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2026-02-03s390/configs: Enable BLK_DEV_NULL_BLK as moduleHalil Pasic
Enable BLK_DEV_NULL_BLK as module in defconfig and debug_defconfig, so the Null Test Block Device Driver can be easily used for testing purposes. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2026-02-03sched/clock: Avoid false sharing for sched_clock_irqtimeWangyang Guo
Read-mostly sched_clock_irqtime may share the same cacheline with frequently updated nohz struct. Make it as static_key to avoid false sharing issue. The only user of disable_sched_clock_irqtime() is tsc_.*mark_unstable() which may be invoked under atomic context and require a workqueue to disable static_key. But both of them calls clear_sched_clock_stable() just before doing disable_sched_clock_irqtime(). We can reuse "sched_clock_work" to also disable sched_clock_irqtime(). One additional case need to handle is if the tsc is marked unstable before late_initcall() phase, sched_clock_work will not be invoked and sched_clock_irqtime will stay enabled although clock is unstable: tsc_init() enable_sched_clock_irqtime() # irqtime accounting is enabled here ... if (unsynchronized_tsc()) # true mark_tsc_unstable() clear_sched_clock_stable() __sched_clock_stable_early = 0; ... if (static_key_count(&sched_clock_running.key) == 2) # Only happens at sched_clock_init_late() __clear_sched_clock_stable(); # Never executed ... # late_initcall() phase sched_clock_init_late() if (__sched_clock_stable_early) # Already false __set_sched_clock_stable(); # sched_clock is never marked stable # TSC unstable, but sched_clock_work won't run to disable irqtime So we need to disable_sched_clock_irqtime() in sched_clock_init_late() if clock is unstable. Reported-by: Benjamin Lei <benjamin.lei@intel.com> Suggested-by: K Prateek Nayak <kprateek.nayak@amd.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Signed-off-by: Wangyang Guo <wangyang.guo@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com> Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com> Reviewed-by: Tianyou Li <tianyou.li@intel.com> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://patch.msgid.link/20260127072509.2627346-1-wangyang.guo@intel.com
2026-02-03Merge branch 'v6.19-rc8'Peter Zijlstra
Update to avoid conflicts with /urgent patches. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2026-02-03arm64/gcs: Fix error handling in arch_set_shadow_stack_status()Breno Leitao
alloc_gcs() returns an error-encoded pointer on failure, which comes from do_mmap(), not NULL. The current NULL check fails to detect errors, which could lead to using an invalid GCS address. Use IS_ERR_VALUE() to properly detect errors, consistent with the check in gcs_alloc_thread_stack(). Fixes: b57180c75c7e ("arm64/gcs: Implement shadow stack prctl() interface") Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Will Deacon <will@kernel.org>
2026-02-02MIPS: tools: relocs: Ship a definition of R_MIPS_PC32Yao Zi
R_MIPS_PC32 is a GNU extension, its definition is available in glibc only since 2.39 (released in 2024), and not available in musl libc yet. Provide our own definition for R_MIPS_PC32 and use it if necessary to fix relocs tool building on musl and older glibc systems. Fixes: ff79d31eb536 ("mips: Add support for PC32 relocations in vmlinux") Signed-off-by: Yao Zi <me@ziyao.cc> Link: https://patch.msgid.link/20260202041610.61389-1-me@ziyao.cc Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-02-02x86/kfence: fix booting on 32bit non-PAE systemsAndrew Cooper
The original patch inverted the PTE unconditionally to avoid L1TF-vulnerable PTEs, but Linux doesn't make this adjustment in 2-level paging. Adjust the logic to use the flip_protnone_guard() helper, which is a nop on 2-level paging but inverts the address bits in all other paging modes. This doesn't matter for the Xen aspect of the original change. Linux no longer supports running 32bit PV under Xen, and Xen doesn't support running any 32bit PV guests without using PAE paging. Link: https://lkml.kernel.org/r/20260126211046.2096622-1-andrew.cooper3@citrix.com Fixes: b505f1944535 ("x86/kfence: avoid writing L1TF-vulnerable PTEs") Reported-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Closes: https://lore.kernel.org/lkml/CAKFNMokwjw68ubYQM9WkzOuH51wLznHpEOMSqtMoV1Rn9JV_gw@mail.gmail.com/ Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-02x86/ibs: Fix typo in dc_l2tlb_miss commentXiang-Bin Shi
The comment for dc_l2tlb_miss incorrectly describes it as a "hit". This contradicts the field name and the actual bit definition. Fix the comment to correctly describe it as a "miss". Signed-off-by: Xiang-Bin Shi <eric91102091@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260123075719.160734-1-eric91102091@gmail.com
2026-02-02KVM: arm64: nv: Avoid NV stage-2 code when NV is not supportedFuad Tabba
The NV stage-2 manipulation functions kvm_nested_s2_unmap(), kvm_nested_s2_wp(), and others, are being called for any stage-2 manipulation regardless of whether nested virtualization is supported or enabled for the VM. For protected KVM (pKVM), `struct kvm_pgtable` uses the `pkvm_mappings` member of the union. This member aliases `ia_bits`, which is used by the non-protected NV code paths. Attempting to read `pgt->ia_bits` in these functions results in treating protected mapping pointers or state values as bit-shift amounts. This triggers a UBSAN shift-out-of-bounds error: UBSAN: shift-out-of-bounds in arch/arm64/kvm/nested.c:1127:34 shift exponent 174565952 is too large for 64-bit type 'unsigned long' Call trace: __ubsan_handle_shift_out_of_bounds+0x28c/0x2c0 kvm_nested_s2_unmap+0x228/0x248 kvm_arch_flush_shadow_memslot+0x98/0xc0 kvm_set_memslot+0x248/0xce0 Since pKVM and NV are mutually exclusive, prevent entry into these NV handling functions if the VM has not allocated any nested MMUs (i.e., `kvm->arch.nested_mmus_size` is 0). Fixes: 7270cc9157f47 ("KVM: arm64: nv: Handle VNCR_EL2 invalidation from MMU notifiers") Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://patch.msgid.link/20260202152310.113467-1-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-02-02arm64: Fix non-atomic __READ_ONCE() with CONFIG_LTO=yMarco Elver
The implementation of __READ_ONCE() under CONFIG_LTO=y incorrectly qualified the fallback "once" access for types larger than 8 bytes, which are not atomic but should still happen "once" and suppress common compiler optimizations. The cast `volatile typeof(__x)` applied the volatile qualifier to the pointer type itself rather than the pointee. This created a volatile pointer to a non-volatile type, which violated __READ_ONCE() semantics. Fix this by casting to `volatile typeof(*__x) *`. With a defconfig + LTO + debug options build, we see the following functions to be affected: xen_manage_runstate_time (884 -> 944 bytes) xen_steal_clock (248 -> 340 bytes) ^-- use __READ_ONCE() to load vcpu_runstate_info structs Fixes: e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y") Cc: stable@vger.kernel.org Reviewed-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Marco Elver <elver@google.com> Tested-by: David Laight <david.laight.linux@gmail.com> Signed-off-by: Will Deacon <will@kernel.org>
2026-02-02KVM: arm64: Use standard seq_file iterator for vgic-debug debugfsFuad Tabba
The current implementation uses `vgic_state_iter` in `struct vgic_dist` to track the sequence position. This effectively makes the iterator shared across all open file descriptors for the VM. This approach has significant drawbacks: - It enforces mutual exclusion, preventing concurrent reads of the debugfs file (returning -EBUSY). - It relies on storing transient iterator state in the long-lived VM structure (`vgic_dist`). Refactor the implementation to use the standard `seq_file` iterator. Instead of storing state in `kvm_arch`, rely on the `pos` argument passed to the `start` and `next` callbacks, which tracks the logical index specific to the file descriptor. This change enables concurrent access and eliminates the `vgic_state_iter` field from `struct vgic_dist`. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://patch.msgid.link/20260202085721.3954942-4-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-02-02KVM: arm64: Reimplement vgic-debug XArray iterationFuad Tabba
The vgic-debug interface implementation uses XArray marks (`LPI_XA_MARK_DEBUG_ITER`) to "snapshot" LPIs at the start of iteration. This modifies global state for a read-only operation and complicates reference counting, leading to leaks if iteration is aborted or fails. Reimplement the iterator to use dynamic iteration logic: - Remove `lpi_idx` from `struct vgic_state_iter`. - Replace the XArray marking mechanism with dynamic iteration using `xa_find_after(..., XA_PRESENT)`. - Wrap XArray traversals in `rcu_read_lock()`/`rcu_read_unlock()` to ensure safety against concurrent modifications (e.g., LPI unmapping). - Handle potential races where an LPI is removed during iteration by gracefully skipping it in `show()`, rather than warning. - Remove the unused `LPI_XA_MARK_DEBUG_ITER` definition. This simplifies the lifecycle management of the iterator and prevents resource leaks associated with the marking mechanism, and paves the way for using a standard seq_file iterator. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://patch.msgid.link/20260202085721.3954942-3-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-02-02KVM: arm64: Use standard seq_file iterator for idregs debugfsFuad Tabba
The current implementation uses `idreg_debugfs_iter` in `struct kvm_arch` to track the sequence position. This effectively makes the iterator shared across all open file descriptors for the VM. This approach has significant drawbacks: - It enforces mutual exclusion, preventing concurrent reads of the debugfs file (returning -EBUSY). - It relies on storing transient iterator state in the long-lived VM structure (`kvm_arch`). - The use of `u8` for the iterator index imposes an implicit limit of 255 registers. While not currently exceeded, this is fragile against future architectural growth. Switching to `loff_t` eliminates this overflow risk. Refactor the implementation to use the standard `seq_file` iterator. Instead of storing state in `kvm_arch`, rely on the `pos` argument passed to the `start` and `next` callbacks, which tracks the logical index specific to the file descriptor. This change enables concurrent access and eliminates the `idreg_debugfs_iter` field from `struct kvm_arch`. Signed-off-by: Fuad Tabba <tabba@google.com> Link: https://patch.msgid.link/20260202085721.3954942-2-tabba@google.com Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-02-02Partial revert "x86/xen: fix balloon target initialization for PVH dom0"Roger Pau Monne
This partially reverts commit 87af633689ce16ddb166c80f32b120e50b1295de so the current memory target for PV guests is still fetched from start_info->nr_pages, which matches exactly what the toolstack sets the initial memory target to. Using get_num_physpages() is possible on PV also, but needs adjusting to take into account the ISA hole and the PFN at 0 not considered usable memory despite being populated, and hence would need extra adjustments. Instead of carrying those extra adjustments switch back to the previous code. That leaves Linux with a difference in how current memory target is obtained for HVM vs PV, but that's better than adding extra logic just for PV. However if switching to start_info->nr_pages for PV domains we need to differentiate between released pages (freed back to the hypervisor) as opposed to pages in the physmap which are not populated to start with. Introduce a new xen_unpopulated_pages to account for papges that have never been populated, and hence in the PV case don't need subtracting. Fixes: 87af633689ce ("x86/xen: fix balloon target initialization for PVH dom0") Reported-by: James Dingwall <james@dingwall.me.uk> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Message-ID: <20260128110510.46425-2-roger.pau@citrix.com>
2026-02-01ARM: versatile: Remove IRQF_ONESHOTSebastian Andrzej Siewior
Passing IRQF_ONESHOT ensures that the interrupt source is masked until the secondary (threaded) handler is done. If only a primary handler is used then the flag makes no sense because the interrupt can not fire (again) while its handler is running. Revert adding IRQF_ONESHOT to irqflags. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Linus Walleij <linusw@kernel.org> Link: https://patch.msgid.link/20260128095540.863589-9-bigeasy@linutronix.de
2026-01-31kernel.h: include linux/instruction_pointer.h explicitlyYury Norov
In preparation for decoupling linux/instruction_pointer.h and linux/kernel.h, include instruction_pointer.h explicitly where needed. Link: https://lkml.kernel.org/r/20260116042510.241009-5-ynorov@nvidia.com Signed-off-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Cc: Aaron Tomlin <atomlin@atomlin.com> Cc: Andi Shyti <andi.shyti@linux.intel.com> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31Merge branch 'mm-hotfixes-stable' into mm-nonmm-stable to pick up changesAndrew Morton
required to merge "kho: use unsigned long for nr_pages".
2026-01-31mm, swap: cleanup swap entry management workflowKairui Song
The current swap entry allocation/freeing workflow has never had a clear definition. This makes it hard to debug or add new optimizations. This commit introduces a proper definition of how swap entries would be allocated and freed. Now, most operations are folio based, so they will never exceed one swap cluster, and we now have a cleaner border between swap and the rest of mm, making it much easier to follow and debug, especially with new added sanity checks. Also making more optimization possible. Swap entry will be mostly freed and free with a folio bound. The folio lock will be useful for resolving many swap related races. Now swap allocation (except hibernation) always starts with a folio in the swap cache, and gets duped/freed protected by the folio lock: - folio_alloc_swap() - The only allocation entry point now. Context: The folio must be locked. This allocates one or a set of continuous swap slots for a folio and binds them to the folio by adding the folio to the swap cache. The swap slots' swap count start with zero value. - folio_dup_swap() - Increase the swap count of one or more entries. Context: The folio must be locked and in the swap cache. For now, the caller still has to lock the new swap entry owner (e.g., PTL). This increases the ref count of swap entries allocated to a folio. Newly allocated swap slots' count has to be increased by this helper as the folio got unmapped (and swap entries got installed). - folio_put_swap() - Decrease the swap count of one or more entries. Context: The folio must be locked and in the swap cache. For now, the caller still has to lock the new swap entry owner (e.g., PTL). This decreases the ref count of swap entries allocated to a folio. Typically, swapin will decrease the swap count as the folio got installed back and the swap entry got uninstalled This won't remove the folio from the swap cache and free the slot. Lazy freeing of swap cache is helpful for reducing IO. There is already a folio_free_swap() for immediate cache reclaim. This part could be further optimized later. The above locking constraints could be further relaxed when the swap table is fully implemented. Currently dup still needs the caller to lock the swap entry container (e.g. PTL), or a concurrent zap may underflow the swap count. Some swap users need to interact with swap count without involving folio (e.g. forking/zapping the page table or mapping truncate without swapin). In such cases, the caller has to ensure there is no race condition on whatever owns the swap count and use the below helpers: - swap_put_entries_direct() - Decrease the swap count directly. Context: The caller must lock whatever is referencing the slots to avoid a race. Typically the page table zapping or shmem mapping truncate will need to free swap slots directly. If a slot is cached (has a folio bound), this will also try to release the swap cache. - swap_dup_entry_direct() - Increase the swap count directly. Context: The caller must lock whatever is referencing the entries to avoid race, and the entries must already have a swap count > 1. Typically, forking will need to copy the page table and hence needs to increase the swap count of the entries in the table. The page table is locked while referencing the swap entries, so the entries all have a swap count > 1 and can't be freed. Hibernation subsystem is a bit different, so two special wrappers are here: - swap_alloc_hibernation_slot() - Allocate one entry from one device. - swap_free_hibernation_slot() - Free one entry allocated by the above helper. All hibernation entries are exclusive to the hibernation subsystem and should not interact with ordinary swap routines. By separating the workflows, it will be possible to bind folio more tightly with swap cache and get rid of the SWAP_HAS_CACHE as a temporary pin. This commit should not introduce any behavior change [kasong@tencent.com: fix leak, per Chris Mason. Remove WARN_ON, per Lai Yi] Link: https://lkml.kernel.org/r/CAMgjq7AUz10uETVm8ozDWcB3XohkOqf0i33KGrAquvEVvfp5cg@mail.gmail.com [ryncsn@gmail.com: fix KSM copy pages for swapoff, per Chris] Link: https://lkml.kernel.org/r/aXxkANcET3l2Xu6J@KASONG-MC4 Link: https://lkml.kernel.org/r/20251220-swap-table-p2-v5-14-8862a265a033@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Signed-off-by: Kairui Song <ryncsn@gmail.com> Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosry.ahmed@linux.dev> Cc: Deepanshu Kartikey <kartikey406@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <ryncsn@gmail.com> Cc: Chris Mason <clm@fb.com> Cc: Chris Mason <clm@meta.com> Cc: Lai Yi <yi1.lai@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31sparc/mm: export symbols for lazy_mmu_mode KUnit testsKevin Brodsky
The lazy_mmu_mode KUnit tests call lazy_mmu_mode_{enable,disable}. These tests may be built as a module, and because of inlining this means that arch_{enter,flush,leave}_lazy_mmu_mode need to be exported. [akpm@linux-foundation.org: remove mm/tests/lazy_mmu_mode_kunit.c comment, per Kevin] Link: https://lkml.kernel.org/r/20251218100541.2667405-1-kevin.brodsky@arm.com Fixes: ee628d9cc8d5 ("mm: add basic tests for lazy_mmu") Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Andreas Larsson <andreas@gaisler.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm: rename CONFIG_MEMORY_BALLOON -> CONFIG_BALLOONDavid Hildenbrand (Red Hat)
Let's make it consistent with the naming of the files but also with the naming of CONFIG_BALLOON_MIGRATION. While at it, add a "/* CONFIG_BALLOON */". Link: https://lkml.kernel.org/r/20260119230133.3551867-24-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm: rename CONFIG_BALLOON_COMPACTION to CONFIG_BALLOON_MIGRATIONDavid Hildenbrand (Red Hat)
While compaction depends on migration, the other direction is not the case. So let's make it clearer that this is all about migration of balloon pages. Adjust all comments/docs in the core to talk about "migration" instead of "compaction". While at it add some "/* CONFIG_BALLOON_MIGRATION */". Link: https://lkml.kernel.org/r/20260119230133.3551867-23-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm: rename balloon_compaction.(c|h) to balloon.(c|h)David Hildenbrand (Red Hat)
Even without CONFIG_BALLOON_COMPACTION this infrastructure implements basic list and page management for a memory balloon. Link: https://lkml.kernel.org/r/20260119230133.3551867-21-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm/balloon_compaction: centralize adjust_managed_page_count() handlingDavid Hildenbrand (Red Hat)
Let's centralize it, by allowing for the driver to enable this handling through a new flag (bool for now) in the balloon device info. Note that we now adjust the counter when adding/removing a page into the balloon list: when removing a page to deflate it, it will now happen before the driver communicated with hypervisor, not afterwards. This shouldn't make a difference in practice. Link: https://lkml.kernel.org/r/20260119230133.3551867-7-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31mm/balloon_compaction: centralize basic page migration handlingDavid Hildenbrand (Red Hat)
Let's update the balloon page references, the balloon page list, the BALLOON_MIGRATE counter and the isolated-pages counter in balloon_page_migrate(), after letting the balloon->migratepage() callback deal with the actual inflation+deflation. Note that we now perform the balloon list modifications outside of any implementation-specific locks: which is fine, there is nothing special about these page actions that the lock would be protecting. The old page is already no longer in the list (isolated) and the new page is not yet in the list. Let's use -ENOENT to communicate the special "inflation of new page failed after already deflating the old page" to balloon_page_migrate() so it can handle it accordingly. While at it, rename balloon->b_dev_info to make it match the other functions. Also, drop the comment above balloon_page_migrate(), which seems unnecessary. Link: https://lkml.kernel.org/r/20260119230133.3551867-6-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31powerpc/pseries/cmm: remove cmm_balloon_compaction_init()David Hildenbrand (Red Hat)
Now that there is not a lot of logic left, let's just inline setting up the migration function. To avoid #ifdef in the caller we can instead use IS_ENABLED() and make the compiler happy by only providing the function declaration. Now that the function is gone, drop the "out_balloon_compaction" label. Note that before commit 68f2736a8583 ("mm: Convert all PageMovable users to movable_operations") we actually had to undo something, now not anymore. Link: https://lkml.kernel.org/r/20260119230133.3551867-4-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-31Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm/shmem,Andrew Morton
swap: fix race of truncate and swap entry split", needed for merging "mm, swap: cleanup swap entry management workflow".
2026-01-31bpf, arm64: Add fsession supportLeon Hwang
Implement fsession support in the arm64 BPF JIT trampoline. Extend the trampoline stack layout to store function metadata and session cookies, and pass the appropriate metadata to fentry and fexit programs. This mirrors the existing x86 behavior and enables session cookies on arm64. Acked-by: Puranjay Mohan <puranjay@kernel.org> Tested-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20260131144950.16294-3-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-31bpf: Add bpf_jit_supports_fsession()Leon Hwang
The added fsession does not prevent running on those architectures, that haven't added fsession support. For example, try to run fsession tests on arm64: test_fsession_basic:PASS:fsession_test__open_and_load 0 nsec test_fsession_basic:PASS:fsession_attach 0 nsec check_result:FAIL:test_run_opts err unexpected error: -14 (errno 14) In order to prevent such errors, add bpf_jit_supports_fsession() to guard those architectures. Fixes: 2d419c44658f ("bpf: add fsession support") Acked-by: Puranjay Mohan <puranjay@kernel.org> Tested-by: Puranjay Mohan <puranjay@kernel.org> Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Link: https://lore.kernel.org/r/20260131144950.16294-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-01-31x86/sev: Don't emit BSS_DECRYPTED section unless it is in useArd Biesheuvel
The BSS_DECRYPTED section that gets emitted into .bss will be empty if CONFIG_AMD_MEM_ENCRYPT is not defined. However, due to the fact that it is injected into .bss rather than emitted as a separate section, the 2 MiB alignment that it specifies is still taken into account unconditionally, pushing .bss out to the next 2 MiB boundary, leaving a gap that is never freed. So only emit a non-empty BSS_DECRYPTED section if it is going to be used. In that case, it would still be nice to free the padding, but that is left for later. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/20260108092526.28586-23-ardb@kernel.org
2026-01-31ARM: 9467/1: mm: Don't use %pK through printkThomas Weissschuh
Restricted pointers ("%pK") were never meant to be used through printk(). They can acquire sleeping locks in atomic contexts. Switch to %px over the more secure %p as this usage is a debugging aid, gated behind CONFIG_DEBUG_VIRTUAL and used by WARN(). Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2026-01-31ARM: 9468/1: fix memset64() on big-endianThomas Weissschuh
On big-endian systems the 32-bit low and high halves need to be swapped for the underlying assembly implementation to work correctly. Fixes: fd1d362600e2 ("ARM: implement memset32 & memset64") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2026-01-31crypto: s390/paes - Refuse clear key material by defaultHarald Freudenberger
This patch exploits the new xflag PKEY_XFLAG_NOCLEARKEY from the pkey layer. So now by default all the paes algorithms refuse the use of clear key material ("clear key tokens") in the setkey function with -EINVAL. With a new kernel module parameter "clrkey" this behavior can be controlled. By default clrkey is 'N' but for testing purpose on module load a true value (1, 'Y') may be given to accept clear key tokens. Note that during selftest clear keys are always used and thus the xflag PKEY_XFLAG_NOCLEARKEY is NOT set as long as the algorithm is in a larval state indicated by crypto_skcipher_tested() returning false. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-01-31crypto: s390/phmac - Refuse clear key material by defaultHarald Freudenberger
This patch exploits the new xflag PKEY_XFLAG_NOCLEARKEY from the pkey layer. So now by default the phmac refuses the use of clear key material ("clear key tokens") in the setkey function with -EINVAL. With a new kernel module parameter "clrkey" this behavior can be controlled. By default clrkey is 'N' but for testing purpose on module load a true value (1, 'Y') may be given to accept clear key tokens. Note that during selftest clear keys are always used and thus the xflag PKEY_XFLAG_NOCLEARKEY is NOT set as long as the algorithm is in a larval state indicated by crypto_ahash_tested() returning false. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-01-31s390/pkey: Support new xflag PKEY_XFLAG_NOCLEARKEYHarald Freudenberger
Introduce a new xflag PKEY_XFLAG_NOCLEARKEY which when given refuses the conversion of "clear key tokens" to protected key material. Some algorithms (PAES, PHMAC) have the need to construct "clear key tokens" to be used during selftest. But in general these algorithms should only support clear key material for testing purpose. So now the algorithm implementation can signal via xflag PKEY_XFLAG_NOCLEARKEY that a conversion of clear key material to protected key is not acceptable and thus the pkey layer (usually one of the handler modules) refuses clear key material with -EINVAL. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2026-01-30Merge tag 'riscv-for-linus-6.19-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Paul Walmsley: - Correct the RISC-V compat.h COMPAT_UTS_MACHINE architecture name - Avoid printing a false warning message on kernels with the SiFive and MIPS errata compiled in - Address a few warnings generated by sparse in the signal handling code - Fix a comment typo * tag 'riscv-for-linus-6.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: compat: fix COMPAT_UTS_MACHINE definition errata/sifive: remove unreliable warn_miss_errata riscv: fix minor typo in syscall.h comment riscv: signal: fix some warnings reported by sparse
2026-01-31PCI/MSI: Convert the boolean no_64bit_msi flag to a DMA address maskVivian Wang
Some PCI devices have PCI_MSI_FLAGS_64BIT in the MSI capability, but implement less than 64 address bits. This breaks on platforms where such a device is assigned an MSI address higher than what's supported. Currently, no_64bit_msi bit is set for these devices, meaning that only 32-bit MSI addresses are allowed for them. However, on some platforms the MSI doorbell address is above the 32-bit limit but within the addressable range of the device. As a first step to enable MSI on those combinations of devices and platforms, convert the boolean no_64bit_msi flag to a DMA mask and fixup the affected usage sites: - no_64bit_msi = 1 -> msi_addr_mask = DMA_BIT_MASK(32) - no_64bit_msi = 0 -> msi_addr_mask = DMA_BIT_MASK(64) - if (no_64bit_msi) -> if (msi_addr_mask < DMA_BIT_MASK(64)) Since no values other than DMA_BIT_MASK(32) and DMA_BIT_MASK(64) are used, this is functionally equivalent. This prepares for changing the binary decision between 32 and 64 bit to a DMA mask based decision which allows to support systems which have a DMA address space less than 64bit but a MSI doorbell address above the 32-bit limit. [ tglx: Massaged changelog ] Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Reviewed-by: Brett Creeley <brett.creeley@amd.com> # ionic Reviewed-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Takashi Iwai <tiwai@suse.de> # sound Link: https://patch.msgid.link/20260129-pci-msi-addr-mask-v4-1-70da998f2750@iscas.ac.cn
2026-01-30x86/fgraph,bpf: Switch kprobe_multi program stack unwind to hw_regs pathJiri Olsa
Mahe reported missing function from stack trace on top of kprobe multi program. The missing function is the very first one in the stacktrace, the one that the bpf program is attached to. # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 ('*' is used for kprobe_multi attachment) The reason is that the previous change (the Fixes commit) fixed stack unwind for tracepoint, but removed attached function address from the stack trace on top of kprobe multi programs, which I also overlooked in the related test (check following patch). The tracepoint and kprobe_multi have different stack setup, but use same unwind path. I think it's better to keep the previous change, which fixed tracepoint unwind and instead change the kprobe multi unwind as explained below. The bpf program stack unwind calls perf_callchain_kernel for kernel portion and it follows two unwind paths based on X86_EFLAGS_FIXED bit in pt_regs.flags. When the bit set we unwind from stack represented by pt_regs argument, otherwise we unwind currently executed stack up to 'first_frame' boundary. The 'first_frame' value is taken from regs.rsp value, but ftrace_caller and ftrace_regs_caller (ftrace trampoline) functions set the regs.rsp to the previous stack frame, so we skip the attached function entry. If we switch kprobe_multi unwind to use the X86_EFLAGS_FIXED bit, we set the start of the unwind to the attached function address. As another benefit we also cut extra unwind cycles needed to reach the 'first_frame' boundary. The speedup can be measured with trigger bench for kprobe_multi program and stacktrace support. - trigger bench with stacktrace on current code: kprobe-multi : 0.810 ± 0.001M/s kretprobe-multi: 0.808 ± 0.001M/s - and with the fix: kprobe-multi : 1.264 ± 0.001M/s kretprobe-multi: 1.401 ± 0.002M/s With the fix, the entry probe stacktrace: # bpftrace -e 'kprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... __x64_sys_newuname+9 do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 The return probe skips the attached function, because it's no longer on the stack at the point of the unwind and this way is the same how standard kretprobe works. # bpftrace -e 'kretprobe:__x64_sys_newuname* { print(kstack)}' Attaching 1 probe... do_syscall_64+134 entry_SYSCALL_64_after_hwframe+118 Fixes: 6d08340d1e35 ("Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"") Reported-by: Mahe Tardy <mahe.tardy@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/bpf/20260126211837.472802-3-jolsa@kernel.org
2026-01-30x86/fgraph: Fix return_to_handler regs.rsp valueJiri Olsa
The previous change (Fixes commit) messed up the rsp register value, which is wrong because it's already adjusted with FRAME_SIZE, we need the original rsp value. This change does not affect fprobe current kernel unwind, the !perf_hw_regs path perf_callchain_kernel: if (perf_hw_regs(regs)) { if (perf_callchain_store(entry, regs->ip)) return; unwind_start(&state, current, regs, NULL); } else { unwind_start(&state, current, NULL, (void *)regs->sp); } which uses pt_regs.sp as first_frame boundary (FRAME_SIZE shift makes no difference, unwind stil stops at the right frame). This change fixes the other path when we want to unwind directly from pt_regs sp/fp/ip state, which is coming in following change. Fixes: 20a0bc10272f ("x86/fgraph,bpf: Fix stack ORC unwind from kprobe_multi return probe") Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/bpf/20260126211837.472802-2-jolsa@kernel.org
2026-01-30KVM: x86: Add x2APIC "features" to control EOI broadcast suppressionKhushit Shah
Add two flags for KVM_CAP_X2APIC_API to allow userspace to control support for Suppress EOI Broadcasts when using a split IRQCHIP (I/O APIC emulated by userspace), which KVM completely mishandles. When x2APIC support was first added, KVM incorrectly advertised and "enabled" Suppress EOI Broadcast, without fully supporting the I/O APIC side of the equation, i.e. without adding directed EOI to KVM's in-kernel I/O APIC. That flaw was carried over to split IRQCHIP support, i.e. KVM advertised support for Suppress EOI Broadcasts irrespective of whether or not the userspace I/O APIC implementation supported directed EOIs. Even worse, KVM didn't actually suppress EOI broadcasts, i.e. userspace VMMs without support for directed EOI came to rely on the "spurious" broadcasts. KVM "fixed" the in-kernel I/O APIC implementation by completely disabling support for Suppress EOI Broadcasts in commit 0bcc3fb95b97 ("KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use"), but didn't do anything to remedy userspace I/O APIC implementations. KVM's bogus handling of Suppress EOI Broadcast is problematic when the guest relies on interrupts being masked in the I/O APIC until well after the initial local APIC EOI. E.g. Windows with Credential Guard enabled handles interrupts in the following order: 1. Interrupt for L2 arrives. 2. L1 APIC EOIs the interrupt. 3. L1 resumes L2 and injects the interrupt. 4. L2 EOIs after servicing. 5. L1 performs the I/O APIC EOI. Because KVM EOIs the I/O APIC at step #2, the guest can get an interrupt storm, e.g. if the IRQ line is still asserted and userspace reacts to the EOI by re-injecting the IRQ, because the guest doesn't de-assert the line until step #4, and doesn't expect the interrupt to be re-enabled until step #5. Unfortunately, simply "fixing" the bug isn't an option, as KVM has no way of knowing if the userspace I/O APIC supports directed EOIs, i.e. suppressing EOI broadcasts would result in interrupts being stuck masked in the userspace I/O APIC due to step #5 being ignored by userspace. And fully disabling support for Suppress EOI Broadcast is also undesirable, as picking up the fix would require a guest reboot, *and* more importantly would change the virtual CPU model exposed to the guest without any buy-in from userspace. Add KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST flags to allow userspace to explicitly enable or disable support for Suppress EOI Broadcasts. This gives userspace control over the virtual CPU model exposed to the guest, as KVM should never have enabled support for Suppress EOI Broadcast without userspace opt-in. Not setting either flag will result in legacy quirky behavior for backward compatibility. Disallow fully enabling SUPPRESS_EOI_BROADCAST when using an in-kernel I/O APIC, as KVM's history/support is just as tragic. E.g. it's not clear that commit c806a6ad35bf ("KVM: x86: call irq notifiers with directed EOI") was entirely correct, i.e. it may have simply papered over the lack of Directed EOI emulation in the I/O APIC. Note, Suppress EOI Broadcasts is defined only in Intel's SDM, not in AMD's APM. But the bit is writable on some AMD CPUs, e.g. Turin, and KVM's ABI is to support Directed EOI (KVM's name) irrespective of guest CPU vendor. Fixes: 7543a635aa09 ("KVM: x86: Add KVM exit for IOAPIC EOIs") Closes: https://lore.kernel.org/kvm/7D497EF1-607D-4D37-98E7-DAF95F099342@nutanix.com Cc: stable@vger.kernel.org Suggested-by: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Khushit Shah <khushit.shah@nutanix.com> Link: https://patch.msgid.link/20260123125657.3384063-1-khushit.shah@nutanix.com [sean: clean up minor formatting goofs and fix a comment typo] Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-30KVM: x86: Harden against unexpected adjustments to kvm_cpu_capsSean Christopherson
Add a flag to track when KVM is actively configuring its CPU caps, and WARN if a cap is set or cleared if KVM isn't in its configuration stage. Modifying CPU caps after {svm,vmx}_set_cpu_caps() can be fatal to KVM, as vendor setup code expects the CPU caps to be frozen at that point, e.g. will do additional configuration based on the caps. Rename kvm_set_cpu_caps() to kvm_initialize_cpu_caps() to pair with the new "finalize", and to make it more obvious that KVM's CPU caps aren't fully configured within the function. Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://patch.msgid.link/20260128014310.3255561-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-30KVM: VMX: Print out "bad" offsets+value on VMCS config mismatchSean Christopherson
When kvm-intel.ko refuses to load due to a mismatched VMCS config, print all mismatching offsets+values to make it easier to debug goofs during development, and to make it at least feasible to triage failures that occur during production. E.g. if a physical core is flaky or is running with the "wrong" microcode patch loaded, then a CPU can get a legitimate mismatch even without KVM bugs. Print the mismatches as 32-bit values as a compromise between hand coding every field (to provide precise information) and printing individual bytes (requires more effort to deduce the mismatch bit(s)). All fields in the VMCS config are either 32-bit or 64-bit values, i.e. in many cases, printing 32-bit values will be 100% precise, and in the others it's close enough, especially when considering that MSR values are split into EDX:EAX anyways. E.g. on mismatch CET entry/exit controls, KVM will print: kvm_intel: VMCS config on CPU 0 doesn't match reference config: Offset 76 REF = 0x107fffff, CPU0 = 0x007fffff, mismatch = 0x10000000 Offset 84 REF = 0x0010f3ff, CPU0 = 0x0000f3ff, mismatch = 0x00100000 Opportunistically tweak the wording on the initial error message to say "mismatch" instead of "inconsistent", as the VMCS config itself isn't inconsistent, and the wording conflates the cross-CPU compatibility check with the error_on_inconsistent_vmcs_config knob that treats inconsistent VMCS configurations as errors (e.g. if a CPU supports CET entry controls but no CET exit controls). Cc: Jim Mattson <jmattson@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://patch.msgid.link/20260128014310.3255561-4-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-30KVM: x86: Explicitly configure supported XSS from {svm,vmx}_set_cpu_caps()Sean Christopherson
Explicitly configure KVM's supported XSS as part of each vendor's setup flow to fix a bug where clearing SHSTK and IBT in kvm_cpu_caps, e.g. due to lack of CET XFEATURE support, makes kvm-intel.ko unloadable when nested VMX is enabled, i.e. when nested=1. The late clearing results in nested_vmx_setup_{entry,exit}_ctls() clearing VM_{ENTRY,EXIT}_LOAD_CET_STATE when nested_vmx_setup_ctls_msrs() runs during the CPU compatibility checks, ultimately leading to a mismatched VMCS config due to the reference config having the CET bits set, but every CPU's "local" config having the bits cleared. Note, kvm_caps.supported_{xcr0,xss} are unconditionally initialized by kvm_x86_vendor_init(), before calling into vendor code, and not referenced between ops->hardware_setup() and their current/old location. Fixes: 69cc3e886582 ("KVM: x86: Add XSS support for CET_KERNEL and CET_USER") Cc: stable@vger.kernel.org Cc: Mathias Krause <minipli@grsecurity.net> Cc: John Allen <john.allen@amd.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Chao Gao <chao.gao@intel.com> Cc: Binbin Wu <binbin.wu@linux.intel.com> Cc: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com> Link: https://patch.msgid.link/20260128014310.3255561-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-30x86/uapi: Stop leaking kconfig references to userspaceThomas Weißschuh
UAPI headers are not supposed to leak references to kconfig symbols. These won't be set when building userspace. Hide the kconfig reference behind 'if defined(__KERNEL__)', so it will be stripped by headers_install.sh. The result for userspace will be the same, but the exceptions in headers_install.sh can also be removed. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-30nios2: uapi: Remove custom asm/swab.h from UAPIThomas Weißschuh
UAPI headers are not supposed to leak references to kconfig symbols. They are undefined there in any case. As all actual definitions of this header are guarded behind a kconfig symbol, for userspace the header is always identical to its asm-generic variant. Make the custom UAPI header a kernel-internal one, so the leaks of kconfig symbols are fixed and userspace will instead use asm-generic/swab.h directly. Suggested-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/lkml/93c55086-931a-4282-a94c-de4954047fa9@app.fastmail.com/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-30ARM: uapi: Drop PSR_ENDSTATEThomas Weißschuh
The symbol PSR_ENDSTATE is pointless for userspace. Drop it from the UAPI headers and instead inline it into the only two callers. As as side-effect, remove a leak of an internal kconfig symbol through the UAPI headers. Suggested-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/lkml/d2ad12f2-3d65-4bef-890c-65d78a33d790@app.fastmail.com/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-30ARC: Always use SWAPE instructions for __arch_swab32()Thomas Weißschuh
Since commit 67a697e7576 ("ARC: retire ARC750 support") all supported CPUs have the 'swape' instruction. Always use the implementation of __arch_swabe() which uses 'swape'. ARCH_USE_BUILTIN_BSWAP can not be used as that results on libcalls on -mcpu=arc700. As as side-effect, remove a leak of an internal kconfig symbol through the UAPI headers. Suggested-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/lkml/0ae2688a-5a22-405b-adaf-9b5ad712b245@app.fastmail.com/ Suggested-by: Vineet Gupta <vgupta@kernel.org> Link: https://lore.kernel.org/lkml/a033a402-e3c5-4982-9fff-b6a4c55817ae@kernel.org/ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2026-01-30arm64: dts: socfpga: agilex: add emmc supportNg Tze Yee
The Agilex devkit supports a separate eMMC daughter card. The eMMC daughter card replaces the SDMMC slot that is on the default daughter card and thus requires a separate board dts file. Signed-off-by: Ng Tze Yee <tzeyee.ng@altera.com> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
2026-01-30arm64: dts: intel: agilex5: Add simple-bus node on top of dma controller nodeKhairul Anuar Romli
Move dma-controller node under simple-bus node to allow bus node specific property able to be properly defined. This is require to fulfill Agilex5 bus limitation that is limited to 40-addressable-bit. Update the compatible string for the DMA controller nodes in the Agilex5 device tree from the generic "snps,axi-dma-1.01a" to the platform-specific "altr,agilex5-axi-dma". Add fallback capability to ensure driver is able to initialize properly. This change enables the use of platform-specific features and constraints in the driver, such as setting a 40-bit DMA addressable mask through dma-ranges, which is required for Agilex5. It also aligns with the updated device tree bindings and driver support for this compatible string. Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@altera.com> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
2026-01-30ARM: dts: socfpga: fix dtbs_check warning for fpga-regionDinh Nguyen
soc (simple-bus): base_fpga_region: 'ranges' is a required property from schema $id: http://devicetree.org/schemas/simple-bus.yaml base_fpga_region (fpga-region): $nodename:0: 'base_fpga_region' does not match '^fpga-region(@.*|-([0-9]|[1-9][0-9]+))?$' from schema $id: http://devicetree.org/schemas/fpga/fpga-region.yaml Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
2026-01-30ARM: dts: socfpga: add #address-cells and #size-cells for sram nodeDinh Nguyen
Add #address-cells and #size-cells for sram node to fix below DTB_CHECK warnings: socfpga_arria5_socdk.dtb: sram@ffff0000 (mmio-sram): '#size-cells' is a required property from schema $id: http://devicetree.org/schemas/sram/sram.yaml Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
2026-01-30arm64: dts: altera: Use lowercase hexKrzysztof Kozlowski
The DTS code coding style expects lowercase hex for values and unit addresses. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>