kernel/linux.git/Documentation/arch/arm64, branch v6.19.11

Merge branches 'for-next/misc', 'for-next/kselftest', 'for-next/efi-preempt', 'for-next/assembler-macro', 'for-next/typos', 'for-next/sme-ptrace-disable', 'for-next/local-tlbi-page-reused', 'for-next/mpam', 'for-next/acpi' and 'for-next/documentation', remote-tracking branch 'arm64/for-next/perf' into for-next/core

2025-11-28T15:47:12+00:00

* arm64/for-next/perf: perf: arm_spe: Add support for filtering on data source perf: Add perf_event_attr::config4 perf/imx_ddr: Add support for PMU in DB (system interconnects) perf/imx_ddr: Get and enable optional clks perf/imx_ddr: Move ida_alloc() from ddr_perf_init() to ddr_perf_probe() dt-bindings: perf: fsl-imx-ddr: Add compatible string for i.MX8QM, i.MX8QXP and i.MX8DXL arch_topology: Provide a stub topology_core_has_smt() for !CONFIG_GENERIC_ARCH_TOPOLOGY perf/arm-ni: Fix and optimise register offset calculation perf: arm_pmuv3: Add new Cortex and C1 CPU PMUs perf: arm_cspmu: fix error handling in arm_cspmu_impl_unregister() perf/arm-ni: Add NoC S3 support perf/arm_cspmu: nvidia: Add pmevfiltr2 support perf/arm_cspmu: nvidia: Add revision id matching perf/arm_cspmu: Add pmpidr support perf/arm_cspmu: Add callback to reset filter config perf: arm_pmuv3: Don't use PMCCNTR_EL0 on SMT cores * for-next/misc: : Miscellaneous patches arm64: atomics: lse: Remove unused parameters from ATOMIC_FETCH_OP_AND macros arm64: remove duplicate ARCH_HAS_MEM_ENCRYPT arm64: mm: use untagged address to calculate page index arm64: mm: make linear mapping permission update more robust for patial range arm64/mm: Elide TLB flush in certain pte protection transitions arm64/mm: Rename try_pgd_pgtable_alloc_init_mm arm64/mm: Allow __create_pgd_mapping() to propagate pgtable_alloc() errors arm64: add unlikely hint to MTE async fault check in el0_svc_common arm64: acpi: add newline to deferred APEI warning arm64: entry: Clean out some indirection arm64/mm: Ensure PGD_SIZE is aligned to 64 bytes when PA_BITS = 52 arm64/mm: Drop cpu_set_[default|idmap]_tcr_t0sz() arm64: remove unused ARCH_PFN_OFFSET arm64: use SOFTIRQ_ON_OWN_STACK for enabling softirq stack arm64: Remove assertion on CONFIG_VMAP_STACK * for-next/kselftest: : arm64 kselftest patches kselftest/arm64: Align zt-test register dumps * for-next/efi-preempt: : arm64: Make EFI calls preemptible arm64/efi: Call EFI runtime services without disabling preemption arm64/efi: Move uaccess en/disable out of efi_set_pgd() arm64/efi: Drop efi_rt_lock spinlock from EFI arch wrapper arm64/fpsimd: Permit kernel mode NEON with IRQs off arm64/fpsimd: Don't warn when EFI execution context is preemptible efi/runtime-wrappers: Keep track of the efi_runtime_lock owner efi: Add missing static initializer for efi_mm::cpus_allowed_lock * for-next/assembler-macro: : arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in headers arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers arm64: Replace __ASSEMBLY__ with __ASSEMBLER__ in uapi headers * for-next/typos: : Random typo/spelling fixes arm64: Fix double word in comments arm64: Fix typos and spelling errors in comments * for-next/sme-ptrace-disable: : Support disabling streaming mode via ptrace on SME only systems kselftest/arm64: Cover disabling streaming mode without SVE in fp-ptrace kselftst/arm64: Test NT_ARM_SVE FPSIMD format writes on non-SVE systems arm64/sme: Support disabling streaming mode via ptrace on SME only systems * for-next/local-tlbi-page-reused: : arm64, mm: avoid TLBI broadcast if page reused in write fault arm64, tlbflush: don't TLBI broadcast if page reused in write fault mm: add spurious fault fixing support for huge pmd * for-next/mpam: (34 commits) : Basic Arm MPAM driver (more to follow) MAINTAINERS: new entry for MPAM Driver arm_mpam: Add kunit tests for props_mismatch() arm_mpam: Add kunit test for bitmap reset arm_mpam: Add helper to reset saved mbwu state arm_mpam: Use long MBWU counters if supported arm_mpam: Probe for long/lwd mbwu counters arm_mpam: Consider overflow in bandwidth counter state arm_mpam: Track bandwidth counter state for power management arm_mpam: Add mpam_msmon_read() to read monitor value arm_mpam: Add helpers to allocate monitors arm_mpam: Probe and reset the rest of the features arm_mpam: Allow configuration to be applied and restored during cpu online arm_mpam: Use a static key to indicate when mpam is enabled arm_mpam: Register and enable IRQs arm_mpam: Extend reset logic to allow devices to be reset any time arm_mpam: Add a helper to touch an MSC from any CPU arm_mpam: Reset MSC controls from cpuhp callbacks arm_mpam: Merge supported features during mpam_enable() into mpam_class arm_mpam: Probe the hardware features resctrl supports arm_mpam: Add helpers for managing the locking around the mon_sel registers ... * for-next/acpi: : arm64 acpi updates ACPI: GTDT: Get rid of acpi_arch_timer_mem_init() * for-next/documentation: : arm64 Documentation updates Documentation/arm64: Fix the typo of register names

Documentation/arm64: Fix the typo of register names

2025-11-25T12:26:31+00:00

The register name 'HWFGWTR_EL2' and 'HWFGRTR_EL2' is wrong, should be 'HFGWTR_EL2' and 'HFGRTR_EL2'. Find the register description on arm website here, https://developer.arm.com/documentation/ddi0601/2025-09/AArch64-Registers/HFGWTR-EL2--Hypervisor-Fine-Grained-Write-Trap-Register https://developer.arm.com/documentation/ddi0601/2025-09/AArch64-Registers/HFGRTR-EL2--Hypervisor-Fine-Grained-Read-Trap-Register?lang=en Signed-off-by: Zenon Xiu Signed-off-by: Catalin Marinas

arm64/sme: Support disabling streaming mode via ptrace on SME only systems

2025-11-17T20:11:54+00:00

Currently it is not possible to disable streaming mode via ptrace on SME only systems, the interface for doing this is to write via NT_ARM_SVE but such writes will be rejected on a system without SVE support. Enable this functionality by allowing userspace to write SVE_PT_REGS_FPSIMD format data via NT_ARM_SVE with the vector length set to 0 on SME only systems. Such writes currently error since we require that a vector length is specified which should minimise the risk that existing software is relying on current behaviour. Reads are not supported since I am not aware of any use case for this and there is some risk that an existing userspace application may be confused if it reads NT_ARM_SVE on a system without SVE. Existing kernels will return FPSIMD formatted register state from NT_ARM_SVE if full SVE state is not stored, for example if the task has not used SVE. Returning a vector length of 0 would create a risk that software would try to do things like allocate space for register state with zero sizes, while returning a vector length of 128 bits would look like SVE is supported. It seems safer to just not make the changes to add read support. It remains possible for userspace to detect a SME only system via the ptrace interface only since reads of NT_ARM_SSVE and NT_ARM_ZA will succeed while reads of NT_ARM_SVE will fail. Read/write access to the FPSIMD registers in non-streaming mode is available via REGSET_FPR. sve_set_common() already avoids allocating SVE storage when doing a FPSIMD formatted write and allocating SME storage when doing a NT_ARM_SVE write so we change the function to validate the new case and skip setting a vector length for it. The aim is to make a minimally invasive change, no operation that would previously have succeeded will be affected, and we use a previously defined interface in new circumstances rather than define completely new ABI. Signed-off-by: Mark Brown Reviewed-by: David Spickett Signed-off-by: Catalin Marinas

Merge branch 'for-next/perf' into for-next/core

2025-09-24T15:34:52+00:00

* for-next/perf: (29 commits) perf/dwc_pcie: Fix use of uninitialized variable Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU Documentation: hisi-pmu: Fix of minor format error drivers/perf: hisi: Add support for L3C PMU v3 drivers/perf: hisi: Refactor the event configuration of L3C PMU drivers/perf: hisi: Extend the field of tt_core drivers/perf: hisi: Extract the event filter check of L3C PMU drivers/perf: hisi: Simplify the probe process of each L3C PMU version drivers/perf: hisi: Export hisi_uncore_pmu_isr() drivers/perf: hisi: Relax the event ID check in the framework perf: Fujitsu: Add the Uncore PMU driver perf/arm-cmn: Fix CMN S3 DTM offset perf: arm_spe: Prevent overflow in PERF_IDX2OFF() coresight: trbe: Prevent overflow in PERF_IDX2OFF() MAINTAINERS: Remove myself from HiSilicon PMU maintainers drivers/perf: hisi: Add support for HiSilicon MN PMU driver drivers/perf: hisi: Add support for HiSilicon NoC PMU perf: arm_pmuv3: Factor out PMCCNTR_EL0 use conditions arm64/boot: Enable EL2 requirements for SPE_FEAT_FDS arm64/boot: Factor out a macro to check SPE version ...

Merge branch 'for-next/docs' into for-next/core

2025-09-24T15:33:58+00:00

* for-next/docs: arm64/sme: Drop inaccurate documentation of streaming mode switches

arm64: errata: Apply workarounds for Neoverse-V3AE

2025-09-22T10:27:14+00:00

Neoverse-V3AE is also affected by erratum #3312417, as described in its Software Developer Errata Notice (SDEN) document: Neoverse V3AE (MP172) SDEN v9.0, erratum 3312417 https://developer.arm.com/documentation/SDEN-2615521/9-0/ Enable the workaround for Neoverse-V3AE, and document this. Signed-off-by: Mark Rutland Cc: James Morse Cc: Will Deacon Cc: Catalin Marinas Signed-off-by: Ryan Roberts Signed-off-by: Will Deacon

arm64/boot: Enable EL2 requirements for SPE_FEAT_FDS

2025-09-18T13:17:02+00:00

SPE data source filtering (optional from Armv8.8) requires that traps to the filter register PMSDSFR be disabled. Document the requirements and disable the traps if the feature is present. Tested-by: Leo Yan Reviewed-by: Leo Yan Signed-off-by: James Clark Signed-off-by: Will Deacon

arm64/hwcap: Add hwcap for FEAT_LSFE

2025-09-16T18:55:11+00:00

FEAT_LSFE (Large System Float Extension), providing atomic floating point memory operations, is optional from v9.5. This feature adds no new architectural stare and we have no immediate use for it in the kernel so simply provide a hwcap for it to support discovery by userspace. Signed-off-by: Mark Brown Signed-off-by: Will Deacon

arm64/sme: Drop inaccurate documentation of streaming mode switches

2025-09-08T12:25:38+00:00

The SME ABI documentation contains an inaccurate description of the architectural streaming mode entry/exit behaviour, just remove it since this is better documented by the architecture or with the rest of the documentation for the specific software interfaces concerned. Signed-off-by: Mark Brown Signed-off-by: Will Deacon

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2025-07-31T00:14:01+00:00

Pull kvm updates from Paolo Bonzini: "ARM: - Host driver for GICv5, the next generation interrupt controller for arm64, including support for interrupt routing, MSIs, interrupt translation and wired interrupts - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on GICv5 hardware, leveraging the legacy VGIC interface - Userspace control of the 'nASSGIcap' GICv3 feature, allowing userspace to disable support for SGIs w/o an active state on hardware that previously advertised it unconditionally - Map supporting endpoints with cacheable memory attributes on systems with FEAT_S2FWB and DIC where KVM no longer needs to perform cache maintenance on the address range - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest hypervisor to inject external aborts into an L2 VM and take traps of masked external aborts to the hypervisor - Convert more system register sanitization to the config-driven implementation - Fixes to the visibility of EL2 registers, namely making VGICv3 system registers accessible through the VGIC device instead of the ONE_REG vCPU ioctls - Various cleanups and minor fixes LoongArch: - Add stat information for in-kernel irqchip - Add tracepoints for CPUCFG and CSR emulation exits - Enhance in-kernel irqchip emulation - Various cleanups RISC-V: - Enable ring-based dirty memory tracking - Improve perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU improvements related to upcoming nested virtualization s390x - Fixes x86: - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time - Share device posted IRQ code between SVM and VMX and harden it against bugs and runtime errors - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n) - For MMIO stale data mitigation, track whether or not a vCPU has access to (host) MMIO based on whether the page tables have MMIO pfns mapped; using VFIO is prone to false negatives - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical - Recalculate all MSR intercepts from scratch on MSR filter changes, instead of maintaining shadow bitmaps - Advertise support for LKGS (Load Kernel GS base), a new instruction that's loosely related to FRED, but is supported and enumerated independently - Fix a user-triggerable WARN that syzkaller found by setting the vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU into VMX Root Mode (post-VMXON). Trying to detect every possible path leading to architecturally forbidden states is hard and even risks breaking userspace (if it goes from valid to valid state but passes through invalid states), so just wait until KVM_RUN to detect that the vCPU state isn't allowed - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can access APERF/MPERF. This has many caveats (APERF/MPERF cannot be zeroed on vCPU creation or saved/restored on suspend and resume, or preserved over thread migration let alone VM migration) but can be useful whenever you're interested in letting Linux guests see the effective physical CPU frequency in /proc/cpuinfo - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been created, as there's no known use case for changing the default frequency for other VM types and it goes counter to the very reason why the ioctl was added to the vm file descriptor. And also, there would be no way to make it work for confidential VMs with a "secure" TSC, so kill two birds with one stone - Dynamically allocation the shadow MMU's hashed page list, and defer allocating the hashed list until it's actually needed (the TDP MMU doesn't use the list) - Extract many of KVM's helpers for accessing architectural local APIC state to common x86 so that they can be shared by guest-side code for Secure AVIC - Various cleanups and fixes x86 (Intel): - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest. Failure to honor FREEZE_IN_SMM can leak host state into guests - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF x86 (AMD): - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty much a static condition and therefore should never happen, but still) - Fix a variety of flaws and bugs in the AVIC device posted IRQ code - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs - Request GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model - Accept any SNP policy that is accepted by the firmware with respect to SMT and single-socket restrictions. An incompatible policy doesn't put the kernel at risk in any way, so there's no reason for KVM to care - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and use WBNOINVD instead of WBINVD when possible for SEV cache maintenance - When reclaiming memory from an SEV guest, only do cache flushes on CPUs that have ever run a vCPU for the guest, i.e. don't flush the caches for CPUs that can't possibly have cache lines with dirty, encrypted data Generic: - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs - Clean up and document/comment the irqfd assignment code - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related to private <=> shared memory conversions - Drop guest_memfd's .getattr() implementation as the VFS layer will call generic_fillattr() if inode_operations.getattr is NULL - Fix issues with dirty ring harvesting where KVM doesn't bound the processing of entries in any way, which allows userspace to keep KVM in a tight loop indefinitely - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking, now that KVM no longer uses assigned_device_count as a heuristic for either irqbypass usage or MDS mitigation Selftests: - Fix a comment typo - Verify KVM is loaded when getting any KVM module param so that attempting to run a selftest without kvm.ko loaded results in a SKIP message about KVM not being loaded/enabled (versus some random parameter not existing) - Skip tests that hit EACCES when attempting to access a file, and print a "Root required?" help message. In most cases, the test just needs to be run with elevated permissions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits) Documentation: KVM: Use unordered list for pre-init VGIC registers RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map() RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs RISC-V: perf/kvm: Add reporting of interrupt events RISC-V: KVM: Enable ring-based dirty memory tracking RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap RISC-V: KVM: Delegate illegal instruction fault to VS mode RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs RISC-V: KVM: Factor-out g-stage page table management RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence RISC-V: KVM: Introduce struct kvm_gstage_mapping RISC-V: KVM: Factor-out MMU related declarations into separate headers RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect() RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range() RISC-V: KVM: Don't flush TLB when PTE is unchanged RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize() RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init() RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list ...