kernel/arch/s390/mm, branch linux-rolling-lts

s390/pfault: Fix virtual vs physical address confusion

2026-03-19T15:08:34Z

commit d879ac6756b662a085a743e76023c768c3241579 upstream. When Linux is running as guest, runs a user space process and the user space process accesses a page that the host has paged out, the guest gets a pfault interrupt and schedules a different process. Without this mechanism the host would have to suspend the whole virtual CPU until the page has been paged in. To setup the pfault interrupt the real address of parameter list should be passed to DIAGNOSE 0x258, but a virtual address is passed instead. That has a performance impact, since the pfault setup never succeeds, the interrupt is never delivered to a guest and the whole virtual CPU is suspended as result. Cc: stable@vger.kernel.org Fixes: c98d2ecae08f ("s390/mm: Uncouple physical vs virtual address spaces") Reported-by: Claudio Imbrenda Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

KVM: s390: Fix gmap_helper_zap_one_page() again

2026-01-08T09:16:41Z

[ Upstream commit 2f393c228cc519ddf19b8c6c05bf15723241aa96 ] A few checks were missing in gmap_helper_zap_one_page(), which can lead to memory corruption in the guest under specific circumstances. Add the missing checks. Fixes: 5deafa27d9ae ("KVM: s390: Fix to clear PTE when discarding a swapped page") Cc: stable@vger.kernel.org Reported-by: Marc Hartmayer Tested-by: Marc Hartmayer Acked-by: Christian Borntraeger Signed-off-by: Claudio Imbrenda Signed-off-by: Heiko Carstens [ adapted ptep_zap_softleaf_entry() and softleaf_from_pte() calls to ptep_zap_swap_entry() and pte_to_swp_entry() ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

s390/mm: Fix __ptep_rdp() inline assembly

2025-11-14T14:58:20Z

When a zero ASCE is passed to the __ptep_rdp() inline assembly, the generated instruction should have the R3 field of the instruction set to zero. However the inline assembly is written incorrectly: for such cases a zero is loaded into a register allocated by the compiler and this register is then used by the instruction. This means that selected TLB entries may not be flushed since the specified ASCE does not match the one which was used when the selected TLB entries were created. Fix this by removing the asce and opt parameters of __ptep_rdp(), since all callers always pass zero, and use a hard-coded register zero for the R3 field. Fixes: 0807b856521f ("s390/mm: add support for RDP (Reset DAT-Protection)") Cc: stable@vger.kernel.org Reviewed-by: Gerald Schaefer Signed-off-by: Heiko Carstens

s390/mm: Fix memory leak in add_marker() when kvrealloc() fails

2025-10-29T13:17:50Z

The function has a memory leak when kvrealloc() fails. The function directly assigns NULL to the markers pointer, losing the reference to the previously allocated memory. This causes kvfree() in pt_dump_init() to free NULL instead of the leaked memory. Fix by: 1. Using kvrealloc() uniformly for all allocations 2. Using a temporary variable to preserve the original pointer until allocation succeeds 3. Removing the error path that sets markers_cnt=0 to keep consistency between markers and markers_cnt Found via static analysis and this is similar to commit 42378a9ca553 ("bpf, verifier: Fix memory leak in array reallocation for stack state") Fixes: d0e7915d2ad3 ("s390/mm/ptdump: Generate address marker array dynamically") Cc: stable@vger.kernel.org Signed-off-by: Miaoqian Lin Signed-off-by: Heiko Carstens

Merge tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2025-10-09T17:51:43Z

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

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

2025-10-04T15:52:16Z

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 ...

Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-10-03T01:18:33Z

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() ...

Merge tag 'loongarch-kvm-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

2025-09-30T17:23:44Z

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.

Merge tag 'kvm-s390-next-6.18-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

2025-09-30T17:09:20Z

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.

KVM: s390: Fix to clear PTE when discarding a swapped page

2025-09-30T13:58:30Z

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 Signed-off-by: Gautam Gala Reviewed-by: Claudio Imbrenda Signed-off-by: Claudio Imbrenda