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2025-12-09Merge tag 'hyperv-next-signed-20251207' of ↵Linus Torvalds1-43/+20
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Enhancements to Linux as the root partition for Microsoft Hypervisor: - Support a new mode called L1VH, which allows Linux to drive the hypervisor running the Azure Host directly - Support for MSHV crash dump collection - Allow Linux's memory management subsystem to better manage guest memory regions - Fix issues that prevented a clean shutdown of the whole system on bare metal and nested configurations - ARM64 support for the MSHV driver - Various other bug fixes and cleanups - Add support for Confidential VMBus for Linux guest on Hyper-V - Secure AVIC support for Linux guests on Hyper-V - Add the mshv_vtl driver to allow Linux to run as the secure kernel in a higher virtual trust level for Hyper-V * tag 'hyperv-next-signed-20251207' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (58 commits) mshv: Cleanly shutdown root partition with MSHV mshv: Use reboot notifier to configure sleep state mshv: Add definitions for MSHV sleep state configuration mshv: Add support for movable memory regions mshv: Add refcount and locking to mem regions mshv: Fix huge page handling in memory region traversal mshv: Move region management to mshv_regions.c mshv: Centralize guest memory region destruction mshv: Refactor and rename memory region handling functions mshv: adjust interrupt control structure for ARM64 Drivers: hv: use kmalloc_array() instead of kmalloc() mshv: Add ioctl for self targeted passthrough hvcalls Drivers: hv: Introduce mshv_vtl driver Drivers: hv: Export some symbols for mshv_vtl static_call: allow using STATIC_CALL_TRAMP_STR() from assembly mshv: Extend create partition ioctl to support cpu features mshv: Allow mappings that overlap in uaddr mshv: Fix create memory region overlap check mshv: add WQ_PERCPU to alloc_workqueue users Drivers: hv: Use kmalloc_array() instead of kmalloc() ...
2025-12-05Merge tag 'uml-for-linux-6.19-rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Johannes Berg: "Apart from the usual small churn, we have - initial SMP support (only kernel) - major vDSO cleanups (and fixes for 32-bit)" * tag 'uml-for-linux-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (33 commits) um: Disable KASAN_INLINE when STATIC_LINK is selected um: Don't rename vmap to kernel_vmap um: drivers: virtio: use string choices helper um: Always set up AT_HWCAP and AT_PLATFORM x86/um: Remove FIXADDR_USER_START and FIXADDR_USE_END um: Remove __access_ok_vsyscall() um: Remove redundant range check from __access_ok_vsyscall() um: Remove fixaddr_user_init() x86/um: Drop gate area handling x86/um: Do not inherit vDSO from host um: Split out default elf_aux_hwcap x86/um: Move ELF_PLATFORM fallback to x86-specific code um: Split out default elf_aux_platform um: Avoid circular dependency on asm-offsets in pgtable.h um: Enable SMP support on x86 asm-generic: percpu: Add assembly guard um: vdso: Remove getcpu support on x86 um: Add initial SMP support um: Define timers on a per-CPU basis um: Determine sleep based on need_resched() ...
2025-12-05Merge tag 'mm-stable-2025-12-03-21-26' of ↵Linus Torvalds3-13/+36
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki) Rework the vmalloc() code to support non-blocking allocations (GFP_ATOIC, GFP_NOWAIT) "ksm: fix exec/fork inheritance" (xu xin) Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not inherited across fork/exec "mm/zswap: misc cleanup of code and documentations" (SeongJae Park) Some light maintenance work on the zswap code "mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira) Enhance the /sys/kernel/debug/page_owner debug feature by adding unique identifiers to differentiate the various stack traces so that userspace monitoring tools can better match stack traces over time "mm/page_alloc: pcp->batch cleanups" (Joshua Hahn) Minor alterations to the page allocator's per-cpu-pages feature "Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra) Address a scalability issue in userfaultfd's UFFDIO_MOVE operation "kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov) "drivers/base/node: fold node register and unregister functions" (Donet Tom) Clean up the NUMA node handling code a little "mm: some optimizations for prot numa" (Kefeng Wang) Cleanups and small optimizations to the NUMA allocation hinting code "mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn) Address long lock hold times at boot on large machines. These were causing (harmless) softlockup warnings "optimize the logic for handling dirty file folios during reclaim" (Baolin Wang) Remove some now-unnecessary work from page reclaim "mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park) Enhance the DAMOS auto-tuning feature "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan) Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace configuration "expand mmap_prepare functionality, port more users" (Lorenzo Stoakes) Enhance the new(ish) file_operations.mmap_prepare() method and port additional callsites from the old ->mmap() over to ->mmap_prepare() "Fix stale IOTLB entries for kernel address space" (Lu Baolu) Fix a bug (and possible security issue on non-x86) in the IOMMU code. In some situations the IOMMU could be left hanging onto a stale kernel pagetable entry "mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang) Clean up and optimize the folio splitting code "mm, swap: misc cleanup and bugfix" (Kairui Song) Some cleanups and a minor fix in the swap discard code "mm/damon: misc documentation fixups" (SeongJae Park) "mm/damon: support pin-point targets removal" (SeongJae Park) Permit userspace to remove a specific monitoring target in the middle of the current targets list "mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo) A couple of cleanups related to mm header file inclusion "mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He) improve the selection of swap devices for NUMA machines "mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista) Change the memory block labels from macros to enums so they will appear in kernel debug info "ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes) Address an inefficiency when KSM unmerges an address range "mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park) Fix leaks and unhandled malloc() failures in DAMON userspace unit tests "some cleanups for pageout()" (Baolin Wang) Clean up a couple of minor things in the page scanner's writeback-for-eviction code "mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu) Move hugetlb's sysfs/sysctl handling code into a new file "introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes) Make the VMA guard regions available in /proc/pid/smaps and improves the mergeability of guarded VMAs "mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes) Reduce mmap lock contention for callers performing VMA guard region operations "vma_start_write_killable" (Matthew Wilcox) Start work on permitting applications to be killed when they are waiting on a read_lock on the VMA lock "mm/damon/tests: add more tests for online parameters commit" (SeongJae Park) Add additional userspace testing of DAMON's "commit" feature "mm/damon: misc cleanups" (SeongJae Park) "make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes) Address the possible loss of a VMA's VM_SOFTDIRTY flag when that VMA is merged with another "mm: support device-private THP" (Balbir Singh) Introduce support for Transparent Huge Page (THP) migration in zone device-private memory "Optimize folio split in memory failure" (Zi Yan) "mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang) Some more cleanups in the folio splitting code "mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes) Clean up our handling of pagetable leaf entries by introducing the concept of 'software leaf entries', of type softleaf_t "reparent the THP split queue" (Muchun Song) Reparent the THP split queue to its parent memcg. This is in preparation for addressing the long-standing "dying memcg" problem, wherein dead memcg's linger for too long, consuming memory resources "unify PMD scan results and remove redundant cleanup" (Wei Yang) A little cleanup in the hugepage collapse code "zram: introduce writeback bio batching" (Sergey Senozhatsky) Improve zram writeback efficiency by introducing batched bio writeback support "memcg: cleanup the memcg stats interfaces" (Shakeel Butt) Clean up our handling of the interrupt safety of some memcg stats "make vmalloc gfp flags usage more apparent" (Vishal Moola) Clean up vmalloc's handling of incoming GFP flags "mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang) Teach soft dirty and userfaultfd write protect tracking to use RISC-V's Svrsw60t59b extension "mm: swap: small fixes and comment cleanups" (Youngjun Park) Fix a small bug and clean up some of the swap code "initial work on making VMA flags a bitmap" (Lorenzo Stoakes) Start work on converting the vma struct's flags to a bitmap, so we stop running out of them, especially on 32-bit "mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park) Address a possible bug in the swap discard code and clean things up a little [ This merge also reverts commit ebb9aeb980e5 ("vfio/nvgrace-gpu: register device memory for poison handling") because it looks broken to me, I've asked for clarification - Linus ] * tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm: fix vma_start_write_killable() signal handling mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate mm/swapfile: fix list iteration when next node is removed during discard fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling mm/kfence: add reboot notifier to disable KFENCE on shutdown memcg: remove inc/dec_lruvec_kmem_state helpers selftests/mm/uffd: initialize char variable to Null mm: fix DEBUG_RODATA_TEST indentation in Kconfig mm: introduce VMA flags bitmap type tools/testing/vma: eliminate dependency on vma->__vm_flags mm: simplify and rename mm flags function for clarity mm: declare VMA flags by bit zram: fix a spelling mistake mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity mm/vmscan: skip increasing kswapd_failures when reclaim was boosted pagemap: update BUDDY flag documentation mm: swap: remove scan_swap_map_slots() references from comments mm: swap: change swap_alloc_slow() to void mm, swap: remove redundant comment for read_swap_cache_async mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational ...
2025-12-05Merge tag 'tracepoints-v6.19' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull unused tracepoints update from Steven Rostedt: "Detect unused tracepoints. If a tracepoint is defined but never used (TRACE_EVENT() created but no trace_<tracepoint>() called), it can take up to or more than 5K of memory each. This can add up as there are around a hundred unused tracepoints with various configs. That is 500K of wasted memory. Add a make build parameter of "UT=1" to have the build warn if an unused tracepoint is detected in the build. This allows detection of unused tracepoints to be upstream so that outreachy and the mentoring project can have new developers look for fixing them, without having these warnings suddenly show up when someone upgrades their kernel. When all known unused tracepoints are removed, then the "UT=1" build parameter can be removed and unused tracepoints will always warn. This will catch new unused tracepoints after the current ones have been removed. Summary: - Separate out elf functions from sorttable.c Move out the ELF parsing functions from sorttable.c so that the tracing tooling can use it. - Add a tracepoint verifier tool to the build process If "UT=1" is added to the kernel command line, any unused tracepoints will trigger a warning at build time. - Do not warn about unused tracepoints for tracepoints that are exported There are sever cases where a tracepoint is created by the kernel and used by modules. Since there's no easy way to detect if these are truly unused since the users are in modules, if a tracepoint is exported, assume it will eventually be used by a module. Note, there's not many exported tracepoints so this should not be a problem to ignore them. - Have building of modules also detect unused tracepoints Do not only check the main vmlinux for unused tracepoints, also check modules. If a module is defining a tracepoint it should be using it. - Add the tracepoint-update program to the ignore file The new tracepoint-update program needs to be ignored by git" * tag 'tracepoints-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: scripts: add tracepoint-update to the list of ignores files tracing: Add warnings for unused tracepoints for modules tracing: Allow tracepoint-update.c to work with modules tracepoint: Do not warn for unused event that is exported tracing: Add a tracepoint verification check at build time sorttable: Move ELF parsing into scripts/elf-parse.[ch]
2025-12-03Merge tag 'bpf-next-6.19' of ↵Linus Torvalds1-28/+32
git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Pull bpf updates from Alexei Starovoitov: - Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to test_progs runner (Alexis Lothoré) - Convert selftests/bpf/test_xsk to test_progs runner (Bastien Curutchet) - Replace bpf memory allocator with kmalloc_nolock() in bpf_local_storage (Amery Hung), and in bpf streams and range tree (Puranjay Mohan) - Introduce support for indirect jumps in BPF verifier and x86 JIT (Anton Protopopov) and arm64 JIT (Puranjay Mohan) - Remove runqslower bpf tool (Hoyeon Lee) - Fix corner cases in the verifier to close several syzbot reports (Eduard Zingerman, KaFai Wan) - Several improvements in deadlock detection in rqspinlock (Kumar Kartikeya Dwivedi) - Implement "jmp" mode for BPF trampoline and corresponding DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong) - Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul Chaignon) - Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel Borkmann) - Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko) - Optimize bpf_map_update_elem() for map-in-map types (Ritesh Oedayrajsingh Varma) - Introduce overwrite mode for BPF ring buffer (Xu Kuohai) * tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits) bpf: optimize bpf_map_update_elem() for map-in-map types bpf: make kprobe_multi_link_prog_run always_inline selftests/bpf: do not hardcode target rate in test_tc_edt BPF program selftests/bpf: remove test_tc_edt.sh selftests/bpf: integrate test_tc_edt into test_progs selftests/bpf: rename test_tc_edt.bpf.c section to expose program type selftests/bpf: Add success stats to rqspinlock stress test rqspinlock: Precede non-head waiter queueing with AA check rqspinlock: Disable spinning for trylock fallback rqspinlock: Use trylock fallback when per-CPU rqnode is busy rqspinlock: Perform AA checks immediately rqspinlock: Enclose lock/unlock within lock entry acquisitions bpf: Remove runqslower tool selftests/bpf: Remove usage of lsm/file_alloc_security in selftest bpf: Disable file_alloc_security hook bpf: check for insn arrays in check_ptr_alignment bpf: force BPF_F_RDONLY_PROG on insn array creation bpf: Fix exclusive map memory leak selftests/bpf: Make CS length configurable for rqspinlock stress test selftests/bpf: Add lock wait time stats to rqspinlock stress test ...
2025-12-02Merge tag 'core-rseq-2025-11-30' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull rseq updates from Thomas Gleixner: "A large overhaul of the restartable sequences and CID management: The recent enablement of RSEQ in glibc resulted in regressions which are caused by the related overhead. It turned out that the decision to invoke the exit to user work was not really a decision. More or less each context switch caused that. There is a long list of small issues which sums up nicely and results in a 3-4% regression in I/O benchmarks. The other detail which caused issues due to extra work in context switch and task migration is the CID (memory context ID) management. It also requires to use a task work to consolidate the CID space, which is executed in the context of an arbitrary task and results in sporadic uncontrolled exit latencies. The rewrite addresses this by: - Removing deprecated and long unsupported functionality - Moving the related data into dedicated data structures which are optimized for fast path processing. - Caching values so actual decisions can be made - Replacing the current implementation with a optimized inlined variant. - Separating fast and slow path for architectures which use the generic entry code, so that only fault and error handling goes into the TIF_NOTIFY_RESUME handler. - Rewriting the CID management so that it becomes mostly invisible in the context switch path. That moves the work of switching modes into the fork/exit path, which is a reasonable tradeoff. That work is only required when a process creates more threads than the cpuset it is allowed to run on or when enough threads exit after that. An artificial thread pool benchmarks which triggers this did not degrade, it actually improved significantly. The main effect in migration heavy scenarios is that runqueue lock held time and therefore contention goes down significantly" * tag 'core-rseq-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) sched/mmcid: Switch over to the new mechanism sched/mmcid: Implement deferred mode change irqwork: Move data struct to a types header sched/mmcid: Provide CID ownership mode fixup functions sched/mmcid: Provide new scheduler CID mechanism sched/mmcid: Introduce per task/CPU ownership infrastructure sched/mmcid: Serialize sched_mm_cid_fork()/exit() with a mutex sched/mmcid: Provide precomputed maximal value sched/mmcid: Move initialization out of line signal: Move MMCID exit out of sighand lock sched/mmcid: Convert mm CID mask to a bitmap cpumask: Cache num_possible_cpus() sched/mmcid: Use cpumask_weighted_or() cpumask: Introduce cpumask_weighted_or() sched/mmcid: Prevent pointless work in mm_update_cpus_allowed() sched/mmcid: Move scheduler code out of global header sched: Fixup whitespace damage sched/mmcid: Cacheline align MM CID storage sched/mmcid: Use proper data structures sched/mmcid: Revert the complex CID management ...
2025-12-01Merge tag 'core-bugs-2025-12-01' of ↵Linus Torvalds1-23/+57
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull bug handling infrastructure updates from Ingo Molnar: "Core updates: - Improve WARN(), which has vararg printf like arguments, to work with the x86 #UD based WARN-optimizing infrastructure by hiding the format in the bug_table and replacing this first argument with the address of the bug-table entry, while making the actual function that's called a UD1 instruction (Peter Zijlstra) - Introduce the CONFIG_DEBUG_BUGVERBOSE_DETAILED Kconfig switch (Ingo Molnar, s390 support by Heiko Carstens) Fixes and cleanups: - bugs/s390: Remove private WARN_ON() implementation (Heiko Carstens) - <asm/bugs.h>: Make i386 use GENERIC_BUG_RELATIVE_POINTERS (Peter Zijlstra)" * tag 'core-bugs-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86/bugs: Make i386 use GENERIC_BUG_RELATIVE_POINTERS x86/bug: Fix BUG_FORMAT vs KASLR x86_64/bug: Inline the UD1 x86/bug: Implement WARN_ONCE() x86_64/bug: Implement __WARN_printf() x86/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED x86/bug: Add BUG_FORMAT basics bug: Allow architectures to provide __WARN_printf() bug: Implement WARN_ON() using __WARN_FLAGS() bug: Add report_bug_entry() bug: Add BUG_FORMAT_ARGS infrastructure bug: Clean up CONFIG_GENERIC_BUG_RELATIVE_POINTERS bug: Add BUG_FORMAT infrastructure x86: Rework __bug_table helpers bugs/s390: Remove private WARN_ON() implementation bugs/core: Reorganize fields in the first line of WARNING output, add ->comm[] output bugs/sh: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output bugs/parisc: Concatenate 'cond_str' with '__FILE__' in __WARN_FLAGS(), to extend WARN_ON/BUG_ON output bugs/riscv: Concatenate 'cond_str' with '__FILE__' in __BUG_FLAGS(), to extend WARN_ON/BUG_ON output bugs/riscv: Pass in 'cond_str' to __BUG_FLAGS() ...
2025-12-01Merge tag 'objtool-core-2025-12-01' of ↵Linus Torvalds1-30/+46
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - klp-build livepatch module generation (Josh Poimboeuf) Introduce new objtool features and a klp-build script to generate livepatch modules using a source .patch as input. This builds on concepts from the longstanding out-of-tree kpatch project which began in 2012 and has been used for many years to generate livepatch modules for production kernels. However, this is a complete rewrite which incorporates hard-earned lessons from 12+ years of maintaining kpatch. Key improvements compared to kpatch-build: - Integrated with objtool: Leverages objtool's existing control-flow graph analysis to help detect changed functions. - Works on vmlinux.o: Supports late-linked objects, making it compatible with LTO, IBT, and similar. - Simplified code base: ~3k fewer lines of code. - Upstream: No more out-of-tree #ifdef hacks, far less cruft. - Cleaner internals: Vastly simplified logic for symbol/section/reloc inclusion and special section extraction. - Robust __LINE__ macro handling: Avoids false positive binary diffs caused by the __LINE__ macro by introducing a fix-patch-lines script which injects #line directives into the source .patch to preserve the original line numbers at compile time. - Disassemble code with libopcodes instead of running objdump (Alexandre Chartre) - Disassemble support (-d option to objtool) by Alexandre Chartre, which supports the decoding of various Linux kernel code generation specials such as alternatives: 17ef: sched_balance_find_dst_group+0x62f mov 0x34(%r9),%edx 17f3: sched_balance_find_dst_group+0x633 | <alternative.17f3> | X86_FEATURE_POPCNT 17f3: sched_balance_find_dst_group+0x633 | call 0x17f8 <__sw_hweight64> | popcnt %rdi,%rax 17f8: sched_balance_find_dst_group+0x638 cmp %eax,%edx ... jump table alternatives: 1895: sched_use_asym_prio+0x5 test $0x8,%ch 1898: sched_use_asym_prio+0x8 je 0x18a9 <sched_use_asym_prio+0x19> 189a: sched_use_asym_prio+0xa | <jump_table.189a> | JUMP 189a: sched_use_asym_prio+0xa | jmp 0x18ae <sched_use_asym_prio+0x1e> | nop2 189c: sched_use_asym_prio+0xc mov $0x1,%eax 18a1: sched_use_asym_prio+0x11 and $0x80,%ecx ... exception table alternatives: native_read_msr: 5b80: native_read_msr+0x0 mov %edi,%ecx 5b82: native_read_msr+0x2 | <ex_table.5b82> | EXCEPTION 5b82: native_read_msr+0x2 | rdmsr | resume at 0x5b84 <native_read_msr+0x4> 5b84: native_read_msr+0x4 shl $0x20,%rdx .... x86 feature flag decoding (also see the X86_FEATURE_POPCNT example in sched_balance_find_dst_group() above): 2faaf: start_thread_common.constprop.0+0x1f jne 0x2fba4 <start_thread_common.constprop.0+0x114> 2fab5: start_thread_common.constprop.0+0x25 | <alternative.2fab5> | X86_FEATURE_ALWAYS | X86_BUG_NULL_SEG 2fab5: start_thread_common.constprop.0+0x25 | jmp 0x2faba <.altinstr_aux+0x2f4> | jmp 0x4b0 <start_thread_common.constprop.0+0x3f> | nop5 2faba: start_thread_common.constprop.0+0x2a mov $0x2b,%eax ... NOP sequence shortening: 1048e2: snapshot_write_finalize+0xc2 je 0x104917 <snapshot_write_finalize+0xf7> 1048e4: snapshot_write_finalize+0xc4 nop6 1048ea: snapshot_write_finalize+0xca nop11 1048f5: snapshot_write_finalize+0xd5 nop11 104900: snapshot_write_finalize+0xe0 mov %rax,%rcx 104903: snapshot_write_finalize+0xe3 mov 0x10(%rdx),%rax ... and much more. - Function validation tracing support (Alexandre Chartre) - Various -ffunction-sections fixes (Josh Poimboeuf) - Clang AutoFDO (Automated Feedback-Directed Optimizations) support (Josh Poimboeuf) - Misc fixes and cleanups (Borislav Petkov, Chen Ni, Dylan Hatch, Ingo Molnar, John Wang, Josh Poimboeuf, Pankaj Raghav, Peter Zijlstra, Thorsten Blum) * tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) objtool: Fix segfault on unknown alternatives objtool: Build with disassembly can fail when including bdf.h objtool: Trim trailing NOPs in alternative objtool: Add wide output for disassembly objtool: Compact output for alternatives with one instruction objtool: Improve naming of group alternatives objtool: Add Function to get the name of a CPU feature objtool: Provide access to feature and flags of group alternatives objtool: Fix address references in alternatives objtool: Disassemble jump table alternatives objtool: Disassemble exception table alternatives objtool: Print addresses with alternative instructions objtool: Disassemble group alternatives objtool: Print headers for alternatives objtool: Preserve alternatives order objtool: Add the --disas=<function-pattern> action objtool: Do not validate IBT for .return_sites and .call_sites objtool: Improve tracing of alternative instructions objtool: Add functions to better name alternatives objtool: Identify the different types of alternatives ...
2025-12-01Merge tag 'vfs-6.19-rc1.misc' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Cheaper MAY_EXEC handling for path lookup. This elides MAY_WRITE permission checks during path lookup and adds the IOP_FASTPERM_MAY_EXEC flag so filesystems like btrfs can avoid expensive permission work. - Hide dentry_cache behind runtime const machinery. - Add German Maglione as virtiofs co-maintainer. Cleanups: - Tidy up and inline step_into() and walk_component() for improved code generation. - Re-enable IOCB_NOWAIT writes to files. This refactors file timestamp update logic, fixing a layering bypass in btrfs when updating timestamps on device files and improving FMODE_NOCMTIME handling in VFS now that nfsd started using it. - Path lookup optimizations extracting slowpaths into dedicated routines and adding branch prediction hints for mntput_no_expire(), fd_install(), lookup_slow(), and various other hot paths. - Enable clang's -fms-extensions flag, requiring a JFS rename to avoid conflicts. - Remove spurious exports in fs/file_attr.c. - Stop duplicating union pipe_index declaration. This depends on the shared kbuild branch that brings in -fms-extensions support which is merged into this branch. - Use MD5 library instead of crypto_shash in ecryptfs. - Use largest_zero_folio() in iomap_dio_zero(). - Replace simple_strtol/strtoul with kstrtoint/kstrtouint in init and initrd code. - Various typo fixes. Fixes: - Fix emergency sync for btrfs. Btrfs requires an explicit sync_fs() call with wait == 1 to commit super blocks. The emergency sync path never passed this, leaving btrfs data uncommitted during emergency sync. - Use local kmap in watch_queue's post_one_notification(). - Add hint prints in sb_set_blocksize() for LBS dependency on THP" * tag 'vfs-6.19-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits) MAINTAINERS: add German Maglione as virtiofs co-maintainer fs: inline step_into() and walk_component() fs: tidy up step_into() & friends before inlining orangefs: use inode_update_timestamps directly btrfs: fix the comment on btrfs_update_time btrfs: use vfs_utimes to update file timestamps fs: export vfs_utimes fs: lift the FMODE_NOCMTIME check into file_update_time_flags fs: refactor file timestamp update logic include/linux/fs.h: trivial fix: regualr -> regular fs/splice.c: trivial fix: pipes -> pipe's fs: mark lookup_slow() as noinline fs: add predicts based on nd->depth fs: move mntput_no_expire() slowpath into a dedicated routine fs: remove spurious exports in fs/file_attr.c watch_queue: Use local kmap in post_one_notification() fs: touch up predicts in path lookup fs: move fd_install() slowpath into a dedicated routine and provide commentary fs: hide dentry_cache behind runtime const machinery fs: touch predicts in do_dentry_open() ...
2025-11-29rqspinlock: Enclose lock/unlock within lock entry acquisitionsKumar Kartikeya Dwivedi1-28/+32
Ritesh reported that timeouts occurred frequently for rqspinlock despite reentrancy on the same lock on the same CPU in [0]. This patch closes one of the races leading to this behavior, and reduces the frequency of timeouts. We currently have a tiny window between the fast-path cmpxchg and the grabbing of the lock entry where an NMI could land, attempt the same lock that was just acquired, and end up timing out. This is not ideal. Instead, move the lock entry acquisition from the fast path to before the cmpxchg, and remove the grabbing of the lock entry in the slow path, assuming it was already taken by the fast path. The TAS fallback is invoked directly without being preceded by the typical fast path, therefore we must continue to grab the deadlock detection entry in that case. Case on lock leading to missed AA: cmpxchg lock A <NMI> ... rqspinlock acquisition of A ... timeout </NMI> grab_held_lock_entry(A) There is a similar case when unlocking the lock. If the NMI lands between the WRITE_ONCE and smp_store_release, it is possible that we end up in a situation where the NMI fails to diagnose the AA condition, leading to a timeout. Case on unlock leading to missed AA: WRITE_ONCE(rqh->locks[rqh->cnt - 1], NULL) <NMI> ... rqspinlock acquisition of A ... timeout </NMI> smp_store_release(A->locked, 0) The patch changes the order on unlock to smp_store_release() succeeded by WRITE_ONCE() of NULL. This avoids the missed AA detection described above, but may lead to a false positive if the NMI lands between these two statements, which is acceptable (and preferred over a timeout). The original intention of the reverse order on unlock was to prevent the following possible misdiagnosis of an ABBA scenario: grab entry A lock A grab entry B lock B unlock B smp_store_release(B->locked, 0) grab entry B lock B grab entry A lock A ! <detect ABBA> WRITE_ONCE(rqh->locks[rqh->cnt - 1], NULL) If the store release were is after the WRITE_ONCE, the other CPU would not observe B in the table of the CPU unlocking the lock B. However, since the threads are obviously participating in an ABBA deadlock, it is no longer appealing to use the order above since it may lead to a 250 ms timeout due to missed AA detection. [0]: https://lore.kernel.org/bpf/CAH6OuBTjG+N=+GGwcpOUbeDN563oz4iVcU3rbse68egp9wj9_A@mail.gmail.com Fixes: 0d80e7f951be ("rqspinlock: Choose trylock fallback for NMI waiters") Reported-by: Ritesh Oedayrajsingh Varma <ritesh@superluminal.eu> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20251128232802.1031906-2-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-11-24mm: userfaultfd: add pgtable_supports_uffd_wp()Chunyan Zhang1-0/+17
Some platforms can customize the PTE/PMD entry uffd-wp bit making it unavailable even if the architecture provides the resource. This patch adds a macro API pgtable_supports_uffd_wp() that allows architectures to define their specific implementations to check if the uffd-wp bit is available on which device the kernel is running. Also this patch is removing "ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP" and "ifdef CONFIG_PTE_MARKER_UFFD_WP" in favor of pgtable_supports_uffd_wp() and uffd_supports_wp_marker() checks respectively that default to IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) and "IS_ENABLED(CONFIG_HAVE_ARCH_USERFAULTFD_WP) && IS_ENABLED(CONFIG_PTE_MARKER_UFFD_WP)" if not overridden by the architecture, no change in behavior is expected. Link: https://lkml.kernel.org/r/20251113072806.795029-3-zhangchunyan@iscas.ac.cn Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Acked-by: David Hildenbrand <david@redhat.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Conor Dooley <conor.dooley@microchip.com> Cc: Conor Dooley <conor@kernel.org> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rob Herring <robh@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: correctly handle UFFD PTE markersLorenzo Stoakes1-8/+0
Patch series "mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries", v3. There's an established convention in the kernel that we treat leaf page tables (so far at the PTE, PMD level) as containing 'swap entries' should they be neither empty (i.e. p**_none() evaluating true) nor present (i.e. p**_present() evaluating true). However, at the same time we also have helper predicates - is_swap_pte(), is_swap_pmd() - which are inconsistently used. This is problematic, as it is logical to assume that should somebody wish to operate upon a page table swap entry they should first check to see if it is in fact one. It also implies that perhaps, in future, we might introduce a non-present, none page table entry that is not a swap entry. This series resolves this issue by systematically eliminating all use of the is_swap_pte() and is swap_pmd() predicates so we retain only the convention that should a leaf page table entry be neither none nor present it is a swap entry. We also have the further issue that 'swap entry' is unfortunately a really rather overloaded term and in fact refers to both entries for swap and for other information such as migration entries, page table markers, and device private entries. We therefore have the rather 'unique' concept of a 'non-swap' swap entry. This series therefore introduces the concept of 'software leaf entries', of type softleaf_t, to eliminate this confusion. A software leaf entry in this sense is any page table entry which is non-present, and represented by the softleaf_t type. That is - page table leaf entries which are software-controlled by the kernel. This includes 'none' or empty entries, which are simply represented by an zero leaf entry value. In order to maintain compatibility as we transition the kernel to this new type, we simply typedef swp_entry_t to softleaf_t. We introduce a number of predicates and helpers to interact with software leaf entries in include/linux/leafops.h which, as it imports swapops.h, can be treated as a drop-in replacement for swapops.h wherever leaf entry helpers are used. Since softleaf_from_[pte, pmd]() treats present entries as they were empty/none leaf entries, this allows for a great deal of simplification of code throughout the code base, which this series utilises a great deal. We additionally change from swap entry to software leaf entry handling where it makes sense to and eliminate functions from swapops.h where software leaf entries obviate the need for the functions. This patch (of 16): PTE markers were previously only concerned with UFFD-specific logic - that is, PTE entries with the UFFD WP marker set or those marked via UFFDIO_POISON. However since the introduction of guard markers in commit 7c53dfbdb024 ("mm: add PTE_MARKER_GUARD PTE marker"), this has no longer been the case. Issues have been avoided as guard regions are not permitted in conjunction with UFFD, but it still leaves very confusing logic in place, most notably the misleading and poorly named pte_none_mostly() and huge_pte_none_mostly(). This predicate returns true for PTE entries that ought to be treated as none, but only in certain circumstances, and on the assumption we are dealing with H/W poison markers or UFFD WP markers. This patch removes these functions and makes each invocation of these functions instead explicitly check what it needs to check. As part of this effort it introduces is_uffd_pte_marker() to explicitly determine if a marker in fact is used as part of UFFD or not. In the HMM logic we note that the only time we would need to check for a fault is in the case of a UFFD WP marker, otherwise we simply encounter a fault error (VM_FAULT_HWPOISON for H/W poisoned marker, VM_FAULT_SIGSEGV for a guard marker), so only check for the UFFD WP case. While we're here we also refactor code to make it easier to understand. [akpm@linux-foundation.org: fix comment typo, per Mike] Link: https://lkml.kernel.org/r/cover.1762812360.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/c38625fd9a1c1f1cf64ae8a248858e45b3dcdf11.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24x86/bug: Implement WARN_ONCE()Peter Zijlstra1-0/+2
Implement WARN_ONCE like WARN using BUGFLAG_ONCE. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115758.339309119@infradead.org
2025-11-24x86/bug: Use BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILEDPeter Zijlstra1-3/+5
Since we have an explicit format string, use it for the condition string instead of frobbing it in the file string. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115758.097401406@infradead.org
2025-11-21bug: Allow architectures to provide __WARN_printf()Peter Zijlstra1-15/+22
In addition to providing __WARN_FLAGS(), allow an architecture to also provide __WARN_printf(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115757.807154591@infradead.org
2025-11-21bug: Implement WARN_ON() using __WARN_FLAGS()Peter Zijlstra1-7/+21
This completes 3bc3c9c3ab6d ("bugs/core: Pass down the condition string of WARN_ON_ONCE(cond) warnings to __WARN_FLAGS()") and makes WARN_ON() and WARN_ON_ONCE() behaviour consistent. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115757.690999560@infradead.org
2025-11-21bug: Add BUG_FORMAT_ARGS infrastructurePeter Zijlstra1-0/+1
Add BUG_FORMAT_ARGS; when an architecture is able to provide a va_list given pt_regs, use this to print format arguments. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115757.457339417@infradead.org
2025-11-21bug: Clean up CONFIG_GENERIC_BUG_RELATIVE_POINTERSPeter Zijlstra1-14/+8
Three repeated CONFIG_GENERIC_BUG_RELATIVE_POINTERS #ifdefs right after one another yields unreadable code. Add a helper. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115757.341703850@infradead.org
2025-11-21bug: Add BUG_FORMAT infrastructurePeter Zijlstra1-0/+7
Add BUG_FORMAT; an architecture opt-in feature that allows adding the WARN_printf() format string to the bug_entry table. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251110115757.223371452@infradead.org
2025-11-21Merge branch 'objtool/core'Peter Zijlstra14-81/+189
Bring in the UDB and objtool data annotations to avoid conflicts while further extending the bug exceptions. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-11-21kbuild: Check for functions with ambiguous -ffunction-sections section namesJosh Poimboeuf1-1/+1
Commit 9c7dc1dd897a ("objtool: Warn on functions with ambiguous -ffunction-sections section names") only works for drivers which are compiled on architectures supported by objtool. Make a script to perform the same check for all architectures. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/a6a49644a34964f7e02f3a8ce43af03e72817180.1763669451.git.jpoimboe@kernel.org
2025-11-20mm: remove unnecessary __GFP_HIGHMEM in __p*d_alloc_one_*()Huacai Chen1-5/+1
__{pgd,p4d,pud,pmd,pte}_alloc_one_*() always allocate pages with GFP flag GFP_PGTABLE_KERNEL/GFP_PGTABLE_USER. These two macros are defined as follows: #define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) There is no __GFP_HIGHMEM in them, so we needn't to clear __GFP_HIGHMEM explicitly. Link: https://lkml.kernel.org/r/20251109021817.346181-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20251107095536.3101371-1-chenhuacai@loongson.cn Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: actually mark kernel page table pagesDave Hansen1-0/+18
Now that the API is in place, mark kernel page table pages just after they are allocated. Unmark them just before they are freed. Note: Unconditionally clearing the 'kernel' marking (via ptdesc_clear_kernel()) would be functionally identical to what is here. But having the if() makes it logically clear that this function can be used for kernel and non-kernel page tables. Link: https://lkml.kernel.org/r/20251022082635.2462433-4-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-15arch/x86: mshyperv: Trap on access for some synthetic MSRsRoman Kisel1-0/+1
hv_set_non_nested_msr() has special handling for SINT MSRs when a paravisor is present. In addition to updating the MSR on the host, the mirror MSR in the paravisor is updated, including with the proxy bit. But with Confidential VMBus, the proxy bit must not be used, so add a special case to skip it. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15arch: hyperv: Get/set SynIC synth.registers via paravisorRoman Kisel1-40/+2
The existing Hyper-V wrappers for getting and setting MSRs are hv_get/set_msr(). Via hv_get/set_non_nested_msr(), they detect when running in a CoCo VM with a paravisor, and use the TDX or SNP guest-host communication protocol to bypass the paravisor and go directly to the host hypervisor for SynIC MSRs. The "set" function also implements the required special handling for the SINT MSRs. Provide functions that allow manipulating the SynIC registers through the paravisor. Move vmbus_signal_eom() to a more appropriate location (which also avoids breaking KVM). Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Alok Tiwari <alok.a.tiwari@oracle.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2025-11-15arch/x86: mshyperv: Discover Confidential VMBus availabilityRoman Kisel1-0/+2
Confidential VMBus requires enabling paravisor SynIC, and the x86_64 guest has to inspect the Virtualization Stack (VS) CPUID leaf to see if Confidential VMBus is available. If it is, the guest shall enable the paravisor SynIC. Read the relevant data from the VS CPUID leaf. Refactor the code to