This patch corrects several minor typographical and spelling errors
in comments across multiple arm64 source files.

No functional changes.

Signed-off-by: mrigendrachaubey <mrigendra.chaubey@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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

  guest_memfd:

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

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

     For more information see:
       - commit a6ad54137af9 ("Merge branch 'guest-memfd-mmap' into HEAD")
       - guest_memfd in Firecracker:
           https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding
       - direct map removal:
           https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/
       - mmap support:
           https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/

  ARM:

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

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

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

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

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

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

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

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

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

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

  LoongArch:

   - Detect page table walk feature on new hardware

   - Add sign extension with kernel MMIO/IOCSR emulation

   - Improve in-kernel IPI emulation

   - Improve in-kernel PCH-PIC emulation

   - Move kvm_iocsr tracepoint out of generic code

  RISC-V:

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

   - Added ONE_REG interface for SBI FWFT extension

   - Added Zicbop and bfloat16 extensions for Guest/VM

   - Enabled more common KVM selftests for RISC-V

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

  s390:

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

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

  x86 selftests:

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

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

   - Minor cleanups and improvements

  x86 (guest side):

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

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

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

  Generic:

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

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits)
  KVM: s390: Fix to clear PTE when discarding a swapped page
  KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs
  KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs
  KVM: arm64: selftests: Cope with arch silliness in EL2 selftest
  KVM: arm64: selftests: Add basic test for running in VHE EL2
  KVM: arm64: selftests: Enable EL2 by default
  KVM: arm64: selftests: Initialize HCR_EL2
  KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters
  KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2
  KVM: arm64: selftests: Select SMCCC conduit based on current EL
  KVM: arm64: selftests: Provide helper for getting default vCPU target
  KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts
  KVM: arm64: selftests: Create a VGICv3 for 'default' VMs
  KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation
  KVM: arm64: selftests: Add helper to check for VGICv3 support
  KVM: arm64: selftests: Initialize VGICv3 only once
  KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code
  KVM: selftests: Add ex_str() to print human friendly name of exception vectors
  selftests/kvm: remove stale TODO in xapic_state_test
  KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount
  ...

The kernel's CFI implementation uses the KCFI ABI specifically, and is
not strictly tied to a particular compiler. In preparation for GCC
supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with
associated options).

Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will
enable CONFIG_CFI during olddefconfig.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>

Similar to the kernel panic, where the instruction code is printed,
we can do the same for hypervisor panics.

This patch does that only in case of “CONFIG_NVHE_EL2_DEBUG” or nvhe.

The next patch adds support for pKVM.

Also, remove the hardcoded argument dump_kernel_instr().

Signed-off-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Kunwu Chan <chentao@kylinos.cn>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>

* arm64/for-next/perf: (23 commits)
  drivers/perf: hisi: Support PMUs with no interrupt
  drivers/perf: hisi: Relax the event number check of v2 PMUs
  drivers/perf: hisi: Add support for HiSilicon SLLC v3 PMU driver
  drivers/perf: hisi: Use ACPI driver_data to retrieve SLLC PMU information
  drivers/perf: hisi: Add support for HiSilicon DDRC v3 PMU driver
  drivers/perf: hisi: Simplify the probe process for each DDRC version
  perf/arm-ni: Support sharing IRQs within an NI instance
  perf/arm-ni: Consolidate CPU affinity handling
  perf/cxlpmu: Fix typos in cxl_pmu.c comments and documentation
  perf/cxlpmu: Remove unintended newline from IRQ name format string
  perf/cxlpmu: Fix devm_kcalloc() argument order in cxl_pmu_probe()
  perf: arm_spe: Relax period restriction
  perf: arm_pmuv3: Add support for the Branch Record Buffer Extension (BRBE)
  KVM: arm64: nvhe: Disable branch generation in nVHE guests
  arm64: Handle BRBE booting requirements
  arm64/sysreg: Add BRBE registers and fields
  perf/arm: Add missing .suppress_bind_attrs
  perf/arm-cmn: Reduce stack usage during discovery
  perf: imx9_perf: make the read-only array mask static const
  perf/arm-cmn: Broaden module description for wider interconnect support
  ...

* for-next/livepatch:
  : Support for HAVE_LIVEPATCH on arm64
  arm64: Kconfig: Keep selects somewhat alphabetically ordered
  arm64: Implement HAVE_LIVEPATCH
  arm64: stacktrace: Implement arch_stack_walk_reliable()
  arm64: stacktrace: Check kretprobe_find_ret_addr() return value
  arm64/module: Use text-poke API for late relocations.

* for-next/user-contig-bbml2:
  : Optimise the TLBI when folding/unfolding contigous PTEs on hardware with BBML2 and no TLB conflict aborts
  arm64/mm: Elide tlbi in contpte_convert() under BBML2
  iommu/arm: Add BBM Level 2 smmu feature
  arm64: Add BBM Level 2 cpu feature
  arm64: cpufeature: Introduce MATCH_ALL_EARLY_CPUS capability type

* for-next/misc:
  : Miscellaneous arm64 patches
  arm64/gcs: task_gcs_el0_enable() should use passed task
  arm64: signal: Remove ISB when resetting POR_EL0
  arm64/mm: Drop redundant addr increment in set_huge_pte_at()
  arm64: Mark kernel as tainted on SAE and SError panic
  arm64/gcs: Don't call gcs_free() when releasing task_struct
  arm64: fix unnecessary rebuilding when CONFIG_DEBUG_EFI=y
  arm64/mm: Optimize loop to reduce redundant operations of contpte_ptep_get
  arm64: pi: use 'targets' instead of extra-y in Makefile

* for-next/acpi:
  : Various ACPI arm64 changes
  ACPI: Suppress misleading SPCR console message when SPCR table is absent
  ACPI: Return -ENODEV from acpi_parse_spcr() when SPCR support is disabled

* for-next/debug-entry:
  : Simplify the debug exception entry path
  arm64: debug: remove debug exception registration infrastructure
  arm64: debug: split bkpt32 exception entry
  arm64: debug: split brk64 exception entry
  arm64: debug: split hardware watchpoint exception entry
  arm64: debug: split single stepping exception entry
  arm64: debug: refactor reinstall_suspended_bps()
  arm64: debug: split hardware breakpoint exception entry
  arm64: entry: Add entry and exit functions for debug exceptions
  arm64: debug: remove break/step handler registration infrastructure
  arm64: debug: call step handlers statically
  arm64: debug: call software breakpoint handlers statically
  arm64: refactor aarch32_break_handler()
  arm64: debug: clean up single_step_handler logic

* for-next/feat_mte_tagged_far:
  : Support for reporting the non-address bits during a synchronous MTE tag check fault
  kselftest/arm64/mte: Add mtefar tests on check_mmap_options
  kselftest/arm64/mte: Refactor check_mmap_option test
  kselftest/arm64/mte: Add verification for address tag in signal handler
  kselftest/arm64/mte: Add address tag related macro and function
  kselftest/arm64/mte: Check MTE_FAR feature is supported
  kselftest/arm64/mte: Register mte signal handler with SA_EXPOSE_TAGBITS
  kselftest/arm64: Add MTE_FAR hwcap test
  KVM: arm64: Expose FEAT_MTE_TAGGED_FAR feature to guest
  arm64: Report address tag when FEAT_MTE_TAGGED_FAR is supported
  arm64/cpufeature: Add FEAT_MTE_TAGGED_FAR feature

* for-next/kselftest:
  : Kselftest updates for arm64
  kselftest/arm64: Handle attempts to disable SM on SME only systems
  kselftest/arm64: Fix SVE write data generation for SME only systems
  kselftest/arm64: Test SME on SME only systems in fp-ptrace
  kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace
  kselftest/arm64: Allow sve-ptrace to run on SME only systems
  kselftest/arm4: Provide local defines for AT_HWCAP3
  kselftest/arm64: Specify SVE data when testing VL set in sve-ptrace
  kselftest/arm64: Fix test for streaming FPSIMD write in sve-ptrace
  kselftest/arm64: Fix check for setting new VLs in sve-ptrace
  kselftest/arm64: Convert tpidr2 test to use kselftest.h

* for-next/mdscr-cleanup:
  : Drop redundant DBG_MDSCR_* macros
  KVM: selftests: Change MDSCR_EL1 register holding variables as uint64_t
  arm64/debug: Drop redundant DBG_MDSCR_* macros

* for-next/vmap-stack:
  : Force VMAP_STACK on arm64
  arm64: remove CONFIG_VMAP_STACK checks from entry code
  arm64: remove CONFIG_VMAP_STACK checks from SDEI stack handling
  arm64: remove CONFIG_VMAP_STACK checks from stacktrace overflow logic
  arm64: remove CONFIG_VMAP_STACK conditionals from traps overflow stack
  arm64: remove CONFIG_VMAP_STACK conditionals from irq stack setup
  arm64: Remove CONFIG_VMAP_STACK conditionals from THREAD_SHIFT and THREAD_ALIGN
  arm64: efi: Remove CONFIG_VMAP_STACK check
  arm64: Mandate VMAP_STACK
  arm64: efi: Fix KASAN false positive for EFI runtime stack
  arm64/ptrace: Fix stack-out-of-bounds read in regs_get_kernel_stack_nth()
  arm64/gcs: Don't call gcs_free() during flush_gcs()
  arm64: Restrict pagetable teardown to avoid false warning
  docs: arm64: Fix ICC_SRE_EL2 register typo in booting.rst

Set TAINT_MACHINE_CHECK when SError or Synchronous External Abort (SEA)
interrupts trigger a panic to flag potential hardware faults. This
tainting mechanism aids in debugging and enables correlation of
hardware-related crashes in large-scale deployments.

This change aligns with similar patches[1] that mark machine check
events when the system crashes due to hardware errors.

Link: https://lore.kernel.org/all/20250702-add_tain-v1-1-9187b10914b9@debian.org/ [1]
Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250716-vmcore_hw_error-v2-1-f187f7d62aba@debian.org
Signed-off-by: Will Deacon <will@kernel.org>

With VMAP_STACK now always enabled on arm64, remove the
CONFIG_VMAP_STACK checks from overflow stack definitions and related
code in arch/arm64/kernel/traps.c. The overflow_stack and
panic_bad_stack() logic are now unconditionally included, simplifying
the source and matching the mandatory stack model.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707-arm64_vmap-v1-5-8de98ca0f91c@debian.org
Signed-off-by: Will Deacon <will@kernel.org>

Now that debug exceptions are handled individually and without the need
for dynamic registration, remove the unused registration infrastructure.

This removes the external caller for `debug_exception_enter()` and
`debug_exception_exit()`.
Make them static again and remove them from the header.

Remove `early_brk64()` as it has been made redundant by
(arm64: debug: split brk64 exception entry) and is not used anymore.
Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally
as a fall-through, but now `call_break_hook()` only calls it if the
immediate matches.
This does not change the behaviour in early boot, as if
`bug_brk_handler()` was called on a non-BUG immediate it would return
DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate
matches.

Remove `trap_init()`, as it would be empty and a weak definition already
exists in `init/main.c`.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Software breakpoints pass an immediate value in ESR ("comment") that can
be used to call a specialized handler (KGDB, KASAN...).
We do so in two different ways :
 - During early boot, `early_brk64` statically checks against known
   immediates and calls the corresponding handler,
 - During init, handlers are dynamically registered into a list. When
   called, the generic software breakpoint handler will iterate over
   the list to find the appropriate handler.

The dynamic registration does not provide any benefit here as it is not
exported and all its uses are within the arm64 tree. It also depends on an
RCU list, whose safe access currently relies on the non-preemptible state
of `do_debug_exception`.

Replace the list iteration logic in `call_break_hooks` to call
the breakpoint handlers statically if they are enabled, like in
`early_brk64`.
Expose the handlers in their respective headers to be reachable from
`arch/arm64/kernel/debug-monitors.c` at link time.

Unify the naming of the software breakpoint handlers to XXX_brk_handler(),
making it clear they are related and to differentiate from the
hardware breakpoints.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20250707114109.35672-4-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

`aarch32_break_handler()` is called in `do_el0_undef()` when we
are trying to handle an exception whose Exception Syndrome is unknown.
It checks if the instruction hit might be a 32-bit arm break (be it
A32 or T2), and sends a SIGTRAP to userspace if it is so that it can
be handled.

However, this is badly represented in the naming of the function, and
is not consistent with the other functions called with the same logic
in `do_el0_undef()`.

Rename it `try_handle_aarch32_break()` and change the return value to
a boolean to align with the logic of the other tentative handlers in
`do_el0_undef()`, the previous error code being ignored anyway.

Signed-off-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Tested-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20250707114109.35672-3-ada.coupriediaz@arm.com
Signed-off-by: Will Deacon <will@kernel.org>