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4 daysMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
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 ee1a586dd1fa "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 ...
6 daysMerge tag 's390-7.3-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Add a cpuidle driver with polling and enabled wait states using the existing CPU idle infrastructure and idle governor to improve latency for frequent sleep/wakeup cycles. Remove the obsolete tick delay heuristic and generic arch_needs_cpu() hook. Add the corresponding driver entry to MAINTAINERS - Add kCFI support using the generic support provided by Clang - Enable Clang CONTEXT_ANALYSIS for various architecture code and for char, PCI, CIO and virtio drivers. Add required lock annotations, exclude unsupported mm helpers and remove conditional PCI locking - Fix secure storage access exception handling and reintroduce DCACHE_WORD_ACCESS previously removed as a workaround - Fix cpum_cf perf crashes when CPUs are brought online while per-task events are active. Allocate and remove per-CPU counter data from CPU hotplug callbacks - Fix a deadlock when an s390dbf debug area is unregistered while one of its debugfs files is being written to - Fix MVIY_PERCPU() with binutils older than 2.39, where an assembler macro silently omitted an instruction needed to repair interrupted operations after CPU migration - Remove/replace cond_resched() calls which are no-ops with the supported s390 preemption models - Fix AP queue depth and maximum message length decoding according to the architecture. Current hardware is not affected, but future hardware could report values which were handled incorrectly - Reflect the configured CPU state in cpu_enabled_mask so deconfigured CPUs are not presented as available for onlining - Restore the vDSO GNU_EH_FRAME program header which was lost when the build switched to direct linker invocation, and mark it read-only - Add SCLP action qualifiers used by Spyre for card initialization, recoverable error and telemetry reporting - Move KMSAN interrupt flag helpers out of line to fix -Wstatic-in-inline build warnings - Use level-specific page table entry accessors for hugetlb entries and ptep_get() when accessing crashed kernel memory in kdump - Make forced AP bus rescans killable so that a user process blocked behind an ongoing scan can still be terminated with SIGKILL - Rework pkey ioctl error paths to remove duplicated cleanup code and avoid freeing error pointers - Allow the protected guest SWIOTLB buffer to be allocated outside the first 2GB. Also enable dynamic SWIOTLB growth and the coherent atomic pool fallback to improve I/O behavior when the initial pool is exhausted - Add program check statistics and spinlock contention tracepoints. Increase the lockdep chain capacity to keep lockdep enabled for complex code paths such as btrfs - Simplify IPL, trap and syscall code and remove the obsolete unistd_32.h generation entry * tag 's390-7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (59 commits) s390/percpu: Fix MVIY_PERCPU() with older binutils s390/debug: Fix deadlock during unregister s390/cpum_cf: Handle CPU hotplug via prepare/dead callbacks s390: Enable CONTEXT_ANALYSIS for various directories s390/mm: Add __context_unsafe() attribute to gmap helper functions s390/mm: Add __context_unsafe() attribute to do_secure_storage_access() s390/sysinfo: Add context analysis attributes s390/irqflags: Add out-of-line definitions of arch_local_irq_*() for KMSAN s390/virtio: Enable CONTEXT_ANALYSIS s390/cio: Enable CONTEXT_ANALYSIS s390/vfio_ccw: Add __must_hold() attribute to vfio_ccw_sch_quiesce() s390/pci: Enable CONTEXT_ANALYSIS s390/pci: Rework __zpci_event_availability() to remove conditional locking s390/pci: Rework __zpci_event_error() to remove conditional locking s390/char: Enable CONTEXT_ANALYSIS s390/con3215: Add __must_hold() attribute to raw3215_make_room() s390/ap: Fix MAPML computation s390/cio: Remove cond_resched() calls s390: Remove cond_resched() calls KVM: s390: Remove cond_resched() calls ...
8 daysMerge tag 'mm-stable-2026-08-18-18-39' of ↵Linus Torvalds
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 ...
8 daysMerge tag 'vfio-v7.3-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Add nv_falcon vfio selftest driver. The Falcon is a general-purpose microcontroller embedded within NVIDIA GPUs, presenting a relatively simple DMA programming interface. This adds another selftest target for vfio-pci with real DMA transfers (Rubin Du, Alex Williamson) - Add allocation assertion helpers to vfio selftests and use them to avoid variable length arrays and the compiler errors they generate (Alex Mastro) - Fix use-after-free hazard where an init path error in MSI support leaves a stray pointer that can later be reused or double-freed (Xiang Mei) - Fix previous refactor of PCI BAR mappings to honor non_mappable_bars flag, which otherwise generates a warning when trying to pci_iomap() a 256TiB BAR on ISM devices on s390 (Farhan Ali) - Add igb vfio selftest driver. Like nv_falcon, this provides another target for DMA testing with vfio selftests, but importantly this driver supports both physical 82576 NICs and the emulation model in QEMU. This therefore enables a vfio selftest vector with no physical hardware requirements (Josh Hilke, Alex Williamson) - Mark selftest fixture objects __maybe_unused to accommodate builds with clang -Wunused-but-set-global (David Matlack) - Add error recovery for vfio-pci devices on s390x. This expands devices which expose the existing error eventfd and introduces a device feature for reporting firmware defined error state information to the user, allowing recovery through hypervisor channels (Farhan Ali) * tag 'vfio-v7.3-rc1' of https://github.com/awilliam/linux-vfio: vfio/pci: Remove the pcie check for VFIO_PCI_ERR_IRQ_INDEX vfio-pci/zdev: Add a device feature for error information s390/pci: Store PCI error information for passthrough devices PCI/MSI: Enable memory decoding before restoring MSI-X messages PCI: Fail FLR when config space is inaccessible PCI: Avoid saving config space state if inaccessible PCI: Allow per function PCI slots to fix slot reset on s390 PCI: Introduce PCI_SLOT_PLACEHOLDER constant for slot_nr placeholder value selftests: harness: Mark test fixture objects __maybe_unused vfio: selftests: Retry on EAGAIN during device reset vfio: selftests: igb: Add driver for Intel 82576 device vfio: selftests: Add helpers to re-enable interrupts vfio/pci: Avoid mapping BARs for devices with non-mappable BARs vfio/pci: clear vdev->msi_perm after freeing it on init failure vfio: selftests: Avoid VLAs vfio: selftests: Add allocation assert helpers vfio: selftests: Add NVIDIA Falcon driver for DMA testing vfio: selftests: Allow drivers without send_msi() support vfio: selftests: Add generic PCI command register helpers vfio: selftests: Add memcpy chunking to vfio_pci_driver_memcpy()
11 daysMerge tag 'timers-cleanups-2026-08-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull treewide timer related cleanups from Thomas Gleixner: - Remove the leftover CLOCK_TICK_RATE which has been scheduled for removal more than a decade ago along with some now empty asm/timex.h files. - Consolidate delay timer calibration The construct of having a define in a header requires that architectures provided asm/timex.h for no reason. Also the function name for reading the delay timer is confusing at best. Use a config switch to enable that functionality and rename the function to delay_read_timer() to make the purpose clear. This removes some more now empty asm/timex.h files as well. * tag 'timers-cleanups-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: calibrate: Rework delay timer calibration treewide: Remove CLOCK_TICK_RATE x86: Use PIT_TICK_RATE instead of CLOCK_TICK_RATE
11 daysMerge tag 'core-entry-2026-08-17' of ↵Linus Torvalds
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() ...
11 daysMerge tag 'locking-core-2026-08-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Futexes: - Use runtime constants for futex_hash computation (K Prateek Nayak, Peter Zijlstra) - Optimise the size check get_futex_key() (Sebastian Andrzej Siewior) - Avoid private hash use-after-free on final put (Felix Hoffmann) - Tell kmemleak we're not leaking __futex_queues (Peter Zijlstra) Rust integration updates: - Implement refcounted interrupt disable and SpinLockIrq for Rust (Boqun Feng, Heiko Carstens, Joel Fernandes, Lyude Paul) - Rust sync: add helpers for mb, dma_mb and friends; add generic memory barriers and use LKMM atomics instead of Rust atomics in the revocable code (Gary Guo) - Add abstraction and integrate synchronize_rcu() (Philipp Stanner) Lock debugging: - Add qspinlock contended_release tracepoint (Dmitry Ilvokhin, Peter Zijlstra) - Enable the printing of held locks of remote running tasks and print task CPU (Ingo Molnar) - percpu-rwsem: Annotate intentional data race in readers_active_check() (Sun Shaojie) Misc fixes and updates by Boqun Feng, Peter Zijlstra, Fangrui Song, Naveen Kumar Chaudhary and Thomas Huth" * tag 'locking-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) rust: sync: Introduce SpinLockIrq::lock_with() and friends rust: sync: Add SpinLockIrq rust: sync: Use super::* in spinlock.rs rust: helper: Add spin_{un,}lock_irq_{enable,disable}() helpers rust: Introduce interrupt module s390/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS arm64: sched/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITS sched: Avoid signed comparison of preempt_count() in __cant_migrate() sched: Remove the unused preempt_offset parameter of __cant_sleep() locking: Switch to _irq_{disable,enable}() variants in cleanup guards irq: Add KUnit test for refcounted interrupt enable/disable irq,spin_lock: Add counted interrupt disabling/enabling openrisc: Include <linux/cpumask.h> in smp.h preempt: Introduce __preempt_count_{sub,add}_return() preempt: Introduce HARDIRQ_DISABLE_BITS preempt: Track NMI nesting to separate per-CPU counter futex: Tell kmemleak we're not leaking __futex_queues x86/paravirt: Trace contended_release on unlock tracing/lock: Use TRACE_EVENT_FN() for contended_release ...
2026-08-13vfio-pci/zdev: Add a device feature for error informationFarhan Ali
For zPCI devices, we have platform specific error information. The platform firmware provides this error information to the operating system in an architecture specific mechanism. To enable recovery from userspace for these devices, we want to expose this error information to userspace. Add a new device feature to expose this information. Userspace needs to be provide a buffer of fixed size. This size is provided to userspace via the VFIO_DEVICE_INFO_CAP_ZPCI_BASE capability. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Link: https://lore.kernel.org/r/20260630165553.725-3-alifm@linux.ibm.com Signed-off-by: Alex Williamson <alex@shazbot.org>
2026-08-13s390/pci: Store PCI error information for passthrough devicesFarhan Ali
For a passthrough device we need co-operation from user space to recover the device. This would require to bubble up any error information to user space. Let's store this error information for passthrough devices, so it can be retrieved later. We can now have userspace drivers (vfio-pci based) on s390x. The userspace drivers will not have any KVM fd and so no kzdev associated with them. So we need to update the logic for detecting passthrough devices to not depend on struct kvm_zdev. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Link: https://lore.kernel.org/r/20260630165553.725-2-alifm@linux.ibm.com Signed-off-by: Alex Williamson <alex@shazbot.org>
2026-08-13s390/percpu: Fix MVIY_PERCPU() with older binutilsKarl Mehltretter
Commit a737737cdb9c ("s390/percpu: Infrastructure for more efficient this_cpu operations") introduced MVIY_PERCPU(), which stringifies arguments that are already C string literals. This generates an assembler macro invocation with whitespace-separated quoted arguments: GEN_MVIY "459712" "%r3" GNU as versions prior to binutils 2.39 drop the separating whitespace between quoted macro arguments during input scrubbing. They consequently parse the invocation as a single argument and emit repeated warnings: Warning: missing closing `"' The .ifc in GEN_MVIY never matches and GNU as exits successfully without emitting the mviy instruction. As a result, the interrupted per-CPU sequence is not marked in lowcore and the exception return path cannot repair the per-CPU address register after migration. All MVIY_PERCPU() callers pass C string literals. Use them directly and separate the assembler macro arguments with an explicit comma. The resulting invocation is: GEN_MVIY 459712, %r3 This form is unambiguous for GNU as and LLVM's integrated assembler. This behavior was fixed in GNU as from binutils 2.39, but Linux supports binutils 2.30. Fixes: a737737cdb9c ("s390/percpu: Infrastructure for more efficient this_cpu operations") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-08-13KVM: s390: gmap: Make storage keys optionalSteffen Eiden
Guard guest storage key handling behind `KVM_S390_MANAGES_S390_GUEST`. This enables other KVM implementations to use gmap without implementing storage key infrastructure. Define KVM_S390_MANAGES_S390_GUEST to 1 for KVM hosts managing s390 guests (in kvm_host_s390.h). A KVM implementation not implementing those features must define KVM_S390_MANAGES_S390_GUEST to 0 in its kvm_host_<guest_arch>.h. No functional changes besides the new guard. Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-08-13KVM: s390: Move PGM code definitions to asm/kvm_host.hSteffen Eiden
Move PGM code definitions from kvm_host_s390.h (back) to the generic kvm_host.h. These definitions are needed by multiple KVM implementations and should be in a shared location. No functional change. Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-08-13KVM: s390: Move kvm_host definitions to kvm_host_s390Steffen Eiden
Rename kvm_host.h to kvm_host_s390.h and kvm_host_types.h to kvm_host_s390_types.h to distinguish s390-specific KVM definitions from the generic kvm_host.h that will be used for shared definitions. No functional change. Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-08-12Merge remote-tracking branch 'kvms390/master' into 'kvms390/next'Christian Borntraeger
2026-08-11s390/irqflags: Add out-of-line definitions of arch_local_irq_*() for KMSANIlya Leoshkevich
Inline KMSAN arch_local_irq_*() definitions run afoul of -Wstatic-in-inline. Move them out-of-line. Make sure decompressor and non-GPL modules see the out-of-line definitions. Cc: Boqun Feng <boqun@kernel.org> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202607131219.euJHPSJ5-lkp@intel.com/ Suggested-by: Heiko Carstens <hca@linux.ibm.com> Fixes: 1b301f5f28ba ("s390/irqflags: do not instrument arch_local_irq_*() with KMSAN") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-08-11KVM: s390: Fix memory corruption by not reinjecting CK machine checksChristian Borntraeger
Channel-subsystem damage machine checks are for the host channel subsystem. The guest channel subsystem is emulated in the userspace VMM. There is no point in forwarding such machine checks into the guest. This also simplifies the machine check reinjection and avoids kfree of a stack variable as reported by sashiko. There might be still machine checks that have the ck bit set with another bit (like instruction damage), mask out the CK bit in s390_backup_mcck_info(), like the CP and ED bits already are. Fixes: 4d62fcc0b692 ("KVM: s390: Inject machine check into the guest") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260806145835.31818-1-borntraeger@linux.ibm.com>
2026-08-10KVM: s390: vsie: Create constant SCB_ALIGNMENT_SHIFTChristoph Schlameuss
Create a simple constant for the SCB alignment shift. Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-08-10s390/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITSHeiko Carstens
Convert s390's preempt_count to 64 bit, and change the preempt primitives accordingly. [boqun: Apply the corrected comment for asm block] Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260804161447.84806-13-boqun@kernel.org
2026-08-08preempt: Introduce __preempt_count_{sub,add}_return()Boqun Feng
In order to use preempt_count() to track the interrupt disable nesting level, __preempt_count_{add,sub}_return() are introduced, as their names suggest, these primitives return the new value of the preempt_count() after changing it. The following example shows the usage of it in local_interrupt_disable(): // increase the HARDIRQ_DISABLE bit new_count = __preempt_count_add_return(HARDIRQ_DISABLE_OFFSET); // if it's the first-time increment, then disable the interrupt // at hardware level. if ((new_count & HARDIRQ_DISABLE_MASK) == HARDIRQ_DISABLE_OFFSET) { local_irq_save(flags); raw_cpu_write(local_interrupt_disable_state, flags); } Having these primitives will avoid a read of preempt_count() after changing preempt_count() on certain architectures. Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://patch.msgid.link/20260804161447.84806-4-boqun@kernel.org
2026-08-05KVM: s390: Remove cond_resched() callsHeiko Carstens
Since [1] cond_resched() is a no-op on s390. Remove all calls. This also entirely removes uv_call_sched() and replaces all call sites with uv_call(), since both functions are identical after the removal of cond_resched(). [1] commit 7dadeaa6e851 ("sched: Further restrict the preemption modes") Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-08-05s390/crypto: Replace cond_resched() with msleep(1)Peter Zijlstra
With [1] cond_resched() is always compiled away and becomes a no-op. The comments for all cond_resched() calls in crypto code however indicate that the current process should be scheduled away to avoid instant re-invocation of a callback. This is not what cond_resched() would do or did. Instead of just removing the cond_resched() calls, replace them with msleep() calls, as suggested by Holger Dengler. This forces the current task to be scheduled away (sleeps) like originally intended. Holger provided information why this intended [2]: " Let me give a bit of background here: The protected key can only get invalid, if the Linux instance (z/VM or KVM guest) is moved to another hypervisor on a different machine (aka life guest relocation). In such a case, the crypto accelerator card and the host has to exchange the "real key", which is wrapped by the host and handed back to the guest as the re-newed protected key. Unfortunately there is no asynchronous trigger on completion, you have to re-try (and maybe get another "in progress" return). And as if that weren't bad enough, if this key exchange between card and host is the first one, card and host has to instantiate a secure communication channel (including a key exchange for the transport layer). " [1] commit 7dadeaa6e851 ("sched: Further restrict the preemption modes") [2] https://lore.kernel.org/all/39570813-27b0-40f9-89c5-8e2dce05e2f0@linux.ibm.com/ [3] https://lore.kernel.org/all/20260731084027.GE776954@noisy.programming.kicks-ass.net/ [hca@linux.ibm.com: took Peter's patch [3] and provided commit message] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-08-05s390/bpf: Add kCFI supportHeiko Carstens
This is the s390 variant of commit 710618c760c0 ("arm64/cfi,bpf: Support kCFI + BPF on arm64"). Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-08-04mm: rename uffd-wp PTE accessors to uffdKiryl Shutsemau (Meta)
Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking PTEs, alongside the write-protected ones it already marks. The bit's meaning now depends on the VMA flag (WP or RWP), not on its name. Rename the kernel-internal names that describe the bit: - pte/pmd/huge_pte accessors (and swap variants) - pgtable_supports_uffd() capability query - SCAN_PTE_UFFD khugepaged enum The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is kept as "pte_uffd_wp" so existing trace-based tooling keeps matching. Pure mechanical rename -- no behavior change. Link: https://lore.kernel.org/20260708111417.173443-4-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau <kas@kernel.org> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@kernel.org> Cc: James Houghton <jthoughton@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04mm: decouple protnone helpers from CONFIG_NUMA_BALANCINGKiryl Shutsemau (Meta)
Patch series "userfaultfd: working set tracking for VM guest memory", v10. This series 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. This patch (of 15): pte_protnone() and pmd_protnone() detect present-but-inaccessible page table entries. This capability is useful beyond NUMA balancing -- for example, userfaultfd working set tracking uses protnone PTEs to track page access without unmapping pages. Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE infrastructure from CONFIG_NUMA_BALANCING. The six architectures that support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now select this option, and CONFIG_NUMA_BALANCING depends on it. No functional change -- the same set of architectures continues to have working protnone support, but the infrastructure is now available independently of NUMA balancing. Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org> Assisted-by: Claude:claude-opus-4-6 Acked-by: SeongJae Park <sj@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@kernel.org> Cc: James Houghton <jthoughton@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-03KVM: s390: Fix unlikely NULL gmap dereferenceClaudio Imbrenda
When creating a new vCPU, kvm_vm_ioctl_create_vcpu() will call kvm_arch_vcpu_postcreate() after the file descriptor for the new vCPU has been created. The new file descriptor has not been returned yet, but a malicious userspace program could try to guess it. If a malicious userspace program manages to start the newly created vCPU before kvm_arch_vcpu_postcreate() is called, __vcpu_run() will try to dereference vcpu->arch.gmap and trigger a NULL pointer dereference. Fix this by adding a new field to struct kvm_vcpu_arch to keep track of the initialization status of the vCPU. Refuse to run a vCPU that is not fully initialized. Fixes: dafd032a15f8 ("KVM: s390: move vcpu specific initalization to a later point") Fixes: e38c884df921 ("KVM: s390: Switch to new gmap") Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260803124040.126471-2-imbrenda@linux.ibm.com>
2026-07-31s390/sclp: Allow SCLP Action Qualifiers for Spyre card status reportingNiklas Schnelle
Add SCLP Action Qualifiers used by the Spyre stack for reporting of the card's initialization status, recoverable errors, and telemetry data. Co-developed-by: Andreas Krebbel <krebbel@linux.ibm.com> Signed-off-by: Andreas Krebbel <krebbel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-31s390/ap: Fix queue depth field lengthFinn Callies
The queue depth field is defined as a 5 bit field in the Z architecture instead of a 4 bit field. The queue depth (qd) can be in range 0-31 and is reported in bits 59-63 of the TAPQ response. Currently this has no effect as all CEX generations report a queue depth of 7, which fits into 4 bits. However, future CEX generations reporting a value >15 would not be properly reflected by the ap bus and therefore all user space applications relying on it. Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Signed-off-by: Finn Callies <fcallies@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-30mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVESUsama Arif
CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. PMD-level device-private entries use the same migration mechanism and therefore require the same architecture support. Upcoming PMD-level swap entries can use the same PMD softleaf helpers without depending on page migration, so rename the architecture gate to CONFIG_ARCH_HAS_PMD_SOFTLEAVES. This describes the PMD entry capability rather than one current user of it. This is a pure rename: the set of selecting architectures (x86, arm64, s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating semantics are unchanged. No functional change intended. Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev Signed-off-by: Usama Arif <usama.arif@linux.dev> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-30s390: Add support for DCACHE_WORD_ACCESS (again)Heiko Carstens
Implement load_unaligned_zeropad() and enable DCACHE_WORD_ACCESS to speed up string operations in fs/dcache.c and fs/namei.c. With the secure storage access exception cases addressed, add support for DCACHE_WORD_ACCESS again. Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-30KVM: s390: pv: Use VM_SPARSE area for guest variable storage areaHeiko Carstens
The guest variable storage area is allocated with vmalloc and then donated to the ultravisor. Any kernel access to that area will result in a secure storage access exception (aka fault). This is a problem if such a memory area is read via /proc/kcore. This causes an exception via vread_iter() and results in an unexpected short read. Avoid this by allocating a custom VM_SPARSE area. If such an area is read, vread_iter() returns zeroes for the entire area. Note that the function which frees the area does not update ptes. This is intentional to allow for deferred / lazy pte updates and TLB flushing like the generic vfree() code is doing that. See vunmap_pte_range(). This assumes that s390 will gain full support for lazy_mmu_mode_enable() and lazy_mmu_mode_disable() in the future, since as of now the used ptep_get_and_clear() in vunmap_pte_range() does indeed invalidate and flush every single pte entry, but only for s390. Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-30s390/traps: Remove PIF_GUEST_FAULTSven Schnelle
PIF_GUEST_FAULT is only used to pass information whether a fault was caused when executing SIE or when executing host code. Instead of using ptregs for this, just pass the flag directly as argument to __do_pgm_check(). This also saves the time required to read the flag from ptregs, although this likely isn't much as it is already in the data cache. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-30s390/uapi: Remove obsolete unistd_32.h from Kbuild fileThomas Huth
unistd_32.h is not build anymore since commit 4ac286c4a8d90 ("s390/syscalls: Switch to generic system call table generation"). Thus drop the superfluous line from the Kbuild file now, too. Signed-off-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-29s390/runtime-const: Introduce runtime_const_mask_32()K Prateek Nayak
Futex hash computation requires a mask operation with read-only after init data that will be converted to a runtime constant in the subsequent commit. Introduce runtime_const_mask_32 to further optimize the mask operation in the futex hash computation hot path. GCC generates a: nilf %r1,<imm32> to tackle arbitrary 32-bit masks and the same is implemented here. Immediate patching pattern for __runtime_fixup_mask() has been adopted from __runtime_fixup_ptr(). Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://patch.msgid.link/20260728052540.4728-7-kprateek.nayak@amd.com
2026-07-27KVM: s390: Fall back to short-term pinning in MAP ioctlJaehoon Kim
FOLL_LONGTERM pinning fails for some memory types, such as file-backed guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and irqfd adapter registration fails even though interrupt delivery could still work via the existing non-atomic path. When FOLL_LONGTERM pinning fails, verify that the page is accessible using a short-term pin instead. If the short-term pin succeeds, unpin the page and add a map entry with pinned=false to preserve MAP/UNMAP symmetry. The non-atomic irqfd path already performs short-term pinning for interrupt delivery, so this restores the previous behavior for memory that cannot be pinned long-term. get_map_info() is updated to return NULL for unpinned entries so that the atomic irqfd fast path falls back to the non-atomic path. kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty marking and unpin for unpinned entries. Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the new MAP/UNMAP behavior. Fixes: c9a568838086 ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest") Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com> Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2026-07-15treewide: Remove CLOCK_TICK_RATEThomas Gleixner
This has been scheduled for removal more than a decade ago and the comments related to it have been dutifully ignored. The last dependencies are gone. Remove it along with various now empty asm/timex.h files. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Link: https://patch.msgid.link/20260410120317.910770161@kernel.org
2026-07-14syscall_user_dispatch: Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCHJinjie Ruan
Currently, only x86 genuinely implements and supports Syscall User Dispatch (SUD). Multiple architectures provide a stub arch_syscall_is_vdso_sigreturn() returning 'false' simply to satisfy GENERIC_ENTRY compilation, which creates a false impression of feature support. Introduce ARCH_SUPPORTS_SYSCALL_USER_DISPATCH to decouple this mechanism from GENERIC_ENTRY. Select it exclusively on x86 and remove the redundant stub functions from other architectures. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Link: https://patch.msgid.link/20260713035422.582771-1-ruanjinjie@huawei.com
2026-07-08s390: Enable TIF_POLLING_NRFLAGMete Durlu
Enable TIF_POLLING_NRFLAG to support idle polling state in the upcoming cpuidle driver. Signed-off-by: Mete Durlu <meted@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-08s390/tick: Remove CIF_NOHZ_DELAY flagMete Durlu
Remove obsolete tick delay heuristic [1]. The upcoming cpuidle driver handles frequent sleep/wakeup cycles more effectively. [1] https://lore.kernel.org/all/20090929122533.402715150@de.ibm.com/ Suggested-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Mete Durlu <meted@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-08s390/mm: Use set_pmd() / set_pud() for hugetlb pagetable entriesGerald Schaefer
hugetlb code is known to view all pagetable entries as PTEs, instead of corresponding upper levels like PMD or PUD. For s390, with different pagetable entry layout for different levels, this requires some conversion action under the hood. The converted PMD and PUD entries are then written via set_pte() function, but that might add some PTE-specific modifications. There is no functional problem with current code, and the clearing of _PAGE_UNUSED in set_pte(). Avoid future problems by using the set_pmd() and set_pud() functions instead. Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2026-07-03Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> ↵Uwe Kleine-König (The Capable Hub)
(headers) <linux/mod_devicetable.h> is included in a many files: $ git grep '<linux/mod_devicetable.h>' ef0c9f75a195 | wc -l 1598 ; some of them are widely used headers. To stop mixing up different and unrelated driver( type)s let the subsystem headers only use the subset of the recently split <linux/mod_devicetable.h> that are relevant for them. The fallout (I hope) is addressed in the previous commits that handle sources relying on e.g. <linux/i2c.h> pulling in the full legacy header and thus providing pci_device_id. Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://patch.msgid.link/199fe46b624ba07fb9bd3e0cd6ff13757932cb5f.1782808461.git.u.kleine-koenig@baylibre.com Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
2026-06-25Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "s390: - Fix S390_USER_OPEREXEC so it can now be enabled regardless of other unrelated capabilities - Fix handling of the _PAGE_UNUSED pte bit that could lead to guest memory corruption in some scenarios - A bunch of misc gmap fixes (locking, behaviour under memory pressure) - Fix CMMA dirty tracking x86: - Tidy up some WARN_ON() and BUG_ON(), replacing them with WARN_ON_ONCE() or KVM_BUG_ON(). All of these have obviously never triggered, or somebody would have been annoyed earlier, but still... - Fix missing interrupt due to stale CR8 intercept - Add a statistic that can come in handy to debug leaks as well as the vulnerability to a class of recently-discovered issues - Do not ask arch/x86/kernel to export default_cpu_present_to_apicid() just for KVM" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits) x86/apic: KVM: Use cpu_physical_id() to get APIC ID of running vCPU for AVIC KVM: x86/mmu: Expose number of shadow MMU shadow pages as a stat KVM: x86: Unconditionally recompute CR8 intercept on PPR update KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails KVM: x86: WARN and fail kvm_set_irq() if a PIC or I/O APIC vector is invalid KVM: x86: Bug the VM, not the kernel, if the ISR count {under,over}flows KVM: x86/mmu: Bug the VM, not the host kernel, if KVM write-protects upper SPTEs KVM: x86: Replace BUG_ON() with WARN_ON_ONCE() on "bad" nested GPA translation KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned() KVM: s390: Return failure in case of failure in kvm_s390_set_cmma_bits() KVM: s390: selftests: Fix cmma selftest KVM: s390: Fix cmma dirty tracking KVM: s390: Fix locking in kvm_s390_set_mem_control() KVM: s390: Fix handle_{sske,pfmf} under memory pressure KVM: s390: Fix code typo in gmap_protect_asce_top_level() KVM: s390: Do not set special large pages dirty KVM: s390: Fix dat_peek_cmma() overflow s390/mm: Fix handling of _PAGE_UNUSED pte bit KVM: s390: Fix typo in UCONTROL documentation ...
2026-06-24Merge tag 'kvm-s390-next-7.2-2' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD * Fix S390_USER_OPEREXEC so it can now be enabled regardless of other unrelated capabilities * Fix handling of the _PAGE_UNUSED pte bit that could lead to guest memory corruption in some scenarios * A bunch of misc gmap fixes (locking, behaviour under memory pressure) * Fix CMMA dirty tracking
2026-06-24s390/mm: Fix handling of _PAGE_UNUSED pte bitClaudio Imbrenda
The _PAGE_UNUSED softbit should not really be lying around. Its sole purpose is to signal to try_to_unmap_one() and try_to_migrate_one() that the page can be discarded instead of being moved / swapped. KVM has no way to know why a page is being unmapped, so it sets the bit on userspace ptes corresponding to unused guest pages every time they get unmapped. KVM has no reasonable way to clear the bit once the page is in use again. While set_ptes() checks and clears the bit, other paths that set new ptes did not. This led to used pages being thrown out as if they were unused, causing guest corruption. Fix the issue by clearing the _PAGE_UNUSED bit for present ptes in set_pte(), i.e. whenever a present pte is getting set. The check in set_ptes() is then redundant and can be removed. Also fix gmap_helper_try_set_pte_unused() to only set the bit if the pte is present; the _PAGE_UNUSED bit is only defined for present ptes and thus should not be set for non-present ptes. Fixes: c98175b7917f ("KVM: s390: Add gmap_helper_set_unused()") Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260623153331.233784-2-imbrenda@linux.ibm.com>
2026-06-22Merge tag 's390-7.2-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - consolidate s390 idle time accounting by moving all CPU time tracking to the architecture backend and eliminate the mix of architecture- specific and common code accounting - Add missing EXPORT_SYMBOL_GPL() to kcpustat_field_idle() and kcpustat_field_iowait() functions - Finalize ptep_get() conversion by replacing direct page table entry dereferencing with proper accessors (ptep_get(), pmdp_get(), etc.) - Explicitly check the buffer length in PKEY_VERIFYPROTK ioctl and pkey_pckmo implementations and fail if the length is exceeded * tag 's390-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pkey: Check length in pkey_pckmo handler implementation s390/pkey: Check length in PKEY_VERIFYPROTK ioctl s390/idle: Add missing EXPORT_SYMBOL_GPL() s390/mm: Complete ptep_get() conversion s390/idle: Remove idle time and count sysfs files s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait() s390/irq/idle: Use stcke instead of stckf for time stamps s390/timex: Move union tod_clock type to separate header
2026-06-21Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen) Fix a taskstats TGID aggregation bug where fields added in the TGID query path were not preserved after thread exit, and adds a kselftest covering the regression. - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko) Improve lib/tests/string_helpers_kunit.c a little - "lib/base64: decode fixes" (Josh Law) Address minor issues in lib/base64.c - "selftests/filelock: Make output more kselftestish" (Mark Brown) Make the output from the ofdlocks test a bit easier for tooling to work with. Also ignore the generated file - "uaccess: unify inline vs outline copy_{from,to}_user() selection" (Yury Norov) Simplify the usercopy code by removing the selectability of inlining copy_{from,to}_user(). - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang) Fix a number of possible issues in the ocfs2 xattr code - "lib and lib/cmdline enhancements" (Dmitry Antipov) Provide additional robustness checking in the cmdline handling code and its in-kernel testing and selftests - "cleanup the RAID6 P/Q library" (Christoph Hellwig) Clean up the RAID6 P/Q library to match the recent updates to the RAID 5 XOR library and other CRC/crypto libraries - "ocfs2: harden inode validators against forged metadata" (Michael Bommarito) Add three structural checks to OCFS2 dinode validation so malformed on-disk fields are rejected before ocfs2_populate_inode() copies them into the in-core inode - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike Rapoport) Clean up the lib/raid code by using kmalloc() in more places * tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits) ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits lib: interval_tree_test: validate benchmark parameters ocfs2: avoid moving extents to occupied clusters treewide: fix transposed "sign" typos and update spelling.txt ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec fat: reject BPB volumes whose data area starts beyond total sectors selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems lib/test_firmware: allocate the configured into_buf size fs: efs: remove unneeded debug prints checkpatch: cuppress warnings when Reported-by: is followed by Link: MAINTAINERS: add Alexander as a kcov reviewer mailmap: update Alexander Sverdlin's Email addresses fs: fat: inode: replace sprintf() with scnprintf() ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release() ocfs2/dlm: require a ref for locking_state debugfs open ocfs2: reject FITRIM ranges shorter than a cluster ocfs2: validate fast symlink target during inode read ocfs2: add journal NULL check in ocfs2_checkpoint_inode() ...
2026-06-19Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "arm64: This is a bit of an odd merge window on the KVM/arm64 front. There is absolutely no new feature in the pull request. It is purely fixes, because it is simply becoming too hard to review new stuff when so many AI-fuelled fixes hit the list. - Significant cleanup of the vgic-v5 PPI support which was merged in 7.1. This makes the code more maintainable, and squashes a couple of bugs in the meantime - Set of fixes for the handling of the MMU in an NV context, particularly VNCR-triggered faults. S1POE support is fixed as well - Large set of pKVM fixes, mostly addressing recurring issues around hypervisor tracking of donated pages in obscure cases where the donation could fail and leave things in a bizarre state - Fixes for the so-called "lazy vgic init", which resulted in sleeping operations in non-preemptible sections. This turned out to be far more invasive than initially expected.. - Reduce the overhead of L1/L2 context switch by not touching the FP registers - Fix the way non-implemented page sizes are dealt with when a guest insist on using them for S2 translation - The usual set of low-impact fixes and cleanups all over the map Loongarch: - On a request for lazy FPU load, load all FPU state that the VM supports instead of enabling only the part (FPU, LSX or LASX) that caused the FPU load request - Some enhancements about interrupt injection - Some bug fixes and other small changes RISC-V: - Batch G-stage TLB flushes for GPA range based page table updates - Convert HGEI line management to fully per-HART - Fix missing CSR dirty marking when FWFT state updated via ONE_REG - Fix stale FWFT feature exposure to Guest/VM - Speed up dirty logging write faults using MMU rwlock and atomic PTE updates using cmpxchg() for permission-only changes - Use flexible array for APLIC IRQ state - Use kvm_slot_dirty_track_enabled() for logging enable check on a memslot - Avoid skipping valid pages in kvm_riscv_gstage_wp_range() - Avoid skipping valid pages in kvm_riscv_gstage_unmap_range() - Use endian-specific __lelong for NACL shared memory S390: - KVM_PRE_FAULT_MEMORY support - Support for 2G hugepages - Support for the ASTFLEIE 2 facility - Support for fast inject using kvm_arch_set_irq_inatomic - Fix potential leak of uninitialized bytes - A few more misc gmap fixes x86: - Generic support for the more granular permissions allowed by EPT, namely "read" (which was previously usurping the U bit) and separate execution bits for kernel and userspace - Do not assume that all page tables start with U=1/W=1/NX=0 at the root, as AMD GMET needs to have U=0 at the root - Introduce common assembly macros for use within Intel and AMD vendor-specific vmentry code. This touches the SPEC_CTRL handling, which is now entirely done in assembly for Intel (by reusing the AMD code that already existed), and register save/restore which uses some macro magic to compute the offsets in the struct. Both of these are preparatory changes for upcoming APX support - Clean up KVM's register tracking and storage, primarily to prepare for APX support, which expands the maximum number of GPRs from 16 to 32 - Keep a single copy of the PDPTRs rather than two, since architecturally there is just one - Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code gets a chance to handle things like reaping the PML buffer - Update KVM's view of PV async enabling if and only if the MSR write fully succeeds - Fix a variety of issues where the emulator doesn't honor guest-debug state, and clean up related code along the way - Synthesize EPT Violation and #NPF "error code" bits when injecting faults into L1 that didn't originate in hardware (in which case the VMCS/VMCB doesn't hold relevant information) - Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID faulting - Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a variety of minor bugs along the way - Fix an OOB memory access due to not checking the VP ID when handling a Hyper-V PV TLB flush for L2 - Fix a bug in the mediated PMU's handling of fixed counters that allowed the guest to bypass the PMU event filter - Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so the KVM can forward a "retry" status code to the guest, and reserve all unused error codes for future usage - Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific logic as possible into the TDX code, and to funnel (almost) all S-EPT updates into a single chokepoint. The motivation is largely to prepare for upcoming Dynamic PAMT support, but the cleanups are nice to have on their own - Plug a hole in shadow page table handling, where KVM fails to recursively zap nested EPT/NPT shadow page tables when the nested hypervisor tears down its own EPT/NPT page tables from the bottom up x86 (Intel): - Support for nested MBEC (Mode-Based Execute Control), see above in the generic section; also run with MBEC enabled even for non-nested mode - Use the kernel's "enum pg_level" in the TDX APIs instead of the TDX-Module's level definitions (which are 0-based) - Rework the TDX memory APIs to not require/assume that guest memory is backed by "struct page" (in prepartion for guest_memfd hugepage support) - Fix a largely benign bug where KVM TDX would incorrectly state it could emulate several x2APIC MSRs - Use the "safe" WRMSR API when proxying LBR MSR writes as the to-be-written value is guest controlled and completely unvalidated x86 (AMD): - Support for nested GMET (Guest Mode Execution Trap), see above in the generic section; also run with GMET enabled even for non-nested mode - Fixes and minor cleanups to GHCB handling, on top of the earlier work already merged into 7.1-rc - Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking fastpath handlers - Add support for virtualizing gPAT (KVM previously just used L1's PAT when running L2) - Fix goofs where KVM mishandles side effects (e.g. single-step and PMC updates) when emulating VMRUN - Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most notably where KVM didn't disable interception of IRR, ISR, and TMR regs - Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU - Don't advertise support for unusable VM types, and account for VM types that are disabled by firmware, e.g. to mitigate security vulnerabilities - Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with bugs and unnecessarily complicated, and add comprehensive tests - Clean up and deduplicate the SEV page pinning code - Fix minor goofs related to writing back CPUID information after firmware rejects a CPUID page for an SNP vCPU Generic: - Rename invalidate_begin() to invalidate_start() throughout KVM to follow the kernel's nomenclature, e.g. for mmu_notifiers - Use guard() to cleanup up various KVM+VFIO flows - Minor cleanups guest_memfd: - Return -EEXIST instead of -EINVAL if userspace attempts to bind a gmem range to multiple memslots, and fix the test that was supposed to ensure KVM returns -EEXIST - Treat memslot binding offsets and sizes as unsigned values to fix a bug where KVM interprets a large "offset + size" as a negative value and allows a nonsensical offset - Use the inode number instead of the page offset for the NUMA interleaving index to fix a bug where the effective index would jump by two for consecutive pages (the caller also adds in the page offset) Selftests: - Randomize the dirty log test's delay when reaping the bitmap on the first pass, as always waiting only 1ms hid a KVM RISC-V bug as the test reaped the bitmap before KVM could build up enough state to hit the bug - A pile of one-off fixes and cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (326 commits) KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level KVM: x86: Fix shadow paging use-after-free due to unexpected role KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject KVM: s390: Enable adapter_indicators_set to use mapped pages KVM: s390: Add map/unmap ioctl and clean mappings post-guest riscv: kvm: Use endian-specific __lelong for NACL shared memory KVM: selftests: access_tracking_perf_test: bump number of NUMA nodes to 32 KVM: s390: vsie: Implement ASTFLEIE facility 2 KVM: s390: vsie: Refactor handle_stfle s390/sclp: Detect ASTFLEIE 2 facility KVM: s390: Minor refactor of base/ext facility lists KVM: x86/mmu: move pdptrs out of the MMU KVM: x86: check that kvm_handle_invpcid is only invoked with shadow paging KVM: nSVM: invalidate cached PDPTRs across nested NPT transitions KVM: nVMX: remove unnecessary code in prepare_vmcs02_rare KVM: x86: remove nested_mmu from mmu_is_nested() KVM: arm64: vgic-its: Make ABI commit helpers return void KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory LoongArch: KVM: Add missing slots_lock for device register/unregister LoongArch: KVM: Validate irqchip index in irqfd routing ...
2026-06-16s390/mm: Complete ptep_get() conversionAlexander Gordeev
Finalize commit c33c794828f2 ("mm: ptep_get() conversion") and replace direct page table entry dereferencing with the proper accessors (ptep_get(), pmdp_get(), etc.). Override the default getter implementations even though they are currently identical: pud_clear(), p4d_clear(), and pgd_clear() require corresponding architecture-specific getters, but these are not yet defined. This avoids a dependency loop. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-06-16Merge branch 'idle-time-acc' into featuresAlexander Gordeev
Heiko Carstens says: =================== This is supposed to improve s390 idle time accounting, and brings it back to the state it was before arch_cpu_idle_time() was removed from s390 [3]. In result all cpu time accounting is done by the s390 architecture backend again, instead of having a mix of architecure specific and common code accounting (common code: idle, s390 architecture: everything else). =================== Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2026-06-16Merge tag 's390-7.2-1' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Use CIO device online variable instead of the internal FSM state to determine device availability during purge operations - Remove extra check of task_stack_page() because try_get_task_stack() already takes care of that when reading /proc/<pid>/wchan - Allow user-space to use the new SCLP action qualifier 4 for to provide NVMe SMART log data to the platform. - Send AP CHANGE uevents on successful bind and successful association to notify user-space about SE operations on AP queue devices - Add an s390dbf kernel parameter to configure debug log levels and area sizes during early boot - On arm64 the empty zero page is going to be mapped read-only. Do the same for s390 with an explicit set_memory_ro() call - Improve s390-specific bcr_serialize() and cpu_relax() implementations - Remove all unused variables to avoid allmodconfig W=1 build fails with latest clang-23 - Cleanup default Kconfig values for s390 selftests - Add a s390-tod trace clock to allow comparing trace timestamps between different systems or virtual machines on s390 - Remove the s390 implementation of strlcat() in favor of the generic variant - Make consistent the calling order between page_table_check_pte_clear() and secure page conversion across all code paths - Rearrange some fields within AP and zcrypt structs to reduce memory consumption and unused holes - Shorten GR_NUM and VX_NUM macros and move them to a separate header - Replace __get_free_page() with kmalloc() in few sources - Introduce an infrastructure for more efficient this_cpu operations. Eliminate conditional branches when PREEMPT_NONE is removed - Enable Rust support - Use z10 as minimum architecture level, similar to the boot code, to enforce a defined architecture level set - Improve and convert various mem*() helper functions to C. For that add .noinstr.text section to avoid orphaned warnings from the linker - Fix the function pointer type in __ret_from_fork() to correct the indirect call to match kernel thread return type of int - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception loop on read from donated Ultravisor pages at unaligned addresses * tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits) s390: Revert support for DCACHE_WORD_ACCESS s390/process: Fix kernel thread function pointer type s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C s390/memmove: Optimize backward copy case s390/string: Convert memset(16|32|64)() to C s390/string: Convert memcpy() to C s390/string: Convert memset() to C s390/string: Convert memmove() to C s390/string: Add -ffreestanding compile option to string.o s390: Add .noinstr.text to boot and purgatory linker scripts s390/purgatory: Enforce z10 minimum architecture level s390: Enable Rust support s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers rust: helpers: Add memchr wrapper for string operations rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support s390/ap: Fix locking issue in SE bind and associate sysfs functions s390/percpu: Provide arch_this_cpu_write() implementation s390/percpu: Provide arch_this_cpu_read() implementation ...
2026-06-15s390/idle: Remove idle time and count sysfs filesHeiko Carstens
Remove the s390 specific idle_time_us and idle_count per cpu sysfs files. They do not provide any additional value. The risk that there are existing applications which rely on these architecture specific files should be very low. However if it turns out such applications exist, this can be easily reverted. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>