Commit Graph

1240 Commits

Author SHA1 Message Date
Linus Torvalds
5e6ff28676 hyperv-next for v7.3-rc1
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Merge tag 'hyperv-next-signed-20260826' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Decrypt netvsc buffer on contiguous direct-map addresses (Kameron
   Carr)

 - Drop WS2012/2012R2 & Win8/8.1 Hyper-V support (Michael Kelley)

 - Use more meaningful errnos for hypercall status code (Hardik Garg)

 - Fix lost interrupts on CPU hot-unplug for Hyper-V PCI/MSI (Naman
   Jain)

 - Reserve more MSHV vectors for Linux root partition (Wei Liu)

* tag 'hyperv-next-signed-20260826' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  clocksource: hyper-v: Remove support for stimer interrupts in message mode
  scsi: storvsc: Remove support for storvsc protocol of old Hyper-V hosts
  hv_netvsc: Remove GPADL teardown special case for old Hyper-V hosts
  hv_sock: Remove check for old Hyper-V hosts
  Drivers: hv: Remove support for WS2012/2012R2 & Win8/8.1 version of Hyper-V
  hv_netvsc: Allocate send/receive buffers using vmbus_alloc_buffer()
  Drivers: hv: vmbus: Add vmbus_alloc_buffer()/vmbus_free_buffer() for CoCo VMs
  Drivers: hv: vmbus: add vmbus_establish_gpadl_caller_decrypted()
  Drivers: hv: vmbus: Skip VMBus module cleanup for non-nested root partition
  x86/hyperv: reserve more vectors
  PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip
  Drivers: hv: Use meaningful errnos for hypercall status codes
2026-08-26 16:47:40 -07:00
Michael Kelley
be0cfab740 clocksource: hyper-v: Remove support for stimer interrupts in message mode
In Hyper-V versions prior to WS2016/Win10, Hyper-V synthetic timers
interrupt the guest by delivering a message that is initially handled
by the Linux VMBus driver. Starting with WS2016/Win10, Hyper-V can
deliver stimer interrupts directly to an assigned interrupt vector
without involving the VMBus driver. This is called "Direct Mode".

With the overall removal of Linux support for running on Hyper-V
hosts earlier than WS2016 and Windows 10, it's no longer necessary
to support the legacy message-based delivery. Remove that delivery
mechanism and always use Direct Mode. If for some reason, the
Hyper-V host does not enumerate Direct Mode, output an error
message but continue to run using the LAPIC timer instead of an
stimer.

With these changes, the VMBus driver no longer calls the stimer
interrupt service routine. This removal has a broader benefit in
unblocking the disentangling of VMBus code and stimer code, as
they should be independent of each other. The final disentangling
will come as a follow-on patch set.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:36:14 +00:00
Michael Kelley
a9a05e801e Drivers: hv: Remove support for WS2012/2012R2 & Win8/8.1 version of Hyper-V
Linux code for running as a Hyper-V guest includes special cases for
running on Hyper-V in WS2012/2012R2 and Windows 8/8.1. These versions
were initially released 14 years ago, and official support ended in 2023
(unless a customer has contracted for extended security updates). Given
the release of subsequent versions with improved functionality, there's
no need to continue to support the latest Linux kernels on these versions
of Hyper-V. If someone is running Linux on one of these older Hyper-V
versions and doesn't want to upgrade, they can continue to do so as
presumably they don't want upgrade the Linux version either.

Simplify Linux code by removing special cases for running on these
old versions of Hyper-V. Remove the negotiation of the VMBus protocol
versions for WS2012/Win8, and remove special case code based on those
VMBus protocol versions. Also update the balloon and snapshot drivers
to no longer negotiate driver-specific protocol versions for these
older Hyper-V versions, and remove any related special cases.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:35:41 +00:00
Kameron Carr
73fe42af95 Drivers: hv: vmbus: Add vmbus_alloc_buffer()/vmbus_free_buffer() for CoCo VMs
On CoCo VMs without confidential VMBus, the netvsc send and receive buffers
must be made host-visible by decrypting them. These buffers are vmalloc'ed,
but set_memory_decrypted()/encrypted() do not work on vmalloc'ed memory.
This use case is (so far) unique to netvsc, so solve it locally rather than
changing the set_memory() or allocation APIs.

Add vmbus_alloc_buffer()/vmbus_free_buffer() to the VMBus core. When the
guest's isolation model requires it, allocate the buffer as a list of
physically-contiguous chunks via alloc_pages_node(), starting at
MAX_PAGE_ORDER and falling back to smaller orders so the allocation still
succeeds under memory fragmentation. Each chunk is decrypted in place via
set_memory_decrypted() on its direct-map address, and the chunks are then
stitched into a single virtually-contiguous range with vmap(). Buffers that
do not need decryption keep using vzalloc().

To free the buffer, vmbus_free_buffer() calls vunmap() on the range then
re-encrypts and frees each chunk individually; any chunk that fails
re-encryption is leaked to prevent accidentally freeing decrypted memory.

This approach minimizes scattering of decrypted 4 KiB pages through the
kernel direct map and the resulting shattering of large page mappings.

Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:33:24 +00:00
Kameron Carr
8f1da3536b Drivers: hv: vmbus: add vmbus_establish_gpadl_caller_decrypted()
Add a new vmbus_establish_gpadl_caller_decrypted() for callers that want to
decrypt their own buffers. Add a new hv_gpadl_type,
HV_GPADL_BUFFER_DECRYPTED, to communicate the decryption status of the
buffer.

No functional change for existing callers.

Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:33:24 +00:00
Michael Kelley
cee0d90bce Drivers: hv: vmbus: Skip VMBus module cleanup for non-nested root partition
The VMBus module initialization function, hv_acpi_init(), currently
does nothing when running in the root partition and root is not nested
in another VM. But the initialization function reports success, so the
VMBus module is indeed loaded. VMBus functionality is not actually
needed, but the VMBus module must be loaded so that hv_vmbus_exists()
can answer correctly. Furthermore, the mshv_root dependency on the
VMBus module is needed as described in the commit message for
840b740a35 ("mshv: Add conditional VMBus dependency").

Loading the VMBus module without actually initializing it causes
failures if the module should later be unloaded. The module unload code
tries to clean up things that were never initialized, resulting in
memory faults and a panic.

Fix this by having VMBus module exit function perform the same
check for non-nested root partition, and do nothing in such a
case, just like hv_acpi_init().

In the long run, the code that manages the Hyper-V provided SynIC
should be refactored to better coordinate the requirements of
root partition scenarios and normal VM scenarios, and to hopefully
remove the hv_vmbus_exists() dependnecy between mshv_root and
VMBus modules. Preventing the current unload failure scenario is
an expediency until such a refactoring is done.

Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-hyperv/20260721154943.A09BD1F00A3D@smtp.kernel.org/
Fixes: 7e279d7866 ("Drivers: hv: vmbus: skip VMBus initialization if Linux is root")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:32:49 +00:00
Hardik Garg
e1fc6e70f3 Drivers: hv: Use meaningful errnos for hypercall status codes
Commit 3817854ba8 ("hyperv: Log hypercall status codes as strings")
converted hv_result_to_errno() from a switch to a table and added status
codes used for string logging. Statuses without an existing specific
mapping were assigned the generic -EIO fallback even when a more specific
errno was available.

Map HV_STATUS_ACCESS_DENIED and HV_STATUS_OPERATION_DENIED to -EACCES,
HV_STATUS_UNKNOWN_PROPERTY and HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE to
-EINVAL, and HV_STATUS_PROCESSOR_FEATURE_NOT_SUPPORTED to -EOPNOTSUPP.
This lets callers distinguish permission, argument, and capability
failures from generic I/O errors.

The table conversion also added duplicate HV_STATUS_INVALID_LP_INDEX and
HV_STATUS_INVALID_REGISTER_VALUE entries. Remove the later -EIO entries,
which are unreachable because find_hv_status_info() returns the first
match.

Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-08-24 00:01:30 +00:00
Linus Torvalds
ed3b875bea mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       501
 Reviews/patch:       1.66
 Reviewed rate:       70%
 
 Excluding DAMON:
 
 Total patches:       356
 Reviews/patch:       2.26
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       329
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Excluding DAMON, selftests and maple_tree:
 
 Total patches:       328
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Summary of patch series in this merge:
 
 - The 2 patch series "mm: drop "sub" prefix from various places" from
   Dev Jain implements some page->folio conversion and a naming cleanup.
 
 - The 2 patch series "mm/kasan: remove redundant initialization for
   kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
 
 - The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
   from Chi Zhiling provides a small speedup in the pagecaache read code.
 
 - The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
   recursion" from Kaitao Cheng improves a few things in the vmalloc code -
   mainly the avoidance of GFP_KERNEL allocations when the caller asked for
   GFP_NOFS or GFP_NOIO.
 
 - The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
   stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
   kmemleak scanning code in extreme situations.
 
 - The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
   collection of unrelated cleanups to the page_owner code.  For some
   reason lots of people have been working on the page_owner code this
   cycle.
 
 - The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
   find_vma()" from Kefeng Wang simplifies and accelerates the page walking
   library function.
 
 - The 3 patch series "mm/migrate: preparatory cleanups for batch copy
   and offload" from Shivank Garg implements cleanups in the migration
   code.
 
 - The 4 patch series "mm/page_owner: add per-fd filter infrastructure
   for print_mode and NUMA filtering" from Zhen Ni provides per-fd
   filtering to page_owner in order to reduce the sometimes vast amount of
   output it can produce.
 
 - The 19 patch series "mm: Refactor bootmem gigantic hugepage
   allocation" from Muchun Song is a "set of fixes and preparatory cleanups
   around bootmem HugeTLB handling, sparse initialization ordering, and
   related vmemmap setup".
 
 - The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
   from Wenchao Hao reduces lock contention in zs_free(), which dominates
   the unmap path under memory pressure on Android (LMK kills) and on x86
   servers running zswap-heavy workloads.  Up to 1.83x improvement in
   microbenchmarking.
 
 - The 2 patch series "move alloc_tag.c file under mm/" from Suren
   Baghdasaryan does that.
 
 - The 6 patch series "samples/damon: handle damon_{start,stop}()
   failures" from SJ Park fixes improper handling of damon_start(),
   damon_stop(), and damon_call() failures across DAMON sample modules to
   prevent potential memory leaks, operation disruptions and use-after-free
   bugs.
 
 - The 11 patch series "mm/damon/sysfs: kobject_del() directories that
   users can create/remove" from SJ Park resolves an issue where delayed
   sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
   creation failures due to duplicate directory names by adding missing
   kobject_del() calls before creating new directories.
 
 - The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
   David Hildenbrand cleans up the core pte handling code.
 
 - The 3 patch series "selftests/damon: misc fixes for test bugs" from
   Kunwu Chan fixes several bugs in the DAMON selftests.
 
 - The 2 patch series "selftests/damon: fix memcg_path staging handling"
   from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
   memcg_path setup, and adds a test case for it in sysfs.py.
 
 - The 2 patch series "selftests/damon: test kdamond refresh_ms" from
   Ruslan Valiyev introduces selftest coverage for DAMON's refresh_ms sysfs
   feature by updating the test control module and verifying that scheme
   stats update automatically without manual intervention.
 
 - The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
   contains miscellaneous DAMON fixups.
 
 - The 2 patch series "mm/damon/core: detect internal variation above
   max_nr_regions/2" from Jiayuan Chen fixes DAMON's region splitting
   behavior when region counts exceed half the maximum budget by
   dynamically scaling down the split fraction as the limit approaches,
   preventing large regions from staying un-split, and adds corresponding
   KUnit test coverage.
 
 - The 6 patch series "mm: preparatory patches for PMD level swap
   entries" from Usama Arif refactors and cleans up PMD softleaf helpers,
   call sites, and architecture flags to lay the groundwork for a follow-up
   series that introduces PMD page table swap entries.
 
 - The 11 patch series "mm/damon: update, optimize, and clean up doc,
   tests, and code" from SJ Park updates DAMON design and ABI
   documentation, expands unit and selftest coverage, optimizes
   damon_commit_target_regions(), and cleans up recently added sysfs
   interface code for better readability.
 
 - The 2 patch series "mm/vmpressure: reduce CPU, memory and code
   overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
   skipping unnecessary work on cgroup v2 for userspace event notifications
   and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
   memory overhead and code complexity.
 
 - The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
   error handling" from Hongfu Li refactors pkeys shared tracing and
   assertion helpers into a common file, unifies protection key selftests
   to use consistent diagnostic logging and assertions, and enforces
   standardized MAP_FAILED return checks for mmap() calls across the tests.
 
 - The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
   Park replaces the error-prone, continuously updated nr_accesses_bp field
   in damon_region with an on-demand moving sum function
   (damon_nr_accesses_mvsum()), reducing structure memory overhead and
   avoiding state corruption bugs.
 
 - The 6 patch series "Open HugeTLB allocation routine for more generic
   use" from Ackerley Tng decouples HugeTLB folio allocation from VMA
   dependencies by introducing hugetlb_alloc_folio(), enabling subsystems
   like guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs.
 
 - The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
   from SJ Park integrates DAMON's probe_hits attribute counter into the
   pseudo moving sum infrastructure, enabling real-time, online monitoring
   without waiting for full aggregation intervals.
 
 - The 18 patch series "mm: Some cleanups for page allocator APIs" from
   Brendan Jackman simplifies and refactors the page allocator entry points
   and flags by unifying allocation paths, adding internal alloc_flags
   arguments, and eliminating redundant __ prefixed alloc_pages variants.
 
 - The 5 patch series "Fix incorrect access of hugetlb pte entries" from
   Dev Jain enforces the consistent use of huge_ptep_get() instead of
   ptep_get() for HugeTLB entries and fixes an unaligned address issue in
   arm64's huge_ptep_get() implementation.
 
 - The 8 patch series "mm/damon: validate all parameters in the core"
   from SJ Park consolidates parameter validation into the DAMON core
   specifically within damon_start() and damon_commit_ctx() to centralize
   error checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency.
 
 - The 3 patch series "tools/mm/page_owner_sort: fix filtering and
   cleanup issues" from Yichong Chen renames is_need() to filter_record()
   for clearer return semantics, fixes per-record allocation memory leaks
   and bounds output copies in search_pattern() to address an existing
   buffer issue.
 
 - The 4 patch series "memcg: bail out reclaim when memcg is dying" from
   Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
   removed while one of its memory control files is doing synchronous
   reclaim.
 
 - The 5 patch series "mm/memory-failure: add panic option for
   unrecoverable pages" from Breno Leitao introduces an opt-in
   vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics
   the kernel on unrecoverable memory errors in kernel-owned pages to
   preserve error context and prevent delayed, silent data corruption.
 
 - The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
   for simple error handling" from SJ Park refactors the DAMON core API
   functions to guarantee that all contexts are fully stopped when
   damon_start(), damon_stop(), or damon_commit() fail, eliminating the
   need for complex and error-prone caller-side cleanup code.
 
 - The 5 patch series "Keep tail page private zero at free and folio
   split" from Zi Yan adds checks to ensure tail_page->private is zero when
   freeing compound or high-order pages and when promoting tail pages
   during large folio splits.  By validating these fields at free and split
   time, it allows the removal of redundant private field clearing inside
   prep_compound_tail().
 
 - The 4 patch series "mm: drop redundant lru_add_drain in anon folio
   reuse paths" from Barry Song eliminates redundant lru_add_drain() calls
   in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead.
 
   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads.
 
 - The 3 patch series "mm: clean up folio LRU and swap declarations" from
   Jianyue Wu reorganizes folio LRU and swap code by relocating
   page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c,
   and moving MM-internal reclaim declarations into mm/internal.h.
 
 - The 15 patch series "userfaultfd: working set tracking for VM guest
   memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
   working set of VM guest memory, so a VMM can identify hot pages and
   reclaim cold ones to tiered or remote storage.
 
 - The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
   2)" from David Hildenbrand removes the remaining pieces of
   CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
   freeing of reserved vmemmap pages on the way.
 
 - The 7 patch series "mm/damon: update probe hits for runtime parameter
   commits" from SJ Park ensures that DAMON's probe_hits attribute counter
   is properly updated when monitoring intervals are changed at runtime,
   matching the behavior of nr_accesses.  To achieve this, it refactors and
   renames existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.
 
 - The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
   from xu xin resolves a severe KSM reverse-mapping performance bottleneck
   where thousands of split VMAs sharing a single anon_vma cause extended
   lock contention.  By adding an interval-filtering check during the rmap
   walk, it reduces worst-case anon_vma lock hold times from over 500ms
   down to under 2ms, preventing application freezes and latency spikes
   under memory pressure.
 
 - The 3 patch series "mm: split a couple of headers from internal.h"
   from Mike Rapoport splits declarations related to mm_init, memblock,
   vmalloc and sparse into new headers.
 
 - The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
   from xu xin applies the interval tree optimization from rmap_walk_ksm()
   to collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.  It hoists loop-invariant address
   initialization and restricts the anon_vma_interval_tree_foreach walk to
   a targeted page offset range, reducing redundant checks and improving
   lookup efficiency.
 
 - The 3 patch series "selftests/mm: avoid false failures in hugetlb and
   KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
   selftest categories that can report failures when the prerequisites for
   the tests are not satisfied.
 
 - The 19 patch series "mm/damon: introduce data attributes only
   monitoring" from SJ Park introduces attribute-weighted region management
   in DAMON, allowing users to prioritize specific data attributes (such as
   page sizes or cgroups) over or instead of access monitoring.
 
   By assigning weights to attribute probes, DAMON can completely disable
   access tracking and adjust monitoring regions based on weighted
   probe-hit counters to optimize monitoring quality for attribute-focused
   workloads.
 
 - The 8 patch series "mm/hmm: Add mmap lock-drop support for
   userfaultfd-backed mappings" from Stanislav Kinsburskii extends
   hmm_range_fault() to support userfaultfd-backed regions by allowing the
   mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.
 
   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd regions
   while preserving backward compatibility for existing callers.
 
 - The 33 patch series "mm: make VMA page offset handling more
   consistent" from Lorenzo Stoakes cleans up and standardizes how
   vma->vm_pgoff is accessed and manipulated across file-backed and
   anonymous mappings in the kernel.
 
   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming
   rmap interval tree helpers to better reflect their functionality.
 
   These changes establish a cleaner foundation for future work that will
   unify virtual page offset indexing for all anonymous and CoW'd folios.
 
 - The 3 patch series "mm: handle device-private PMDs in walk callbacks"
   from Usama Arif addresses kernel panics and state corruption caused by
   MM walk callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations.
 
   It ensures that functions which acquire pmd_trans_huge_lock() properly
   recognize device-private PMDs instead of assuming a present THP or a
   standard migration entry.
 
 - The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
   refactors try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree,
   and anonymous-swapbacked logic into dedicated functions, laying the
   structural groundwork for batched anonymous large folio unmapping.
 
 - The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
   additions" from Song Hu fixes typos and fills in missing entries in the
   DAMON sysfs ABI document.
 
 - The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
   from Gregory Price introduces an atomic sysfs state attribute and
   supporting DAX/MM infrastructure to prevent userland races when
   offlining and removing entire memory regions.
 
   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.
 
 - The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
   from Lorenzo Stoakes continues transitioning the kernel from the
   deprecated vm_flags_t type to vma_flags_t across core memory management
   infrastructure.
 
   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.
 
 - The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
   xu xin refactors mm_slot.h by introducing mm_slot_remove() to unify
   duplicate slot deletion sequences in khugepaged and KSM.  It also adds
   code documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.
 
 - The 10 patch series "mm/damon/core: hide core-private struct fields"
   from SJ Park cleans up DAMON core structures by consistently marking
   internal-only fields with private: comment tags to prevent improper
   direct access from outer layers.
 
   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.
 
 - The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
   de-ref and races" from SJ Park addresses potential infinite loops, NULL
   dereferences, and race conditions identified in DAMON.
 
   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.
 
 - The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
   RT/UP" from Brendan Jackman fixes an NMI safety flaw in
   __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT
   kernels can bypass can_spin_trylock() checks via non-PCP or isolated
   migration paths.
 
   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.
 
 - The 4 patch series "mm/page_alloc: couple of followups for recent
   cleanups" from Brendan Jackman cleans up and updates page allocator
   nomenclature, documentation, and debug assertions.
 
   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete VM_BUG_ON()
   assertions in allocation paths.
 
 - The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
   refactors and simplifies the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.
 
   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates
   mm_struct parameters to enforce that sealing applies only to
   current->mm, and streamlines overall logic and comments with no
   functional changes intended.
 
 - The 4 patch series "mm/vmscan: fix swappiness=max and clean up
   per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
   bugs and cleans up function parameters across memory reclaim paths.
 
   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead of
   collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask
   parameter from __node_reclaim().
 
 - The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
   cleans up and simplifies the mincore code.  Most importantly, it removes
   the historical special behavior that always reports VM_PFNMAP pages as
   non-resident.
 
 - The 2 patch series "mm/huge_memory: drop dead split helper variants"
   from Kiryl Shutsemau implements two trivial cleanups in the folio split
   API.
 
 - The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
   exec expectation bugs" from SJ Park resolves minor operational and
   testing bugs in DAMON identified by Sashiko.  It initializes the
   damos->last_applied field to prevent occasional efficiency degradation
   and fixes invalid memory accesses in DAMON KUnit tests during test
   failure handling.
 
 - The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
   cleans up and refactors stable_page_flags() used by /proc/kpageflags
   without altering functionality.
 
   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
 
 - The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
   extends batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities
   to pte_install_uffd_wp_if_needed().
 
   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.
 
 - The 3 patch series "mm/early_ioremap: clarify and clean up
   early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans up the
   architecture-specific usage of __late_set_fixmap() and
   __late_clear_fixmap() after early_ioremap_reset().
 
   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset calls
   in the RISC-V and ARM64 architectures.
 
 - The 4 patch series "mm: fix reclaim storms in defrag_mode" from
   Johannes Weiner addresses severe performance regressions, swap storms,
   and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure
   in Meta production.
 
   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.
 
 - The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
   optimizes and fixes lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolating lock classes across multiple instances.
 
   It reduces memory overhead by replacing per-entry lockdep_map instances
   with a single map per struct zram, and assigns a dynamic lock_class_key
   to each instance to prevent false deadlock reports when different zram
   devices are backed by distinct filesystems.
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Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm: drop "sub" prefix from various places" (Dev Jain)

   page->folio conversion and a naming cleanup

 - "mm/kasan: remove redundant initialization for kasan_flag_write_only"
   (Igor Putko)

   KASAN cleanup work

 - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)

   Small speedup in the pagecaache read code

 - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)

   Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
   allocations when the caller asked for GFP_NOFS or GFP_NOIO

 - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
   Leitao)

   Avoid a soft lockup watchdog trigger from the kmemleak scanning code
   in extreme situations

 - "mm/page_owner: misc cleanups" (Ye Liu)

   Cleanups to the page_owner code. For some reason lots of people have
   been working on the page_owner code this cycle.

 - "mm: convert to walk_page_range_vma() to eliminate find_vma()"
   (Kefeng Wang)

   Simplify and accelerate the page walking library function

 - "mm/migrate: preparatory cleanups for batch copy and offload"
   (Shivank Garg)

   Cleanups in the migration code

 - "mm/page_owner: add per-fd filter infrastructure for print_mode and
   NUMA filtering" (Zhen Ni)

   Per-fd filtering to page_owner in order to reduce the sometimes vast
   amount of output it can produce

 - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)

   Fixes and preparatory cleanups around bootmem HugeTLB handling,
   sparse initialization ordering, and related vmemmap setup

 - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)

   Reduce lock contention in zs_free(), which dominates the unmap path
   under memory pressure on Android (LMK kills) and on x86 servers
   running zswap-heavy workloads.

   Up to 1.83x improvement in microbenchmarking.

 - "move alloc_tag.c file under mm/" (Suren Baghdasaryan)

 - "samples/damon: handle damon_{start,stop}() failures" (SJ Park)

   Fix improper handling of damon_start(), damon_stop(), and
   damon_call() failures across DAMON sample modules to prevent
   potential memory leaks, operation disruptions and use-after-free
   bugs

 - "mm/damon/sysfs: kobject_del() directories that users can
   create/remove" (SJ Park)

   Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
   causeing creation failures due to duplicate directory names by adding
   missing kobject_del() calls before creating new directories

 - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)

   Clean up the core pte handling code

 - "selftests/damon: misc fixes for test bugs" (Kunwu Chan)

   Fix several bugs in the DAMON selftests

 - "selftests/damon: fix memcg_path staging handling" (Cheng Nie)

   Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
   add a test case for it in sysfs.py.

 - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)

   Selftest coverage for DAMON's refresh_ms sysfs feature by updating
   the test control module and verifying that scheme stats update
   automatically without manual intervention

 - "mm/damon: five misc fixups" (Akinobu Mita)

   Miscellaneous DAMON fixups.

 - "mm/damon/core: detect internal variation above max_nr_regions/2"
   (Jiayuan Chen)

   Fix DAMON's region splitting behavior when region counts exceed half
   the maximum budget by dynamically scaling down the split fraction as
   the limit approaches, preventing large regions from staying un-split,
   and add corresponding KUnit test coverage

 - "mm: preparatory patches for PMD level swap entries" (Usama Arif)

   Refactor and clean up PMD softleaf helpers, call sites, and
   architecture flags to lay the groundwork for a follow-up series that
   introduces PMD page table swap entries

 - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
   Park)

   Update DAMON design and ABI documentation, expands unit and selftest
   coverage, optimize damon_commit_target_regions(), and clean up
   recently added sysfs interface code for better readability

 - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
   (Usama Arif)

   Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
   userspace event notifications and refactor v1-only eventfd handling
   into mm/memcontrol-v1.c to reduce memory overhead and code complexity

 - "selftests/mm: refactor pkey helpers and fix mmap error handling"
   (Hongfu Li)

   Refactor pkeys shared tracing and assertion helpers into a common
   file, unify protection key selftests to use consistent diagnostic
   logging and assertions, and enforce standardized MAP_FAILED return
   checks for mmap() calls across the tests

 - "mm/damon: optimize out nr_accesses_bp" (SJ Park)

   Replace the error-prone, continuously updated nr_accesses_bp field in
   damon_region with an on-demand moving sum function, reducing
   structure memory overhead and avoiding state corruption bugs

 - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)

   Decouple HugeTLB folio allocation from VMA dependencies by
   introducing hugetlb_alloc_folio(), enabling subsystems like
   guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs

 - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)

   Integrate DAMON's probe_hits attribute counter into the pseudo moving
   sum infrastructure, enabling real-time, online monitoring without
   waiting for full aggregation intervals

 - "mm: Some cleanups for page allocator APIs" (Brendan Jackman)

   Simplify and refactor the page allocator entry points and flags by
   unifying allocation paths, adding internal alloc_flags arguments, and
   eliminating redundant __ prefixed alloc_pages variants.

 - "Fix incorrect access of hugetlb pte entries" (Dev Jain)

   Enforce the consistent use of huge_ptep_get() instead of ptep_get()
   for HugeTLB entries and fixes an unaligned address issue in arm64's
   huge_ptep_get() implementation

 - "mm/damon: validate all parameters in the core" (SJ Park)

   Consolidate parameter validation into the DAMON core specifically
   within damon_start() and damon_commit_ctx() to centralize error
   checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency

 - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
   Chen)

   Rename is_need() to filter_record() for clearer return semantics, fix
   per-record allocation memory leaks and bound output copies in
   search_pattern() to address an existing buffer issue

 - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)

   Mitigate a system-wide stall which occurs when a cgroup is removed
   while one of its memory control files is doing synchronous reclaim

 - "mm/memory-failure: add panic option for unrecoverable pages" (Breno
   Leitao)

   Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
   that immediately panics the kernel on unrecoverable memory errors in
   kernel-owned pages to preserve error context and prevent delayed,
   silent data corruption

 - "mm/damon: refactor damon_{start,stop,commit}() for simple error
   handling" (SJ Park)

   Refactor the DAMON core API functions to guarantee that all contexts
   are fully stopped when damon_start(), damon_stop(), or damon_commit()
   fail, eliminating the need for complex and error-prone caller-side
   cleanup code

 - "Keep tail page private zero at free and folio split" (Zi Yan)

   Add checks to ensure tail_page->private is zero when freeing compound
   or high-order pages and when promoting tail pages during large folio
   splits. By validating these fields at free and split time, it allows
   the removal of redundant private field clearing inside
   prep_compound_tail()

 - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
   Song)

   Eliminate redundant lru_add_drain() calls in
   wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead

   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads

 - "mm: clean up folio LRU and swap declarations" (Jianyue Wu)

   Reorganize folio LRU and swap code by relocating page-cluster state
   to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
   MM-internal reclaim declarations into mm/internal.h.

 - "userfaultfd: working set tracking for VM guest memory" (Kiryl
   Shutsemau)

   Add userfaultfd support for tracking the working set of VM guest
   memory, so a VMM can identify hot pages and reclaim cold ones to
   tiered or remote storage

 - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
   Hildenbrand)

   Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
   performing some smaller cleanups around freeing of reserved vmemmap
   pages on the way.

 - "mm/damon: update probe hits for runtime parameter commits" (SJ Park)

   Ensure that DAMON's probe_hits attribute counter is properly updated
   when monitoring intervals are changed at runtime, matching the
   behavior of nr_accesses. To achieve this, it refactors and renames
   existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.

 - "KSM: performance optimizations for rmap_walk_ksm" (xu xin)

   Resolve a severe KSM reverse-mapping performance bottleneck where
   thousands of split VMAs sharing a single anon_vma cause extended lock
   contention.

   By adding an interval-filtering check during the rmap walk, it
   reduces worst-case anon_vma lock hold times from over 500ms down to
   under 2ms, preventing application freezes and latency spikes under
   memory pressure.

 - "mm: split a couple of headers from internal.h" (Mike Rapoport)

   Split declarations related to mm_init, memblock, vmalloc and sparse
   into new headers

 - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)

   Apply the interval tree optimization from rmap_walk_ksm() to
   collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.

   It hoists loop-invariant address initialization and restricts the
   anon_vma_interval_tree_foreach walk to a targeted page offset range,
   reducing redundant checks and improving lookup efficiency.

 - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
   Patil)

   Fix issues in the hugetlb and KSM MM selftest categories that can
   report failures when the prerequisites for the tests are not
   satisfied

 - "mm/damon: introduce data attributes only monitoring" (SJ Park)

   Introduce attribute-weighted region management in DAMON, allowing
   users to prioritize specific data attributes (such as page sizes or
   cgroups) over or instead of access monitoring.

   By assigning weights to attribute probes, DAMON can completely
   disable access tracking and adjust monitoring regions based on
   weighted probe-hit counters to optimize monitoring quality for
   attribute-focused workloads.

 - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
   (Stanislav Kinsburskii)

   Extend hmm_range_fault() to support userfaultfd-backed regions by
   allowing the mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.

   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd
   regions while preserving backward compatibility for existing callers.

 - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)

   Clean up and standardize how vma->vm_pgoff is accessed and
   manipulated across file-backed and anonymous mappings in the kernel

   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
   renaming rmap interval tree helpers to better reflect their
   functionality.

   These changes establish a cleaner foundation for future work that
   will unify virtual page offset indexing for all anonymous and CoW'd
   folios.

 - "mm: handle device-private PMDs in walk callbacks" (Usama Arif)

   Address kernel panics and state corruption caused by MM walk
   callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations

   It ensures that functions which acquire pmd_trans_huge_lock()
   properly recognize device-private PMDs instead of assuming a present
   THP or a standard migration entry.

 - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)

   Refactor try_to_unmap_one by modularizing Hugetlb,
   anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
   functions, laying the structural groundwork for batched anonymous
   large folio unmapping.

 - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)

   Fix typos and fills in missing entries in the DAMON sysfs ABI
   document

 - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)

   Introduce an atomic sysfs state attribute and supporting DAX/MM
   infrastructure to prevent userland races when offlining and removing
   entire memory regions

   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.

 - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)

   Continue transitioning the kernel from the deprecated vm_flags_t type
   to vma_flags_t across core memory management infrastructure.

   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.

 - "Two small patches to clean up mm/mm_slot.h" (xu xin)

   Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
   slot deletion sequences in khugepaged and KSM. It also adds code
   documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.

 - "mm/damon/core: hide core-private struct fields" (SJ Park)

   Clean up DAMON core structures by consistently marking internal-only
   fields with private: comment tags to prevent improper direct access
   from outer layers.

   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.

 - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
   (SJ Park)

   Address potential infinite loops, NULL dereferences, and race
   conditions identified in DAMON

   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.

 - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
   Jackman)

   Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
   on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
   via non-PCP or isolated migration paths.

   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.

 - "mm/page_alloc: couple of followups for recent cleanups" (Brendan
   Jackman)

   Clean up and update page allocator nomenclature, documentation, and
   debug assertions.

   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete
   VM_BUG_ON() assertions in allocation paths.

 - "mm/mseal: further cleanups" (Lorenzo Stoakes)

   Refactor and simplify the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.

   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
   eliminates mm_struct parameters to enforce that sealing applies only
   to current->mm, and streamlines overall logic and comments with no
   functional changes intended.

 - "mm/vmscan: fix swappiness=max and clean up per-node proactive
   reclaim" (Ridong Chen)

   Resolve reclaim behavior bugs and clean up function parameters across
   memory reclaim paths

   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead
   of collapsing all failures into -EAGAIN, and removes the obsolete
   gfp_mask parameter from __node_reclaim().

 - "mm: mincore: misc cleanups" (Kefeng Wang)

   Clean up and simplifies the mincore code. Most importantly, it
   removes the historical special behavior that always reports VM_PFNMAP
   pages as non-resident.

 - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)

   Two trivial cleanups in the folio split API

 - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
   bugs" (SJ Park)

   Resolve minor operational and testing bugs in DAMON identified by
   Sashiko. It initializes the damos->last_applied field to prevent
   occasional efficiency degradation and fixes invalid memory accesses
   in DAMON KUnit tests during test failure handling.

 - "cleanup for stable_page_flags()" (Jinjiang Tu)

   Clean up and refactor stable_page_flags() used by /proc/kpageflags
   without altering functionality.

   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.

 - "Batch unmap of uffd-wp file folios" (Dev Jain)

   Extend batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching
   capabilities to pte_install_uffd_wp_if_needed().

   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.

 - "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
   (Sang-Heon Jeon)

   Clarify and clean up the architecture-specific usage of
   __late_set_fixmap() and __late_clear_fixmap() after
   early_ioremap_reset()

   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset
   calls in the RISC-V and ARM64 architectures.

 - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)

   Address severe performance regressions, swap storms, and spurious
   OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
   production

   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.

 - "zram: lockmap tweaks" (Sebastian Siewior)

   Optimize and fix lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolate lock classes across multiple instances

   This reduces memory overhead by replacing per-entry lockdep_map
   instances with a single map per struct zram, and assigns a dynamic
   lock_class_key to each instance to prevent false deadlock reports
   when different zram devices are backed by distinct filesystems.

* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
  selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
  selftests/mm: unpoison pages in memory-failure teardown
  mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
  mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
  mm/zsmalloc: fix release order of locks in zs_page_migrate()
  Documentation: zram: remove sections numbering
  ksm: stop iterating VMAs when ksm_test_exit returns true
  mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
  mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
  zram: use a custom key for each zram object
  zram: move lockmap to be per-zram instead per table
  selftests/mm: fix gup_longterm EINVAL error message
  mm: page_alloc: fix non-movable reclaim storm in defrag_mode
  mm: page_alloc: move capture_control to the page allocator
  mm: compaction: support non-movable compaction for pageblock requests
  mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
  hugetlb: evaluate subpool free state while locked
  mm/damon: remove trailing semicolons after function definitions
  mm/damon/ops-common: prevent migration fallback to non-target nodes
  mm/damon: update outdated comment about DAMOS filter handling
  ...
2026-08-20 18:17:08 -07:00
Stanislav Kinsburskii
39899823ad mshv: use hmm_range_fault_unlocked_timeout() for region faults
MSHV currently faults movable memory regions by taking mmap_read_lock()
around hmm_range_fault().  That prevents the fault path from handling VMAs
whose fault handlers need to drop mmap_lock, such as userfaultfd-backed
mappings.

Use hmm_range_fault_unlocked_timeout() instead.  Passing a timeout of 0
preserves MSHV's existing unbounded retry behavior while letting the HMM
helper own mmap_lock acquisition and refresh range->notifier_seq
internally before walking the range.  After the fault succeeds, MSHV still
takes mreg_mutex and checks mmu_interval_read_retry() before installing
the pages into the region, so the existing invalidation synchronization is
preserved.

Fold the small fault-and-lock helper into mshv_region_range_fault(), since
the remaining retry path is just the standard "fault, take the driver
lock, check the interval notifier sequence" pattern.

Link: https://lore.kernel.org/20260723-hmm-v10-v11-4-c55b003a4b61@gmail.com
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lizhi Hou <lizhi.hou@amd.com>
Cc: Long Li <longli@microsoft.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Lyude <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04 19:18:54 -07:00
Yi Xie
22dfdc17ce mshv_vtl: bounds-check cpu index in vtl mmap fault handler
cpu is taken from pgoff & 0xffff.  cpu_online() does not reject cpu >=
nr_cpu_ids, and per_cpu_ptr() can then walk off __per_cpu_offset.

Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:02:04 +00:00
Stanislav Kinsburskii
72e3b0311a mshv: Publish VP to pt_vp_array before installing the file descriptor
mshv_partition_ioctl_create_vp() called anon_inode_getfd() before
publishing the new VP into partition->pt_vp_array.  anon_inode_getfd()
includes fd_install(), so the fd was live in current->files before the
publish ran.

A concurrent MSHV_RUN_VP ioctl on that fd does not serialise against the
in-progress MSHV_CREATE_VP — it takes vp->vp_mutex, not the partition
mutex.  Once the VP starts running and traps, mshv_intercept_isr() can look
up partition->pt_vp_array[vp_index] and observe NULL, silently dropping the
intercept message.

Split the fd creation: reserve an fd with get_unused_fd_flags(), create the
file with anon_inode_getfile(), publish the VP via smp_store_release(), and
finally call fd_install() as the userspace-visibility commit point.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:02:03 +00:00
Hardik Garg
92d0593128 Drivers: hv: vmbus: add VTL2 redirect connection ID
VMBus sends CHANNELMSG_INITIATE_CONTACT through a Hyper-V message
connection ID. Older protocol versions use VMBUS_MESSAGE_CONNECTION_ID,
while protocol version 5.0 and newer normally use
VMBUS_MESSAGE_CONNECTION_ID_4.

For a VTL2 kernel using VMBus protocol 5.0 or newer, the host
may expect INITIATE_CONTACT on either the redirect connection ID or
VMBUS_MESSAGE_CONNECTION_ID_4. There is no capability indication that
identifies which ID is active, so the driver must determine it at runtime.

During VMBus negotiation, the redirect ID is tried first because it is
used by VTL2 configurations with VMBus redirection enabled. If the
redirect ID is unavailable, the host rejects it synchronously with
HV_STATUS_INVALID_CONNECTION_ID, allowing fallback to the standard ID.

Return a distinct error for an invalid Initiate Contact connection ID so
this fallback does not mask other post-message failures or
protocol-version rejections. Preserve the existing connection ID
selection for older protocol versions or when running below VTL2.

Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:02:03 +00:00
Stanislav Kinsburskii
b098dc8692 mshv: Order pt_vp_array publish against irqfd assertion path
mshv_partition_ioctl_create_vp() initialises a VP struct (allocations,
mutex_init, init_waitqueue_head, page mappings) and then publishes the
pointer into partition->pt_vp_array.  Several ISR paths read this array
locklessly: the intercept ISR, the two scheduler ISRs, and
mshv_try_assert_irq_fast() on the irqfd fast path.

Of these, only mshv_try_assert_irq_fast() can structurally race the
publish.  It runs from an eventfd waker without holding pt_mutex, and
MSHV_IRQFD does not require the target lapic_apic_id (== vp_index) to
refer to an existing VP at registration time.  A user can therefore
register an irqfd targeting a yet-to-be-created VP, then trigger
mshv_try_assert_irq_fast() concurrently with MSHV_CREATE_VP for the
same index.  On weakly-ordered architectures the reader can observe a
non-NULL pointer in pt_vp_array before the initialising stores to the
VP struct become visible, leading to use of partially-initialised
fields (e.g. vp_register_page).

The other ISR readers cannot reach this race: the hypervisor will not
generate intercept or scheduler messages for a VP that has never been
told to run, and the user can only call MSHV_RUN_VP on the VP fd
returned by MSHV_CREATE_VP, which by construction is returned after
the publish.  Leave those readers as plain loads.

Use smp_store_release() in mshv_partition_ioctl_create_vp() to publish
the pointer, and pair it with smp_load_acquire() in
mshv_try_assert_irq_fast().  On x86 these compile to plain accesses
under TSO; on ARM64 they emit one-instruction acquire/release barriers,
acceptable on this fast path.

The destroy-side path (destroy_partition() clearing pt_vp_array[i] to
NULL after kfree(vp)) has a separate ordering and lifetime concern
that is out of scope here.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:01:59 +00:00
Stanislav Kinsburskii
f546be6a19 mshv: Fix missing error code on VP allocation failure
In mshv_partition_ioctl_create_vp(), when kzalloc for the VP struct
fails, the code jumps to the cleanup path without setting ret. At that
point ret is 0 from the preceding successful mshv_vp_stats_map() call,
so the function returns success to userspace despite having failed to
create the VP. No fd is installed and no VP is registered in pt_vp_array,
but userspace has no way to know the operation failed.

Set ret to -ENOMEM before jumping to the cleanup path.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:01:57 +00:00
Stanislav Kinsburskii
0289a67cd7 mshv: Fix level-triggered check on uninitialized data
In mshv_irqfd_assign(), the level-triggered validation for resample
irqfds checks irqfd_lapic_irq.lapic_control.level_triggered before
mshv_irqfd_update() has populated the field. Since the irqfd struct is
zero-allocated, level_triggered is always 0 at that point, causing the
check to always reject resample irqfds with -EINVAL. This makes
level-triggered interrupt resampling — used to avoid interrupt storms
with assigned devices — completely non-functional.

Move the check after the mshv_irqfd_update() call, which resolves the
IRQ routing entry and populates irqfd_lapic_irq with the actual trigger
mode.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:01:57 +00:00
Stanislav Kinsburskii
0762262ac3 mshv: Fix race in mshv_irqfd_deassign
mshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list
require pt->pt_irqfds_lock to be held, but mshv_irqfd_deassign()
omits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(),
which does take the lock before calling mshv_irqfd_deactivate().

Additionally, mshv_irqfd_deactivate() uses hlist_del() which poisons
the node pointers rather than resetting them. Since
mshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev ==
NULL), a poisoned node still appears active. If a concurrent path calls
mshv_irqfd_deactivate() again on the same irqfd, the guard fails to
prevent a double hlist_del() on poisoned pointers.

Fix both issues:
- Add the missing spin_lock_irq/spin_unlock_irq around the list
  traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release().
- Use hlist_del_init() instead of hlist_del() so the node is properly
  marked as unhashed after removal, making the is_active guard reliable.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:01:56 +00:00
Stanislav Kinsburskii
5cb5c2f4a8 mshv: Use kfree_rcu in mshv_portid_free
mshv_portid_free() uses synchronize_rcu() followed by kfree() to
reclaim port table entries. This blocks the caller until a full RCU
grace period elapses, which is unnecessary since the same module already
uses the non-blocking kfree_rcu() pattern in mshv_port_table_fini().

Replace with kfree_rcu() to avoid the blocking wait and keep the
reclamation strategy consistent across the file.

Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-31 20:01:43 +00:00
Stanislav Kinsburskii
a9708e550d mshv: Fix sleeping under spinlock in mshv_portid_alloc
idr_alloc() is called with GFP_KERNEL inside idr_lock(), which holds a
spinlock. GFP_KERNEL allows the allocator to sleep, triggering a
sleeping-while-atomic bug.

Fix by using idr_preload(GFP_KERNEL) before taking the lock to
pre-allocate memory in a sleepable context, then idr_alloc() with
GFP_NOWAIT inside the spinlock-protected section.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:30 +00:00
Stanislav Kinsburskii
649dd13549 mshv: Fix duplicate GSI detection for GSI 0
The duplicate routing entry check in mshv_update_routing_table() uses
guest_irq_num != 0 to detect whether a GSI slot is already occupied.
This fails for GSI 0 because its guest_irq_num is 0 both when the slot
is unused (zero-initialized) and when legitimately assigned. As a
result, duplicate entries for GSI 0 are silently accepted, with the
second entry overwriting the first — corrupting the routing table
without any error reported to userspace.

While GSI 0 (legacy timer) is unlikely to appear in MSI-based routing
in practice, the check is semantically wrong — it conflates
"uninitialized" with "GSI number 0." Use girq_entry_valid instead,
which is explicitly set to true when an entry is populated and remains
zero for unused slots regardless of the GSI number.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:25 +00:00
Sebastian Andrzej Siewior
66688e655d Drivers: hv: vmbus: Remove vmbus_irq_initialized
vmbus_irq_initialized is only true if the registration of the per-CPU
threads succeeded. If it failed, the whole registration aborts and the
vmbus_exit() path is never called.

Remove vmbus_irq_initialized.

Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:19 +00:00
Sebastian Andrzej Siewior
8c7ab779c8 Drivers: hv: vmbus: Replace lockdep_hardirq_threaded() with lockdep annotation
lockdep_hardirq_threaded() is supposed to be used within IRQ core code
and not within drivers. It is not obvious from within the driver, that
this is the only interrupt service routing and that it is not shared
handler.

Replace lockdep_hardirq_threaded() with a lockdep annotation limiting
threaded context on PREEMPT_RT to __vmbus_isr().

Fixes: f8e6343b7a ("Drivers: hv: vmbus: Use kthread for vmbus interrupts on PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:14 +00:00
Yi Xie
ec08dd5b9f mshv_vtl: fix fd leak in mshv_ioctl_create_vtl()
put_unused_fd() if anon_inode_getfile() fails.

Fixes: 7bfe3b8ea6 ("Drivers: hv: Introduce mshv_vtl driver")
Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:09 +00:00
Yousef Alhouseen
b496f042e0 mshv_vtl: clear hypercall output before copyout
mshv_vtl_hvcall_call() copies output_size bytes to userspace.

The output page is freshly allocated. Userspace chooses the copyout length.

If the hypercall writes less, the tail can contain stale page data.

Clear the copied range before issuing the hypercall.

Also check both bounce page allocations before either page is used.

Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:51:04 +00:00
Michael Kelley
ab96bc97cd Drivers: hv: vmbus: Set DMA coherent mask for VMBus devices
In current code, the coherent_dma_mask for VMBus devices is not set, so
it has the default value of 0, which essentially means "invalid". Because
drivers for VMBus devices do not use dma_alloc_*() functions, the usual
use of the coherent mask does not occur, and no errors result.

However, a valid coherent_dma_mask may be needed even though the drivers
don't use dma_alloc_*() functions. In a CoCo VM, the VMBus storvsc and
netvsc drivers must bounce buffer DMA operations through the swiotlb
because the Hyper-V host can't DMA into encrypted guest memory. If the
kernel is built with CONFIG_SWIOTLB_DYNAMIC and the initial swiotlb size
is small, swiotlb code may need to grow the swiotlb in response to a DMA
mapping request. That growth first allocates a transient pool while the
swiotlb is expanded in the background. The transient pool memory is
allocated from the DMA atomic pools, and the allocation code checks for
a valid coherent_dma_mask. With current code, this check fails, then the
DMA mapping request from the storvsc or netvsc driver fails, and finally
an I/O error occurs.

Fix this problem by setting coherent_dma_mask for VMBus devices at the
same time that dma_mask is set. Being a synthetic bus, VMBus does not
have any restrictions on coherent DMA, so the coherent mask is set to
the full 64 bits for all VMBus devices, just like with dma_mask.

Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-07-22 23:50:26 +00:00
Linus Torvalds
6e869de3a1 hyperv-next for v7.2-rc1
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Merge tag 'hyperv-next-signed-20260621' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Use wakeup mailbox to boot APs in Hyper-V VTL2 TDX guests (Yunhong
   Jiang, Ricardo Neri)

 - Move the Hyper-V IOMMU to its own subdirectory (Mukesh Rathor)

 - Cosmetic changes to mshv and balloon driver (Junrui Luo, Markus
   Elfring)

* tag 'hyperv-next-signed-20260621' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  mshv: add bounds check on vp_index in mshv_intercept_isr()
  hv_balloon: Simplify data output in hv_balloon_debug_show()
  x86/hyperv: Cosmetic changes in irqdomain.c for readability
  iommu/hyperv: Create hyperv subdirectory under drivers/iommu
  x86/hyperv/vtl: Use the wakeup mailbox to boot secondary CPUs
  x86/hyperv/vtl: Mark the wakeup mailbox page as private
  x86/acpi: Add a helper to get the address of the wakeup mailbox
  x86/hyperv/vtl: Setup the 64-bit trampoline for TDX guests
  x86/realmode: Make the location of the trampoline configurable
  x86/hyperv/vtl: Set real_mode_header in hv_vtl_init_platform()
  x86/dt: Parse the Wakeup Mailbox for Intel processors
  dt-bindings: reserved-memory: Wakeup Mailbox for Intel processors
  x86/acpi: Add functions to setup and access the wakeup mailbox
  x86/topology: Add missing struct declaration and attribute dependency
2026-06-22 08:06:13 -07:00
Linus Torvalds
7561361d76 x86/msr updates for v7.2:
- Large series to reorganize the rdmsr/wrmsr APIs to remove
    32-bit variants and convert to 64-bit variants (Juergen Gross)
 
  - Fix W=1 warning (HyeongJun An)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull x86/msr updates from Ingo Molnar:

 - Large series to reorganize the rdmsr/wrmsr APIs to remove
   32-bit variants and convert to 64-bit variants (Juergen Gross)

 - Fix W=1 warning (HyeongJun An)

* tag 'x86-msr-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
  x86/msr: Remove wrmsrl()
  x86/msr: Switch wrmsrl() users to wrmsrq()
  x86/msr: Remove rdmsrl()
  x86/msr: Switch rdmsrl() users to rdmsrq()
  x86/msr: Remove wrmsr_safe_on_cpu()
  x86/msr: Switch wrmsr_safe_on_cpu() users to wrmsrq_safe_on_cpu()
  x86/msr: Remove rdmsr_safe_on_cpu()
  x86/msr: Switch rdmsr_safe_on_cpu() users to rdmsrq_safe_on_cpu()
  x86/msr: Don't use rdmsr_safe_on_cpu() in rdmsrq_safe_on_cpu()
  x86/msr: Remove wrmsr_on_cpu()
  x86/msr: Switch wrmsr_on_cpu() users to wrmsrq_on_cpu()
  x86/msr: Remove rdmsr_on_cpu()
  x86/msr: Switch rdmsr_on_cpu() users to rdmsrq_on_cpu()
  x86/msr: Remove rdmsrl_on_cpu()
  x86/msr: Switch rdmsrl_on_cpu() user to rdmsrq_on_cpu()
  x86/process: Convert rdmsr() to rdmsrq() in arch_post_acpi_subsys_init() to address W=1 warning
2026-06-15 15:08:14 +05:30
Linus Torvalds
36808d5e98 Driver core changes for 7.2-rc1
- deferred probe:
   - Fix race where deferred probe timeout work could be permanently
     canceled by using mod_delayed_work()
   - Fix missing jiffies conversion in deferred_probe_extend_timeout()
   - Guard timeout extension with delayed_work_pending() to prevent
     premature firing
   - Use system_percpu_wq instead of the deprecated system_wq
   - Update deferred_probe_timeout documentation
 
 - device:
   - Replace direct struct device bitfield access (can_match, dma_iommu,
     dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
     of_node_reused, offline, offline_disabled) with flag-based
     accessors using bit operations
   - Reject devices with unregistered buses
   - Delete unused DEVICE_ATTR_PREALLOC()
   - Add low-level device attribute macros with const show/store
     callbacks, allowing device attributes to reside in read-only memory
   - Move core device attributes to read-only memory
   - Constify group array pointers in driver_add_groups() /
     driver_remove_groups(), struct bus_type, and struct device_driver
 
 - device property:
   - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
   - Initialize all fields of fwnode_handle in fwnode_init()
   - Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
   - Allow passing struct software_node_ref_args pointers directly to
     PROPERTY_ENTRY_REF()
 
 - driver_override:
   - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
     infrastructure, fixing a UAF from unsynchronized access to
     driver_override in bus match() callbacks
   - Remove the now-unused driver_set_override()
 
 - firmware loader:
   - Fix recursive lock deadlock in device_cache_fw_images() when async
     work falls back to synchronous execution
   - Fix device reference leak in firmware_upload_register()
 
 - platform:
   - Pass KBUILD_MODNAME through the platform driver registration macro
     to create module symlinks in sysfs for built-in drivers; move
     module_kset initialization to a pure_initcall and tegra cbb
     registration to core_initcall to ensure correct ordering
   - Pass THIS_MODULE implicitly through a coresight_init_driver() macro
 
 - sysfs:
   - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
     WARN
   - Add return value clamping to sysfs_kf_read()
 
 - Rust:
   - ACPI:
     - Fix missing match data for PRP0001 by exporting
       acpi_of_match_device()
 
   - Auxiliary:
     - Replace drvdata() with dedicated registration data on
       auxiliary_device. drvdata() exposed the driver's bus device
       private data beyond the driver's own scope, creating ordering
       constraints and forcing the data to outlive all registrations
       that access it. Registration data is instead scoped structurally
       to the Registration object, making lifecycle ordering enforced
       by construction rather than convention.
 
   - Rust-native device driver lifetimes (HRT):
     - Allow Rust device drivers to carry a lifetime parameter on their
       bus device private data, tied to the device binding scope -- the
       interval during which a bus device is bound to a driver. Device
       resources like pci::Bar<'a> and IoMem<'a> can be stored directly
       in the driver's bus device private data with a lifetime bounded
       by the binding scope, so the compiler enforces at build time that
       they do not outlive the binding. This removes Devres indirection
       from every access site and eliminates try_access() failure paths
       in destructors.
 
       Bus driver traits use a Generic Associated Type (GAT)
       Data<'bound> to introduce the lifetime on the private data,
       rather than parameterizing the Driver trait itself. Auxiliary
       registration data, where the lifetime is not introduced by a
       trait callback but must be threaded through Registration, uses
       the ForLt trait (a type-level abstraction for types generic over
       a lifetime).
 
 - Misc:
   - Fix DT overlayed devices not probing by reverting the broken
     treewide overlay fix and re-running fw_devlink consumer pickup when
     an overlay is applied to a bound device
   - Use root_device_register() for faux bus root device; add sanity
     check for failed bus init
   - Fix dev_has_sync_state() data race with READ_ONCE() and move it to
     base.h
   - Avoid spurious device_links warning when removing a device while
     its supplier is unbinding
   - Switch ISA bus to dynamic root device
   - Fix suspicious RCU usage in kernfs_put()
   - Remove devcoredump exit callback
   - Constify devfreq_event_class
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Merge tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core updates from Danilo Krummrich:
 "Deferred probe:
   - Fix race where deferred probe timeout work could be permanently
     canceled by using mod_delayed_work()
   - Fix missing jiffies conversion in deferred_probe_extend_timeout()
   - Guard timeout extension with delayed_work_pending() to prevent
     premature firing
   - Use system_percpu_wq instead of the deprecated system_wq
   - Update deferred_probe_timeout documentation

  device:
   - Replace direct struct device bitfield access (can_match, dma_iommu,
     dma_skip_sync, dma_ops_bypass, state_synced, dma_coherent,
     of_node_reused, offline, offline_disabled) with flag-based
     accessors using bit operations
   - Reject devices with unregistered buses
   - Delete unused DEVICE_ATTR_PREALLOC()
   - Add low-level device attribute macros with const show/store
     callbacks, allowing device attributes to reside in read-only memory
   - Move core device attributes to read-only memory
   - Constify group array pointers in driver_add_groups() /
     driver_remove_groups(), struct bus_type, and struct device_driver

  device property:
   - Fix fwnode reference leak in fwnode_graph_get_endpoint_by_id()
   - Initialize all fields of fwnode_handle in fwnode_init()
   - Provide swnode_get()/swnode_put() wrappers around kobject_get/put()
   - Allow passing struct software_node_ref_args pointers directly to
     PROPERTY_ENTRY_REF()

  driver_override:
   - Migrate amba, cdx, vmbus, and rpmsg to the generic driver_override
     infrastructure, fixing a UAF from unsynchronized access to
     driver_override in bus match() callbacks
   - Remove the now-unused driver_set_override()

  firmware loader:
   - Fix recursive lock deadlock in device_cache_fw_images() when async
     work falls back to synchronous execution
   - Fix device reference leak in firmware_upload_register()

  platform:
   - Pass KBUILD_MODNAME through the platform driver registration macro
     to create module symlinks in sysfs for built-in drivers; move
     module_kset initialization to a pure_initcall and tegra cbb
     registration to core_initcall to ensure correct ordering
   - Pass THIS_MODULE implicitly through a coresight_init_driver() macro

  sysfs:
   - Upgrade OOB write detection in sysfs_kf_seq_show() from printk to
     WARN
   - Add return value clamping to sysfs_kf_read()

  Rust:
   - ACPI:

     Fix missing match data for PRP0001 by exporting
     acpi_of_match_device()

   - Auxiliary:

     Replace drvdata() with dedicated registration data on
     auxiliary_device. drvdata() exposed the driver's bus device private
     data beyond the driver's own scope, creating ordering constraints
     and forcing the data to outlive all registrations that access it.
     Registration data is instead scoped structurally to the
     Registration object, making lifecycle ordering enforced by
     construction rather than convention.

   - Rust-native device driver lifetimes (HRT):

     Allow Rust device drivers to carry a lifetime parameter on their
     bus device private data, tied to the device binding scope -- the
     interval during which a bus device is bound to a driver. Device
     resources like pci::Bar<'a> and IoMem<'a> can be stored directly in
     the driver's bus device private data with a lifetime bounded by the
     binding scope, so the compiler enforces at build time that they do
     not outlive the binding. This removes Devres indirection from every
     access site and eliminates try_access() failure paths in
     destructors.

     Bus driver traits use a Generic Associated Type (GAT) Data<'bound>
     to introduce the lifetime on the private data, rather than
     parameterizing the Driver trait itself. Auxiliary registration
     data, where the lifetime is not introduced by a trait callback but
     must be threaded through Registration, uses the ForLt trait (a
     type-level abstraction for types generic over a lifetime).

  Misc:
   - Fix DT overlayed devices not probing by reverting the broken
     treewide overlay fix and re-running fw_devlink consumer pickup when
     an overlay is applied to a bound device
   - Use root_device_register() for faux bus root device; add sanity
     check for failed bus init
   - Fix dev_has_sync_state() data race with READ_ONCE() and move it to
     base.h
   - Avoid spurious device_links warning when removing a device while
     its supplier is unbinding
   - Switch ISA bus to dynamic root device
   - Fix suspicious RCU usage in kernfs_put()
   - Remove devcoredump exit callback
   - Constify devfreq_event_class"

* tag 'driver-core-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/driver-core/driver-core: (81 commits)
  software node: allow passing reference args to PROPERTY_ENTRY_REF()
  driver core: platform: set mod_name in driver registration
  coresight: pass THIS_MODULE implicitly through a macro
  kernel: param: initialize module_kset in a pure_initcall
  soc/tegra: cbb: Move driver registration from pure_initcall to core_initcall
  firmware_loader: Fix recursive lock in device_cache_fw_images()
  driver core: Use system_percpu_wq instead of system_wq
  driver core: remove driver_set_override()
  rpmsg: use generic driver_override infrastructure
  Drivers: hv: vmbus: use generic driver_override infrastructure
  cdx: use generic driver_override infrastructure
  amba: use generic driver_override infrastructure
  rust: devres: add 'static bound to Devres<T>
  samples: rust: rust_driver_auxiliary: showcase lifetime-bound registration data
  rust: auxiliary: generalize Registration over ForLt
  rust: types: add `ForLt` trait for higher-ranked lifetime support
  gpu: nova-core: separate driver type from driver data
  samples: rust: rust_driver_pci: use HRT lifetime for Bar
  rust: io: make IoMem and ExclusiveIoMem lifetime-parameterized
  rust: pci: make Bar lifetime-parameterized
  ...
2026-06-15 12:41:17 +05:30
Juergen Gross
2232959db2 x86/msr: Switch wrmsrl() users to wrmsrq()
wrmsrl() is a deprecated synonym for wrmsrq(). Switch its users to
wrmsrq().

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Long Li <longli@microsoft.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20260608082809.3492719-4-jgross@suse.com
2026-06-08 13:16:35 +02:00
Juergen Gross
72ac0e45c2 x86/msr: Switch rdmsrl() users to rdmsrq()
rdmsrl() is a deprecated synonym for rdmsrq(). Switch its users to
rdmsrq().

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Long Li <longli@microsoft.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Link: https://patch.msgid.link/20260608082809.3492719-2-jgross@suse.com
2026-06-08 13:16:34 +02:00
Junrui Luo
a4ffc59238 mshv: add bounds check on vp_index in mshv_intercept_isr()
mshv_intercept_isr() extracts vp_index from the hypervisor message
payload and uses it directly to index into pt_vp_array without
validation. handle_bitset_message() and handle_pair_message() already
validate vp_index against MSHV_MAX_VPS before array access.

Add the same MSHV_MAX_VPS bounds check for consistency with the other
message handlers.

Fixes: 621191d709 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-06-07 23:22:46 -07:00
Markus Elfring
145613eb15 hv_balloon: Simplify data output in hv_balloon_debug_show()
Move the specification for a line break from a seq_puts() call
to a seq_printf() call.

The source code was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Sahil Chandna <sahilchandna@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-06-07 23:13:15 -07:00
Danilo Krummrich
331d890012 Drivers: hv: vmbus: use generic driver_override infrastructure
When a driver is probed through __driver_attach(), the bus' match()
callback is called without the device lock held, thus accessing the
driver_override field without a lock, which can cause a UAF.

Fix this by using the driver-core driver_override infrastructure taking
care of proper locking internally.

Note that calling match() from __driver_attach() without the device lock
held is intentional. [1]

Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1]
Reported-by: Gui-Dong Han <hanguidong02@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789
Fixes: d765edbb30 ("vmbus: add driver_override support")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260505133935.3772495-4-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-30 22:25:36 +02:00
Anirudh Rayabharam (Microsoft)
98e0fc32e5 mshv: support 1G hugepages by passing them as 2M-aligned chunks
The hypervisor's map GPA hypercall coalesces contiguous 2M-aligned
chunks into 1G mappings when alignment permits, so the driver can
support 1G hugepages by feeding them in as 2M chunks. Note that this
is the only way to make 1G mappings; there is no way to directly map
a 1G hugepage using the hypercall.

Always emit a 2M (PMD_ORDER) stride for the huge-page case. The
hypercall has no 1G stride, so 1G folios are processed as a
sequence of 2M chunks. Folios whose order is less than PMD_ORDER
(e.g. mTHP) fall back to single-page stride; mapping them as 2M
would fail in the hypervisor anyway.

Assisted-by: Copilot-CLI:claude-opus-4.7
Signed-off-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Acked-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27 15:30:15 -07:00
Dexuan Cui
016a25e4b0 Drivers: hv: vmbus: Improve the logic of reserving fb_mmio on Gen2 VMs
If vmbus_reserve_fb() in the kdump/kexec kernel fails to properly reserve
the framebuffer MMIO range (which is below 4GB) due to a Gen2 VM's
screen.lfb_base being zero [1], there is an MMIO conflict between the
drivers hyperv-drm and pci-hyperv: when the driver pci-hyperv's
hv_allocate_config_window() calls vmbus_allocate_mmio() to get an
MMIO range, typically it gets a 32-bit MMIO range that overlaps with the
framebuffer MMIO range, and later hv_pci_enter_d0() fails with an
error message "PCI Pass-through VSP failed D0 Entry with status" since
the host thinks that PCI devices must not use MMIO space that the
host has assigned to the framebuffer.

This is especially an issue if pci-hyperv is built-in and hyperv-drm is
built as a module. Consequently, the kdump/kexec kernel fails to detect
PCI devices via pci-hyperv, and may fail to mount the root file system,
which may reside in a NVMe disk. The issue described here has existed
for SR-IOV VF NICs since day one of the pci-hyperv driver, and has been
worked around on x64 when possible. With the recent introduction of
ARM64 VMs that boot from NVMe, there is no workaround, so we need a
formal fix.

On Gen2 VMs, if the screen.lfb_base is 0 in the kdump/kexec kernel [1],
fall back to the low MMIO base, which should be equal to the framebuffer
MMIO base [2] (the statement is true according to my testing on x64
Windows Server 2016, and on x64 and ARM64 Windows Server 2025 and on
Azure. I checked with the Hyper-V team and they said the statement should
continue to be true for Gen2 VMs). In the first kernel, screen.lfb_base
is not 0; if the user specifies a very high resolution, it's not enough
to only reserve 8MB: let's always reserve half of the space below 4GB,
but cap the reservation to 128MB, which is the required framebuffer size
of the highest resolution 7680*4320 supported by Hyper-V.

While at it, fix the comparison "end > VTPM_BASE_ADDRESS" by changing
the > to >=. Here the 'end' is an inclusive end (typically, it's
0xFFFF_FFFF for the low MMIO range).

Note: vmbus_reserve_fb() now also reserves an MMIO range at the beginning
of the low MMIO range on CVMs, which have no framebuffers (the
'screen.lfb_base' in vmbus_reserve_fb() is 0 for CVMs), just in case the
host might treat the beginning of the low MMIO range specially [3]. BTW,
the OpenHCL kernel is not affected by the change, because that kernel
boots with DeviceTree rather than ACPI (so vmbus_reserve_fb() won't run
there), and there is no framebuffer device for that kernel.

Note: normally Gen1 VMs don't have the MMIO conflict issue because the
framebuffer MMIO range (which is hardcoded to base=4GB-128MB and
size=64MB for Gen1 VMs by the host) is always reported via the legacy PCI
graphics device's BAR, so the kdump/kexec kernel can reserve the 64MB
MMIO range; however, if the VM is configured to use a very high resolution
and the required framebuffer size exceeds 64MB (AFAIK, in practice, this
isn't a typical configuration by users), the hyperv-drm driver may need to
allocate an MMIO range above 4GB and change the framebuffer MMIO location
to the allocated MMIO range -- in this case, there can still be issues [4]
which can't be easily fixed: any possible affected Gen1 users would have
to use a resolution whose framebuffer size is <= 64MB, or switch to Gen2
VMs.

[1] https://lore.kernel.org/all/SA1PR21MB692176C1BC53BFC9EAE5CF8EBF51A@SA1PR21MB6921.namprd21.prod.outlook.com/
[2] https://lore.kernel.org/all/SA1PR21MB69218F955B62DFF62E3E88D2BF222@SA1PR21MB6921.namprd21.prod.outlook.com/
[3] https://lore.kernel.org/all/SN6PR02MB415726B17D5A6027CD1717E8D4342@SN6PR02MB4157.namprd02.prod.outlook.com/
[4] https://lore.kernel.org/all/SA1PR21MB69213486F821CA5A2C793C81BF342@SA1PR21MB6921.namprd21.prod.outlook.com/

Fixes: 4daace0d8c ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
CC: stable@vger.kernel.org
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27 15:28:33 -07:00
Can Peng
c53763aa2b mshv: use kmalloc_array in mshv_root_scheduler_init
Replace kmalloc() with kmalloc_array() to prevent potential
overflow, as recommended in Documentation/process/deprecated.rst.

No functional change.

Signed-off-by: Can Peng <pengcan@kylinos.cn>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27 15:26:23 -07:00
Michael Kelley
840b740a35 mshv: Add conditional VMBus dependency
When the VMBus driver is not part of the kernel (CONFIG_HYPERV_VMBUS=n),
the MSHV root driver fails to link:

ERROR: modpost: "hv_vmbus_exists" [drivers/hv/mshv_root.ko] undefined!

Fix this while meeting these requirements:
* It must be possible to include the MSHV root driver without the
  VMBus driver. In such case, the MSHV root driver can be built-in
  to the kernel image, or it can be built as a separate module.
* If both the MSHV root driver and the VMBus driver are present, the
  MSHV root driver and VMBus driver can both be built-in, or they can
  both be separate modules. Or the MSHV root driver can be a module
  while the VMBus driver can be built-in, but the reverse is
  disallowed. Regardless of the build choices, the VMBus driver must
  be loaded before the MSHV driver in order for the SynIC to be
  managed properly (see comments in the MSHV SynIC code).

The fix has two parts:
* Add a Kconfig entry for MSHV_ROOT to depend on HYPERV_VMBUS if
  HYPERV_VMBUS is present. The entry disallows MSHV_ROOT being
  built-in when HYPERV_VMBUS is a module, but without requiring that
  HYPERV_VMBUS be built.
* Add a stub implementation of hv_vmbus_exists() for when the
  VMBus driver is not present so that the MSHV root driver has
  no module dependency on VMBus. When the VMBus driver *is*
  present, the module dependency ensures that the VMBus driver
  loads first when both are built as modules.

Existing code ensures that the VMBus driver loads first if it is
built-in. The VMBus driver uses subsys_initcall(), which is
initcall level 4. The MSHV root driver uses module_init(), which
becomes device_init() when built-in, and device_init() is
initcall level 6.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/all/20260520074044.923728-1-arnd@kernel.org/
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Hardik Garg <hargar@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-27 15:11:05 -07:00
Michael Kelley
c5c3ef8d49 Drivers: hv: vmbus: Provide option to skip VMBus unload on panic
Currently, VMBus code initiates a VMBus unload in the panic path so
that if a kdump kernel is loaded, it can start fresh in setting up its
own VMBus connection. However, a driver for the VMBus virtual frame
buffer may need to flush dirty portions of the frame buffer back to
the Hyper-V host so that panic information is visible in the graphics
console. To support such flushing, provide exported functions for the
frame buffer driver to specify that the VMBus unload should not be
done by the VMBus driver, and to initiate the VMBus unload itself.
Together these allow a frame buffer driver to delay the VMBus unload
until after it has completed the flush.

Ideally, the VMBus driver could use its own panic-path callback to do
the unload after all frame buffer drivers have finished. But DRM frame
buffer drivers use the kmsg dump callback, and there are no callbacks
after that in the panic path. Hence this somewhat messy approach to
properly sequencing the frame buffer flush and the VMBus unload.

Fixes: 3671f37777 ("drm/hyperv: Add support for drm_panic")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-05-13 22:29:32 +00:00
Jork Loeser
6e55a8d9f2 mshv: unmap debugfs stats pages on kexec
On L1VH, debugfs stats pages are overlay pages: the kernel allocates
them and registers the GPAs with the hypervisor via
HVCALL_MAP_STATS_PAGE2. These overlay mappings persist in the
hypervisor across kexec. If the kexec'd kernel reuses those physical
pages, the hypervisor's overlay semantics cause a machine check
exception.

Fix this by calling mshv_debugfs_exit() from the reboot notifier,
which issues HVCALL_UNMAP_STATS_PAGE for each mapped stats page before
kexec. This releases the overlay bindings so the physical pages can be
safely reused. Guard mshv_debugfs_exit() against being called when
init failed.

Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29 22:56:53 +00:00
Jork Loeser
efe0fb8c3f mshv: clean up SynIC state on kexec for L1VH
The reboot notifier that tears down the SynIC cpuhp state guards the
cleanup with hv_root_partition(), so on L1VH (where
hv_root_partition() is false) SINT0, SINT5, and SIRBP are never
cleaned up before kexec. The kexec'd kernel then inherits stale
unmasked SINTs and an enabled SIRBP pointing to freed memory.

Remove the hv_root_partition() guard so the cleanup runs for all
parent partitions.

Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29 22:56:53 +00:00
Jork Loeser
f1a9e67c11 mshv: limit SynIC management to MSHV-owned resources
The SynIC is shared between VMBus and MSHV. VMBus owns the message
page (SIMP), event flags page (SIEFP), global enable (SCONTROL),
and SINT2. MSHV adds SINT0, SINT5, and the event ring page (SIRBP).

Currently mshv_synic_cpu_init() redundantly enables SIMP, SIEFP, and
SCONTROL that VMBus already configured, and mshv_synic_cpu_exit()
disables all of them. This is wrong because MSHV can be torn down
while VMBus is still active. In particular, a kexec reboot notifier
tears down MSHV first. Disabling SCONTROL, SIMP, and SIEFP out
from under VMBus causes its later cleanup to write SynIC MSRs while
SynIC is disabled, which the hypervisor does not tolerate.

Restrict MSHV to managing only the resources it owns:
- SINT0, SINT5: mask on cleanup, unmask on init
- SIRBP: enable/disable as before
- SIMP, SIEFP, SCONTROL: leave to VMBus when it is active (L1VH
  and nested root partition); on a non-nested root partition VMBus
  does not run, so MSHV must enable/disable them

While here, fix the SIEFP and SIRBP memremap() and virt_to_phys()
calls to use HV_HYP_PAGE_SHIFT/HV_HYP_PAGE_SIZE instead of
PAGE_SHIFT/PAGE_SIZE. The hypervisor always uses 4K pages for SynIC
register GPAs regardless of the kernel page size, so using PAGE_SHIFT
produces wrong addresses on ARM64 with 64K pages.

Note that initialization order matters - VMBUS first, MSHV second,
and the reverse on de-init. Ideally, we would want a dedicated SYNIC
driver that replaces the cross-dependencies with a clear API and
dynamic tracking. Such refactor should go into its own dedicated
series, outside of this kexec fix series.

Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29 22:56:53 +00:00
Thorsten Blum
3f8c8497b4 hv: utils: replace deprecated strcpy with strscpy in kvp_register
strcpy() has been deprecated [1] because it performs no bounds checking
on the destination buffer, which can lead to buffer overflows. While the
current code works correctly, replace strcpy() with the safer strscpy()
to follow secure coding best practices. Use ->body.kvp_register.version
directly as the destination buffer and remove the local variable.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strcpy

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29 22:15:31 +00:00
Thorsten Blum
3fcf923302 hv: utils: handle and propagate errors in kvp_register
Make kvp_register() return an error code instead of silently ignoring
failures, and propagate the error from kvp_handle_handshake() instead of
returning success.

This propagates both kzalloc_obj() and hvutil_transport_send() failures
to kvp_handle_handshake() and thus to kvp_on_msg().

Fixes: 245ba56a52 ("Staging: hv: Implement key/value pair (KVP)")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-29 21:13:58 +00:00
Linus Torvalds
cf950766e9 drm fixes for 7.1-rc1
atomic:
 - raise the vblank timeout to avoid it on virtual drivers
 - fix colorop duplication
 
 bridge:
 - stm_lvds: state check fix
 - dw-mipi-dsi: bridge reference leak fix
 
 panel:
 - visionx-rm69299: init fix
 
 dma-fence:
 - fix sparse warning
 
 dma-buf:
 - UAF fix
 
 panthor:
 - mapping fix
 
 arcgpu:
 - device_node reference leak fix
 
 nouveau:
 - memory leak in error path fix
 - overflow in reloc path for old hw fix
 
 hv:
 - Kconfig fix
 
 v3d:
 - infinite loop fix
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Merge tag 'drm-fixes-2026-04-24' of https://gitlab.freedesktop.org/drm/kernel

Pull more drm fixes from Dave Airlie:
 "These are the regular fixes that have built up over last couple of
  weeks, all pretty minor and spread all over.

  atomic:
   - raise the vblank timeout to avoid it on virtual drivers
   - fix colorop duplication

  bridge:
   - stm_lvds: state check fix
   - dw-mipi-dsi: bridge reference leak fix

  panel:
   - visionx-rm69299: init fix

  dma-fence:
   - fix sparse warning

  dma-buf:
   - UAF fix

  panthor:
   - mapping fix

  arcgpu:
   - device_node reference leak fix

  nouveau:
   - memory leak in error path fix
   - overflow in reloc path for old hw fix

  hv:
   - Kconfig fix

  v3d:
   - infinite loop fix"

* tag 'drm-fixes-2026-04-24' of https://gitlab.freedesktop.org/drm/kernel:
  drm/nouveau: fix u32 overflow in pushbuf reloc bounds check
  MAINTAINERS: split hisilicon maintenance and add Yongbang Shi for hibmc-drm matainers
  drm/v3d: Reject empty multisync extension to prevent infinite loop
  drm/panel: visionox-rm69299: Make use of prepare_prev_first
  drm/drm_atomic: duplicate colorop states if plane color pipeline in use
  drm/nouveau: fix nvkm_device leak on aperture removal failure
  hv: Select CONFIG_SYSFB only for CONFIG_HYPERV_VMBUS
  dma-fence: Silence sparse warning in dma_fence_describe
  drm/bridge: dw-mipi-dsi: Fix bridge leak when host attach fails
  drm/arcpgu: fix device node leak
  drm/panthor: Fix outdated function documentation
  drm/panthor: Extend VM locked region for remap case to be a superset
  dma-buf: fix UAF in dma_buf_put() tracepoint
  drm/bridge: stm_lvds: Do not fail atomic_check on disabled connector
  drm/atomic: Increase timeout in drm_atomic_helper_wait_for_vblanks()
2026-04-24 11:44:52 -07:00
Dave Airlie
56d0a0b38f This week in drm-misc-fixes, we have:
- A patch to raise the vblank timeout to avoid it on virtual drivers
 - a state check fix for stm_lvds
 - a use-after-free fix for dma-buf
 - a mapping fix for panthor
 - a device_node reference leak fix for arcgpu
 - a bridge reference leak fix for dw-mipi-dsi
 - a sparse warning fix for dma-fence
 - a kconfig fix for hv
 - a memory leak fix for nouveau
 - a fix to duplicate colorop when duplicating states
 - a panel initialisation order fix for visionox-rm69299
 - a fix to prevent an infinite loop for v3d
 - an overflow fix for nouveau
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Merge tag 'drm-misc-fixes-2026-04-23' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes

This week in drm-misc-fixes, we have:
- A patch to raise the vblank timeout to avoid it on virtual drivers
- a state check fix for stm_lvds
- a use-after-free fix for dma-buf
- a mapping fix for panthor
- a device_node reference leak fix for arcgpu
- a bridge reference leak fix for dw-mipi-dsi
- a sparse warning fix for dma-fence
- a kconfig fix for hv
- a memory leak fix for nouveau
- a fix to duplicate colorop when duplicating states
- a panel initialisation order fix for visionox-rm69299
- a fix to prevent an infinite loop for v3d
- an overflow fix for nouveau

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@redhat.com>
Link: https://patch.msgid.link/20260423-realistic-eager-reindeer-4dacf7@houat
2026-04-24 13:56:54 +10:00
Linus Torvalds
8fd12b03c7 hyperv-next for v7.1
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Merge tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - Fix cross-compilation for hv tools (Aditya Garg)

 - Fix vmemmap_shift exceeding MAX_FOLIO_ORDER in mshv_vtl (Naman Jain)

 - Limit channel interrupt scan to relid high water mark (Michael
   Kelley)

 - Export hv_vmbus_exists() and use it in pci-hyperv (Dexuan Cui)

 - Fix cleanup and shutdown issues for MSHV (Jork Loeser)

 - Introduce more tracing support for MSHV (Stanislav Kinsburskii)

* tag 'hyperv-next-signed-20260421' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Skip LP/VP creation on kexec
  x86/hyperv: move stimer cleanup to hv_machine_shutdown()
  Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing
  mshv: Add tracepoint for GPA intercept handling
  mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER
  tools: hv: Fix cross-compilation
  Drivers: hv: vmbus: Export hv_vmbus_exists() and use it in pci-hyperv
  mshv: Introduce tracing support
  Drivers: hv: vmbus: Limit channel interrupt scan to relid high water mark
2026-04-22 09:50:46 -07:00
Jork Loeser
5170a82e89 x86/hyperv: Skip LP/VP creation on kexec
After a kexec the logical processors and virtual processors already
exist in the hypervisor because they were created by the previous
kernel. Attempting to add them again causes either a BUG_ON or
corrupted VP state leading to MCEs in the new kernel.

Add hv_lp_exists() to probe whether an LP is already present by
calling HVCALL_GET_LOGICAL_PROCESSOR_RUN_TIME. When it succeeds the
LP exists and we skip the add-LP and create-VP loops entirely.

Also add hv_call_notify_all_processors_started() which informs the
hypervisor that all processors are online. This is required after
adding LPs (fresh boot) and is a no-op on kexec since we skip that
path.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Co-developed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Jork Loeser
f7ce370b52 x86/hyperv: move stimer cleanup to hv_machine_shutdown()
Move hv_stimer_global_cleanup() from vmbus's hv_kexec_handler() to
hv_machine_shutdown() in the platform code. This ensures stimer cleanup
happens before the vmbus unload, which is required for root partition
kexec to work correctly.

Co-developed-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Jork Loeser
3c42b33433 Drivers: hv: vmbus: fix hyperv_cpuhp_online variable shadowing
vmbus_alloc_synic_and_connect() declares a local 'int
hyperv_cpuhp_online' that shadows the file-scope global of the same
name. The cpuhp state returned by cpuhp_setup_state() is stored in
the local, leaving the global at 0 (CPUHP_OFFLINE). When
hv_kexec_handler() or hv_machine_shutdown() later call
cpuhp_remove_state(hyperv_cpuhp_online) they pass 0, which hits the
BUG_ON in __cpuhp_remove_state_cpuslocked().

Remove the local declaration so the cpuhp state is stored in the
file-scope global where hv_kexec_handler() and hv_machine_shutdown()
expect it.

Fixes: 2647c96649 ("Drivers: hv: Support establishing the confidential VMBus connection")
Signed-off-by: Jork Loeser <jloeser@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Stanislav Kinsburskii
cfc42685e5 mshv: Add tracepoint for GPA intercept handling
Provide visibility into GPA intercept operations for debugging and
performance analysis of Microsoft Hypervisor guest memory management.

Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2026-04-22 06:23:25 +00:00
Linus Torvalds
334fbe734e mm.git review status for linus..mm-stable
Everything:
 
 Total patches:       368
 Reviews/patch:       1.56
 Reviewed rate:       74%
 
 Excluding DAMON:
 
 Total patches:       316
 Reviews/patch:       1.77
 Reviewed rate:       81%
 
 Excluding DAMON and zram:
 
 Total patches:       306
 Reviews/patch:       1.81
 Reviewed rate:       82%
 
 Excluding DAMON, zram and maple_tree:
 
 Total patches:       276
 Reviews/patch:       2.01
 Reviewed rate:       91%
 
 Significant patch series in this merge:
 
 - The 30 patch series "maple_tree: Replace big node with maple copy"
   from Liam Howlett is mainly prepararatory work for ongoing development
   but it does reduce stack usage and is an improvement.
 
 - The 12 patch series "mm, swap: swap table phase III: remove swap_map"
   from Kairui Song offers memory savings by removing the static swap_map.
   It also yields some CPU savings and implements several cleanups.
 
 - The 2 patch series "mm: memfd_luo: preserve file seals" from Pratyush
   Yadav adds file seal preservation to LUO's memfd code.
 
 - The 2 patch series "mm: zswap: add per-memcg stat for incompressible
   pages" from Jiayuan Chen adds additional userspace stats reportng to
   zswap.
 
 - The 4 patch series "arch, mm: consolidate empty_zero_page" from Mike
   Rapoport implements some cleanups for our handling of ZERO_PAGE() and
   zero_pfn.
 
 - The 2 patch series "mm/kmemleak: Improve scan_should_stop()
   implementation" from Zhongqiu Han provides an robustness improvement and
   some cleanups in the kmemleak code.
 
 - The 4 patch series "Improve khugepaged scan logic" from Vernon Yang
   "improves the khugepaged scan logic and reduces CPU consumption by
   prioritizing scanning tasks that access memory frequently".
 
 - The 2 patch series "Make KHO Stateless" from Jason Miu simplifies
   Kexec Handover by "transitioning KHO from an xarray-based metadata
   tracking system with serialization to a radix tree data structure that
   can be passed directly to the next kernel"
 
 - The 3 patch series "mm: vmscan: add PID and cgroup ID to vmscan
   tracepoints" from Thomas Ballasi and Steven Rostedt enhances vmscan's
   tracepointing.
 
 - The 5 patch series "mm: arch/shstk: Common shadow stack mapping helper
   and VM_NOHUGEPAGE" from Catalin Marinas is a cleanup for the shadow
   stack code: remove per-arch code in favour of a generic implementation.
 
 - The 2 patch series "Fix KASAN support for KHO restored vmalloc
   regions" from Pasha Tatashin fixes a WARN() which can be emitted the KHO
   restores a vmalloc area.
 
 - The 4 patch series "mm: Remove stray references to pagevec" from Tal
   Zussman provides several cleanups, mainly udpating references to "struct
   pagevec", which became folio_batch three years ago.
 
 - The 17 patch series "mm: Eliminate fake head pages from vmemmap
   optimization" from Kiryl Shutsemau simplifies the HugeTLB vmemmap
   optimization (HVO) by changing how tail pages encode their relationship
   to the head page.
 
 - The 2 patch series "mm/damon/core: improve DAMOS quota efficiency for
   core layer filters" from SeongJae Park improves two problematic
   behaviors of DAMOS that makes it less efficient when core layer filters
   are used.
 
 - The 3 patch series "mm/damon: strictly respect min_nr_regions" from
   SeongJae Park improves DAMON usability by extending the treatment of the
   min_nr_regions user-settable parameter.
 
 - The 3 patch series "mm/page_alloc: pcp locking cleanup" from Vlastimil
   Babka is a proper fix for a previously hotfixed SMP=n issue.  Code
   simplifications and cleanups ennsed.
 
 - The 16 patch series "mm: cleanups around unmapping / zapping" from
   David Hildenbrand implements "a bunch of cleanups around unmapping and
   zapping.  Mostly simplifications, code movements, documentation and
   renaming of zapping functions".
 
 - The 6 patch series "support batched checking of the young flag for
   MGLRU" from Baolin Wang supports batched checking of the young flag for
   MGLRU.  It's part cleanups; one benchmark shows large performance
   benefits for arm64.
 
 - The 5 patch series "memcg: obj stock and slab stat caching cleanups"
   from Johannes Weiner provides memcg cleanup and robustness improvements.
 
 - The 5 patch series "Allow order zero pages in page reporting" from
   Yuvraj Sakshith enhances page_reporting's free page reporting - it is
   presently and undesirably order-0 pages when reporting free memory.
 
 - The 6 patch series "mm: vma flag tweaks" from Lorenzo Stoakes is
   cleanup work following from the recent conversion of the VMA flags to a
   bitmap.
 
 - The 10 patch series "mm/damon: add optional debugging-purpose sanity
   checks" from SeongJae Park adds some more developer-facing debug checks
   into DAMON core.
 
 - The 2 patch series "mm/damon: test and document power-of-2
   min_region_sz requirement" from SeongJae Park adds an additional DAMON
   kunit test and makes some adjustments to the addr_unit parameter
   handling.
 
 - The 3 patch series "mm/damon/core: make passed_sample_intervals
   comparisons overflow-safe" from SeongJae Park fixes a hard-to-hit time
   overflow issue in DAMON core.
 
 - The 7 patch series "mm/damon: improve/fixup/update ratio calculation,
   test and documentation" from SeongJae Park is a "batch of misc/minor
   improvements and fixups" for DAMON.
 
 - The 4 patch series "mm: move vma_(kernel|mmu)_pagesize() out of
   hugetlb.c" from David Hildenbrand fixes a possible issue with dax-device
   when CONFIG_HUGETLB=n.  Some code movement was required.
 
 - The 6 patch series "zram: recompression cleanups and tweaks" from
   Sergey Senozhatsky provides "a somewhat random mix of fixups,
   recompression cleanups and improvements" in the zram code.
 
 - The 11 patch series "mm/damon: support multiple goal-based quota
   tuning algorithms" from SeongJae Park extend DAMOS quotas goal
   auto-tuning to support multiple tuning algorithms that users can select.
 
 - The 4 patch series "mm: thp: reduce unnecessary
   start_stop_khugepaged()" from Breno Leitao fixes the khugpaged sysfs
   handling so we no longer spam the logs with reams of junk when
   starting/stopping khugepaged.
 
 - The 3 patch series "mm: improve map count checks" from Lorenzo Stoakes
   provides some cleanups and slight fixes in the mremap, mmap and vma
   code.
 
 - The 5 patch series "mm/damon: support addr_unit on default monitoring
   targets for modules" from SeongJae Park extends the use of DAMON core's
   addr_unit tunable.
 
 - The 5 patch series "mm: khugepaged cleanups and mTHP prerequisites"
   from Nico Pache provides cleanups in the khugepaged and is a base for
   Nico's planned khugepaged mTHP support.
 
 - The 15 patch series "mm: memory hot(un)plug and SPARSEMEM cleanups"
   from David Hildenbrand implements code movement and cleanups in the
   memhotplug and sparsemem code.
 
 - The 2 patch series "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and
   cleanup CONFIG_MIGRATION" from David Hildenbrand rationalizes some
   memhotplug Kconfig support.
 
 - The 6 patch series "change young flag check functions to return bool"
   from Baolin Wang is "a cleanup patchset to change all young flag check
   functions to return bool".
 
 - The 3 patch series "mm/damon/sysfs: fix memory leak and NULL
   dereference issues" from Josh Law and SeongJae Park fixes a few
   potential DAMON bugs.
 
 - The 25 patch series "mm/vma: convert vm_flags_t to vma_flags_t in vma
   code" from "converts a lot of the existing use of the legacy vm_flags_t
   data type to the new vma_flags_t type which replaces it".  Mainly in the
   vma code.
 
 - The 21 patch series "mm: expand mmap_prepare functionality and usage"
   from Lorenzo Stoakes "expands the mmap_prepare functionality, which is
   intended to replace the deprecated f_op->mmap hook which has been the
   source of bugs and security issues for some time".  Cleanups,
   documentation, extension of mmap_prepare into filesystem drivers.
 
 - The 13 patch series "mm/huge_memory: refactor zap_huge_pmd()" from
   Lorenzo Stoakes simplifies and cleans up zap_huge_pmd().  Additional
   cleanups around vm_normal_folio_pmd() and the softleaf functionality are
   performed.
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Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "maple_tree: Replace big node with maple copy" (Liam Howlett)

   Mainly prepararatory work for ongoing development but it does reduce
   stack usage and is an improvement.

 - "mm, swap: swap table phase III: remove swap_map" (Kairui Song)

   Offers memory savings by removing the static swap_map. It also yields
   some CPU savings and implements several cleanups.

 - "mm: memfd_luo: preserve file seals" (Pratyush Yadav)

   File seal preservation to LUO's memfd code

 - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan
   Chen)

   Additional userspace stats reportng to zswap

 - "arch, mm: consolidate empty_zero_page" (Mike Rapoport)

   Some cleanups for our handling of ZERO_PAGE() and zero_pfn

 - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu
   Han)

   A robustness improvement and some cleanups in the kmemleak code

 - "Improve khugepaged scan logic" (Vernon Yang)

   Improve khugepaged scan logic and reduce CPU consumption by
   prioritizing scanning tasks that access memory frequently

 - "Make KHO Stateless" (Jason Miu)

   Simplify Kexec Handover by transitioning KHO from an xarray-based
   metadata tracking system with serialization to a radix tree data
   structure that can be passed directly to the next kernel

 - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas
   Ballasi and Steven Rostedt)

   Enhance vmscan's tracepointing

 - "mm: arch/shstk: Common shadow stack mapping helper and
   VM_NOHUGEPAGE" (Catalin Marinas)

   Cleanup for the shadow stack code: remove per-arch code in favour of
   a generic implementation

 - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin)

   Fix a WARN() which can be emitted the KHO restores a vmalloc area

 - "mm: Remove stray references to pagevec" (Tal Zussman)

   Several cleanups, mainly udpating references to "struct pagevec",
   which became folio_batch three years ago

 - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl
   Shutsemau)

   Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail
   pages encode their relationship to the head page

 - "mm/damon/core: improve DAMOS quota efficiency for core layer
   filters" (SeongJae Park)

   Improve two problematic behaviors of DAMOS that makes it less
   efficient when core layer filters are used

 - "mm/damon: strictly respect min_nr_regions" (SeongJae Park)

   Improve DAMON usability by extending the treatment of the
   min_nr_regions user-settable parameter

 - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka)

   The proper fix for a previously hotfixed SMP=n issue. Code
   simplifications and cleanups ensued

 - "mm: cleanups around unmapping / zapping" (David Hildenbrand)

   A bunch of cleanups around unmapping and zapping. Mostly
   simplifications, code movements, documentation and renaming of
   zapping functions

 - "support batched checking of the young flag for MGLRU" (Baolin Wang)

   Batched checking of the young flag for MGLRU. It's part cleanups; one
   benchmark shows large performance benefits for arm64

 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner)

   memcg cleanup and robustness improvements

 - "Allow order zero pages in page reporting" (Yuvraj Sakshith)

   Enhance free page reporting - it is presently and undesirably order-0
   pages when reporting free memory.

 - "mm: vma flag tweaks" (Lorenzo Stoakes)

   Cleanup work following from the recent conversion of the VMA flags to
   a bitmap

 - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae
   Park)

   Add some more developer-facing debug checks into DAMON core

 - "mm/damon: test and document power-of-2 min_region_sz requirement"
   (SeongJae Park)

   An additional DAMON kunit test and makes some adjustments to the
   addr_unit parameter handling

 - "mm/damon/core: make passed_sample_intervals comparisons
   overflow-safe" (SeongJae Park)

   Fix a hard-to-hit time overflow issue in DAMON core

 - "mm/damon: improve/fixup/update ratio calculation, test and
   documentation" (SeongJae Park)

   A batch of misc/minor improvements and fixups for DAMON

 - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David
   Hildenbrand)

   Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code
   movement was required.

 - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky)

   A somewhat random mix of fixups, recompression cleanups and
   improvements in the zram code

 - "mm/damon: support multiple goal-based quota tuning algorithms"
   (SeongJae Park)

   Extend DAMOS quotas goal auto-tuning to support multiple tuning
   algorithms that users can select

 - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao)

   Fix the khugpaged sysfs handling so we no longer spam the logs with
   reams of junk when starting/stopping khugepaged

 - "mm: improve map count checks" (Lorenzo Stoakes)

   Provide some cleanups and slight fixes in the mremap, mmap and vma
   code

 - "mm/damon: support addr_unit on default monitoring targets for
   modules" (SeongJae Park)

   Extend the use of DAMON core's addr_unit tunable

 - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache)

   Cleanups to khugepaged and is a base for Nico's planned khugepaged
   mTHP support

 - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand)

   Code movement and cleanups in the memhotplug and sparsemem code

 - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup
   CONFIG_MIGRATION" (David Hildenbrand)

   Rationalize some memhotplug Kconfig support

 - "change young flag check functions to return bool" (Baolin Wang)

   Cleanups to change all young flag check functions to return bool

 - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh
   Law and SeongJae Park)

   Fix a few potential DAMON bugs

 - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo
   Stoakes)

   Convert a lot of the existing use of the legacy vm_flags_t data type
   to the new vma_flags_t type which replaces it. Mainly in the vma
   code.

 - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes)

   Expand the mmap_prepare functionality, which is intended to replace
   the deprecated f_op->mmap hook which has been the source of bugs and
   security issues for some time. Cleanups, documentation, extension of
   mmap_prepare into filesystem drivers

 - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes)

   Simplify and clean up zap_huge_pmd(). Additional cleanups around
   vm_normal_folio_pmd() and the softleaf functionality are performed.

* tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm: fix deferred split queue races during migration
  mm/khugepaged: fix issue with tracking lock
  mm/huge_memory: add and use has_deposited_pgtable()
  mm/huge_memory: add and use normal_or_softleaf_folio_pmd()
  mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio()
  mm/huge_memory: separate out the folio part of zap_huge_pmd()
  mm/huge_memory: use mm instead of tlb->mm
  mm/huge_memory: remove unnecessary sanity checks
  mm/huge_memory: deduplicate zap deposited table call
  mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE()
  mm/huge_memory: add a common exit path to zap_huge_pmd()
  mm/huge_memory: handle buggy PMD entry in zap_huge_pmd()
  mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc
  mm/huge: avoid big else branch in zap_huge_pmd()
  mm/huge_memory: simplify vma_is_specal_huge()
  mm: on remap assert that input range within the proposed VMA
  mm: add mmap_action_map_kernel_pages[_full]()
  uio: replace deprecated mmap hook with mmap_prepare in uio_info
  drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare
  mm: allow handling of stacked mmap_prepare hooks in more drivers
  ...
2026-04-15 12:59:16 -07:00