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7 daysMerge tag 's390-6.18-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - Compile the decompressor with -Wno-pointer-sign flag to avoid a clang warning - Fix incomplete conversion to flag output macros in __xsch(), to avoid always zero return value instead of the expected condition code - Remove superfluous newlines from inline assemblies to improve compiler inlining decisions - Expose firmware provided UID Checking state in sysfs regardless of the device presence or state - CIO does not unregister subchannels when the attached device is invalid or unavailable. Update the purge function to remove I/O subchannels if the device number is found on cio_ignore list - Consolidate PAI crypto allocation and cleanup paths - The uv_get_secret_metadata() function has been removed some few months ago, remove also the function mention it in a comment * tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uv: Fix comment of uv_find_secret() function s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths s390/cio: Update purge function to unregister the unused subchannels s390/pci: Expose firmware provided UID Checking state in sysfs s390: Remove superfluous newlines from inline assemblies s390/cio/ioasm: Fix __xsch() condition code handling s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR
10 daysMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull x86 kvm updates from Paolo Bonzini: "Generic: - Rework almost all of KVM's exports to expose symbols only to KVM's x86 vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko x86: - Rework almost all of KVM x86's exports to expose symbols only to KVM's vendor modules, i.e. to kvm-{amd,intel}.ko - Add support for virtualizing Control-flow Enforcement Technology (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD (Shadow Stacks). It is worth noting that while SHSTK and IBT can be enabled separately in CPUID, it is not really possible to virtualize them separately. Therefore, Intel processors will really allow both SHSTK and IBT under the hood if either is made visible in the guest's CPUID. The alternative would be to intercept XSAVES/XRSTORS, which is not feasible for performance reasons - Fix a variety of fuzzing WARNs all caused by checking L1 intercepts when completing userspace I/O. KVM has already committed to allowing L2 to to perform I/O at that point - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the MSR is supposed to exist for v2 PMUs - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs - Add support for the immediate forms of RDMSR and WRMSRNS, sans full emulator support (KVM should never need to emulate the MSRs outside of forced emulation and other contrived testing scenarios) - Clean up the MSR APIs in preparation for CET and FRED virtualization, as well as mediated vPMU support - Clean up a pile of PMU code in anticipation of adding support for mediated vPMUs - Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI vmexits needed to faithfully emulate an I/O APIC for such guests - Many cleanups and minor fixes - Recover possible NX huge pages within the TDP MMU under read lock to reduce guest jitter when restoring NX huge pages - Return -EAGAIN during prefault if userspace concurrently deletes/moves the relevant memslot, to fix an issue where prefaulting could deadlock with the memslot update x86 (AMD): - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is supported - Require a minimum GHCB version of 2 when starting SEV-SNP guests via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate errors instead of latent guest failures - Add support for SEV-SNP's CipherText Hiding, an opt-in feature that prevents unauthorized CPU accesses from reading the ciphertext of SNP guest private memory, e.g. to attempt an offline attack. This feature splits the shared SEV-ES/SEV-SNP ASID space into separate ranges for SEV-ES and SEV-SNP guests, therefore a new module parameter is needed to control the number of ASIDs that can be used for VMs with CipherText Hiding vs. how many can be used to run SEV-ES guests - Add support for Secure TSC for SEV-SNP guests, which prevents the untrusted host from tampering with the guest's TSC frequency, while still allowing the the VMM to configure the guest's TSC frequency prior to launch - Validate the XCR0 provided by the guest (via the GHCB) to avoid bugs resulting from bogus XCR0 values - Save an SEV guest's policy if and only if LAUNCH_START fully succeeds to avoid leaving behind stale state (thankfully not consumed in KVM) - Explicitly reject non-positive effective lengths during SNP's LAUNCH_UPDATE instead of subtly relying on guest_memfd to deal with them - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the host's desired TSC_AUX, to fix a bug where KVM was keeping a different vCPU's TSC_AUX in the host MSR until return to userspace KVM (Intel): - Preparation for FRED support - Don't retry in TDX's anti-zero-step mitigation if the target memslot is invalid, i.e. is being deleted or moved, to fix a deadlock scenario similar to the aforementioned prefaulting case - Misc bugfixes and minor cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits) KVM: x86: Export KVM-internal symbols for sub-modules only KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.c KVM: Export KVM-internal symbols for sub-modules only KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent KVM: VMX: Make CR4.CET a guest owned bit KVM: selftests: Verify MSRs are (not) in save/restore list when (un)supported KVM: selftests: Add coverage for KVM-defined registers in MSRs test KVM: selftests: Add KVM_{G,S}ET_ONE_REG coverage to MSRs test KVM: selftests: Extend MSRs test to validate vCPUs without supported features KVM: selftests: Add support for MSR_IA32_{S,U}_CET to MSRs test KVM: selftests: Add an MSR test to exercise guest/host and read/write KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors KVM: x86: Define Control Protection Exception (#CP) vector KVM: x86: Add human friendly formatting for #XM, and #VE KVM: SVM: Enable shadow stack virtualization for SVM KVM: SEV: Synchronize MSR_IA32_XSS from the GHCB when it's valid KVM: SVM: Pass through shadow stack MSRs as appropriate KVM: SVM: Update dump_vmcb with shadow stack save area additions KVM: nSVM: Save/load CET Shadow Stack state to/from vmcb12/vmcb02 ...
12 dayss390/pci: Expose firmware provided UID Checking state in sysfsRamesh Errabolu
The sysfs file /sys/bus/pci/devices/<device_id>/uid_is_unique provides the UID Checking state as a per device attribute, highlighting its effect of providing the guarantee that a device's UID is unique. As a device attribute, this parameter is however unavailable if no device is configured. Expose the UID Checking state as: - A platform-level parameter - Available regardless of device presence or state Signed-off-by: Ramesh Errabolu <ramesh@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
12 daysMerge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "This excludes the bulk of the x86 changes, which I will send separately. They have two not complex but relatively unusual conflicts so I will wait for other dust to settle. guest_memfd: - Add support for host userspace mapping of guest_memfd-backed memory for VM types that do NOT use support KVM_MEMORY_ATTRIBUTE_PRIVATE (which isn't precisely the same thing as CoCo VMs, since x86's SEV-MEM and SEV-ES have no way to detect private vs. shared). This lays the groundwork for removal of guest memory from the kernel direct map, as well as for limited mmap() for guest_memfd-backed memory. For more information see: - commit a6ad54137af9 ("Merge branch 'guest-memfd-mmap' into HEAD") - guest_memfd in Firecracker: https://github.com/firecracker-microvm/firecracker/tree/feature/secret-hiding - direct map removal: https://lore.kernel.org/all/20250221160728.1584559-1-roypat@amazon.co.uk/ - mmap support: https://lore.kernel.org/all/20250328153133.3504118-1-tabba@google.com/ ARM: - Add support for FF-A 1.2 as the secure memory conduit for pKVM, allowing more registers to be used as part of the message payload. - Change the way pKVM allocates its VM handles, making sure that the privileged hypervisor is never tricked into using uninitialised data. - Speed up MMIO range registration by avoiding unnecessary RCU synchronisation, which results in VMs starting much quicker. - Add the dump of the instruction stream when panic-ing in the EL2 payload, just like the rest of the kernel has always done. This will hopefully help debugging non-VHE setups. - Add 52bit PA support to the stage-1 page-table walker, and make use of it to populate the fault level reported to the guest on failing to translate a stage-1 walk. - Add NV support to the GICv3-on-GICv5 emulation code, ensuring feature parity for guests, irrespective of the host platform. - Fix some really ugly architecture problems when dealing with debug in a nested VM. This has some bad performance impacts, but is at least correct. - Add enough infrastructure to be able to disable EL2 features and give effective values to the EL2 control registers. This then allows a bunch of features to be turned off, which helps cross-host migration. - Large rework of the selftest infrastructure to allow most tests to transparently run at EL2. This is the first step towards enabling NV testing. - Various fixes and improvements all over the map, including one BE fix, just in time for the removal of the feature. LoongArch: - Detect page table walk feature on new hardware - Add sign extension with kernel MMIO/IOCSR emulation - Improve in-kernel IPI emulation - Improve in-kernel PCH-PIC emulation - Move kvm_iocsr tracepoint out of generic code RISC-V: - Added SBI FWFT extension for Guest/VM with misaligned delegation and pointer masking PMLEN features - Added ONE_REG interface for SBI FWFT extension - Added Zicbop and bfloat16 extensions for Guest/VM - Enabled more common KVM selftests for RISC-V - Added SBI v3.0 PMU enhancements in KVM and perf driver s390: - Improve interrupt cpu for wakeup, in particular the heuristic to decide which vCPU to deliver a floating interrupt to. - Clear the PTE when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code. x86 selftests: - Add #DE coverage in the fastops test (the only exception that's guest- triggerable in fastop-emulated instructions). - Fix PMU selftests errors encountered on Granite Rapids (GNR), Sierra Forest (SRF) and Clearwater Forest (CWF). - Minor cleanups and improvements x86 (guest side): - For the legacy PCI hole (memory between TOLUD and 4GiB) to UC when overriding guest MTRR for TDX/SNP to fix an issue where ACPI auto-mapping could map devices as WB and prevent the device drivers from mapping their devices with UC/UC-. - Make kvm_async_pf_task_wake() a local static helper and remove its export. - Use native qspinlocks when running in a VM with dedicated vCPU=>pCPU bindings even when PV_UNHALT is unsupported. Generic: - Remove a redundant __GFP_NOWARN from kvm_setup_async_pf() as __GFP_NOWARN is now included in GFP_NOWAIT. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (178 commits) KVM: s390: Fix to clear PTE when discarding a swapped page KVM: arm64: selftests: Cover ID_AA64ISAR3_EL1 in set_id_regs KVM: arm64: selftests: Remove a duplicate register listing in set_id_regs KVM: arm64: selftests: Cope with arch silliness in EL2 selftest KVM: arm64: selftests: Add basic test for running in VHE EL2 KVM: arm64: selftests: Enable EL2 by default KVM: arm64: selftests: Initialize HCR_EL2 KVM: arm64: selftests: Use the vCPU attr for setting nr of PMU counters KVM: arm64: selftests: Use hyp timer IRQs when test runs at EL2 KVM: arm64: selftests: Select SMCCC conduit based on current EL KVM: arm64: selftests: Provide helper for getting default vCPU target KVM: arm64: selftests: Alias EL1 registers to EL2 counterparts KVM: arm64: selftests: Create a VGICv3 for 'default' VMs KVM: arm64: selftests: Add unsanitised helpers for VGICv3 creation KVM: arm64: selftests: Add helper to check for VGICv3 support KVM: arm64: selftests: Initialize VGICv3 only once KVM: arm64: selftests: Provide kvm_arch_vm_post_create() in library code KVM: selftests: Add ex_str() to print human friendly name of exception vectors selftests/kvm: remove stale TODO in xapic_state_test KVM: selftests: Handle Intel Atom errata that leads to PMU event overcount ...
14 daysMerge tag 'mm-stable-2025-10-01-19-00' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "mm, swap: improve cluster scan strategy" from Kairui Song improves performance and reduces the failure rate of swap cluster allocation - "support large align and nid in Rust allocators" from Vitaly Wool permits Rust allocators to set NUMA node and large alignment when perforning slub and vmalloc reallocs - "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets for virtual address spaces for ops-level DAMOS filters - "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren Baghdasaryan reduces mmap_lock contention during reads of /proc/pid/maps - "mm/mincore: minor clean up for swap cache checking" from Kairui Song performs some cleanup in the swap code - "mm: vm_normal_page*() improvements" from David Hildenbrand provides code cleanup in the pagemap code - "add persistent huge zero folio support" from Pankaj Raghav provides a block layer speedup by optionalls making the huge_zero_pagepersistent, instead of releasing it when its refcount falls to zero - "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to the recently added Kexec Handover feature - "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To end the constant struggle with space shortage on 32-bit conflicting with 64-bit's needs - "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap code - "selftests/mm: Fix false positives and skip unsupported tests" from Donet Tom fixes a few things in our selftests code - "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised" from David Hildenbrand "allows individual processes to opt-out of THP=always into THP=madvise, without affecting other workloads on the system". It's a long story - the [1/N] changelog spells out the considerations - "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on the memdesc project. Please see https://kernelnewbies.org/MatthewWilcox/Memdescs and https://blogs.oracle.com/linux/post/introducing-memdesc - "Tiny optimization for large read operations" from Chi Zhiling improves the efficiency of the pagecache read path - "Better split_huge_page_test result check" from Zi Yan improves our folio splitting selftest code - "test that rmap behaves as expected" from Wei Yang adds some rmap selftests - "remove write_cache_pages()" from Christoph Hellwig removes that function and converts its two remaining callers - "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD selftests issues - "introduce kernel file mapped folios" from Boris Burkov introduces the concept of "kernel file pages". Using these permits btrfs to account its metadata pages to the root cgroup, rather than to the cgroups of random inappropriate tasks - "mm/pageblock: improve readability of some pageblock handling" from Wei Yang provides some readability improvements to the page allocator code - "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON to understand arm32 highmem - "tools: testing: Use existing atomic.h for vma/maple tests" from Brendan Jackman performs some code cleanups and deduplication under tools/testing/ - "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes a couple of 32-bit issues in tools/testing/radix-tree.c - "kasan: unify kasan_enabled() and remove arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific initialization code into a common arch-neutral implementation - "mm: remove zpool" from Johannes Weiner removes zspool - an indirection layer which now only redirects to a single thing (zsmalloc) - "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a couple of cleanups in the fork code - "mm: remove nth_page()" from David Hildenbrand makes rather a lot of adjustments at various nth_page() callsites, eventually permitting the removal of that undesirable helper function - "introduce kasan.write_only option in hw-tags" from Yeoreum Yun creates a KASAN read-only mode for ARM, using that architecture's memory tagging feature. It is felt that a read-only mode KASAN is suitable for use in production systems rather than debug-only - "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does some tidying in the hugetlb folio allocation code - "mm: establish const-correctness for pointer parameters" from Max Kellermann makes quite a number of the MM API functions more accurate about the constness of their arguments. This was getting in the way of subsystems (in this case CEPH) when they attempt to improving their own const/non-const accuracy - "Cleanup free_pages() misuse" from Vishal Moola fixes a number of code sites which were confused over when to use free_pages() vs __free_pages() - "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the mapletree code accessible to Rust. Required by nouveau and by its forthcoming successor: the new Rust Nova driver - "selftests/mm: split_huge_page_test: split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and some cleanups to the thp selftesting code - "mm, swap: introduce swap table as swap cache (phase I)" from Chris Li and Kairui Song is the first step along the path to implementing "swap tables" - a new approach to swap allocation and state tracking which is expected to yield speed and space improvements. This patchset itself yields a 5-20% performance benefit in some situations - "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc layer to clean up the ptdesc code a little - "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some issues in our 5-level pagetable selftesting code - "Minor fixes for memory allocation profiling" from Suren Baghdasaryan addresses a couple of minor issues in relatively new memory allocation profiling feature - "Small cleanups" from Matthew Wilcox has a few cleanups in preparation for more memdesc work - "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in furtherance of supporting arm highmem - "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad Anjum adds that compiler check to selftests code and fixes the fallout, by removing dead code - "Improvements to Victim Process Thawing and OOM Reaper Traversal Order" from zhongjinji makes a number of improvements in the OOM killer: mainly thawing a more appropriate group of victim threads so they can release resources - "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park is a bunch of small and unrelated fixups for DAMON - "mm/damon: define and use DAMON initialization check function" from SeongJae Park implement reliability and maintainability improvements to a recently-added bug fix - "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from SeongJae Park provides additional transparency to userspace clients of the DAMON_STAT information - "Expand scope of khugepaged anonymous collapse" from Dev Jain removes some constraints on khubepaged's collapsing of anon VMAs. It also increases the success rate of MADV_COLLAPSE against an anon vma - "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards removal of file_operations.mmap(). This patchset concentrates upon clearing up the treatment of stacked filesystems - "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau provides some fixes and improvements to mlock's tracking of large folios. /proc/meminfo's "Mlocked" field became more accurate - "mm/ksm: Fix incorrect accounting of KSM counters during fork" from Donet Tom fixes several user-visible KSM stats inaccuracies across forks and adds selftest code to verify these counters - "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses some potential but presently benign issues in KSM's mm_slot handling * tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits) mm: swap: check for stable address space before operating on the VMA mm: convert folio_page() back to a macro mm/khugepaged: use start_addr/addr for improved readability hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list alloc_tag: fix boot failure due to NULL pointer dereference mm: silence data-race in update_hiwater_rss mm/memory-failure: don't select MEMORY_ISOLATION mm/khugepaged: remove definition of struct khugepaged_mm_slot mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL hugetlb: increase number of reserving hugepages via cmdline selftests/mm: add fork inheritance test for ksm_merging_pages counter mm/ksm: fix incorrect KSM counter handling in mm_struct during fork drivers/base/node: fix double free in register_one_node() mm: remove PMD alignment constraint in execmem_vmalloc() mm/memory_hotplug: fix typo 'esecially' -> 'especially' mm/rmap: improve mlock tracking for large folios mm/filemap: map entire large folio faultaround mm/fault: try to map the entire file folio in finish_fault() mm/rmap: mlock large folios in try_to_unmap_one() mm/rmap: fix a mlock race condition in folio_referenced_one() ...
2025-09-30Merge tag 'core-core-2025-09-29' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull TIF bit unification updates from Thomas Gleixner: "A set of changes to consolidate the generic TIF (thread info flag) bits accross architectures. All architectures define the same set of generic TIF bits. This makes it pointlessly hard to add a new generic TIF bit or to change an existing one. Provide a generic variant and convert the architectures which utilize the generic entry code over to use it. The TIF space is divided into 16 generic bits and 16 architecture specific bits, which turned out to provide enough space on both sides" * tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: LoongArch: Fix bitflag conflict for TIF_FIXADE riscv: Use generic TIF bits loongarch: Use generic TIF bits s390/entry: Remove unused TIF flags s390: Use generic TIF bits x86: Use generic TIF bits asm-generic: Provide generic TIF infrastructure
2025-09-30KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalentSean Christopherson
Use kvm_is_gpa_in_memslot() to check the validity of the notification indicator byte address instead of open coding equivalent logic in the VFIO AP driver. Opportunistically use a dedicated wrapper that exists and is exported expressly for the VFIO AP module. kvm_is_gpa_in_memslot() is generally unsuitable for use outside of KVM; other drivers typically shouldn't rely on KVM's memslots, and using the API requires kvm->srcu (or slots_lock) to be held for the entire duration of the usage, e.g. to avoid TOCTOU bugs. handle_pqap() is a bit of a special case, as it's explicitly invoked from KVM with kvm->srcu already held, and the VFIO AP driver is in many ways an extension of KVM that happens to live in a separate module. Providing a dedicated API for the VFIO AP driver will allow restricting the vast majority of generic KVM's exports to KVM submodules (e.g. to x86's kvm-{amd,intel}.ko vendor mdoules). No functional change intended. Acked-by: Anthony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20250919003303.1355064-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-09-30Merge tag 'loongarch-kvm-6.18' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.18 1. Add PTW feature detection on new hardware. 2. Add sign extension with kernel MMIO/IOCSR emulation. 3. Improve in-kernel IPI emulation. 4. Improve in-kernel PCH-PIC emulation. 5. Move kvm_iocsr tracepoint out of generic code.
2025-09-30Merge tag 'kvm-s390-next-6.18-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: A bugfix and a performance improvement * Improve interrupt cpu for wakeup, change the heuristic to decide wich vCPU to deliver a floating interrupt to. * Clear the pte when discarding a swapped page because of CMMA; this bug was introduced in 6.16 when refactoring gmap code.
2025-09-30KVM: s390: Fix to clear PTE when discarding a swapped pageGautam Gala
KVM run fails when guests with 'cmm' cpu feature and host are under memory pressure and use swap heavily. This is because npages becomes ENOMEN (out of memory) in hva_to_pfn_slow() which inturn propagates as EFAULT to qemu. Clearing the page table entry when discarding an address that maps to a swap entry resolves the issue. Fixes: 200197908dc4 ("KVM: s390: Refactor and split some gmap helpers") Cc: stable@vger.kernel.org Suggested-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Gautam Gala <ggala@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2025-09-29Merge tag 's390-6.18-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Refactor SCLP memory hotplug code - Introduce common boot_panic() decompressor helper macro and use it to get rid of nearly few identical implementations - Take into account additional key generation flags and forward it to the ep11 implementation. With that allow users to modify the key generation process, e.g. provide valid combinations of XCP_BLOB_* flags - Replace kmalloc() + copy_from_user() with memdup_user_nul() in s390 debug facility and HMC driver - Add DAX support for DCSS memory block devices - Make the compiler statement attribute "assume" available with a new __assume macro - Rework ffs() and fls() family bitops functions, including source code improvements and generated code optimizations. Use the newly introduced __assume macro for that - Enable additional network features in default configurations - Use __GFP_ACCOUNT flag for user page table allocations to add missing kmemcg accounting - Add WQ_PERCPU flag to explicitly request the use of the per-CPU workqueue for 3590 tape driver - Switch power reading to the per-CPU and the Hiperdispatch to the default workqueue - Add memory allocation profiling hooks to allow better profiling data and the /proc/allocinfo output similar to other architectures * tag 's390-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (21 commits) s390/mm: Add memory allocation profiling hooks s390: Replace use of system_wq with system_dfl_wq s390/diag324: Replace use of system_wq with system_percpu_wq s390/tape: Add WQ_PERCPU to alloc_workqueue users s390/bitops: Switch to generic ffs() if supported by compiler s390/bitops: Switch to generic fls(), fls64(), etc. s390/mm: Use __GFP_ACCOUNT for user page table allocations s390/configs: Enable additional network features s390/bitops: Cleanup __flogr() s390/bitops: Use __assume() for __flogr() inline assembly return value compiler_types: Add __assume macro s390/bitops: Limit return value range of __flogr() s390/dcssblk: Add DAX support s390/hmcdrv: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/debug: Replace kmalloc() + copy_from_user() with memdup_user_nul() s390/pkey: Forward keygenflags to ep11_unwrapkey s390/boot: Add common boot_panic() code s390/bitops: Optimize inlining s390/bitops: Slightly optimize ffs() and fls64() s390/sclp: Move memory hotplug code for better modularity ...
2025-09-29Merge tag 'ffs-const-v6.18-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull ffs const-attribute cleanups from Kees Cook: "While working on various hardening refactoring a while back we encountered inconsistencies in the application of __attribute_const__ on the ffs() family of functions. This series fixes this across all archs and adds KUnit tests. Notably, this found a theoretical underflow in PCI (also fixed here) and uncovered an inefficiency in ARC (fixed in the ARC arch PR). I kept the series separate from the general hardening PR since it is a stand-alone "topic". - PCI: Fix theoretical underflow in use of ffs(). - Universally apply __attribute_const__ to all architecture's ffs()-family of functions. - Add KUnit tests for ffs() behavior and const-ness" * tag 'ffs-const-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: KUnit: ffs: Validate all the __attribute_const__ annotations sparc: Add __attribute_const__ to ffs()-family implementations xtensa: Add __attribute_const__ to ffs()-family implementations s390: Add __attribute_const__ to ffs()-family implementations parisc: Add __attribute_const__ to ffs()-family implementations mips: Add __attribute_const__ to ffs()-family implementations m68k: Add __attribute_const__ to ffs()-family implementations openrisc: Add __attribute_const__ to ffs()-family implementations riscv: Add __attribute_const__ to ffs()-family implementations hexagon: Add __attribute_const__ to ffs()-family implementations alpha: Add __attribute_const__ to ffs()-family implementations sh: Add __attribute_const__ to ffs()-family implementations powerpc: Add __attribute_const__ to ffs()-family implementations x86: Add __attribute_const__ to ffs()-family implementations csky: Add __attribute_const__ to ffs()-family implementations bitops: Add __attribute_const__ to generic ffs()-family implementations KUnit: Introduce ffs()-family tests PCI: Test for bit underflow in pcie_set_readrq()
2025-09-29s390: Remove superfluous newlines from inline assembliesHeiko Carstens
Remove superfluous newlines from inline assemblies. Compilers use the number of lines of inline assemblies as heuristic for the complexity and inline decisions. Therefore inline assemblies should only contain as many lines as required. A lot of inline assemblies contain a superfluous newline for the last line. Remove such newlines to improve compiler inlining decisions. Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-25s390/mm: Add memory allocation profiling hooksHeiko Carstens
Similar to common code changes [1] add alloc_hook() wrappers to page table allocation functions to allow for memory allocation profiling. If CONFIG_MEM_ALLOC_PROFILING is enabled call sites of page table allocations are accounted, instead of e.g. only crst_table_alloc() and page_table_alloc(). This allows for slightly better profiling data, and the output of /proc/allocinfo is similar to other architectures. Without alloc_hook() wrappers the output of /proc/allocinfo looks like this: 17096704 4174 mm/memory.c:1061 func:folio_prealloc 17809408 4348 mm/memory.c:1063 func:folio_prealloc 0 0 mm/memory.c:4422 func:alloc_swap_folio 0 0 mm/memory.c:4286 func:__alloc_swap_folio 0 0 mm/memory.c:4971 func:alloc_anon_folio ... 1589248 97 arch/s390/mm/pgalloc.c:25 func:crst_table_alloc 0 0 arch/s390/mm/pgalloc.c:124 func:page_table_alloc_pgste 4280320 1045 arch/s390/mm/pgalloc.c:149 func:page_table_alloc With alloc_hook() wrappers: 1097728 268 mm/memory.c:5147 func:__do_fault 20119552 4912 mm/memory.c:1061 func:folio_prealloc 17534976 4281 mm/memory.c:1063 func:folio_prealloc 0 0 mm/memory.c:4422 func:alloc_swap_folio 0 0 mm/memory.c:4286 func:__alloc_swap_folio 786432 192 mm/memory.c:452 func:__pte_alloc 405504 99 mm/memory.c:464 func:__pte_alloc_kernel 1880064 459 mm/memory.c:5525 func:do_fault_around 0 0 mm/memory.c:6403 func:__p4d_alloc 0 0 mm/memory.c:6426 func:__pud_alloc 1064960 65 mm/memory.c:6450 func:__pmd_alloc 0 0 mm/memory.c:4971 func:alloc_anon_folio 0 0 mm/memory.c:5233 func:do_set_pmd [1] commit 2c321f3f70bc ("mm: change inlined allocation helpers to account at the call site") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-24s390/bitops: Switch to generic ffs() if supported by compilerHeiko Carstens
Use generic ffs() / __builtin_ffs() if supported by the compiler. GCC 16 will have support for __builtin_ffs(). See gcc commit f50cff9766c5 ("s390: Implement clz and ctz for SI mode"). In the distant future when GCC 16 becomes the minimum supported version, this allows to get rid of the flogr inline assembly. Kernel image size is reduced by ~500 bytes (gcc 16 beta + defconfig). Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-24s390/bitops: Switch to generic fls(), fls64(), etc.Heiko Carstens
Switch to generic fls(), fls64(), etc. which are implemented with __builtin_ctzl(), __builtin_clzl(). Those builtins are available for all supported compilers. Kernel image size is reduced by ~10kb (gcc 15.1.0 + defconfig). Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18s390/bitops: Cleanup __flogr()Heiko Carstens
The flogr() inline assembly has no side effects and generates the same output if the input does not change. Therefore remove the volatile qualifier to allow the compiler to optimize the inline assembly away, if possible. Also remove the superfluous '\n' which makes the inline assembly appear larger than it is according to compiler heuristics (number of lines). Furthermore change the return type of flogr() to unsigned long and add the const attribute to the function. This reduces the kernel image size by 994 bytes (defconfig, gcc 15.2.0). Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18s390/bitops: Use __assume() for __flogr() inline assembly return valueHeiko Carstens
Use __assume() to tell compilers that the output operand of the __flogr() inline assembly contains a value in the range of 0..64. This allows to optimize the logical AND operation away. This reduces the kernel image size by 2804 bytes (defconfig, gcc 15.2.0). Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-18s390/bitops: Limit return value range of __flogr()Heiko Carstens
With the recent ffs() and ffs64() optimization a logical AND operation was removed, which allowed the compiler to tell the return value range of both functions. This may lead to compile warnings as reported by the kernel test robot: drivers/infiniband/hw/mlx5/mr.c: In function 'mlx5r_cache_create_ent_locked': >> drivers/infiniband/hw/mlx5/mr.c:840:31: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=] 840 | sprintf(ent->name, "%d", order); | ^ In function 'mlx5_mkey_cache_debugfs_add_ent', inlined from 'mlx5r_cache_create_ent_locked' at drivers/infiniband/hw/mlx5/mr.c:930:3: drivers/infiniband/hw/mlx5/mr.c:840:9: note: 'sprintf' output between 2 and 5 bytes into a destination of size 4 840 | sprintf(ent->name, "%d", order); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Add the AND operation again to address the warning. From a correctness point of view the AND operation is not necessary, however there is no other way to tell the compiler that the returned value of the flogr inline assembly is in the range of 0..64. This increases the kernel image size by 566 bytes (defconfig, gcc 15.2.0). Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202508211859.UoYsJbLN-lkp@intel.com/ Fixes: de88e74889a3 ("s390/bitops: Slightly optimize ffs() and fls64()") Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-09-17s390/entry: Remove unused TIF flagsSven Schnelle
The conversion of s390 to generic entry missed to remove the TIF_SYSCALL*/TIF_SECCOMP flags. Remove them as they are unused now. Fixes: 56e62a737028 ("s390: convert to generic entry") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com>
2025-09-17s390: Use generic TIF bitsThomas Gleixner
No point in defining generic items and the upcoming RSEQ optimizations are only available with this _and_ the generic entry infrastructure, which is already used by s390. So no further action required here. This leaves a comment about the AUDIT/TRACE/SECCOMP bits which are handled by SYSCALL_WORK in the generic code, so they seem redundant, but that's a problem for the s390 wizards to think about. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com>
2025-09-13mm: introduce memdesc_flags_tMatthew Wilcox (Oracle)
Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-08s390: Add __attribute_const__ to ffs()-family implementationsKees Cook
While tracking down a problem where constant expressions used by BUILD_BUG_ON() suddenly stopped working[1], we found that an added static initializer was convincing the compiler that it couldn't track the state of the prior statically initialized value. Tracing this down found that ffs() was used in the initializer macro, but since it wasn't marked with __attribute__const__, the compiler had to assume the function might change variable states as a side-effect (which is not true for ffs(), which provides deterministic math results). Add missing __attribute_const__ annotations to S390's implementations of ffs(), __ffs(), fls(), and __fls() functions. These are pure mathematical functions that always return the same result for the same input with no side effects, making them eligible for compiler optimization. Build tested ARCH=s390 defconfig with GCC s390x-linux-gnu 14.2.0. Link: https://github.com/KSPP/linux/issues/364 [1] Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250804164417.1612371-14-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-08KVM: s390: improve interrupt cpu for wakeupChristian Borntraeger
Turns out that picking an idle CPU for floating interrupts has some negative side effects. The guest will keep the IO workload on its CPU and rather use an IPI from the interrupt CPU instead of moving workload. For example a guest with 2 vCPUs and 1 fio process might run that fio on vcpu1. If after diag500 both vCPUs are idle then vcpu0 is woken up. The guest will then do an IPI from vcpu0 to vcpu1. So lets change the heuristics and prefer the last CPU that went to sleep. This one is likely still in halt polling and can be woken up quickly. This patch shows significant improvements in terms of bandwidth or cpu consumption for fio and uperf workloads and seems to be a net win. Link: https://lore.kernel.org/linux-s390/20250904113927.119306-1-borntraeger@linux.ibm.com/ Reviewed-by: Christoph Schlameuß <schlameuss@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2025-09-05iommu/s390: Make attach succeed when the device was surprise removedNiklas Schnelle
When a PCI device is removed with surprise hotplug, there may still be attempts to attach the device to the default domain as part of tear down via (__iommu_release_dma_ownership()), or because the removal happens during probe (__iommu_probe_device()). In both cases zpci_register_ioat() fails with a cc value indicating that the device handle is invalid. This is because the device is no longer part of the instance as far as the hypervisor is concerned. Currently this leads to an error return and s390_iommu_attach_device() fails. This triggers the WARN_ON() in __iommu_group_set_domain_nofail() because attaching to the default domain must never fail. With the device fenced by the hypervisor no DMAs to or from memory are possible and the IOMMU translations have no effect. Proceed as if the registration was successful and let the hotplug event handling clean up the device. This is similar to how devices in the error state are handled since commit 59bbf596791b ("iommu/s390: Make attach succeed even if the device is in error state") except that for removal the domain will not be registered later. This approach was also previously discussed at the link. Handle both cases, error state and removal, in a helper which checks if the error needs to be propagated or ignored. Avoid magic number condition codes by using the pre-existing, but never used, defines for PCI load/store condition codes and rename them to reflect that they apply to all PCI instructions. Cc: stable@vger.kernel.org # v6.2 Link: https://lore.kernel.org/linux-iommu/20240808194155.GD1985367@ziepe.ca/ Suggested-by: Jason Gunthorpe <jgg@ziepe.ca> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Link: https://lore.kernel.org/r/20250904-iommu_succeed_attach_removed-v1-1-e7f333d2f80f@linux.ibm.com Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-08-20s390/bitops: Optimize inliningJuergen Christ
GCC inlining heuristics prevent code growth due to inlining into cold paths. This causes GCC to emit a partially specialized version of __flogr for non-constant input for all occurrences on cold paths. This happens since the overhead seen during inlining includes setting up a union register_pair, calling flogr, and extracting and casting the result. This overhead is not removed until the function is lowered into RTL. But this happens after inlining. For -ftrivial-var-auto-init=zero builds, an additional initialization of the union register_pair adds another statement to be inlinined. This is unneeded since the even register is initialized anyway and the odd register is not an input register. It is only marked as such since the whole pair has to be marked as a read/write output register. Mark the union register_pair as uninitialized to get rid of this statement. This, however, does not change the code since the initialization happens when part of the register pair is written. Nevertheless, GCC function size approximation during inlining is reduced by one statement. Force inlining of flogr and also flatten some other functions that should be leaf functions but are called in cold context, like, e.g., __init functions. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-08-20s390/bitops: Slightly optimize ffs() and fls64()Heiko Carstens
Use a simpler algorithm to calculate the result of ffs() and fls64(). This generates slightly better code and increases readability. Kernel image size is reduced by ~3kb (gcc 15.1.0 + defconfig). Suggested-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-08-08Merge tag 's390-6.17-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - Support MMIO read/write tracing - Enable THP swapping and THP migration - Unmask SLCF bit ("stateless command filtering") introduced with CEX8 cards, so that user space applications like lszcrypt could evaluate and list this feature - Fix the value of high_memory variable, so it considers possible tailing offline memory blocks - Make vmem_pte_alloc() consistent and always allocate memory of PAGE_SIZE for page tables. This ensures a page table occupies the whole page, as the rest of the code assumes - Fix kernel image end address in the decompressor debug output - Fix a typo in debug_sprintf_format_fn() comment * tag 's390-6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/debug: Fix typo in debug_sprintf_format_fn() comment s390/boot: Fix startup debugging log s390/mm: Allocate page table with PAGE_SIZE granularity s390/mm: Enable THP_SWAP and THP_MIGRATION s390: Support CONFIG_TRACE_MMIO_ACCESS s390/mm: Set high_memory at the end of the identity mapping s390/ap: Unmask SLCF bit in card and queue ap functions sysfs
2025-07-31Merge tag 'mm-stable-2025-07-30-15-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "As usual, many cleanups. The below blurbiage describes 42 patchsets. 21 of those are partially or fully cleanup work. "cleans up", "cleanup", "maintainability", "rationalizes", etc. I never knew the MM code was so dirty. "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes) addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for merging with existing adjacent VMAs. "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park) adds a new kernel module which simplifies the setup and usage of DAMON in production environments. "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig) is a cleanup to the writeback code which removes a couple of pointers from struct writeback_control. "drivers/base/node.c: optimization and cleanups" (Donet Tom) contains largely uncorrelated cleanups to the NUMA node setup and management code. "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman) does some maintenance work on the userfaultfd code. "Readahead tweaks for larger folios" (Ryan Roberts) implements some tuneups for pagecache readahead when it is reading into order>0 folios. "selftests/mm: Tweaks to the cow test" (Mark Brown) provides some cleanups and consistency improvements to the selftests code. "Optimize mremap() for large folios" (Dev Jain) does that. A 37% reduction in execution time was measured in a memset+mremap+munmap microbenchmark. "Remove zero_user()" (Matthew Wilcox) expunges zero_user() in favor of the more modern memzero_page(). "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand) addresses some warts which David noticed in the huge page code. These were not known to be causing any issues at this time. "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park) provides some cleanup and consolidation work in DAMON. "use vm_flags_t consistently" (Lorenzo Stoakes) uses vm_flags_t in places where we were inappropriately using other types. "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy) increases the reliability of large page allocation in the memfd code. "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple) removes several now-unneeded PFN_* flags. "mm/damon: decouple sysfs from core" (SeongJae Park) implememnts some cleanup and maintainability work in the DAMON sysfs layer. "madvise cleanup" (Lorenzo Stoakes) does quite a lot of cleanup/maintenance work in the madvise() code. "madvise anon_name cleanups" (Vlastimil Babka) provides additional cleanups on top or Lorenzo's effort. "Implement numa node notifier" (Oscar Salvador) creates a standalone notifier for NUMA node memory state changes. Previously these were lumped under the more general memory on/offline notifier. "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan) cleans up the pageblock isolation code and fixes a potential issue which doesn't seem to cause any problems in practice. "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park) adds additional drgn- and python-based DAMON selftests which are more comprehensive than the existing selftest suite. "Misc rework on hugetlb faulting path" (Oscar Salvador) fixes a rather obscure deadlock in the hugetlb fault code and follows that fix with a series of cleanups. "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport) rationalizes and cleans up the highmem-specific code in the CMA allocator. "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand) provides cleanups and future-preparedness to the migration code. "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park) adds some tracepoints to some DAMON auto-tuning code. "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park) does that. "mm/damon: misc cleanups" (SeongJae Park) also does what it claims. "mm: folio_pte_batch() improvements" (David Hildenbrand) cleans up the large folio PTE batching code. "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park) facilitates dynamic alteration of DAMON's inter-node allocation policy. "Remove unmap_and_put_page()" (Vishal Moola) provides a couple of page->folio conversions. "mm: per-node proactive reclaim" (Davidlohr Bueso) implements a per-node control of proactive reclaim - beyond the current memcg-based implementation. "mm/damon: remove damon_callback" (SeongJae Park) replaces the damon_callback interface with a more general and powerful damon_call()+damos_walk() interface. "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes) implements a number of mremap cleanups (of course) in preparation for adding new mremap() functionality: newly permit the remapping of multiple VMAs when the user is specifying MREMAP_FIXED. It still excludes some specialized situations where this cannot be performed reliably. "drop hugetlb_free_pgd_range()" (Anthony Yznaga) switches some sparc hugetlb code over to the generic version and removes the thus-unneeded hugetlb_free_pgd_range(). "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park) augments the present userspace-requested update of DAMON sysfs monitoring files. Automatic update is now provided, along with a tunable to control the update interval. "Some randome fixes and cleanups to swapfile" (Kemeng Shi) does what is claims. "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand) provides (and uses) a means by which debug-style functions can grab a copy of a pageframe and inspect it locklessly without tripping over the races inherent in operating on the live pageframe directly. "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan) addresses the large contention issues which can be triggered by reads from that procfs file. Latencies are reduced by more than half in some situations. The series also introduces several new selftests for the /proc/pid/maps interface. "__folio_split() clean up" (Zi Yan) cleans up __folio_split()! "Optimize mprotect() for large folios" (Dev Jain) provides some quite large (>3x) speedups to mprotect() when dealing with large folios. "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian) does some cleanup work in the selftests code. "tools/testing: expand mremap testing" (Lorenzo Stoakes) extends the mremap() selftest in several ways, including adding more checking of Lorenzo's recently added "permit mremap() move of multiple VMAs" feature. "selftests/damon/sysfs.py: test all parameters" (SeongJae Park) extends the DAMON sysfs interface selftest so that it tests all possible user-requested parameters. Rather than the present minimal subset" * tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits) MAINTAINERS: add missing headers to mempory policy & migration section MAINTAINERS: add missing file to cgroup section MAINTAINERS: add MM MISC section, add missing files to MISC and CORE MAINTAINERS: add missing zsmalloc file MAINTAINERS: add missing files to page alloc section MAINTAINERS: add missing shrinker files MAINTAINERS: move memremap.[ch] to hotplug section MAINTAINERS: add missing mm_slot.h file THP section MAINTAINERS: add missing interval_tree.c to memory mapping section MAINTAINERS: add missing percpu-internal.h file to per-cpu section mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info() selftests/damon: introduce _common.sh to host shared function selftests/damon/sysfs.py: test runtime reduction of DAMON parameters selftests/damon/sysfs.py: test non-default parameters runtime commit selftests/damon/sysfs.py: generalize DAMON context commit assertion selftests/damon/sysfs.py: generalize monitoring attributes commit assertion selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion selftests/damon/sysfs.py: test DAMOS filters commitment selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion selftests/damon/sysfs.py: test DAMOS destinations commitment ...
2025-07-31s390/mm: Enable THP_SWAP and THP_MIGRATIONGerald Schaefer
After hugetlbfs PTE_MARKER support for s390 introduced region-third and segment table swap entries, it is now possible to also enable THP_SWAP and THP_MIGRATION for s390. s390 has different layout for PTE and region / segment table entries (RSTE). This is also true for swap entries, and their swap type and offset encoding. For hugetlbfs PTE_MARKER support, s390 has internal __swp_type_rste() and __swp_offset_rste() helpers to correctly handle RSTE swap entries. But common swap code does not know about this difference, and only uses __swp_type(), __swp_offset() and __swp_entry() helpers for conversion between arch-dependent and arch-independent representation of swp_entry_t for all pagetable levels. On s390, those helpers only work for PTE swap entries. Therefore, implement __pmd_to_swp_entry() to build a fake PTE swap entry and return the arch-dependent representation of that. Correspondingly, implement __swp_entry_to_pmd() to convert that into a proper PMD swap entry again. With this, the arch-dependent swp_entry_t representation will always look like a PTE swap entry in common code. This is somewhat similar to fake PTEs in hugetlbfs code for s390, but only requires conversion of the swap type and offset, and not all the possible PTE bits. For PMD swap entry SOFT_DIRTY handling, use the same helpers as for normal PMDs. Similar to PTEs, the SOFT_DIRTY bit location is the same for swap and normal entries. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-07-31s390/ap: Unmask SLCF bit in card and queue ap functions sysfsHarald Freudenberger
The SLCF bit ("stateless command filtering") introduced with CEX8 cards was because of the function mask's default value suppressed when user space read the ap function for an AP card or queue. Unmask this bit so that user space applications like lszcrypt can evaluate and list this feature. Fixes: d4c53ae8e494 ("s390/ap: store TAPQ hwinfo in struct ap_card") Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-07-31Merge tag 'v6.17-p1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "API: - Allow hash drivers without fallbacks (e.g., hardware key) Algorithms: - Add hmac hardware key support (phmac) on s390 - Re-enable sha384 in FIPS mode - Disable sha1 in FIPS mode - Convert zstd to acomp Drivers: - Lower priority of qat skcipher and aead - Convert aspeed to partial block API - Add iMX8QXP support in caam - Add rate limiting support for GEN6 devices in qat - Enable telemetry for GEN6 devices in qat - Implement full backlog mode for hisilicon/sec2" * tag 'v6.17-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (116 commits) crypto: keembay - Use min() to simplify ocs_create_linked_list_from_sg() crypto: hisilicon/hpre - fix dma unmap sequence crypto: qat - make adf_dev_autoreset() static crypto: ccp - reduce stack usage in ccp_run_aes_gcm_cmd crypto: qat - refactor ring-related debug functions crypto: qat - fix seq_file position update in adf_ring_next() crypto: qat - fix DMA direction for compression on GEN2 devices crypto: jitter - replace ARRAY_SIZE definition with header include crypto: engine - remove {prepare,unprepare}_crypt_hardware callbacks crypto: engine - remove request batching support crypto: qat - flush misc workqueue during device shutdown crypto: qat - enable rate limiting feature for GEN6 devices crypto: qat - add compression slice count for rate limiting crypto: qat - add get_svc_slice_cnt() in device data structure crypto: qat - add adf_rl_get_num_svc_aes() in rate limiting crypto: qat - relocate service related functions crypto: qat - consolidate service enums crypto: qat - add decompression service for rate limiting crypto: qat - validate service in rate limiting sysfs api crypto: hisilicon/sec2 - implement full backlog mode for sec ...
2025-07-30Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Host driver for GICv5, the next generation interrupt controller for arm64, including support for interrupt routing, MSIs, interrupt translation and wired interrupts - Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on GICv5 hardware, leveraging the legacy VGIC interface - Userspace control of the 'nASSGIcap' GICv3 feature, allowing userspace to disable support for SGIs w/o an active state on hardware that previously advertised it unconditionally - Map supporting endpoints with cacheable memory attributes on systems with FEAT_S2FWB and DIC where KVM no longer needs to perform cache maintenance on the address range - Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest hypervisor to inject external aborts into an L2 VM and take traps of masked external aborts to the hypervisor - Convert more system register sanitization to the config-driven implementation - Fixes to the visibility of EL2 registers, namely making VGICv3 system registers accessible through the VGIC device instead of the ONE_REG vCPU ioctls - Various cleanups and minor fixes LoongArch: - Add stat information for in-kernel irqchip - Add tracepoints for CPUCFG and CSR emulation exits - Enhance in-kernel irqchip emulation - Various cleanups RISC-V: - Enable ring-based dirty memory tracking - Improve perf kvm stat to report interrupt events - Delegate illegal instruction trap to VS-mode - MMU improvements related to upcoming nested virtualization s390x - Fixes x86: - Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC, and PIT emulation at compile time - Share device posted IRQ code between SVM and VMX and harden it against bugs and runtime errors - Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1) instead of O(n) - For MMIO stale data mitigation, track whether or not a vCPU has access to (host) MMIO based on whether the page tables have MMIO pfns mapped; using VFIO is prone to false negatives - Rework the MSR interception code so that the SVM and VMX APIs are more or less identical - Recalculate all MSR intercepts from scratch on MSR filter changes, instead of maintaining shadow bitmaps - Advertise support for LKGS (Load Kernel GS base), a new instruction that's loosely related to FRED, but is supported and enumerated independently - Fix a user-triggerable WARN that syzkaller found by setting the vCPU in INIT_RECEIVED state (aka wait-for-SIPI), and then putting the vCPU into VMX Root Mode (post-VMXON). Trying to detect every possible path leading to architecturally forbidden states is hard and even risks breaking userspace (if it goes from valid to valid state but passes through invalid states), so just wait until KVM_RUN to detect that the vCPU state isn't allowed - Add KVM_X86_DISABLE_EXITS_APERFMPERF to allow disabling interception of APERF/MPERF reads, so that a "properly" configured VM can access APERF/MPERF. This has many caveats (APERF/MPERF cannot be zeroed on vCPU creation or saved/restored on suspend and resume, or preserved over thread migration let alone VM migration) but can be useful whenever you're interested in letting Linux guests see the effective physical CPU frequency in /proc/cpuinfo - Reject KVM_SET_TSC_KHZ for vm file descriptors if vCPUs have been created, as there's no known use case for changing the default frequency for other VM types and it goes counter to the very reason why the ioctl was added to the vm file descriptor. And also, there would be no way to make it work for confidential VMs with a "secure" TSC, so kill two birds with one stone - Dynamically allocation the shadow MMU's hashed page list, and defer allocating the hashed list until it's actually needed (the TDP MMU doesn't use the list) - Extract many of KVM's helpers for accessing architectural local APIC state to common x86 so that they can be shared by guest-side code for Secure AVIC - Various cleanups and fixes x86 (Intel): - Preserve the host's DEBUGCTL.FREEZE_IN_SMM when running the guest. Failure to honor FREEZE_IN_SMM can leak host state into guests - Explicitly check vmcs12.GUEST_DEBUGCTL on nested VM-Enter to prevent L1 from running L2 with features that KVM doesn't support, e.g. BTF x86 (AMD): - WARN and reject loading kvm-amd.ko instead of panicking the kernel if the nested SVM MSRPM offsets tracker can't handle an MSR (which is pretty much a static condition and therefore should never happen, but still) - Fix a variety of flaws and bugs in the AVIC device posted IRQ code - Inhibit AVIC if a vCPU's ID is too big (relative to what hardware supports) instead of rejecting vCPU creation - Extend enable_ipiv module param support to SVM, by simply leaving IsRunning clear in the vCPU's physical ID table entry - Disable IPI virtualization, via enable_ipiv, if the CPU is affected by erratum #1235, to allow (safely) enabling AVIC on such CPUs - Request GA Log interrupts if and only if the target vCPU is blocking, i.e. only if KVM needs a notification in order to wake the vCPU - Intercept SPEC_CTRL on AMD if the MSR shouldn't exist according to the vCPU's CPUID model - Accept any SNP policy that is accepted by the firmware with respect to SMT and single-socket restrictions. An incompatible policy doesn't put the kernel at risk in any way, so there's no reason for KVM to care - Drop a superfluous WBINVD (on all CPUs!) when destroying a VM and use WBNOINVD instead of WBINVD when possible for SEV cache maintenance - When reclaiming memory from an SEV guest, only do cache flushes on CPUs that have ever run a vCPU for the guest, i.e. don't flush the caches for CPUs that can't possibly have cache lines with dirty, encrypted data Generic: - Rework irqbypass to track/match producers and consumers via an xarray instead of a linked list. Using a linked list leads to O(n^2) insertion times, which is hugely problematic for use cases that create large numbers of VMs. Such use cases typically don't actually use irqbypass, but eliminating the pointless registration is a future problem to solve as it likely requires new uAPI - Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *", to avoid making a simple concept unnecessarily difficult to understand - Decouple device posted IRQs from VFIO device assignment, as binding a VM to a VFIO group is not a requirement for enabling device posted IRQs - Clean up and document/comment the irqfd assignment code - Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e. ensure an eventfd is bound to at most one irqfd through the entire host, and add a selftest to verify eventfd:irqfd bindings are globally unique - Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related to private <=> shared memory conversions - Drop guest_memfd's .getattr() implementation as the VFS layer will call generic_fillattr() if inode_operations.getattr is NULL - Fix issues with dirty ring harvesting where KVM doesn't bound the processing of entries in any way, which allows userspace to keep KVM in a tight loop indefinitely - Kill off kvm_arch_{start,end}_assignment() and x86's associated tracking, now that KVM no longer uses assigned_device_count as a heuristic for either irqbypass usage or MDS mitigation Selftests: - Fix a comment typo - Verify KVM is loaded when getting any KVM module param so that attempting to run a selftest without kvm.ko loaded results in a SKIP message about KVM not being loaded/enabled (versus some random parameter not existing) - Skip tests that hit EACCES when attempting to access a file, and print a "Root required?" help message. In most cases, the test just needs to be run with elevated permissions" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (340 commits) Documentation: KVM: Use unordered list for pre-init VGIC registers RISC-V: KVM: Avoid re-acquiring memslot in kvm_riscv_gstage_map() RISC-V: KVM: Use find_vma_intersection() to search for intersecting VMAs RISC-V: perf/kvm: Add reporting of interrupt events RISC-V: KVM: Enable ring-based dirty memory tracking RISC-V: KVM: Fix inclusion of Smnpm in the guest ISA bitmap RISC-V: KVM: Delegate illegal instruction fault to VS mode RISC-V: KVM: Pass VMID as parameter to kvm_riscv_hfence_xyz() APIs RISC-V: KVM: Factor-out g-stage page table management RISC-V: KVM: Add vmid field to struct kvm_riscv_hfence RISC-V: KVM: Introduce struct kvm_gstage_mapping RISC-V: KVM: Factor-out MMU related declarations into separate headers RISC-V: KVM: Use ncsr_xyz() in kvm_riscv_vcpu_trap_redirect() RISC-V: KVM: Implement kvm_arch_flush_remote_tlbs_range() RISC-V: KVM: Don't flush TLB when PTE is unchanged RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize() RISC-V: KVM: Drop the return value of kvm_riscv_vcpu_aia_init() RISC-V: KVM: Check kvm_riscv_vcpu_alloc_vector_context() return value KVM: arm64: selftests: Add FEAT_RAS EL2 registers to get-reg-list ...
2025-07-30Merge tag 'kvm-s390-next-6.17-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD RCU wakeup fix for KVM s390 guest entry
2025-07-29Merge tag 's390-6.17-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Standardize on the __ASSEMBLER__ macro that is provided by GCC and Clang compilers and replace __ASSEMBLY__ with __ASSEMBLER__ in both uapi and non-uapi headers - Explicitly include <linux/export.h> in architecture and driver files which contain an EXPORT_SYMBOL() and remove the include from the files which do not contain the EXPORT_SYMBOL() - Use the full title of "z/Architecture Principles of Operation" manual and the name of a section where facility bits are listed - Use -D__DISABLE_EXPORTS for files in arch/s390/boot to avoid unnecessary slowing down of the build and confusing external kABI tools that process symtypes data - Print additional unrecoverable machine check information to make the root cause analysis easier - Move cmpxchg_user_key() handling to uaccess library code, since the generated code is large anyway and there is no benefit if it is inlined - Fix a problem when cmpxchg_user_key() is executing a code with a non-default key: if a system is IPL-ed with "LOAD NORMAL", and the previous system used storage keys where the fetch-protection bit was set for some pages, and the cmpxchg_user_key() is located within such page, a protection exception happens - Either the external call or emergency signal order is used to send an IPI to a remote CPU. Use the external order only, since it is at least as good and sometimes even better, than the emergency signal - In case of an early crash the early program check handler prints more or less random value of the last breaking event address, since it is not initialized properly. Copy the last breaking event address from the lowcore to pt_regs to address this - During STP synchronization check udelay() can not be used, since the first CPU modifies tod_clock_base and get_tod_clock_monotonic() might return a non-monotonic time. Instead, busy-loop on other CPUs, while the the first CPU actually handles the synchronization operation - When debugging the early kernel boot using QEMU with the -S flag and GDB attached, skip the decompressor and start directly in kernel - Rename PAI Crypto event 4210 according to z16 and z17 "z/Architecture Principles of Operation" manual - Remove the in-kernel time steering support in favour of the new s390 PTP driver, which allows the kernel clock steered more precisely - Remove a possible false-positive warning in pte_free_defer(), which could be triggered in a valid case KVM guest process is initializing * tag 's390-6.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (29 commits) s390/mm: Remove possible false-positive warning in pte_free_defer() s390/stp: Default to enabled s390/stp: Remove leap second support s390/time: Remove in-kernel time steering s390/sclp: Use monotonic clock in sclp_sync_wait() s390/smp: Use monotonic clock in smp_emergency_stop() s390/time: Use monotonic clock in get_cycles() s390/pai_crypto: Rename PAI Crypto event 4210 scripts/gdb/symbols: make lx-symbols skip the s390 decompressor s390/boot: Introduce jump_to_kernel() function s390/stp: Remove udelay from stp_sync_clock() s390/early: Copy last breaking event address to pt_regs s390/smp: Remove conditional emergency signal order code usage s390/uaccess: Merge cmpxchg_user_key() inline assemblies s390/uaccess: Prevent kprobes on cmpxchg_user_key() functions s390/uaccess: Initialize code pages executed with non-default access key s390/skey: Provide infrastructure for executing with non-default access key s390/uaccess: Make cmpxchg_user_key() library code s390/page: Add memory clobber to page_set_storage_key() s390/page: Cleanup page_set_storage_key() inline assemblies ...
2025-07-21KVM: s390: Rework guest entry logicMark Rutland
In __vcpu_run() and do_vsie_run(), we enter an RCU extended quiescent state (EQS) by calling guest_enter_irqoff(), which lasts until __vcpu_run() calls guest_exit_irqoff(). However, between the two we enable interrupts and may handle interrupts during the EQS. As the IRQ entry code will not wake RCU in this case, we may run the core IRQ code and IRQ handler without RCU watching, leading to various potential problems. It is necessary to unmask (host) interrupts around entering the guest, as entering the guest via SIE will not automatically unmask these. When a host interrupt is taken from a guest, it is taken via its regular host IRQ handler rather than being treated as a direct exit from SIE. Due to this, we cannot simply mask interrupts around guest entry, and must handle interrupts during this window, waking RCU as required. Additionally, between guest_enter_irqoff() and guest_exit_irqoff(), we use local_irq_enable() and local_irq_disable() to unmask interrupts, violating the ordering requirements for RCU/lockdep/tracing around entry/exit sequences. Further, since this occurs in an instrumentable function, it's possible that instrumented code runs during this window, with potential usage of RCU, etc. To fix the RCU wakeup problem, an s390 implementation of arch_in_rcu_eqs() is added which checks for PF_VCPU in current->flags. PF_VCPU is set/cleared by guest_timing_{enter,exit}_irqoff(), which surround the actual guest entry. To fix the remaining issues, the lower-level guest entry logic is moved into a shared noinstr helper function using the guest_state_{enter,exit}_irqoff() helpers. These perform all the lockdep/RCU/tracing manipulation necessary, but as sie64a() does not enable/disable interrupts, we must do this explicitly with the non-instrumented arch_local_irq_{enable,disable}() helpers: guest_state_enter_irqoff() arch_local_irq_enable(); sie64a(...); arch_local_irq_disable(); guest_state_exit_irqoff(); [ajd@linux.ibm.com: rebase, fix commit message] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20250708092742.104309-3-ajd@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20250708092742.104309-3-ajd@linux.ibm.com>
2025-07-21s390/time: Remove in-kernel time steeringSven Schnelle
Remove the in-kernel time steering in favour of the new ptp s390 driver, which allows the kernel clock to be steered more precise. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-07-21s390/time: Use monotonic clock in get_cycles()Sven Schnelle
Otherwise the code might not work correctly when the clock is changed. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-07-09mm/percpu: conditionally define _shared_alloc_tag via ↵Hao Ge
CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU Recently discovered this entry while checking kallsyms on ARM64: ffff800083e509c0 D _shared_alloc_tag If ARCH_NEEDS_WEAK_PER_CPU is not defined(it is only defined for s390 and alpha architectures), there's no need to statically define the percpu variable _shared_alloc_tag. Therefore, we need to implement isolation for this purpose. When building the core kernel code for s390 or alpha architectures, ARCH_NEEDS_WEAK_PER_CPU remains undefined (as it is gated by #if defined(MODULE)). However, when building modules for these architectures, the macro is explicitly defined. Therefore, we remove all instances of ARCH_NEEDS_WEAK_PER_CPU from the code and introduced CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU to replace the relevant logic. We can now conditionally define the perpcu variable _shared_alloc_tag based on CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU. This allows architectures (such as s390/alpha) that require weak definitions for percpu variables in modules to include the definition, while others can omit it via compile-time exclusion. Link: https://lkml.kernel.org/r/20250618015809.1235761-1-hao.ge@linux.dev Signed-off-by: Hao Ge <gehao@kylinos.cn> Suggested-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Chistoph Lameter <cl@linux.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-29Merge branch 'uaccess-key' into featuresAlexander Gordeev
Heiko Carstens says: =================== A rather large series which is supposed to fix the crash below[1], which was seen when running the memop kernel kvm selftest. Problem is that cmpxchg_user_key() is executing code with a non-default key. If a system is IPL'ed with "LOAD NORMAL", and in addition the previous system used storage keys where the fetch-protection bit is set for some pages, and the cmpxchg_user_key() is located within such page a protection exception will happen when executing such code. Idea of this series is to register all code locations running with a non-default key at compile time. All functions, which run with a non-default key, then must explicitly call an init function which initializes the storage key of all pages containing such code locations with default key, which prevents such protection exceptions. Furthermore all functions containing code which may be executed with a non-default access key must be marked with __kprobes to prevent out-of-line execution of any instruction of such functions, which would result in the same problem. By default the kernel will not issue any storage key changing instructions like before, which will preserve the keyless-subset mode optimizations in hosts. Other possible implementations which I discarded: - Moving the code to an own section. This would require an s390 specific change to modpost.c, which complains about section mismatches (EX_TABLE entries in non-default text section). No other architecture has something similar, so let's keep this architecture specific hack local. - Just apply the default storage key to the whole kprobes text section. However this would add special s390 semantics to the kprobes text section, which no other architecture has. History has shown that such hacks fire back sooner or later. Furthermore, and to keep this whole stuff quite simple, this only works for code locations in core kernel code, not within modules. After this series there is no module code left with such code, and as of now I don't see any new kernel code which runs with a non-default access key. Note: the original crash can be reproduced by replacing page_set_storage_key(real, PAGE_DEFAULT_KEY, 1); with page_set_storage_key(real, 8, 1); in arch/s390/kernel/skey.c:__skey_regions_initialize() And then run tools/testing/selftests/kvm/s390/memop from the kernel selftests. [1]: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 0000000000000000 TEID: 000000000000080b Fault in home space mode while using kernel ASCE. AS:0000000002528007 R3:00000001ffffc007 S:00000001ffffb801 P:000000000000013d Oops: 0004 ilc:1 [#1]SMP Modules linked in: CPU: 3 UID: 0 PID: 791 Comm: memop Not tainted 6.16.0-rc1-00006-g3b568201d0a6-dirty #11 NONE Hardware name: IBM 3931 A01 704 (z/VM 7.4.0) Krnl PSW : 0794f00180000000 000003ffe0f4d91e (__cmpxchg_user_key1+0xbe/0x190) R:0 T:1 IO:1 EX:1 Key:9 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 Krnl GPRS: 070003ffdfbf6af0 0000000000070000 0000000095b5a300 0000000000000000 00000000f1000000 0000000000000000 0000000000000090 0000000000000000 0000000000000040 0000000000000018 000003ff9b23d000 0000037fe0ef7bd8 000003ffdfbf7500 00000000962e4000 0000037f00ffffff 0000037fe0ef7aa0 Krnl Code: 000003ffe0f4d912: ad03f0a0 stosm 160(%r15),3 000003ffe0f4d916: a7780000 lhi %r7,0 #000003ffe0f4d91a: b20a6000 spka 0(%r6) >000003ffe0f4d91e: b2790100 sacf 256 000003ffe0f4d922: a56f0080 llill %r6,128 000003ffe0f4d926: 5810a000 l %r1,0(%r10) 000003ffe0f4d92a: 141e nr %r1,%r14 000003ffe0f4d92c: c0e7ffffffff xilf %r14,4294967295 Call Trace: [<000003ffe0f4d91e>] __cmpxchg_user_key1+0xbe/0x190 [<000003ffe0189c6e>] cmpxchg_guest_abs_with_key+0x2fe/0x370 [<000003ffe016d28e>] kvm_s390_vm_mem_op_cmpxchg+0x17e/0x350 [<000003ffe0173284>] kvm_arch_vm_ioctl+0x354/0x6f0 [<000003ffe015fedc>] kvm_vm_ioctl+0x2cc/0x6e0 [<000003ffe05348ae>] vfs_ioctl+0x2e/0x70 [<000003ffe0535e70>] __s390x_sys_ioctl+0xe0/0x100 [<000003ffe0f40f06>] __do_syscall+0x136/0x340 [<000003ffe0f4cb2e>] system_call+0x6e/0x90 Last Breaking-Event-Address: [<000003ffe0f4d896>] __cmpxchg_user_key1+0x36/0x190 =================== Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-29s390/skey: Provide infrastructure for executing with non-default access keyHeiko Carstens
The current assumption is that kernel code is always executed with access key zero, which means that storage key protection does not apply. However this assumption is not correct: cmpxchg_user_key() may be executed with a non-zero key; if then the storage key of the page which belongs to the cmpxchg_user_key() code contains a key with fetch-protection enabled the result is a protection exception. For several performance optimizations storage keys are not initialized on system boot. To keep these optimizations add infrastructure which allows to define code ranges within functions which are executed with a non-default key. When such code is executed such functions must explicitly call skey_regions_initialize(). This will initialize all storage keys belonging to such code ranges in a way that no protection exceptions happen when the code is executed with a non-default access key. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-29s390/uaccess: Make cmpxchg_user_key() library codeHeiko Carstens
Move cmpxchg_user_key() handling to uaccess library code. The generated code is large in any case so that there is hardly any benefit if it is inlined. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-29s390/page: Add memory clobber to page_set_storage_key()Heiko Carstens
Add memory clobbers to the page_set_storage_key() inline assemblies. This allows for data dependencies from other code, which is important to prevent the compiler from reordering instructions if required. Note that this doesn't fix a bug in existing code; this is just a prerequisite for upcoming code changes. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-29s390/page: Cleanup page_set_storage_key() inline assembliesHeiko Carstens
Add extra lines, indentations, and symbolic names for operands in order to make the two page_set_storage_key() inline assemblies a bit more readable. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-26s390/nmi: Print additional informationHeiko Carstens
In case of an unrecoverable machine check only the machine check interrupt code is printed to the console before the machine is stopped. This makes root cause analysis sometimes hard. Print additional machine check information to make analysis easier. The output now looks like this: Unrecoverable machine check, code: 00400F5F4C3B0000 6.16.0-rc2-11605-g987a9431e53a-dirty HW: IBM 3931 A01 704 (z/VM 7.4.0) PSW: 0706C00180000000 000003FFE0F0462E PFX: 0000000000070000 LBA: 000003FFE0F0462A EDC: 0000000000000000 FSA: 0000000000000000 CRS: 0080000014966A12 0000000087CB41C7 0000000000BFF140 0000000000000000 000000000000FFFF 0000000000BFF140 0000000071000000 0000000087CB41C7 0000000000008000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 00000000024C0007 00000000DB000000 0000000000BFF000 GPRS: FFFFFFFF00000000 000003FFE0F0462E E10EA4F489F897A6 0000000000000000 7FFFFFF2C0413C4C 000003FFE19B7010 0000000000000000 0000000000000000 0000000000000000 00000001F76B3380 000003FFE15D4050 0000000000000005 0000000000000000 0000000000070000 000003FFE0F0586C 0000037FE00B7DA0 System stopped Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-26s390/crypto: Add protected key hmac subfunctions for KMACHolger Dengler
The CPACF KMAC instruction supports new subfunctions for protected key hmac. Add defines for these 4 new subfuctions. Signed-off-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-06-17s390: Explicitly include <linux/export.h>Heiko Carstens
Explicitly include <linux/export.h> in files which contain an EXPORT_SYMBOL(). See commit a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1") for more details. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-17s390/ptrace: Fix pointer dereferencing in regs_get_kernel_stack_nth()Heiko Carstens
The recent change which added READ_ONCE_NOCHECK() to read the nth entry from the kernel stack incorrectly dropped dereferencing of the stack pointer in order to read the requested entry. In result the address of the entry is returned instead of its content. Dereference the pointer again to fix this. Reported-by: Will Deacon <will@kernel.org> Closes: https://lore.kernel.org/r/20250612163331.GA13384@willie-the-truck Fixes: d93a855c31b7 ("s390/ptrace: Avoid KASAN false positives in regs_get_kernel_stack_nth()") Cc: stable@vger.kernel.org Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-16s390: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headersThomas Huth
While the GCC and Clang compilers already define __ASSEMBLER__ automatically when compiling assembler code, __ASSEMBLY__ is a macro that only gets defined by the Makefiles in the kernel. This is bad since macros starting with two underscores are names that are reserved by the C language. It can also be very confusing for the developers when switching between userspace and kernelspace coding, or when dealing with uapi headers that rather should use __ASSEMBLER__ instead. So let's now standardize on the __ASSEMBLER__ macro that is provided by the compilers. This is a completely mechanical patch (done with a simple "sed -i" statement), with some manual fixups done later while rebasing the patch. Signed-off-by: Thomas Huth <thuth@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20250611140046.137739-3-thuth@redhat.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2025-06-11mm: pgtable: fix pte_swp_exclusiveMagnus Lindholm
Make pte_swp_exclusive return bool instead of int. This will better reflect how pte_swp_exclusive is actually used in the code. This fixes swap/swapoff problems on Alpha due pte_swp_exclusive not returning correct values when _PAGE_SWP_EXCLUSIVE bit resides in upper 32-bits of PTE (like on alpha). Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Magnus Lindholm <linmag7@gmail.com> Cc: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/lkml/20250218175735.19882-2-linmag7@gmail.com/ Link: https://lore.kernel.org/lkml/20250602041118.GA2675383@ZenIV/ [ Applied as the 'sed' script Al suggested - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>