into arch code.  This allows arch code to consume vcpu_id
   without having to worry about cross-vCPU clobbering (at least s390 and x86
   have had related bugs).
 
 * Rework the so called "prepare" and "invalidate" guest_memfd hooks to prepare
   for in-place private<=>shared conversion, and clean up a few warts along the
   way.
 
 Selftests:
 
 * Automatically allocate a full page for L2 guest stacks on x86 instead of
   requiring test-specific L1 guest code to carve out a portion of the L1
   stack for L2 usage, and to ensure the L2 stack also adheres to the x86-64
   calling convention ABI.
 
 * Add a selftest to verify {Guest,Host}-Only behavior in x86's mediated PMU.
 
 * Clean up nested SVM's handling of GPRs on L2<=>L1 transitions, reuse the
   functionality for nested VMX, and drop the ucall hack that was fudging
   around the lack of GPR switching on nVMX.
 
 * Add a stress test to verify KVM doesn't clobber/drop #PF state, e.g. CR2,
   across save/restore, including when L2 is active.
 
 * Add a test to verify KVM_CREATE_VM accepts exactly what is reported by
   KVM_CAP_VM_TYPES.
 
 * Misc selftests fixes and cleanups
 
 * Fix several issues with seeding the pRNG, and rework the pRNG APIs to that
   the pRNG can be sanely used in host code, not just guest code.
 
 * Add an IRQ test to validate virtual IRQ deliverty for IRQs wired up via
   KVM_IRQFD + KVM_SET_GSI_ROUTING, with optional support for triggering IRQs
   via writes to an assigned VFIO device.
 
 * Add syscall wrappers to assert success on a variety of pthreads and CPU
   affinity APIs.
 
 * Set vCPU pthread affinity as early as possible to reduce contention issues
   that were surfaced by PREEMPT_LAZY, which result in runtimes of over a
   minute on large hosts, versus the expected ~5 seconds.
 
 * Rework the PMU counters test to run each testcase using a single VM with
   many vCPUs for each sub-testcase, instead of using a unique VM for each
   sub-testcase.  This cuts the runtime by ~20x.
 
 Miscellaneous:
 
 * MAINTAINERS updates for vfio-ap, guest_memfd, kvm-x86.  Mostly representing
   the status quo more accurately, but also... welcome David Hildenbrand
   as guest_memfd reviewer!
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Add support for 'slot' based PMU events, paired with new UAPI that
     compels the user to select a specific PMU implementation

   - Lazy save/restore of vCPU state for pKVM, along with various fixes
     and cleanups to the management of vCPU state between the untrusted
     host and pKVM hypervisor

   - Disable traps of EL1 registers for nested hypervisors when
     FEAT_NV2p1 is present, guaranteeing that EL2-specific register bits
     are stateful in the EL1 counterpart

   - Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the
     scope of those instructions remains 'in host' (i.e. L1
     kernel/userspace)

   - Pile of fixes for the management of the VNCR pseudo-TLB, such as
     under-invalidations and races with concurrent TLBIs on other vCPUs

   - Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
     runtime-patched constant, allowing the same data to be shared with
     pKVM prior to dropping host privileges

   - Considerable pile of LLM-assisted fixes around the shop but mostly
     in the VGIC, our in-kernel generator of bugs (and sometimes
     interrupts)

  LoongArch:

   - Advertise already-supported capabilities

   - Some bug fixes about timer and MMIO

   - Some hardening about interrupt injection

   - Replace kvm_err() with kvm_pr_unimpl()

   - Add FPU/LSX/LASX test cases for selftests

  RISC-V:

   - Svadu/Zicfiss/Zicfilp FWFT support for Guest

   - Use try_cmpxchg for IMSIC MRIF RMW

   - More arch-specific tracepoints in KVM RISC-V

   - Eager page splitting when enabling dirty logging

   - Optimize hfence request handling for SMP Guests

   - Improve dirty log clearing by skipping zero bits in mask

   - Guard HFENCE range loops against overflow

   - CPU PM notifiers in KVM RISC-V for non-retentive idle states

   - Fix kernel-mode vector context save/restore for Guest

  s390:

   - Fixes for vfio-ap

   - Fixes for the gmap rework

   - Fixes for vsie

   - AI triggered fixes all over

   - diag9c tracing

   - code move preparation for the additional arm64 support

   - enable CONTEXT_ANALYSIS

  x86:

   - Perform spring cleaning on x86.{c,h} and asm/kvm_host.h, by adding
     regs.c (the kvm_cache_regs.h => regs.h is already applied) and
     msrs.{c,h}, and moving relevant code out of x86.c

   - Split kvm_mmu in three parts, respectively to describe the format
     of page tables, walking the guest page tables and building the page
     tables. Always use the same page table walker kvm->arch.gva_walk as
     the entry point to convert a guest's virtual address, where the
     previous code used two different kvm_mmu structs depending on
     whether the walk included nested EPT/NPT or not. Make page fault
     vmexits reuse the permission checking machinery that is used for
     guest page faults. This is both a cleanup and a baby step towards
     supporting XS/XU memory permissions

   - Document some of the "fun" gotchas with the APIC base when creating
     IRQCHIPs on x86

   - Remove a defunct masterclock update from kvm_xen_shared_info_init().
     It could result in incorrect kvmclock due to triggering an
     unnecessary switch to/from masterclock mode

   - Skip Xen runstate time updates if time has effectively gone
     backwards, so that the guest doesn't report 100% steal time for
     a very, very long time

   - Drop KVM's runtime updates of the Xen PV timing CPUID leaf, as KVM
     was updating the wrong sub-leaf, and upstream KVM will soon provide
     all the information needed by userspace to populate the CPUID field
     itself

   - Fix a bug where KVM would walk a newly created rmap without holding
     the rmap lock (or mmu_lock) during aging

   - Fix a bug where aging TDP MMU SPTEs could clobber FROZEN SPTEs

   - Fix a variety of #DB priority bugs

   - Fix a class of races related to enabling Hyper-V emulation on a
     vCPU after the vCPU is visible to the rest of KVM

   - Use static calls for nested virtualization ops

   - Move more KVM-internal code out of x86's kvm_host.h

   - Enumerate support for a variety of Zhaoxin instructions that don't
     require explicit virtualization

   - Fix missing EFER validation bugs, including in the KVM_SET_SREGS*
     path

   - Harden kvm_vcpu_map() against double-mapping and thus leaking
     references

   - Misc fixes and cleanups, e.g. for largely benign syzkaller splats

  x86 (Intel):

   - Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used
     for IPI virtualization when the vCPU is freed, to fix a
     use-after-free where hardware will write to a freed vCPU's PID

   - Service local TLB flushes on a failed nested VM-Enter to fix a bug
     where KVM could miss a TLB on a future, successful VM-Enter with
     the same L2 VPID

   - Cap the maximum value shoved into the VMX Preemption Timer to
     workaround an erratum that affects all existing Intel CPUs that
     support CPUID 0x15

   - Fix VPID virtualization bugs where KVM would fail to flush hardware
     TLBs

   - Harden the TDX "populate" ioctls against bad input, and to prepare
     for supporting in-place private<=>shared conversion

  x86 (AMD):

   - Forcefully invalidate SNP VMSA pages if their backing guest_memfd
     page is zapped/invalidated, e.g. due to a PUNCH_HOLE in response to
     a Page-State Change request

   - Remove a dying VM from the GA Log notifier list before the VM is
     actually destroyed, to fix a potential use-after-free

   - While FOLL_WRITE was needed in the past to trigger CoW unsharing,
     nowadays FOLL_LONGTERM does that already even without FOLL_WRITE,
     and in fact, get_user_pages() actually disallows FOLL_WRITE
     together with FOLL_LONGTERM. So don't pass FOLL_WRITE when
     registering encrypted memory regions, i.e. when pinning SEV/SEV-ES
     guest memory, to fix a regression with file-backed memory
     introduced by KVM's (correct) usage of long-term pins

     (This was reviewed by mm maintainers; for more information, see
     commit ee1a586dd1 "KVM: SEV: Drop FOLL_WRITE for encrypted region
     registration")

   - Allocate full pages for SEV/SEV-ES {DE,EN}CRYPT ops on SNP-enabled
     hosts to fix a data corruption issue due to the PSP driver
     assigning to-be-written pages to firmware (as required by the SNP
     specs)

   - Unconditionally intercept ICBEP so that KVM generates the correct
     guest RIP when handling an ICEBP-induced TASK_SWITCH #VMEXIT

   - Harden the SNP "populate" ioctls against bad input, and to prepare
     for supporting in-place private<=>shared conversion

  Generic:

   - Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's
     debugfs

   - Add a per-VM bitmap to track which vCPU IDs have been "claimed" but
     for which the vCPU isn't yet online, and use the bitmap to reject
     duplicate IDs before calling into arch code. This allows arch code
     to consume vcpu_id without having to worry about cross-vCPU
     clobbering (at least s390 and x86 have had related bugs)

   - Rework the so called "prepare" and "invalidate" guest_memfd hooks
     to prepare for in-place private<=>shared conversion, and clean up a
     few warts along the way

  Selftests:

   - Automatically allocate a full page for L2 guest stacks on x86
     instead of requiring test-specific L1 guest code to carve out a
     portion of the L1 stack for L2 usage, and to ensure the L2 stack
     also adheres to the x86-64 calling convention ABI

   - Add a selftest to verify {Guest,Host}-Only behavior in x86's
     mediated PMU

   - Clean up nested SVM's handling of GPRs on L2<=>L1 transitions,
     reuse the functionality for nested VMX, and drop the ucall hack
     that was fudging around the lack of GPR switching on nVMX

   - Add a stress test to verify KVM doesn't clobber/drop #PF state,
     e.g. CR2, across save/restore, including when L2 is active

   - Add a test to verify KVM_CREATE_VM accepts exactly what is reported
     by KVM_CAP_VM_TYPES

   - Misc selftests fixes and cleanups

   - Fix several issues with seeding the pRNG, and rework the pRNG APIs
     to that the pRNG can be sanely used in host code, not just guest
     code

   - Add an IRQ test to validate virtual IRQ deliverty for IRQs wired up
     via KVM_IRQFD + KVM_SET_GSI_ROUTING, with optional support for
     triggering IRQs via writes to an assigned VFIO device

   - Add syscall wrappers to assert success on a variety of pthreads and
     CPU affinity APIs

   - Set vCPU pthread affinity as early as possible to reduce contention
     issues that were surfaced by PREEMPT_LAZY, which result in runtimes
     of over a minute on large hosts, versus the expected ~5 seconds

   - Rework the PMU counters test to run each testcase using a single VM
     with many vCPUs for each sub-testcase, instead of using a unique VM
     for each sub-testcase. This cuts the runtime by ~20x

  Miscellaneous:

   - MAINTAINERS updates for vfio-ap, guest_memfd, kvm-x86. Mostly
     representing the status quo more accurately, but also... welcome
     David Hildenbrand as guest_memfd reviewer!"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (413 commits)
  KVM: arm64: Validate GICv5 timer PPIs before claiming ownership
  KVM: arm64: vgic: Reject out-of-range GICv5 PPI IDs
  KVM: arm64: vgic: Prevent speculative SPI array underflow
  KVM: arm64: vgic: Free gic_kvm_info on initialization failure
  KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params'
  s390/vfio-ap: Fix NULL deref in status_show() during queue probe
  s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed
  s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap
  s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove
  s390/vfio-ap: Fix required lock not held during update of ap_matrix_mdev object
  s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects
  s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL
  s390/vfio-ap: Fix stale do_remove flag across iterations in vfio_ap_mdev_cfg_remove
  RISC-V: KVM: fix vcpu vector context handling for kernel-mode vector
  riscv: vector: allow non-preemptible kernel-mode vector with IRQs off
  riscv: vector: refactor riscv_v_start_kernel_context
  KVM: s390: gmap: Make prefix handling optional
  KVM: s390: gmap: Make CMMA optional
  KVM: s390: gmap: Make storage keys optional
  KVM: s390: Prepare gmap for a second KVM implementation
  ...
2026-08-25 11:48:04 -07:00
Paolo Bonzini
76671054f9 KVM/arm64 changes for 7.3
- Add support for 'slot' based PMU events, paired with new UAPI that
    compels the user to select a specific PMU implementation
 
  - Lazy save/restore of vCPU state for pKVM, along with various fixes
    and cleanups to the management of vCPU state between the untrusted
    host and pKVM hypervisor
 
  - Disable traps of EL1 registers for nested hypervisors when FEAT_NV2p1
    is present, guaranteeing that EL2-specific register bits are stateful
    in the EL1 counterpart
 
  - Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the scope
    of those instructions remains 'in host' (i.e. L1 kernel/userspace)
 
  - Pile of fixes for the management of the VNCR pseudo-TLB, such as
    under-invalidations and races with concurrent TLBIs on other vCPUs
 
  - Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
    runtime-patched constant, allowing the same data to be shared with
    pKVM prior to dropping host privileges
 
  - Considerable pile of LLM-assisted fixes around the shop but mostly in
    the VGIC, our in-kernel generator of bugs (and sometimes interrupts)
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Merge tag 'kvmarm-7.3' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 changes for 7.3

 - Add support for 'slot' based PMU events, paired with new UAPI that
   compels the user to select a specific PMU implementation

 - Lazy save/restore of vCPU state for pKVM, along with various fixes
   and cleanups to the management of vCPU state between the untrusted
   host and pKVM hypervisor

 - Disable traps of EL1 registers for nested hypervisors when FEAT_NV2p1
   is present, guaranteeing that EL2-specific register bits are stateful
   in the EL1 counterpart

 - Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the scope
   of those instructions remains 'in host' (i.e. L1 kernel/userspace)

 - Pile of fixes for the management of the VNCR pseudo-TLB, such as
   under-invalidations and races with concurrent TLBIs on other vCPUs

 - Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
   runtime-patched constant, allowing the same data to be shared with
   pKVM prior to dropping host privileges

 - Considerable pile of LLM-assisted fixes around the shop but mostly in
   the VGIC, our in-kernel generator of bugs (and sometimes interrupts)
2026-08-24 12:42:07 -04:00
Linus Torvalds
ed3b875bea mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       501
 Reviews/patch:       1.66
 Reviewed rate:       70%
 
 Excluding DAMON:
 
 Total patches:       356
 Reviews/patch:       2.26
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       329
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Excluding DAMON, selftests and maple_tree:
 
 Total patches:       328
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Summary of patch series in this merge:
 
 - The 2 patch series "mm: drop "sub" prefix from various places" from
   Dev Jain implements some page->folio conversion and a naming cleanup.
 
 - The 2 patch series "mm/kasan: remove redundant initialization for
   kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
 
 - The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
   from Chi Zhiling provides a small speedup in the pagecaache read code.
 
 - The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
   recursion" from Kaitao Cheng improves a few things in the vmalloc code -
   mainly the avoidance of GFP_KERNEL allocations when the caller asked for
   GFP_NOFS or GFP_NOIO.
 
 - The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
   stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
   kmemleak scanning code in extreme situations.
 
 - The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
   collection of unrelated cleanups to the page_owner code.  For some
   reason lots of people have been working on the page_owner code this
   cycle.
 
 - The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
   find_vma()" from Kefeng Wang simplifies and accelerates the page walking
   library function.
 
 - The 3 patch series "mm/migrate: preparatory cleanups for batch copy
   and offload" from Shivank Garg implements cleanups in the migration
   code.
 
 - The 4 patch series "mm/page_owner: add per-fd filter infrastructure
   for print_mode and NUMA filtering" from Zhen Ni provides per-fd
   filtering to page_owner in order to reduce the sometimes vast amount of
   output it can produce.
 
 - The 19 patch series "mm: Refactor bootmem gigantic hugepage
   allocation" from Muchun Song is a "set of fixes and preparatory cleanups
   around bootmem HugeTLB handling, sparse initialization ordering, and
   related vmemmap setup".
 
 - The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
   from Wenchao Hao reduces lock contention in zs_free(), which dominates
   the unmap path under memory pressure on Android (LMK kills) and on x86
   servers running zswap-heavy workloads.  Up to 1.83x improvement in
   microbenchmarking.
 
 - The 2 patch series "move alloc_tag.c file under mm/" from Suren
   Baghdasaryan does that.
 
 - The 6 patch series "samples/damon: handle damon_{start,stop}()
   failures" from SJ Park fixes improper handling of damon_start(),
   damon_stop(), and damon_call() failures across DAMON sample modules to
   prevent potential memory leaks, operation disruptions and use-after-free
   bugs.
 
 - The 11 patch series "mm/damon/sysfs: kobject_del() directories that
   users can create/remove" from SJ Park resolves an issue where delayed
   sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
   creation failures due to duplicate directory names by adding missing
   kobject_del() calls before creating new directories.
 
 - The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
   David Hildenbrand cleans up the core pte handling code.
 
 - The 3 patch series "selftests/damon: misc fixes for test bugs" from
   Kunwu Chan fixes several bugs in the DAMON selftests.
 
 - The 2 patch series "selftests/damon: fix memcg_path staging handling"
   from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
   memcg_path setup, and adds a test case for it in sysfs.py.
 
 - The 2 patch series "selftests/damon: test kdamond refresh_ms" from
   Ruslan Valiyev introduces selftest coverage for DAMON's refresh_ms sysfs
   feature by updating the test control module and verifying that scheme
   stats update automatically without manual intervention.
 
 - The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
   contains miscellaneous DAMON fixups.
 
 - The 2 patch series "mm/damon/core: detect internal variation above
   max_nr_regions/2" from Jiayuan Chen fixes DAMON's region splitting
   behavior when region counts exceed half the maximum budget by
   dynamically scaling down the split fraction as the limit approaches,
   preventing large regions from staying un-split, and adds corresponding
   KUnit test coverage.
 
 - The 6 patch series "mm: preparatory patches for PMD level swap
   entries" from Usama Arif refactors and cleans up PMD softleaf helpers,
   call sites, and architecture flags to lay the groundwork for a follow-up
   series that introduces PMD page table swap entries.
 
 - The 11 patch series "mm/damon: update, optimize, and clean up doc,
   tests, and code" from SJ Park updates DAMON design and ABI
   documentation, expands unit and selftest coverage, optimizes
   damon_commit_target_regions(), and cleans up recently added sysfs
   interface code for better readability.
 
 - The 2 patch series "mm/vmpressure: reduce CPU, memory and code
   overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
   skipping unnecessary work on cgroup v2 for userspace event notifications
   and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
   memory overhead and code complexity.
 
 - The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
   error handling" from Hongfu Li refactors pkeys shared tracing and
   assertion helpers into a common file, unifies protection key selftests
   to use consistent diagnostic logging and assertions, and enforces
   standardized MAP_FAILED return checks for mmap() calls across the tests.
 
 - The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
   Park replaces the error-prone, continuously updated nr_accesses_bp field
   in damon_region with an on-demand moving sum function
   (damon_nr_accesses_mvsum()), reducing structure memory overhead and
   avoiding state corruption bugs.
 
 - The 6 patch series "Open HugeTLB allocation routine for more generic
   use" from Ackerley Tng decouples HugeTLB folio allocation from VMA
   dependencies by introducing hugetlb_alloc_folio(), enabling subsystems
   like guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs.
 
 - The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
   from SJ Park integrates DAMON's probe_hits attribute counter into the
   pseudo moving sum infrastructure, enabling real-time, online monitoring
   without waiting for full aggregation intervals.
 
 - The 18 patch series "mm: Some cleanups for page allocator APIs" from
   Brendan Jackman simplifies and refactors the page allocator entry points
   and flags by unifying allocation paths, adding internal alloc_flags
   arguments, and eliminating redundant __ prefixed alloc_pages variants.
 
 - The 5 patch series "Fix incorrect access of hugetlb pte entries" from
   Dev Jain enforces the consistent use of huge_ptep_get() instead of
   ptep_get() for HugeTLB entries and fixes an unaligned address issue in
   arm64's huge_ptep_get() implementation.
 
 - The 8 patch series "mm/damon: validate all parameters in the core"
   from SJ Park consolidates parameter validation into the DAMON core
   specifically within damon_start() and damon_commit_ctx() to centralize
   error checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency.
 
 - The 3 patch series "tools/mm/page_owner_sort: fix filtering and
   cleanup issues" from Yichong Chen renames is_need() to filter_record()
   for clearer return semantics, fixes per-record allocation memory leaks
   and bounds output copies in search_pattern() to address an existing
   buffer issue.
 
 - The 4 patch series "memcg: bail out reclaim when memcg is dying" from
   Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
   removed while one of its memory control files is doing synchronous
   reclaim.
 
 - The 5 patch series "mm/memory-failure: add panic option for
   unrecoverable pages" from Breno Leitao introduces an opt-in
   vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics
   the kernel on unrecoverable memory errors in kernel-owned pages to
   preserve error context and prevent delayed, silent data corruption.
 
 - The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
   for simple error handling" from SJ Park refactors the DAMON core API
   functions to guarantee that all contexts are fully stopped when
   damon_start(), damon_stop(), or damon_commit() fail, eliminating the
   need for complex and error-prone caller-side cleanup code.
 
 - The 5 patch series "Keep tail page private zero at free and folio
   split" from Zi Yan adds checks to ensure tail_page->private is zero when
   freeing compound or high-order pages and when promoting tail pages
   during large folio splits.  By validating these fields at free and split
   time, it allows the removal of redundant private field clearing inside
   prep_compound_tail().
 
 - The 4 patch series "mm: drop redundant lru_add_drain in anon folio
   reuse paths" from Barry Song eliminates redundant lru_add_drain() calls
   in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead.
 
   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads.
 
 - The 3 patch series "mm: clean up folio LRU and swap declarations" from
   Jianyue Wu reorganizes folio LRU and swap code by relocating
   page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c,
   and moving MM-internal reclaim declarations into mm/internal.h.
 
 - The 15 patch series "userfaultfd: working set tracking for VM guest
   memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
   working set of VM guest memory, so a VMM can identify hot pages and
   reclaim cold ones to tiered or remote storage.
 
 - The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
   2)" from David Hildenbrand removes the remaining pieces of
   CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
   freeing of reserved vmemmap pages on the way.
 
 - The 7 patch series "mm/damon: update probe hits for runtime parameter
   commits" from SJ Park ensures that DAMON's probe_hits attribute counter
   is properly updated when monitoring intervals are changed at runtime,
   matching the behavior of nr_accesses.  To achieve this, it refactors and
   renames existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.
 
 - The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
   from xu xin resolves a severe KSM reverse-mapping performance bottleneck
   where thousands of split VMAs sharing a single anon_vma cause extended
   lock contention.  By adding an interval-filtering check during the rmap
   walk, it reduces worst-case anon_vma lock hold times from over 500ms
   down to under 2ms, preventing application freezes and latency spikes
   under memory pressure.
 
 - The 3 patch series "mm: split a couple of headers from internal.h"
   from Mike Rapoport splits declarations related to mm_init, memblock,
   vmalloc and sparse into new headers.
 
 - The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
   from xu xin applies the interval tree optimization from rmap_walk_ksm()
   to collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.  It hoists loop-invariant address
   initialization and restricts the anon_vma_interval_tree_foreach walk to
   a targeted page offset range, reducing redundant checks and improving
   lookup efficiency.
 
 - The 3 patch series "selftests/mm: avoid false failures in hugetlb and
   KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
   selftest categories that can report failures when the prerequisites for
   the tests are not satisfied.
 
 - The 19 patch series "mm/damon: introduce data attributes only
   monitoring" from SJ Park introduces attribute-weighted region management
   in DAMON, allowing users to prioritize specific data attributes (such as
   page sizes or cgroups) over or instead of access monitoring.
 
   By assigning weights to attribute probes, DAMON can completely disable
   access tracking and adjust monitoring regions based on weighted
   probe-hit counters to optimize monitoring quality for attribute-focused
   workloads.
 
 - The 8 patch series "mm/hmm: Add mmap lock-drop support for
   userfaultfd-backed mappings" from Stanislav Kinsburskii extends
   hmm_range_fault() to support userfaultfd-backed regions by allowing the
   mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.
 
   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd regions
   while preserving backward compatibility for existing callers.
 
 - The 33 patch series "mm: make VMA page offset handling more
   consistent" from Lorenzo Stoakes cleans up and standardizes how
   vma->vm_pgoff is accessed and manipulated across file-backed and
   anonymous mappings in the kernel.
 
   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming
   rmap interval tree helpers to better reflect their functionality.
 
   These changes establish a cleaner foundation for future work that will
   unify virtual page offset indexing for all anonymous and CoW'd folios.
 
 - The 3 patch series "mm: handle device-private PMDs in walk callbacks"
   from Usama Arif addresses kernel panics and state corruption caused by
   MM walk callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations.
 
   It ensures that functions which acquire pmd_trans_huge_lock() properly
   recognize device-private PMDs instead of assuming a present THP or a
   standard migration entry.
 
 - The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
   refactors try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree,
   and anonymous-swapbacked logic into dedicated functions, laying the
   structural groundwork for batched anonymous large folio unmapping.
 
 - The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
   additions" from Song Hu fixes typos and fills in missing entries in the
   DAMON sysfs ABI document.
 
 - The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
   from Gregory Price introduces an atomic sysfs state attribute and
   supporting DAX/MM infrastructure to prevent userland races when
   offlining and removing entire memory regions.
 
   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.
 
 - The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
   from Lorenzo Stoakes continues transitioning the kernel from the
   deprecated vm_flags_t type to vma_flags_t across core memory management
   infrastructure.
 
   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.
 
 - The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
   xu xin refactors mm_slot.h by introducing mm_slot_remove() to unify
   duplicate slot deletion sequences in khugepaged and KSM.  It also adds
   code documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.
 
 - The 10 patch series "mm/damon/core: hide core-private struct fields"
   from SJ Park cleans up DAMON core structures by consistently marking
   internal-only fields with private: comment tags to prevent improper
   direct access from outer layers.
 
   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.
 
 - The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
   de-ref and races" from SJ Park addresses potential infinite loops, NULL
   dereferences, and race conditions identified in DAMON.
 
   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.
 
 - The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
   RT/UP" from Brendan Jackman fixes an NMI safety flaw in
   __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT
   kernels can bypass can_spin_trylock() checks via non-PCP or isolated
   migration paths.
 
   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.
 
 - The 4 patch series "mm/page_alloc: couple of followups for recent
   cleanups" from Brendan Jackman cleans up and updates page allocator
   nomenclature, documentation, and debug assertions.
 
   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete VM_BUG_ON()
   assertions in allocation paths.
 
 - The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
   refactors and simplifies the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.
 
   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates
   mm_struct parameters to enforce that sealing applies only to
   current->mm, and streamlines overall logic and comments with no
   functional changes intended.
 
 - The 4 patch series "mm/vmscan: fix swappiness=max and clean up
   per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
   bugs and cleans up function parameters across memory reclaim paths.
 
   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead of
   collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask
   parameter from __node_reclaim().
 
 - The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
   cleans up and simplifies the mincore code.  Most importantly, it removes
   the historical special behavior that always reports VM_PFNMAP pages as
   non-resident.
 
 - The 2 patch series "mm/huge_memory: drop dead split helper variants"
   from Kiryl Shutsemau implements two trivial cleanups in the folio split
   API.
 
 - The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
   exec expectation bugs" from SJ Park resolves minor operational and
   testing bugs in DAMON identified by Sashiko.  It initializes the
   damos->last_applied field to prevent occasional efficiency degradation
   and fixes invalid memory accesses in DAMON KUnit tests during test
   failure handling.
 
 - The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
   cleans up and refactors stable_page_flags() used by /proc/kpageflags
   without altering functionality.
 
   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
 
 - The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
   extends batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities
   to pte_install_uffd_wp_if_needed().
 
   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.
 
 - The 3 patch series "mm/early_ioremap: clarify and clean up
   early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans up the
   architecture-specific usage of __late_set_fixmap() and
   __late_clear_fixmap() after early_ioremap_reset().
 
   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset calls
   in the RISC-V and ARM64 architectures.
 
 - The 4 patch series "mm: fix reclaim storms in defrag_mode" from
   Johannes Weiner addresses severe performance regressions, swap storms,
   and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure
   in Meta production.
 
   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.
 
 - The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
   optimizes and fixes lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolating lock classes across multiple instances.
 
   It reduces memory overhead by replacing per-entry lockdep_map instances
   with a single map per struct zram, and assigns a dynamic lock_class_key
   to each instance to prevent false deadlock reports when different zram
   devices are backed by distinct filesystems.
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Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm: drop "sub" prefix from various places" (Dev Jain)

   page->folio conversion and a naming cleanup

 - "mm/kasan: remove redundant initialization for kasan_flag_write_only"
   (Igor Putko)

   KASAN cleanup work

 - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)

   Small speedup in the pagecaache read code

 - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)

   Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
   allocations when the caller asked for GFP_NOFS or GFP_NOIO

 - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
   Leitao)

   Avoid a soft lockup watchdog trigger from the kmemleak scanning code
   in extreme situations

 - "mm/page_owner: misc cleanups" (Ye Liu)

   Cleanups to the page_owner code. For some reason lots of people have
   been working on the page_owner code this cycle.

 - "mm: convert to walk_page_range_vma() to eliminate find_vma()"
   (Kefeng Wang)

   Simplify and accelerate the page walking library function

 - "mm/migrate: preparatory cleanups for batch copy and offload"
   (Shivank Garg)

   Cleanups in the migration code

 - "mm/page_owner: add per-fd filter infrastructure for print_mode and
   NUMA filtering" (Zhen Ni)

   Per-fd filtering to page_owner in order to reduce the sometimes vast
   amount of output it can produce

 - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)

   Fixes and preparatory cleanups around bootmem HugeTLB handling,
   sparse initialization ordering, and related vmemmap setup

 - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)

   Reduce lock contention in zs_free(), which dominates the unmap path
   under memory pressure on Android (LMK kills) and on x86 servers
   running zswap-heavy workloads.

   Up to 1.83x improvement in microbenchmarking.

 - "move alloc_tag.c file under mm/" (Suren Baghdasaryan)

 - "samples/damon: handle damon_{start,stop}() failures" (SJ Park)

   Fix improper handling of damon_start(), damon_stop(), and
   damon_call() failures across DAMON sample modules to prevent
   potential memory leaks, operation disruptions and use-after-free
   bugs

 - "mm/damon/sysfs: kobject_del() directories that users can
   create/remove" (SJ Park)

   Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
   causeing creation failures due to duplicate directory names by adding
   missing kobject_del() calls before creating new directories

 - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)

   Clean up the core pte handling code

 - "selftests/damon: misc fixes for test bugs" (Kunwu Chan)

   Fix several bugs in the DAMON selftests

 - "selftests/damon: fix memcg_path staging handling" (Cheng Nie)

   Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
   add a test case for it in sysfs.py.

 - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)

   Selftest coverage for DAMON's refresh_ms sysfs feature by updating
   the test control module and verifying that scheme stats update
   automatically without manual intervention

 - "mm/damon: five misc fixups" (Akinobu Mita)

   Miscellaneous DAMON fixups.

 - "mm/damon/core: detect internal variation above max_nr_regions/2"
   (Jiayuan Chen)

   Fix DAMON's region splitting behavior when region counts exceed half
   the maximum budget by dynamically scaling down the split fraction as
   the limit approaches, preventing large regions from staying un-split,
   and add corresponding KUnit test coverage

 - "mm: preparatory patches for PMD level swap entries" (Usama Arif)

   Refactor and clean up PMD softleaf helpers, call sites, and
   architecture flags to lay the groundwork for a follow-up series that
   introduces PMD page table swap entries

 - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
   Park)

   Update DAMON design and ABI documentation, expands unit and selftest
   coverage, optimize damon_commit_target_regions(), and clean up
   recently added sysfs interface code for better readability

 - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
   (Usama Arif)

   Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
   userspace event notifications and refactor v1-only eventfd handling
   into mm/memcontrol-v1.c to reduce memory overhead and code complexity

 - "selftests/mm: refactor pkey helpers and fix mmap error handling"
   (Hongfu Li)

   Refactor pkeys shared tracing and assertion helpers into a common
   file, unify protection key selftests to use consistent diagnostic
   logging and assertions, and enforce standardized MAP_FAILED return
   checks for mmap() calls across the tests

 - "mm/damon: optimize out nr_accesses_bp" (SJ Park)

   Replace the error-prone, continuously updated nr_accesses_bp field in
   damon_region with an on-demand moving sum function, reducing
   structure memory overhead and avoiding state corruption bugs

 - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)

   Decouple HugeTLB folio allocation from VMA dependencies by
   introducing hugetlb_alloc_folio(), enabling subsystems like
   guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs

 - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)

   Integrate DAMON's probe_hits attribute counter into the pseudo moving
   sum infrastructure, enabling real-time, online monitoring without
   waiting for full aggregation intervals

 - "mm: Some cleanups for page allocator APIs" (Brendan Jackman)

   Simplify and refactor the page allocator entry points and flags by
   unifying allocation paths, adding internal alloc_flags arguments, and
   eliminating redundant __ prefixed alloc_pages variants.

 - "Fix incorrect access of hugetlb pte entries" (Dev Jain)

   Enforce the consistent use of huge_ptep_get() instead of ptep_get()
   for HugeTLB entries and fixes an unaligned address issue in arm64's
   huge_ptep_get() implementation

 - "mm/damon: validate all parameters in the core" (SJ Park)

   Consolidate parameter validation into the DAMON core specifically
   within damon_start() and damon_commit_ctx() to centralize error
   checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency

 - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
   Chen)

   Rename is_need() to filter_record() for clearer return semantics, fix
   per-record allocation memory leaks and bound output copies in
   search_pattern() to address an existing buffer issue

 - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)

   Mitigate a system-wide stall which occurs when a cgroup is removed
   while one of its memory control files is doing synchronous reclaim

 - "mm/memory-failure: add panic option for unrecoverable pages" (Breno
   Leitao)

   Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
   that immediately panics the kernel on unrecoverable memory errors in
   kernel-owned pages to preserve error context and prevent delayed,
   silent data corruption

 - "mm/damon: refactor damon_{start,stop,commit}() for simple error
   handling" (SJ Park)

   Refactor the DAMON core API functions to guarantee that all contexts
   are fully stopped when damon_start(), damon_stop(), or damon_commit()
   fail, eliminating the need for complex and error-prone caller-side
   cleanup code

 - "Keep tail page private zero at free and folio split" (Zi Yan)

   Add checks to ensure tail_page->private is zero when freeing compound
   or high-order pages and when promoting tail pages during large folio
   splits. By validating these fields at free and split time, it allows
   the removal of redundant private field clearing inside
   prep_compound_tail()

 - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
   Song)

   Eliminate redundant lru_add_drain() calls in
   wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead

   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads

 - "mm: clean up folio LRU and swap declarations" (Jianyue Wu)

   Reorganize folio LRU and swap code by relocating page-cluster state
   to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
   MM-internal reclaim declarations into mm/internal.h.

 - "userfaultfd: working set tracking for VM guest memory" (Kiryl
   Shutsemau)

   Add userfaultfd support for tracking the working set of VM guest
   memory, so a VMM can identify hot pages and reclaim cold ones to
   tiered or remote storage

 - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
   Hildenbrand)

   Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
   performing some smaller cleanups around freeing of reserved vmemmap
   pages on the way.

 - "mm/damon: update probe hits for runtime parameter commits" (SJ Park)

   Ensure that DAMON's probe_hits attribute counter is properly updated
   when monitoring intervals are changed at runtime, matching the
   behavior of nr_accesses. To achieve this, it refactors and renames
   existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.

 - "KSM: performance optimizations for rmap_walk_ksm" (xu xin)

   Resolve a severe KSM reverse-mapping performance bottleneck where
   thousands of split VMAs sharing a single anon_vma cause extended lock
   contention.

   By adding an interval-filtering check during the rmap walk, it
   reduces worst-case anon_vma lock hold times from over 500ms down to
   under 2ms, preventing application freezes and latency spikes under
   memory pressure.

 - "mm: split a couple of headers from internal.h" (Mike Rapoport)

   Split declarations related to mm_init, memblock, vmalloc and sparse
   into new headers

 - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)

   Apply the interval tree optimization from rmap_walk_ksm() to
   collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.

   It hoists loop-invariant address initialization and restricts the
   anon_vma_interval_tree_foreach walk to a targeted page offset range,
   reducing redundant checks and improving lookup efficiency.

 - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
   Patil)

   Fix issues in the hugetlb and KSM MM selftest categories that can
   report failures when the prerequisites for the tests are not
   satisfied

 - "mm/damon: introduce data attributes only monitoring" (SJ Park)

   Introduce attribute-weighted region management in DAMON, allowing
   users to prioritize specific data attributes (such as page sizes or
   cgroups) over or instead of access monitoring.

   By assigning weights to attribute probes, DAMON can completely
   disable access tracking and adjust monitoring regions based on
   weighted probe-hit counters to optimize monitoring quality for
   attribute-focused workloads.

 - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
   (Stanislav Kinsburskii)

   Extend hmm_range_fault() to support userfaultfd-backed regions by
   allowing the mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.

   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd
   regions while preserving backward compatibility for existing callers.

 - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)

   Clean up and standardize how vma->vm_pgoff is accessed and
   manipulated across file-backed and anonymous mappings in the kernel

   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
   renaming rmap interval tree helpers to better reflect their
   functionality.

   These changes establish a cleaner foundation for future work that
   will unify virtual page offset indexing for all anonymous and CoW'd
   folios.

 - "mm: handle device-private PMDs in walk callbacks" (Usama Arif)

   Address kernel panics and state corruption caused by MM walk
   callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations

   It ensures that functions which acquire pmd_trans_huge_lock()
   properly recognize device-private PMDs instead of assuming a present
   THP or a standard migration entry.

 - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)

   Refactor try_to_unmap_one by modularizing Hugetlb,
   anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
   functions, laying the structural groundwork for batched anonymous
   large folio unmapping.

 - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)

   Fix typos and fills in missing entries in the DAMON sysfs ABI
   document

 - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)

   Introduce an atomic sysfs state attribute and supporting DAX/MM
   infrastructure to prevent userland races when offlining and removing
   entire memory regions

   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.

 - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)

   Continue transitioning the kernel from the deprecated vm_flags_t type
   to vma_flags_t across core memory management infrastructure.

   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.

 - "Two small patches to clean up mm/mm_slot.h" (xu xin)

   Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
   slot deletion sequences in khugepaged and KSM. It also adds code
   documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.

 - "mm/damon/core: hide core-private struct fields" (SJ Park)

   Clean up DAMON core structures by consistently marking internal-only
   fields with private: comment tags to prevent improper direct access
   from outer layers.

   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.

 - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
   (SJ Park)

   Address potential infinite loops, NULL dereferences, and race
   conditions identified in DAMON

   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.

 - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
   Jackman)

   Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
   on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
   via non-PCP or isolated migration paths.

   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.

 - "mm/page_alloc: couple of followups for recent cleanups" (Brendan
   Jackman)

   Clean up and update page allocator nomenclature, documentation, and
   debug assertions.

   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete
   VM_BUG_ON() assertions in allocation paths.

 - "mm/mseal: further cleanups" (Lorenzo Stoakes)

   Refactor and simplify the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.

   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
   eliminates mm_struct parameters to enforce that sealing applies only
   to current->mm, and streamlines overall logic and comments with no
   functional changes intended.

 - "mm/vmscan: fix swappiness=max and clean up per-node proactive
   reclaim" (Ridong Chen)

   Resolve reclaim behavior bugs and clean up function parameters across
   memory reclaim paths

   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead
   of collapsing all failures into -EAGAIN, and removes the obsolete
   gfp_mask parameter from __node_reclaim().

 - "mm: mincore: misc cleanups" (Kefeng Wang)

   Clean up and simplifies the mincore code. Most importantly, it
   removes the historical special behavior that always reports VM_PFNMAP
   pages as non-resident.

 - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)

   Two trivial cleanups in the folio split API

 - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
   bugs" (SJ Park)

   Resolve minor operational and testing bugs in DAMON identified by
   Sashiko. It initializes the damos->last_applied field to prevent
   occasional efficiency degradation and fixes invalid memory accesses
   in DAMON KUnit tests during test failure handling.

 - "cleanup for stable_page_flags()" (Jinjiang Tu)

   Clean up and refactor stable_page_flags() used by /proc/kpageflags
   without altering functionality.

   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.

 - "Batch unmap of uffd-wp file folios" (Dev Jain)

   Extend batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching
   capabilities to pte_install_uffd_wp_if_needed().

   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.

 - "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
   (Sang-Heon Jeon)

   Clarify and clean up the architecture-specific usage of
   __late_set_fixmap() and __late_clear_fixmap() after
   early_ioremap_reset()

   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset
   calls in the RISC-V and ARM64 architectures.

 - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)

   Address severe performance regressions, swap storms, and spurious
   OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
   production

   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.

 - "zram: lockmap tweaks" (Sebastian Siewior)

   Optimize and fix lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolate lock classes across multiple instances

   This reduces memory overhead by replacing per-entry lockdep_map
   instances with a single map per struct zram, and assigns a dynamic
   lock_class_key to each instance to prevent false deadlock reports
   when different zram devices are backed by distinct filesystems.

* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
  selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
  selftests/mm: unpoison pages in memory-failure teardown
  mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
  mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
  mm/zsmalloc: fix release order of locks in zs_page_migrate()
  Documentation: zram: remove sections numbering
  ksm: stop iterating VMAs when ksm_test_exit returns true
  mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
  mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
  zram: use a custom key for each zram object
  zram: move lockmap to be per-zram instead per table
  selftests/mm: fix gup_longterm EINVAL error message
  mm: page_alloc: fix non-movable reclaim storm in defrag_mode
  mm: page_alloc: move capture_control to the page allocator
  mm: compaction: support non-movable compaction for pageblock requests
  mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
  hugetlb: evaluate subpool free state while locked
  mm/damon: remove trailing semicolons after function definitions
  mm/damon/ops-common: prevent migration fallback to non-target nodes
  mm/damon: update outdated comment about DAMOS filter handling
  ...
2026-08-20 18:17:08 -07:00
Oliver Upton
aa8e5dc6a7 Merge branch 'kvm-arm64/misc-7.3' into next
* kvm-arm64/misc-7.3:
  : Miscellaneous fixes for KVM/arm64, 7.3
  :
  :  - Fixes for saving invalid table entries as part of saving the ITS
  :    tables (Fuad Tabba)
  :
  :  - Don't reallocate the SPI array for re-attempted vgic_init(), avoiding
  :    a memory leak (Fuad Tabba)
  :
  :  - Hold a reference on an LPI when saving the pending state (Qihang)
  :
  :  - Don't WARN for out-of-range, guest-supplied INTID (Karl)
  :
  :  - Avoid corrupting GPRs for 32-bit CP64 reads (Karl)
  :
  :  - Reset 'in kernel' VGIC state when private IRQ allocation fails (Fuad)
  :
  :  - Avoid kallsyms lookup in nVHE panic unless the host stage-2 is also
  :    disabled (Vincent)
  :
  :  - Disregard Pending+Active state when computing maintenance IRQ for
  :    ICH_MISR_EL2.NP (Kajetan)
  :
  :  - Various Sashiko-identified issues dealing with GICv5 (Sascha)
  :
  :  - Fix CPU onlining in pKVM due to mismatched accesses when the MMU is
  :    disabled (Will)
  KVM: arm64: Validate GICv5 timer PPIs before claiming ownership
  KVM: arm64: vgic: Reject out-of-range GICv5 PPI IDs
  KVM: arm64: vgic: Prevent speculative SPI array underflow
  KVM: arm64: vgic: Free gic_kvm_info on initialization failure
  KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params'
  KVM: arm64: vgic: Fix detection of MI on no pending LR
  KVM: arm64: Drop %pB on nVHE panic when stage-2 is active
  KVM: arm64: vgic: Reset in_kernel on private IRQ allocation failure
  KVM: arm64: GICv2: Don't WARN on out-of-range GICV_DIR INTID
  KVM: arm64: Preserve GPRs for AArch32 CP64 reads generating an UNDEF
  KVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables
  KVM: arm64: vgic-its: Point saved ITEs at the next valid entry
  KVM: arm64: vgic-its: Don't save collections the table cannot hold
  KVM: arm64: vgic: Don't leak the SPI array when init is retried
  KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save

Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 14:08:24 -07:00
Oliver Upton
2791de5354 Merge branch 'kvm-arm64/vtr-patch' into next
* kvm-arm64/vtr-patch:
  : Inline patching of ICH_VTR_EL2 constant, courtesy of Marc Zyngier
  :
  : Unify readers of ICH_VTR_EL2 on an instruction-patched constant value,
  : avoiding system register accesses known to trap under nested
  : virtualization and sharing the implementation between pKVM and 'regular'
  : KVM.
  KVM: arm64: vgic-v3: Kill kvm_vgic_global_state.ich_vtr_el2
  KVM: arm64: vgic-v3: Simplify initial GICv3 configuration sampling
  KVM: arm64: Convert most ICH_VTR_EL2 accesses to inlined literal value
  KVM: arm64: Add a helper providing an inlined literal value for ICH_VTR_EL2
  KVM: arm64: Move GICv3 broken SEIS implementation detection to a CPU errrata
  KVM: arm64: vgic-v3: Make vtr_to_* helpers use architectural field symbols

Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 14:05:49 -07:00
Linus Torvalds
4994ef0fe0 IOMMU updates for Linux v7.3:
- ARM SMMUv2:
   - Device-tree binding updates for Qualcomm Eliza, Maili, Shikra and
     IPQ9650 SoCs.
   - Add support for Qualcomm SM8450.
   - Numerous fixes for lifetime and ordering issues found by Sashiko in
     the Qualcomm driver.
 
 - ARM SMMUv3:
   - Fix interrupt type in device-tree binding example for NVIDIA CMDQV.
   - Numerous fixes for issues identified by Sashiko in the NVIDIA CMDQV
     driver.
   - Work around TLB erratum T264-SMMU-3 on Tegra264 by repeating the
     invalidation sequence.
   - Add support for HAFT (hardware access flag in table entries) when
     using SVA.
   - Probe for 52-bit addressing with a page size smaller than 64k ('DS')
     but don't do anything with it for now.
   - Minor driver improvements (remove sort_nonatomic(), use
     readl_relaxed_poll_timeout_atomic(), fix IOPF teardown ordering).
 
 - Intel VT-d:
   - Consolidation of complex enablement logic into a clean, priority-based
     state machine.
   - Support for the DMA_REMAP_OPT_OUT flag from the VT-d v5.2
     specification.
   - An update to cache_tag_flush_devtlb_psi() to use full-range constants
     instead of modifying shared variables for CACHE_TAG_NESTING_DEVTLB.
   - A fix for the UCTP context-table slot when copying root entries.
   - Fixes for several pre-existing issues reported by Sashiko.
   - General code cleanup and refinement.
 
 - AMD IOMMU:
   - Add SNP page-mode-0 support, enabling passthrough, v2 DMA page
     tables and host SVA on supporting systems.
   - Fix invalid PPR handling, COMPLETE_PPR responses and guest-mode
     reporting.
   - Improve Southbridge IOAPIC validation and remove the dependency on
     hard-coded device IDs.
   - Fix PCI-device lifetime, debugfs and diagnostic issues.
 
 - IOMMU core and IOMMUFD:
   - Restore serialization of the shared MSI-page list.
   - Fix SVA-handle publication and several IOMMUFD reference and error
     path leaks.
   - Return the expected zero result for invalid generic page-table
     translations.
   - Allocate per-CPU IOVA magazines lazily to reduce memory use on
     large systems.
 
 - PCI ATS:
   - Make VF support checks account for the associated PF and validate
     that VF and PF Smallest Translation Unit settings agree.
 
 - Platform drivers:
   - Fix Qualcomm runtime-PM, probe unwind, fault reporting and page
     table initialization races.
   - Rework Rockchip state handling and fix clock, probe and stale-fault
     handling.
   - Fix smaller issues in the MSM and MediaTek drivers.
 
 - Device-tree bindings:
   - Add new Qualcomm SMMU compatibles, convert the OMAP IOMMU binding
     to YAML, and fix the Tegra264 CMDQV interrupt example.
 
 - Various smaller cleanups, documentation fixes and a Rust IOMMU
   safety/readability improvement.
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Merge tag 'iommu-updates-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux

Pull iommu updates from Joerg Roedel:
 "ARM SMMUv2:
   - Device-tree binding updates for Qualcomm Eliza, Maili, Shikra and
     IPQ9650 SoCs
   - Add support for Qualcomm SM8450
   - Numerous fixes for lifetime and ordering issues found by Sashiko in
     the Qualcomm driver

  ARM SMMUv3:
   - Fix interrupt type in device-tree binding example for NVIDIA CMDQV
   - Numerous fixes for issues identified by Sashiko in the NVIDIA CMDQV
     driver
   - Work around TLB erratum T264-SMMU-3 on Tegra264 by repeating the
     invalidation sequence
   - Add support for HAFT (hardware access flag in table entries) when
     using SVA
   - Probe for 52-bit addressing with a page size smaller than 64k
     ('DS') but don't do anything with it for now
   - Minor driver improvements (remove sort_nonatomic(), use
     readl_relaxed_poll_timeout_atomic(), fix IOPF teardown ordering)

  Intel VT-d:
   - Consolidation of complex enablement logic into a clean,
     priority-based state machine
   - Support for the DMA_REMAP_OPT_OUT flag from the VT-d v5.2
     specification
   - An update to cache_tag_flush_devtlb_psi() to use full-range
     constants instead of modifying shared variables for
     CACHE_TAG_NESTING_DEVTLB
   - A fix for the UCTP context-table slot when copying root entries
   - Fixes for several pre-existing issues reported by Sashiko
   - General code cleanup and refinement

  AMD IOMMU:
   - Add SNP page-mode-0 support, enabling passthrough, v2 DMA page
     tables and host SVA on supporting systems
   - Fix invalid PPR handling, COMPLETE_PPR responses and guest-mode
     reporting
   - Improve Southbridge IOAPIC validation and remove the dependency on
     hard-coded device IDs
   - Fix PCI-device lifetime, debugfs and diagnostic issues

  IOMMU core and IOMMUFD:
   - Restore serialization of the shared MSI-page list
   - Fix SVA-handle publication and several IOMMUFD reference and error
     path leaks
   - Return the expected zero result for invalid generic page-table
     translations
   - Allocate per-CPU IOVA magazines lazily to reduce memory use on
     large systems

  PCI ATS:
   - Make VF support checks account for the associated PF and validate
     that VF and PF Smallest Translation Unit settings agree

  Platform drivers:
   - Fix Qualcomm runtime-PM, probe unwind, fault reporting and page
     table initialization races
   - Rework Rockchip state handling and fix clock, probe and stale-fault
     handling
   - Fix smaller issues in the MSM and MediaTek drivers

  Device-tree bindings:
   - Add new Qualcomm SMMU compatibles, convert the OMAP IOMMU binding
     to YAML, and fix the Tegra264 CMDQV interrupt example

  Various smaller cleanups, documentation fixes and a Rust IOMMU
  safety/readability improvement"

* tag 'iommu-updates-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (93 commits)
  iommu/amd: Add SNP page mode 0 support
  iommu/amd: Fix GN bit setting in COMPLETE_PPR_REQUEST command
  iommu/amd: Rate limit INVALID_PPR_REQUEST error logging
  iommu/amd: Fix missing CMD_COMPLETE_PPR response for invalid PPR requests
  iommu/amd: Introduce PPR_TAG_LAST_PAGE() macro
  iommu/amd: Fix incorrect device ID in invalid PASID error message
  iommu/vt-d: Flush context cache with correct SID when tearing down aliases
  iommu/vt-d: Tear down scalable-mode context on probe failure
  iommu/vt-d: Fix iopf_refcount leak on RID domain replacement
  iommu/vt-d: Clear Present bit before tearing down copied context entry
  iommu/vt-d: Fix copied_tables bitmap leak on error in copy_translation_tables
  iommu/vt-d: Cache max domain ID to avoid redundant calculation
  iommu/vt-d: Support the new DMA_REMAP_OPT_OUT flag bit
  iommu/vt-d: Remove dmar_disabled
  iommu/vt-d: Remove the 'force_on' variable
  iommu/vt-d: Call dmar_can_force_on() for tboot opt-in
  iommu/vt-d: Use dmar_can_force_on() for platform opt-in
  iommu/vt-d: Consolidate dmar policy management and force_on logic
  iommu/vt-d: Remove dead code when CONFIG_INTEL_IOMMU is not set
  iommu/vt-d: Force requesting ACS when tboot is enabled
  ...
2026-08-19 12:38:26 -07:00
Oliver Upton
5f44f603b0 Merge branch 'kvm-arm64/feat-nv3' into next
* kvm-arm64/feat-nv3: (29 commits)
  : Support for FEAT_NV2p1 and FEAT_NV3, courtesy of Marc Zyngier
  :
  : Couple of accelerations for nested virtualization:
  :
  :  - Elide traps for EL1 alias registers when hardware guarantees that
  :    EL2-only bits are stateful (NV2p1)
  :
  :  - Use TGE-aware hardware to avoid unnecesary ERET/TLBI traps that
  :    remain 'in-context' (i.e. L1 kernel/userspace)
  arm64: Add override for ID_AA64MMFR4_EL1.NV_frac
  KVM: arm64: selftest: Add NVHCR_EL2 to get-reg-list
  KVM: arm64: Expose FEAT_NV3 to guests
  KVM: arm64: Add FEAT_NV3 detection
  KVM: arm64: Engage NV3 TLBI trap elision
  KVM: arm64: Engage NV3 ERET trap elision
  KVM: arm64: Add NVHCR_EL2 context switching
  KVM: arm64: Add routing for NVHCR_EL2 trap
  KVM: arm64: Add NVHCR_EL2 handling to the sysreg array
  KVM: arm64: Add sanitisation for NVHCR_EL2
  KVM: arm64: Make HCR_EL2 a non-VNCR register
  KVM: arm64: Add kvm_has_nv{2,3}() predicates
  KVM: arm64: Add NV3 control bits to HCRX_EL2 sanitisation
  KVM: arm64: Split NV-specific exit fixups from the non-NV handling
  arm64: Add ARM64_HAS_NV3 capability
  arm64: sysreg: Add HCRX_EL2 bits related to FEAT_NV3
  arm64: sysreg: Add NVHCR_EL2 description as a mirror of HCR_EL2
  arm64: Add FEAT_NV2p1 detection
  KVM: arm64: Expose FEAT_NV2p1 to NV guests
  KVM: arm64: Relax CNTHCTL_EL2 handling when FEAT_NV2p1 is present
  ...

Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 12:27:53 -07:00
Will Deacon
028d8df0a1 KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params'
When running with hVHE enabled, ___kvm_hyp_init() calls
__kvm_init_el2_state() on the CPU initialisation path during onlining
and resume from suspend.

In order to avoid clobbering the link register across this call, it is
stashed away in the 'tmp' member of 'struct kvm_nvhe_init_params',
however this save/restore operation is performed with the stage-1 MMU
disabled at EL2 and therefore gives rise to coherency problems because
the field is not aligned or padded to the CWG. For example, a cacheable
write to a physically-adjacent structure sharing the same cacheline
could lead to an eviction and subsequent write-back, overwriting the
saved LR while the incoming CPU is executing __kvm_init_el2_state().

Save the lr in far_el2 and remove the 'tmp' member from
'struct kvm_nvhe_init_params' altogether.

Cc: Oliver Upton <oupton@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Fixes: afa9b48f32 ("KVM: arm64: Shave a few bytes from the EL2 idmap code")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260813131717.5885-1-will@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-08-19 12:22:24 -07:00
Linus Torvalds
104a813376 VDSO updates:
- Consolidate the VDSO datastore further and provide support for
    mlock_all() and prefaulting.
 
  - Provide 32-bit legacy time related functionality only if
    CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists, but
    architecture code still exposes the legacy functionality even disabled.
 
    Clean this up by adding the missing guards and validating at build time
    that the VDSO is legacy free if disabled.
 
  - Consolidate the VDSO related config options in core and drivers, which
    removes some non-sensical dependencies and quite an amount of #ifdeffery.
 
  - Clean up the PAGE_SIZE definition maze
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Merge tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO updates from Thomas Gleixner:

 - Consolidate the VDSO datastore further and provide support for
   mlock_all() and prefaulting.

 - Provide 32-bit legacy time related functionality only if
   CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists,
   but architecture code still exposes the legacy functionality even
   disabled.

   Clean this up by adding the missing guards and validating at build
   time that the VDSO is legacy free if disabled.

 - Consolidate the VDSO related config options in core and drivers,
   which removes some non-sensical dependencies and quite an amount of
   #ifdeffery.

 - Clean up the PAGE_SIZE definition maze

* tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  random: vDSO: Drop custom PAGE_SIZE definitions
  LoongArch: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/timer-riscv: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/arm_arch_timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/mips-gic-timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  MIPS: csrc-r4k: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY
  kbuild: Support generated asm-headers in subdirectories
  vdso: Rename HAVE_GENERIC_VDSO to VDSO_DATASTORE
  vdso: Drop HAVE_GENERIC_VDSO from architecture kconfig files
  vdso: Automatically select HAVE_GENERIC_VDSO if necessary
  MIPS: vdso: Stop using CONFIG_HAVE_GENERIC_VDSO
  vdso: Remove the dependency on HAVE_GENERIC_VDSO from ARCH_HAS_VDSO_ARCH_DATA
  futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK
  vdso/gettimeofday: Verify COMPAT_32BIT_TIME interactions
  sparc: vdso: Respect COMPAT_32BIT_TIME
  MIPS: VDSO: Respect COMPAT_32BIT_TIME
  powerpc/vdso: Respect COMPAT_32BIT_TIME
  ARM: VDSO: Respect COMPAT_32BIT_TIME
  arm64: vdso32: Respect COMPAT_32BIT_TIME
  ...
2026-08-18 16:56:25 -07:00
Linus Torvalds
3424d8c18a Generic entry code updates:
- Make syscall user dispatching configurable
 
     Not all architectures can makes use of syscall user dispatching. Allow
     them to disable the feature completely.
 
   - Consolidate stack randomization for the generic entry code and the
     architectures using it.
 
     Stack randomization on syscall entry was sprinkled throughout the
     architecture specific low level entry code and in some cases at the
     wrong points, e.g. before establishing state, which violates the
     non-instrumentable constraints of that code.
 
     Clean this up by integrating stack randomization into the generic entry
     code helpers so that it is invoked at the earliest possible point right
     after establishing state and converting all generic entry code using
     architecture over.
 
   - Clean up the syscall number handling in the generic entry code. It
     works correctly for architectures which have a separate return value
     storage in pt_regs, but fails to distinguish the case where user space
     handed in -1 as syscall number from the case where the entry code
     rejects it by returning -1 to the callers. Aside of that the return
     value functionality of those interfaces is not really intuitive.
 
     Fix this by separating the decision to reject a syscall (user dispatch,
     ptrace, seccomp ...) from the potential modification of the syscall
     number through these mechanisms.
 
     This solves most of the problems for architectures which do not have a
     separate return value storage in pt_regs except for the case where a
     tracepoint has a BPF script or a probe attached which overwrite both
     the syscall number and the return value. But that's a problem which
     cannot be solved in the generic code, that only can be addressed by
     separating the storage model in the affected architectures.
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Merge tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull generic entry code updates from Thomas Gleixner:

 - Make syscall user dispatching configurable

   Not all architectures can makes use of syscall user dispatching.
   Allow them to disable the feature completely.

 - Consolidate stack randomization for the generic entry code and the
   architectures using it.

   Stack randomization on syscall entry was sprinkled throughout the
   architecture specific low level entry code and in some cases at the
   wrong points, e.g. before establishing state, which violates the
   non-instrumentable constraints of that code.

   Clean this up by integrating stack randomization into the generic
   entry code helpers so that it is invoked at the earliest possible
   point right after establishing state and converting all generic entry
   code using architecture over.

 - Clean up the syscall number handling in the generic entry code. It
   works correctly for architectures which have a separate return value
   storage in pt_regs, but fails to distinguish the case where user
   space handed in -1 as syscall number from the case where the entry
   code rejects it by returning -1 to the callers. Aside of that the
   return value functionality of those interfaces is not really
   intuitive.

   Fix this by separating the decision to reject a syscall (user
   dispatch, ptrace, seccomp ...) from the potential modification of the
   syscall number through these mechanisms.

   This solves most of the problems for architectures which do not have
   a separate return value storage in pt_regs except for the case where
   a tracepoint has a BPF script or a probe attached which overwrite
   both the syscall number and the return value. But that's a problem
   which cannot be solved in the generic code, that only can be
   addressed by separating the storage model in the affected
   architectures.

* tag 'core-entry-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall execution
  entry: Make return type of syscall_trace_enter() bool
  entry: Rework trace_syscall_enter()
  entry: Rework syscall_audit_enter()
  syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH
  entry: Fix seccomp bypass after ptrace with TSYNC
  x86/entry: Simplify the syscall number logic
  x86/entry: Get rid of the sys_ni_syscall() indirection
  x86/entry: Make syscall functions static
  ptrace, treewide: Rename ptrace_report_syscall_entry() to ptrace_report_syscall_permit_entry()
  seccomp, treewide: Rename and convert __secure_computing() to return boolean
  entry: Use syscall number instead of rereading it
  entry: Remove syscall_enter_from_user_mode()
  x86/syscall: Use [syscall_]enter_from_user_mode_randomize_stack()
  s390/syscall: Use enter_from_user_mode_randomize_stack()
  riscv/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  powerpc/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  loongarch/syscall: Use syscall_enter_from_user_mode_randomize_stack()
  entry: Provide [syscall_]enter_from_user_mode_randomize_stack()
  randomize_kstack: Provide add_random_kstack_offset_irqsoff()
  ...
2026-08-18 15:00:56 -07:00
Linus Torvalds
85cdaca697 arm64 updates for 7.3
ACPI:
 - Combine reads of AMU counters into a single FFH feedback counter op.
 
 Confidential computing:
 - Fix smp_processor_id() in preemptible context when retrieving an
   attestation token inside a realm.
 
 - Convert pKVM over to a "CC platform".
 
 - Clean-up our SWIOTLB configuration in preparation for reworking the
   handling of encrypted/decryped DMA buffers in the dma-mapping tree.
 
 CPU errata handling:
 - Work around broken device memory ordering on NVIDIA Olympus cores.
 
 - Fix broken 'nospectre_bhb' command-line option.
 
 - Select the idle loop backend instruction on the command-line.
 
 CPU features:
 - Replace our BBML2-noabort feature with the new architectural BBML3
   feature.
 
 - Disable in-kernel BTI for recent versions of Clang due to issues with
   livepatch that are still being investigated.
 
 - Clean-up documentation describing which ID register fields are exposed
   to userspace.
 
 Interrupts:
 - Preliminary work towards supporting FEAT_NMI, which cleans up our
   IRQ entry code and fixes some latent issues with pseudo-NMI.
 
 - Support for an SDEI backend to trigger an NMI backtrace.
 
 Memory management:
 - Treat all devices as coherent when CLIDR_EL1.LoC == 0.
 
 - Fix no-map handling of sub-page-sized regions.
 
 - Second attempt at unmapping the linear aliases of the kernel data and
   bss sections.
 
 - Fix EFI runtime calls when software-PAN is enabled.
 
 Miscellaneous:
 - Add Mark Rutland as a reviewer!
 
 - Tidy-up our futex cmpxchg logic when using the new LSUI instructions.
 
 - Drop the requirement on DYNAMIC_FTRACE_WITH_CALL_OPS when selecting
   HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS.
 
 - Fix a false-positive KCSCAN splat in the delay loop.
 
 - Use a portable typedef for 128-bit scalar types in our UAPI headers.
 
 - Non-critical fixes for Sashiko reports all over.
 
 MPAM:
 - Hook MPAM memory bandwidth counters into resctrl's counter assignment
   interface.
 
 - Fix a quirk in the MPAM bandwidth counting on Nvidia T241 so that it
   also applies to 63 bit counters.
 
 Perf:
 - Workarounds for hardware issues in the CMN-S3 PMU (Graviton 5) and CPU
   PMU (NVIDIA Olympus again!)
 
 - Add support for the DDR PMU on Marvell CN20K SoCs.
 
 - Add support for Picoheart implementations of the DCW PCIe PMU.
 
 - Add support for Channel/Rank/Bank filtering in the CXL PMU driver.
 
 - Add support for 64-bit counters in the CSPMU device.
 
 - Add support for revision 2 of the CMN S3 PMU.
 
 Ptrace:
 - Fix a decade-old bug in our handling of seccomp and tracing on syscall
   entry.
 
 - Fix regset handling for inactive SVE and SSVE registers.
 
 Selftests
 - Add some tests for the decade-old bug that we just tried to fix in our
   syscall entry path.
 
 - Fix SVE test crash on SME-only CPUs.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "There's a reasonable amount of stuff here, including a bunch of
  updates to the perf PMU drivers and some MPAM updates to expose the
  memory bandwidth counters via resctrl.

  On the architecture side, some highlights include support for BBML3
  and steps towards support for an architectural NMI solution, all
  wrapped up in a web of fixes for latent issues identified by Sashiko.

  ACPI:

   - Combine reads of AMU counters into a single FFH feedback counter op

  Confidential computing:

   - Fix smp_processor_id() in preemptible context when retrieving an
     attestation token inside a realm

   - Convert pKVM over to a "CC platform"

   - Clean-up our SWIOTLB configuration in preparation for reworking the
     handling of encrypted/decryped DMA buffers in the dma-mapping tree

  CPU errata handling:

   - Work around broken device memory ordering on NVIDIA Olympus cores

   - Fix broken 'nospectre_bhb' command-line option

   - Select the idle loop backend instruction on the command-line

  CPU features:

   - Replace our BBML2-noabort feature with the new architectural BBML3
     feature

   - Disable in-kernel BTI for recent versions of Clang due to issues
     with livepatch that are still being investigated

   - Clean-up documentation describing which ID register fields are
     exposed to userspace

  Interrupts:

   - Preliminary work towards supporting FEAT_NMI, which cleans up our
     IRQ entry code and fixes some latent issues with pseudo-NMI

   - Support for an SDEI backend to trigger an NMI backtrace

  Memory management:

   - Treat all devices as coherent when CLIDR_EL1.LoC == 0

   - Fix no-map handling of sub-page-sized regions

   - Second attempt at unmapping the linear aliases of the kernel data
     and bss sections

   - Fix EFI runtime calls when software-PAN is enabled

  Miscellaneous:

   - Add Mark Rutland as a reviewer!

   - Tidy-up our futex cmpxchg logic when using the new LSUI
     instructions

   - Drop the requirement on DYNAMIC_FTRACE_WITH_CALL_OPS when
     selecting HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS

   - Fix a false-positive KCSCAN splat in the delay loop

   - Use a portable typedef for 128-bit scalar types in our UAPI headers

   - Non-critical fixes for Sashiko reports all over

  MPAM:

   - Hook MPAM memory bandwidth counters into resctrl's counter
     assignment interface

   - Fix a quirk in the MPAM bandwidth counting on Nvidia T241 so that
     it also applies to 63 bit counters

  Perf:

   - Workarounds for hardware issues in the CMN-S3 PMU (Graviton 5) and
     CPU PMU (NVIDIA Olympus again!)

   - Add support for the DDR PMU on Marvell CN20K SoCs

   - Add support for Picoheart implementations of the DCW PCIe PMU

   - Add support for Channel/Rank/Bank filtering in the CXL PMU driver

   - Add support for 64-bit counters in the CSPMU device

   - Add support for revision 2 of the CMN S3 PMU

  Ptrace:

   - Fix a decade-old bug in our handling of seccomp and tracing on
     syscall entry

   - Fix regset handling for inactive SVE and SSVE registers

  Selftests

   - Add some tests for the decade-old bug that we just tried to fix in
     our syscall entry path

   - Fix SVE test crash on SME-only CPUs"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (95 commits)
  arm64/efi: Avoid voluntary preemption with efi_mm installed
  arm64: bti: Disable in-kernel BTI with recent versions of Clang
  arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit
  irqchip/gic-v3: make the unmasking of pseudo-NMIs explicit when handling IRQs
  arm64: Disable KCSAN instrumentation in delay.o
  arm_mpam: Disable driver unbind to avoid UAF
  arm_mpam: Fix a NULL pointer dereference on unbinding after an error interrupt
  perf: arm_pmuv3: Zero initialize hw_id branch stack field
  arm64: mm: Unmap kernel data/bss entirely from the linear map
  iommu/arm-smmu-v3-sva: Use system_supports_bbml3() to detect CPU feature
  perf/arm-cmn: Support CMN S3 r2
  perf/arm-cmn: Plumb in new filter types
  perf/arm-cmn: Refactor event filter data
  perf/arm-cmn: Refactor event filter programming
  perf/arm-cmn: Rename filter variables for clarity
  arm64: mm: fix accidental linear mapping of no-map reserved memory
  tools: Ensure tools copy of linux/filter.h exports the UAPI
  kselftest/arm64: Fix abi test compilation errors
  arch: arm64: add early_param idle=<wfi|yield|nop>
  arm64: entry: mask DAIF before returning from C EL1 handlers
  ...
2026-08-18 11:57:17 -07:00
Linus Torvalds
ba24659b1d kexec: updates for v7.3-rc1
* Deduplicate crash memory allocation and the exclusion of reserved crash
   kernel regions from architecture specific code into a generic
   crash_prepare_headers() and enable crashkernel CMA reservation on arm64 and
   riscv reservation on arm64 and riscv.
 * Skip purgatory checksum verification when the kexec segments cannot be
   corrupted by DMA, which saves about 250ms on kexec.
 * Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in
   include/linux/kexec.h.
 * Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key restore
   path, which over-dropped the user keyring reference when more than one key
   was restored.
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Merge tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux

Pull kexec updates from Mike Rapoport:

 - Deduplicate crash memory allocation and the exclusion of reserved
   crash kernel regions from architecture specific code into a generic
   crash_prepare_headers() and enable crashkernel CMA reservation on
   arm64 and riscv reservation on arm64 and riscv.

 - Skip purgatory checksum verification when the kexec segments cannot
   be corrupted by DMA, which saves about 250ms on kexec.

 - Replace __ASSEMBLY__ with the compiler provided __ASSEMBLER__ in
   include/linux/kexec.h.

 - Fix a keyring refcount imbalance in the kdump kernel's dm-crypt key
   restore path, which over-dropped the user keyring reference when
   more than one key was restored.

* tag 'kexec-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux:
  crash_dump: release keyring reference at the correct time
  kexec: Replace __ASSEMBLY__ with __ASSEMBLER__ in header file
  kexec_file: skip checksum verification when safe
  riscv: kexec_file: Add support for crashkernel CMA reservation
  arm64: kexec_file: Add support for crashkernel CMA reservation
  powerpc/kexec_file: Use crash_exclude_core_ranges() helper
  LoongArch: kexec_file: Use crash_prepare_headers() helper to simplify code
  riscv: kexec_file: Use crash_prepare_headers() helper to simplify code
  x86/crash: Use crash_prepare_headers() helper to simplify code
  arm64: kexec_file: Use crash_prepare_headers() helper to simplify code
  crash: Add crash_prepare_headers() to exclude crash kernel memory
  powerpc/crash: sort crash memory ranges before preparing elfcorehdr
  riscv: kexec_file: Fix crashk_low_res not exclude bug
2026-08-18 10:28:28 -07:00
Will Deacon
824cbbf2e5 Merge branch 'for-next/sdei' into for-next/core
* for-next/sdei:
  arm64: escalate smp_send_stop() to an SDEI NMI as a last resort
  drivers/firmware: add SDEI cross-CPU NMI service for arm64
  firmware: arm_sdei: add SDEI_EVENT_SIGNAL support
  firmware: arm_sdei: add sdei_is_present()
2026-08-14 10:16:12 +00:00
Will Deacon
8e10aaf503 Merge branch 'for-next/ptrace' into for-next/core
* for-next/ptrace:
  arm64: syscall: Pass 'orig_x0' as first argument to native system call
  arm64: ptrace: Keep 'orig_x0' in-sync with x0 on syscall entry
  arm64/fpsimd: ptrace: Fix inactive SVE and SSVE regsets
2026-08-14 10:16:11 +00:00
Will Deacon
221349eab6 Merge branch 'for-next/nmi' into for-next/core
* for-next/nmi:
  arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit
  irqchip/gic-v3: make the unmasking of pseudo-NMIs explicit when handling IRQs
  arm64: entry: mask DAIF before returning from C EL1 handlers
  arm64: suspend: Initialize PMR on resume
  arm64: suspend: rely on daif helpers to handle PMR
  arm64: hibernate: Restore DAIF state on error
  arm64: hibernate: mask DAIF before restoring hibernated kernel
  arm64: debug: don't mask DAIF for mdscr_write()
  arm64: ptrace: Remove INIT_PSTATE_EL2
2026-08-14 10:16:10 +00:00
Will Deacon
1a6b708e89 Merge branch 'for-next/mm' into for-next/core
* for-next/mm:
  arm64/efi: Avoid voluntary preemption with efi_mm installed
  arm64: mm: Unmap kernel data/bss entirely from the linear map
  arm64: mm: fix accidental linear mapping of no-map reserved memory
  arm64: pgtable: convert pte_present() from macro to static inline
  arm64: mm: Treat all devices as dma-coherent when CLIDR_EL1.LoC == 0
2026-08-14 10:16:09 +00:00
Will Deacon
130bb50546 Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  arm64: Disable KCSAN instrumentation in delay.o
  MAINTAINERS: arm64: Add Mark Rutland as an official Reviewer
  arm64: smp: Fix IPI teardown for GICv5 flow
  arm64: futex: Consolidate 'old == new' check in __lsui_cmpxchg32()
  arm64: ftrace: allow DIRECT_CALLS without CALL_OPS
  arm64: ftrace: prepare ftrace_modify_call() for use without CALL_OPS
2026-08-14 10:16:08 +00:00
Will Deacon
ba3349fc55 Merge branch 'for-next/errata' into for-next/core
* for-next/errata:
  arch: arm64: add early_param idle=<wfi|yield|nop>
  arm64: proton-pack: Restore the nospectre_bhb command-line option
  arm64: errata: work around NVIDIA Olympus device store/load ordering
  arm64: Clarify ARM64_WORKAROUND_REPEAT_TLBI semantics
2026-08-14 10:16:08 +00:00
Will Deacon
dc61684f5c Merge branch 'for-next/cpufeature' into for-next/core
* for-next/cpufeature:
  arm64: bti: Disable in-kernel BTI with recent versions of Clang
  iommu/arm-smmu-v3-sva: Use system_supports_bbml3() to detect CPU feature
  arm64: cpufeature: Detect BBML3 based on ID_AA64MMFR2_EL1.BBM
  arm64: cpufeature: Rename BBML2_NOABORT as BBML3
  arm64: sysreg: Add BBM_3
  arm64: cpufeature: Extend bbml2_noabort support list
  arm64: cputype: Add C1-Nano definitions
  arm64: cputype: Add Cortex-A520AE definitions
  arm64: cpucaps: Remove stale comment about keeping capabilities sorted
  arm64: fix cpu-feature-registers Malformed table
  arm64: Remove hidden bitfields from cpu-feature-registers.rst
  arm64: Sort registers in cpu-feature-registers.rst
  arm64: Document missing bitfields in cpu-feature-registers.rst
  arm64: Don't number registers in cpu-feature-registers.rst
2026-08-14 10:16:07 +00:00
Will Deacon
c28a6a5bdd Merge branch 'for-next/coco' into for-next/core
* for-next/coco:
  arm64: RSI: fix field-spanning write warning in attestation token init
  virt: arm-cca-guest: Drop unused assignment of platform_device_id driver data
  arm64/coco: Add pKVM as a CC platform
  arm64/mm: Simplify SWIOTLB setup in arch_mm_preinit()
  virt: arm-cca-guest: use migrate_disable() for attestation token requests
2026-08-14 10:16:06 +00:00
Will Deacon
e98a9d0146 arm64/efi: Avoid voluntary preemption with efi_mm installed
Gus reports a bad kernel memory access when using software PAN
(CONFIG_ARM64_SW_TTBR0_PAN=y) on a machine with support for EFI runtime
services:

  Unable to handle kernel access to user memory outside uaccess routines
    at virtual address 00000000f322ff30
  Mem abort info:
    ESR = 0x0000000096000004
    FSC = 0x04: level 0 translation fault
  Internal error: Oops: 0000000096000004 [#1]  SMP
  Workqueue: efi_rts_wq efi_call_rts
  pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : efi_call_rts+0xd8/0x288
  Call trace:
   efi_call_rts+0xd8/0x288 (P)
   process_one_work+0x178/0x4f8
   worker_thread+0x194/0x328

This is because the fpsimd context management code called from
__efi_fpsimd_begin() can preempt voluntarily, returning later to the EFI
code with an incorrect value for TTBR0_EL1 thanks to the deferred mm
switching used by the software PAN implementation.

Since EFI runtime services cannot preempt voluntarily and because the
fpsimd switching code does not rely on the TTBR0_EL1 mappings, simply
reorder the fpsimd switch so that it occurs before we change the
page-table.

Cc: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Gus Bourg <gus@bourg.net>
Tested-by: Gus Bourg <gus@bourg.net>
Fixes: a5baf582f4 ("arm64/efi: Call EFI runtime services without disabling preemption")
Link: https://lore.kernel.org/all/20260806000144.3388823-1-gus@bourg.net/
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-12 10:21:20 +00:00
Vladimir Murzin
39aebe0e89 arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit
Currently, when exiting to kernel mode, we attempt involuntary
preemption. The preemption logic expects IRQs to be disabled, which is
why we call local_irq_disable() before attempting preemption.

However, depending on the context, local_irq_disable() may be
unnecessary:

- __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so
  local_irq_disable() is redundant.

- irqentry_exit_to_kernel_mode_preempt() immediately returns when
  exiting from an NMI-like context, so calling local_irq_disable()
  beforehand is unnecessary work.

Furthermore, it confuses the pNMI state tracking when we are in a
context with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set
in the PMR, leading to a warning when
CONFIG_ARM64_DEBUG_PRIORITY_MASKING=y:

     WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805
     CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY
     pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--)
     pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63)
     lr : el1_abort (arch/arm64/kernel/entry-common.c:323)
     pmr: 000000f0
     Call trace:
      arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P)
      el1_abort (arch/arm64/kernel/entry-common.c:323)
      el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449)
      el1h_64_sync (arch/arm64/kernel/entry.S:589)
      [...]

Split arm64_exit_to_kernel_mode() into preempt, non-preempt, and
dispatch parts so that we can avoid this extra work where it is not
needed and avoid breaking the pNMI tracking logic.

Reported-by: Breno Leitao <leitao@debian.org>
Fixes: ae654112ea ("arm64: entry: Use split preemption logic")
Link: https://lore.kernel.org/all/20260807-arm64_fix-v1-1-d069ccf9d71b@debian.org/
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-11 11:35:08 +00:00
Joerg Roedel
3c6a2bac15 Merge branches 'arm/smmu/updates', 'arm/smmu/bindings', 'mediatek', 'qualcomm/msm', 'rockchip', 'ti/omap', 'riscv', 'intel/vt-d', 'amd/amd-vi', 'core' and 'typos' into next 2026-08-11 09:12:19 +02:00
Sang-Heon Jeon
23e82f0223 arm64: remove early_ioremap_reset() call and __late_* macros
On arm64, __early_set_fixmap(), __late_set_fixmap() and
__late_clear_fixmap() are all __set_fixmap().  Calling
early_ioremap_reset() changes nothing.  So remove the call and the macros.

No functional change.

Link: https://lore.kernel.org/20260708170647.362562-4-ekffu200098@gmail.com
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06 18:57:22 -07:00
Yureka Lilian
d97afae6f1 arch: arm64: add early_param idle=<wfi|yield|nop>
Overriding the idle mechanism might be useful for debugging and performance
testing. Add a cmdline parameter for it, similar to the existing idle=
parameter already present for the x86 and ppc architectures.

It is also useful on platforms where the WFI instruction misbehaves,
such as Apple Silicon SoCs. Generally, a misbehaving instruction should
be treated as an erratum and patched using the alternatives framework.
However, in the Apple Silicon case we need more flexibility because it is
difficult to detect whether the erratum applies. For example, Linux VMs
inside macOS have the same MIDR and may even seem like they're running
in EL2 in the case of NV, but should continue using WFI (it's trapped and
handled correctly by the hypervisor there). Thus, we prefer to
let the m1n1 bootloader add the idle=nop parameter[1].

Link[1]: https://lore.kernel.org/all/99b69262-e54b-424e-baa2-96ef7013b87a@kernel.org/
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Yureka Lilian <yureka@cyberchaos.dev>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:10:03 +00:00
Ada Couprie Diaz
0d774e0517 arm64: entry: mask DAIF before returning from C EL1 handlers
Most EL1 exceptions already call local_daif_mask() before returning,
with the exception of debug exception handlers which do not change
DAIF, and the IRQ/FIQ/Error handlers.

However, DAIF get masked in kernel_exit() in all cases when returning
from EL1 C handlers anyway.

Move this masking from assembly to C by calling local_daif_mask()
before irqentry_nmi_exit(). Unlike the raw DAIF masking helper,
local_daif_mask() invokes trace_hardirqs_off(), so it must execute
while RCU is still watching.

Remove the disable_daif assembly macro, as this was its only use.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:07:46 +00:00
Ada Couprie Diaz
630ca6c58f arm64: suspend: rely on daif helpers to handle PMR
Commit 77345ef704 ("arm64: suspend: Use cpuidle context helpers
in cpu_suspend()") added cpuidle helpers to handle PMR manipulation
and restoration to ensure that the CPU receives interrupts when suspended
and pseudo-NMIs are enabled.

However, those helpers are called in between a pair of `local_daif_save()`
and `local_daif_restore()`, which already configure the PMR as expected.
Effectively, `arm_cpuidle_save_irq_context()` is a no-op here,
even when using pseudo-NMIs, and `arm_cpuidle_restore_irq_context()`
would not restore proper interrupt masking configuration early enough
if there were unexpected changes during suspend or resume.
(This can be observed with Trusted Firmware A (TF-A) at EL3 handling
suspend through PSCI. Even though it should not be the case, TF-A can
reset `ICC_PMR_EL1` during CPU_SUSPEND, thus resuming the kernel
with an inconsistent priority mask value on hardware implementing
more than the minimum number of priority levels, such as Morello.)

Thus : remove the cpuidle context helpers as they do not do anything,
but keep the comment mentioning the need for interrupts to reach the CPU
if we are using pseudo-NMIs.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:07:45 +00:00
Vladimir Murzin
5415498278 arm64: hibernate: Restore DAIF state on error
Sashiko AI has reported that if swsusp_mte_save_tags() for some reason
fails we return from swsusp_arch_suspend() with DAIF being masked -
that is not what we'd expect. Restore the saved DAIF state before
returning from the error path.

Fixes: ee11f332af ("arm64: mte: Save tags when hibernating")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:07:45 +00:00
Ada Couprie Diaz
684bde1001 arm64: hibernate: mask DAIF before restoring hibernated kernel
The arm64 hibernate code manages the exception masking in an unsound
way, leading to potential crashes and/or warnings during resume.

When a hibernation image is saved in `swsusp_arch_suspend()`, all DAIF
exceptions are masked (by virtue of `local_daif_save()`), and the
suspended image is saved assuming that all DAIF exceptions will remain
masked when the image is restored.

When a hibernation image is resumed by `swsusp_arch_resume()`, only
interrupts are masked (by virtue of `local_irq_disable()` in
`resume_target_kernel()`). When pseudo-NMI is enabled the DAIF.IF bits
will be clear, and regardless of pseudo-NMI the DAIF.DA bits will be
clear.

This means that there are two problems:

(1) It is possible to take Debug, SError, or pseudo-NMI exceptions
    during the resume process. This is unsafe, as during the resume
    process both the old ane new kernels will tranisently be in an
    inconsistent state, and swsusp_arch_suspend_exit() won't retain
    an executable mapping of any exception vectors.

    Any exception taken here will be fatal and silent.

(2) When re-entering the resumed kernel, some DAIF bits will be clear
    unexpectedly. This permits Debug, SError, or pseudo-NMI exceptions
    to be taken for a short period while the resumed kernel is not yet
    in a consistent state.

    This is detected by CONFIG_ARM64_DEBUG_PRIORITY_MASKING.

Avoid these issues by masking all DAIF exceptions during resume.

Fixes: 82869ac57b ("arm64: kernel: Add support for hibernate/suspend-to-disk")
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:07:45 +00:00
Ada Couprie Diaz
7cf2d6efb8 arm64: debug: don't mask DAIF for mdscr_write()
Masking DAIF around the write to MDSCR_EL1 doesn't do anything: we can
write to sysregs with interrupts unmasked, and writing to PSTATE is
not a context synchronization event so it does not synchronize it.

This is done in the context of a general interrupt handling cleanup,
so it does not address the missing context synchronization for the
MDSCR_EL1 write, staying consistent with the current state.  This
should be addressed in a future patch.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 13:07:45 +00:00
Linu Cherian
879aca5119 arm64: cpufeature: Detect BBML3 based on ID_AA64MMFR2_EL1.BBM
Add ID_AA64MMFR2_EL1.BBM based BBML3 feature detection in
cpu_supports_bbml3() so that cpus with the feature would
not have to be added into MIDR based supports_bbml3_list.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Linu Cherian <linu.cherian@arm.com>
[will: Tidy up cpu_supports_bbml3()]
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 12:15:30 +00:00
Linu Cherian
94104e3cfa arm64: cpufeature: Rename BBML2_NOABORT as BBML3
- As bbml2_noabort is functionally equivalent to bbml3,
  rename cpu/system_supports_bbml2_noabort to
  cpu/system_supports_bbml3.
  The ARM64 capability name is also renamed accordingly.

- As BBML2_NOABORT or the equivalent BBML3 is the
  kernel requirement for setting up linear map with
  block/contpte mappings and not BBML2, replace all
  bbml2 references with bbml3.

FEAT_BBML3, is introduced as part of 2025 Architecture Extensions.
https://developer.arm.com/documentation/109697/2026_03/2025-Architecture-Extensions

No functional changes are introduced with this patch.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Linu Cherian <linu.cherian@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 12:15:30 +00:00
Linu Cherian
a7ac604144 arm64: cpufeature: Extend bbml2_noabort support list
Add below cpus to the midr list, which supports
BBML2_NOABORT.

Cortex A520(AE)
Cortex A715
Cortex A720(AE)
Cortex A725
Neoverse N3
C1-Nano
C1-Pro
C1-Ultra
C1-Premium

C1-Ultra and C1-Premium both suffer from erratum 3683289,
where Break-Before-Make must be followed to avoid a livelock.
For both CPUs, the erratum is fixed from r1p1.
Hence we do not enable BBML2_NOABORT for CPU revisions <= r1p0.

The relevant SDENs are:
* C1-Ultra: https://developer.arm.com/documentation/111077/9-00/
* C1-Premium: https://developer.arm.com/documentation/111078/9-00/

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Linu Cherian <linu.cherian@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-06 12:15:30 +00:00
Robin Murphy
91038c83a2 arm64: Add override for MMFR1.HAFDBS
In general it might be nice to have the ability to disable hardware
access/dirty bit management for debugging or performance comparison
purposes without having to rebuild the kernel. However once FEAT_HAFT
comes into the picture we also start to have a real functional concern
where the decision to use HAFT based on the boot CPUs can prevent SVA
or late-onlining if SMMUs/CPUs are later found to lack HAFT support.

To that end, add the appropriate MMFR1 override, with an easy "nohaft"
alias for the significant case, partly since the feature/field naming
isn't the most obvious, but also so it could potentially be redirected
in future if someone wanted to attempt a higher-level means of turning
off just HAFT usage independently from FEAT_HDBSS.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 10:04:52 +00:00
Will Deacon
88b839ce49 arm64: ptrace: Keep 'orig_x0' in-sync with x0 on syscall entry
Commit e057b94772 ("arm64: syscall: Ensure saved x0 is kept in-sync
with tracer updates") attempted to resolve a long-standing issue with
syscall entry tracing, where a tracer is able to manipulate the first
syscall argument without being subjected to seccomp or audit checking.

Unfortunately, that fix was incomplete [1], as it failed to update
'orig_x0' between a tracer updating x0 during a seccomp ptrace exit
(SECCOMP_RET_TRACE) and the seccomp filter being re-evaluated.

Rather than add hooks to the core seccomp code, instead move the
synchronisation code into the ptrace GPR and syscall setting code so
that 'orig_x0' is kept up to date with x0 whenever we're stopped on the
syscall entry path.

Cc: Kees Cook <kees@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://sashiko.dev/#/patchset/20260716120640.6590-1-will@kernel.org [1]
Reported-by: Yiqi Sun <sunyiqixm@gmail.com>
Link: https://lore.kernel.org/all/20260529065444.1336608-1-sunyiqixm@gmail.com/
Fixes: e057b94772 ("arm64: syscall: Ensure saved x0 is kept in-sync with tracer updates")
Fixes: a5cd110cb8 ("arm64/ptrace: run seccomp after ptrace")
Tested-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 09:52:36 +00:00
Karl Mehltretter
c3f83d0211 arm64/fpsimd: ptrace: Fix inactive SVE and SSVE regsets
sve_init_header_from_task() takes header as a pointer, so for the
inactive mode

	header->size = sizeof(header);

stores 8 rather than sizeof(struct user_sve_header), which is 16.
Userspace sees an impossible size smaller than the header it
describes.

The inactive-mode check in sve_get_common() compares header.size
against sizeof(header) as well, but there header is a struct, so the
check can never fire. Reads of NT_ARM_SVE and NT_ARM_SSVE for the
inactive mode therefore still return the other mode's FPSIMD data,
exactly the situation the check was added to prevent.

Fix the size, and make the check return the remaining membuf space
instead of 0, which regset_get() would interpret as the entire
(zero-filled) buffer having been populated.

Fixes: b93e685ecf ("arm64/fpsimd: ptrace: Do not present register data for inactive mode")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 09:46:07 +00:00
Vladimir Murzin
4c9c81a086 arm64: smp: Fix IPI teardown for GICv5 flow
Sashiko reported that during CPU offlining, __cpu_disable() is
executed by the stopper thread via take_cpu_down() with local
interrupts disabled. __cpu_disable() calls ipi_teardown(), which
invokes ipi_lpi_disable(). For the GICv5 flow, this eventually calls
the sleepable disable_irq().

This can be reproduced easily with CONFIG_DEBUG_ATOMIC_SLEEP=y by
offlining a CPU:

  BUG: sleeping function called from invalid context at kernel/irq/manage.c:702
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 20, name: migration/1
  preempt_count: 1, expected: 0
  no locks held by migration/1/20.
  irq event stamp: 186
  hardirqs last  enabled at (185): [<ffff800080b084c8>] _raw_spin_unlock_irq+0x38/0x68
  hardirqs last disabled at (186): [<ffff8000801f8e08>] multi_cpu_stop+0xc8/0x190
  softirqs last  enabled at (80): [<ffff8000800c48b8>] handle_softirqs+0x410/0x468
  softirqs last disabled at (75): [<ffff8000800102f4>] __do_softirq+0x1c/0x28

Fix this by using disable_irq_nosync() instead, which is safe in this
atomic context.

Fixes: ba1004f861 ("arm64: smp: Support non-SGIs for IPIs")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 09:26:12 +00:00
Kiryl Shutsemau (Meta)
d639f76262 arm64: escalate smp_send_stop() to an SDEI NMI as a last resort
A CPU wedged with interrupts masked ignores the stop IPI, and without
pseudo-NMI there is no NMI IPI to escalate to: a reboot proceeds with
the CPU still running, and a kdump misses its registers.

Add a third rung to smp_send_stop(): once the IPI (and pseudo-NMI IPI,
if enabled) rungs have run, signal SDEI event 0 at whatever stayed
online. Firmware delivers it regardless of the target's DAIF, so it
reaches a CPU a plain IPI cannot; the target acks by going offline,
which the caller already polls for.

Fold the stop bookkeeping into one arm64_nmi_cpu_stop(regs,
die_on_crash), shared by the stop IPI handlers, panic_smp_self_stop()
and the SDEI handler, replacing the near-duplicate local_cpu_stop() and
ipi_cpu_crash_stop(). @die_on_crash is the only difference: the IPI
handlers pass true and PSCI CPU_OFF the CPU on a crash stop so a capture
kernel can reclaim it; the SDEI handler and self-stop pass false and
park. The SDEI park is required, not conservative -- its handler runs
inside an SDEI event that is never completed (completing it resumes the
wedged context), and a CPU_OFF from that unfinished-event context wedges
EL3 on some firmware (left as a follow-up). The dump is unaffected; only
re-onlining the CPU in an SMP capture kernel is lost.

Suggested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Yin Fengwei <fengwei_yin@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 09:21:06 +00:00
Kiryl Shutsemau (Meta)
0c2c56598c drivers/firmware: add SDEI cross-CPU NMI service for arm64
Deliver an NMI-like event to an interrupt-masked arm64 CPU via the
standard SDEI software-signalled event (event 0), without the pseudo-NMI
hot-path cost: register a handler for event 0 and poke a target with
sdei_event_signal(0, mpidr).

First user is arch_trigger_cpumask_backtrace() (sysrq-l, RCU stalls,
hung-task/soft-lockup dumps), which otherwise rides an IPI that can't
reach a masked CPU. Falls back to the IPI path when SDEI is absent; no
watchdog backend yet, so the stock detector is untouched.

Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Yin Fengwei <fengwei_yin@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
2026-08-02 09:21:06 +00:00
Marc Zyngier
13c164acef arm64: Add override for ID_AA64MMFR4_EL1.NV_frac
In a very unsurprising turn of events, there is a large class of
firmware that is totally unable to deal with FEAT_NV3, and doesn't
set the required SCR2_EL3.NV3En bit, leading to an UNDEF exception
or an unhandled trap to EL3, depending on the implementation.

Allow the unfortunate user to override ID_AA64MMFR4_EL1.NV_frac
and get a working system. Hopefully firmware will be fixed before
actually HW ships, but I have been there before... :-/

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260730071022.296811-30-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-07-31 00:17:05 -07:00