Commit Graph

7677 Commits

Author SHA1 Message Date
Seongsu Park
3d443691ed mm/pkeys: remove unused tsk parameter from arch_set_user_pkey_access()
The tsk parameter in arch_set_user_pkey_access() is never used in the
function implementations across all architectures (arm64, powerpc, x86).

Link: https://lkml.kernel.org/r/20260219063506.545148-1-sgsu.park@samsung.com
Signed-off-by: Seongsu Park <sgsu.park@samsung.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05 13:52:57 -07:00
Sayali Patil
6bc9c0a905 powerpc: fix KUAP warning in VMX usercopy path
On powerpc with PREEMPT_FULL or PREEMPT_LAZY and function tracing enabled,
KUAP warnings can be triggered from the VMX usercopy path under memory
stress workloads.

KUAP requires that no subfunctions are called once userspace access has
been enabled. The existing VMX copy implementation violates this
requirement by invoking enter_vmx_usercopy() from the assembly path after
userspace access has already been enabled. If preemption occurs
in this window, the AMR state may not be preserved correctly,
leading to unexpected userspace access state and resulting in
KUAP warnings.

Fix this by restructuring the VMX usercopy flow so that VMX selection
and VMX state management are centralized in raw_copy_tofrom_user(),
which is invoked by the raw_copy_{to,from,in}_user() wrappers.

The new flow is:

  - raw_copy_{to,from,in}_user() calls raw_copy_tofrom_user()
  - raw_copy_tofrom_user() decides whether to use the VMX path
    based on size and CPU capability
  - Call enter_vmx_usercopy() before enabling userspace access
  - Enable userspace access as per the copy direction
    and perform the VMX copy
  - Disable userspace access as per the copy direction
  - Call exit_vmx_usercopy()
  - Fall back to the base copy routine if the VMX copy faults

With this change, the VMX assembly routines no longer perform VMX state
management or call helper functions; they only implement the
copy operations.
The previous feature-section based VMX selection inside
__copy_tofrom_user_power7() is removed, and a dedicated
__copy_tofrom_user_power7_vmx() entry point is introduced.

This ensures correct KUAP ordering, avoids subfunction calls
while KUAP is unlocked, and eliminates the warnings while preserving
the VMX fast path.

Fixes: de78a9c42a ("powerpc: Add a framework for Kernel Userspace Access Protection")
Reported-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Closes: https://lore.kernel.org/all/20260109064917.777587-2-sshegde@linux.ibm.com/
Suggested-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Co-developed-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Signed-off-by: Aboorva Devarajan <aboorvad@linux.ibm.com>
Signed-off-by: Sayali Patil <sayalip@linux.ibm.com>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260304122201.153049-1-sayalip@linux.ibm.com
2026-03-12 11:03:47 +05:30
Christophe Leroy (CS GROUP)
0ee95a1d45 powerpc/uaccess: Fix inline assembly for clang build on PPC32
Test robot reports the following error with clang-16.0.6:

   In file included from kernel/rseq.c:75:
   include/linux/rseq_entry.h:141:3: error: invalid operand for instruction
                   unsafe_get_user(offset, &ucs->post_commit_offset, efault);
                   ^
   include/linux/uaccess.h:608:2: note: expanded from macro 'unsafe_get_user'
           arch_unsafe_get_user(x, ptr, local_label);      \
           ^
   arch/powerpc/include/asm/uaccess.h:518:2: note: expanded from macro 'arch_unsafe_get_user'
           __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
           ^
   arch/powerpc/include/asm/uaccess.h:284:2: note: expanded from macro '__get_user_size_goto'
           __get_user_size_allowed(x, ptr, size, __gus_retval);    \
           ^
   arch/powerpc/include/asm/uaccess.h:275:10: note: expanded from macro '__get_user_size_allowed'
           case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
                   ^
   arch/powerpc/include/asm/uaccess.h:258:4: note: expanded from macro '__get_user_asm2'
                   "       li %1+1,0\n"                    \
                    ^
   <inline asm>:7:5: note: instantiated into assembly here
           li 31+1,0
              ^
   1 error generated.

On PPC32, for 64 bits vars a pair of registers is used. Usually the
lower register in the pair is the high part and the higher register is
the low part. GCC uses r3/r4 ... r11/r12 ... r14/r15 ... r30/r31

In older kernel code inline assembly was using %1 and %1+1 to represent
64 bits values. However here it looks like clang uses r31 as high part,
allthough r32 doesn't exist hence the error.

Allthoug %1+1 should work, most places now use %L1 instead of %1+1, so
let's do the same here.

With that change, the build doesn't fail anymore and a disassembly shows
clang uses r17/r18 and r31/r14 pair when GCC would have used r16/r17 and
r30/r31:

	Disassembly of section .fixup:

	00000000 <.fixup>:
	   0:	38 a0 ff f2 	li      r5,-14
	   4:	3a 20 00 00 	li      r17,0
	   8:	3a 40 00 00 	li      r18,0
	   c:	48 00 00 00 	b       c <.fixup+0xc>
				c: R_PPC_REL24	.text+0xbc
	  10:	38 a0 ff f2 	li      r5,-14
	  14:	3b e0 00 00 	li      r31,0
	  18:	39 c0 00 00 	li      r14,0
	  1c:	48 00 00 00 	b       1c <.fixup+0x1c>
				1c: R_PPC_REL24	.text+0x144

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602021825.otcItxGi-lkp@intel.com/
Fixes: c20beffeec ("powerpc/uaccess: Use flexible addressing with __put_user()/__get_user()")
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Acked-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/8ca3a657a650e497a96bfe7acde2f637dadab344.1770103646.git.chleroy@kernel.org
2026-03-04 11:06:02 +05:30
Christophe Leroy
b9e7e3ea60 powerpc/e500: Always use 64 bits PTE
Today there are two PTE formats for e500:
- The 64 bits format, used
 - On 64 bits kernel
 - On 32 bits kernel with 64 bits physical addresses
 - On 32 bits kernel with support of huge pages
- The 32 bits format, used in other cases

Maintaining two PTE formats means unnecessary maintenance burden
because every change needs to be implemented and tested for both
formats.

Remove the 32 bits PTE format. The memory usage increase due to
larger PTEs is minimal (approx. 0,1% of memory).

This also means that from now on huge pages are supported also
with 32 bits physical addresses.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/04a658209ea78dcc0f3dbde6b2c29cf1939adfe9.1767721208.git.chleroy@kernel.org
2026-03-04 11:05:06 +05:30
Linus Torvalds
4cff5c05e0 Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - "powerpc/64s: do not re-activate batched TLB flush" makes
   arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)

   It adds a generic enter/leave layer and switches architectures to use
   it. Various hacks were removed in the process.

 - "zram: introduce compressed data writeback" implements data
   compression for zram writeback (Richard Chang and Sergey Senozhatsky)

 - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
   page ranges for hugepages. Large improvements during demand faulting
   are demonstrated (David Hildenbrand)

 - "memcg cleanups" tidies up some memcg code (Chen Ridong)

 - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
   stats" improves DAMOS stat's provided information, deterministic
   control, and readability (SeongJae Park)

 - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
   issues in the hugetlb cgroup charging selftests (Li Wang)

 - "Fix va_high_addr_switch.sh test failure - again" addresses several
   issues in the va_high_addr_switch test (Chunyu Hu)

 - "mm/damon/tests/core-kunit: extend existing test scenarios" improves
   the KUnit test coverage for DAMON (Shu Anzai)

 - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
   glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
   transiently return -EAGAIN (Shivank Garg)

 - "arch, mm: consolidate hugetlb early reservation" reworks and
   consolidates a pile of straggly code related to reservation of
   hugetlb memory from bootmem and creation of CMA areas for hugetlb
   (Mike Rapoport)

 - "mm: clean up anon_vma implementation" cleans up the anon_vma
   implementation in various ways (Lorenzo Stoakes)

 - "tweaks for __alloc_pages_slowpath()" does a little streamlining of
   the page allocator's slowpath code (Vlastimil Babka)

 - "memcg: separate private and public ID namespaces" cleans up the
   memcg ID code and prevents the internal-only private IDs from being
   exposed to userspace (Shakeel Butt)

 - "mm: hugetlb: allocate frozen gigantic folio" cleans up the
   allocation of frozen folios and avoids some atomic refcount
   operations (Kefeng Wang)

 - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
   of memory betewwn the active and inactive LRUs and adds auto-tuning
   of the ratio-based quotas and of monitoring intervals (SeongJae Park)

 - "Support page table check on PowerPC" makes
   CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)

 - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
   nodes_and() and nodes_andnot() propagate the return values from the
   underlying bit operations, enabling some cleanup in calling code
   (Yury Norov)

 - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
   some DAMON internal interfaces (SeongJae Park)

 - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
   in khupaged and fixes a scan limit accounting issue (Shivank Garg)

 - "mm: balloon infrastructure cleanups" goes to town on the balloon
   infrastructure and its page migration function. Mainly cleanups, also
   some locking simplification (David Hildenbrand)

 - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
   additional tracepoints to the page reclaim code (Jiayuan Chen)

 - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
   part of Marco's kernel-wide migration from the legacy workqueue APIs
   over to the preferred unbound workqueues (Marco Crivellari)

 - "Various mm kselftests improvements/fixes" provides various unrelated
   improvements/fixes for the mm kselftests (Kevin Brodsky)

 - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
   folio allocation, mainly by avoiding unnecessary work in
   pfn_range_valid_contig() (Kefeng Wang)

 - "selftests/damon: improve leak detection and wss estimation
   reliability" improves the reliability of two of the DAMON selftests
   (SeongJae Park)

 - "mm/damon: cleanup kdamond, damon_call(), damos filter and
   DAMON_MIN_REGION" does some cleanup work in the core DAMON code
   (SeongJae Park)

 - "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
   performs maintenance work on the DAMON documentation (SeongJae Park)

 - "mm: add and use vma_assert_stabilised() helper" refactors and cleans
   up the core VMA code. The main aim here is to be able to use the mmap
   write lock's lockdep state to perform various assertions regarding
   the locking which the VMA code requires (Lorenzo Stoakes)

 - "mm, swap: swap table phase II: unify swapin use" removes some old
   swap code (swap cache bypassing and swap synchronization) which
   wasn't working very well. Various other cleanups and simplifications
   were made. The end result is a 20% speedup in one benchmark (Kairui
   Song)

 - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
   available on 64-bit alpha, loongarch, mips, parisc, and um. Various
   cleanups were performed along the way (Qi Zheng)

* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
  mm/memory: handle non-split locks correctly in zap_empty_pte_table()
  mm: move pte table reclaim code to memory.c
  mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
  mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
  mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
  zsmalloc: make common caches global
  mm: add SPDX id lines to some mm source files
  mm/zswap: use %pe to print error pointers
  mm/vmscan: use %pe to print error pointers
  mm/readahead: fix typo in comment
  mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
  mm: refactor vma_map_pages to use vm_insert_pages
  mm/damon: unify address range representation with damon_addr_range
  mm/cma: replace snprintf with strscpy in cma_new_area
  ...
2026-02-12 11:32:37 -08:00
Linus Torvalds
192c015940 Merge tag 'powerpc-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates for 7.0

 - Implement masked user access

 - Add bpf support for internal only per-CPU instructions and inline the
   bpf_get_smp_processor_id() and bpf_get_current_task() functions

 - Fix pSeries MSI-X allocation failure when quota is exceeded

 - Fix recursive pci_lock_rescan_remove locking in EEH event handling

 - Support tailcalls with subprogs & BPF exceptions on 64bit

 - Extend "trusted" keys to support the PowerVM Key Wrapping Module
   (PKWM)

Thanks to Abhishek Dubey, Christophe Leroy, Gaurav Batra, Guangshuo Li,
Jarkko Sakkinen, Mahesh Salgaonkar, Mimi Zohar, Miquel Sabaté Solà, Nam
Cao, Narayana Murty N, Nayna Jain, Nilay Shroff, Puranjay Mohan, Saket
Kumar Bhaskar, Sourabh Jain, Srish Srinivasan, and Venkat Rao Bagalkote.

* tag 'powerpc-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (27 commits)
  powerpc/pseries: plpks: export plpks_wrapping_is_supported
  docs: trusted-encryped: add PKWM as a new trust source
  keys/trusted_keys: establish PKWM as a trusted source
  pseries/plpks: add HCALLs for PowerVM Key Wrapping Module
  pseries/plpks: expose PowerVM wrapping features via the sysfs
  powerpc/pseries: move the PLPKS config inside its own sysfs directory
  pseries/plpks: fix kernel-doc comment inconsistencies
  powerpc/smp: Add check for kcalloc() failure in parse_thread_groups()
  powerpc: kgdb: Remove OUTBUFMAX constant
  powerpc64/bpf: Additional NVR handling for bpf_throw
  powerpc64/bpf: Support exceptions
  powerpc64/bpf: Add arch_bpf_stack_walk() for BPF JIT
  powerpc64/bpf: Avoid tailcall restore from trampoline
  powerpc64/bpf: Support tailcalls with subprogs
  powerpc64/bpf: Moving tail_call_cnt to bottom of frame
  powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling
  powerpc/pseries: Fix MSI-X allocation failure when quota is exceeded
  powerpc/iommu: bypass DMA APIs for coherent allocations for pre-mapped memory
  powerpc64/bpf: Inline bpf_get_smp_processor_id() and bpf_get_current_task/_btf()
  powerpc64/bpf: Support internal-only MOV instruction to resolve per-CPU addrs
  ...
2026-02-10 21:46:12 -08:00
Linus Torvalds
57cb845067 Merge tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 paravirt updates from Borislav Petkov:

 - A nice cleanup to the paravirt code containing a unification of the
   paravirt clock interface, taming the include hell by splitting the
   pv_ops structure and removing of a bunch of obsolete code (Juergen
   Gross)

* tag 'x86_paravirt_for_v7.0_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/paravirt: Use XOR r32,r32 to clear register in pv_vcpu_is_preempted()
  x86/paravirt: Remove trailing semicolons from alternative asm templates
  x86/pvlocks: Move paravirt spinlock functions into own header
  x86/paravirt: Specify pv_ops array in paravirt macros
  x86/paravirt: Allow pv-calls outside paravirt.h
  objtool: Allow multiple pv_ops arrays
  x86/xen: Drop xen_mmu_ops
  x86/xen: Drop xen_cpu_ops
  x86/xen: Drop xen_irq_ops
  x86/paravirt: Move pv_native_*() prototypes to paravirt.c
  x86/paravirt: Introduce new paravirt-base.h header
  x86/paravirt: Move paravirt_sched_clock() related code into tsc.c
  x86/paravirt: Use common code for paravirt_steal_clock()
  riscv/paravirt: Use common code for paravirt_steal_clock()
  loongarch/paravirt: Use common code for paravirt_steal_clock()
  arm64/paravirt: Use common code for paravirt_steal_clock()
  arm/paravirt: Use common code for paravirt_steal_clock()
  sched: Move clock related paravirt code to kernel/sched
  paravirt: Remove asm/paravirt_api_clock.h
  x86/paravirt: Move thunk macros to paravirt_types.h
  ...
2026-02-10 19:01:45 -08:00
Qi Zheng
086498aed3 mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
For architectures that define __HAVE_ARCH_TLB_REMOVE_TABLE, the page
tables at the pmd/pud level are generally not of struct ptdesc type, and
do not have pt_rcu_head member, thus these architectures cannot support
PT_RECLAIM.

In preparation for enabling PT_RECLAIM on more architectures, convert
__HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config,
so that we can make conditional judgments in Kconfig.

Link: https://lkml.kernel.org/r/5ebfa3d4b56e63c6906bda5eccaa9f7194d3a86b.1769515122.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Tested-by: Andreas Larsson <andreas@gaisler.com>	[sparc, UP&SMP]
Acked-by: Andreas Larsson <andreas@gaisler.com>		[sparc]
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-06 15:47:19 -08:00
Srish Srinivasan
133aa79e21 pseries/plpks: add HCALLs for PowerVM Key Wrapping Module
The hypervisor generated wrapping key is an AES-GCM-256 symmetric key which
is stored in a non-volatile, secure, and encrypted storage called the Power
LPAR Platform KeyStore. It has policy based protections that prevent it
from being read out or exposed to the user.

Implement H_PKS_GEN_KEY, H_PKS_WRAP_OBJECT, and H_PKS_UNWRAP_OBJECT HCALLs
to enable using the PowerVM Key Wrapping Module (PKWM) as a new trust
source for trusted keys. Disallow H_PKS_READ_OBJECT, H_PKS_SIGNED_UPDATE,
and H_PKS_WRITE_OBJECT for objects with the 'wrapping key' policy set.
Capture the availability status for the H_PKS_WRAP_OBJECT interface.

Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260127145228.48320-5-ssrish@linux.ibm.com
2026-01-30 09:27:26 +05:30
Srish Srinivasan
447eb1d5ef pseries/plpks: expose PowerVM wrapping features via the sysfs
Starting with Power11, PowerVM supports a new feature called "Key Wrapping"
that protects user secrets by wrapping them using a hypervisor generated
wrapping key. The status of this feature can be read by the
H_PKS_GET_CONFIG HCALL.

Expose the Power LPAR Platform KeyStore (PLPKS) wrapping features config
via the sysfs file /sys/firmware/plpks/config/wrapping_features.

Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260127145228.48320-4-ssrish@linux.ibm.com
2026-01-30 09:27:26 +05:30
Srish Srinivasan
40850c909f powerpc/pseries: move the PLPKS config inside its own sysfs directory
The /sys/firmware/secvar/config directory represents Power LPAR Platform
KeyStore (PLPKS) configuration properties such as max_object_size, signed_
update_algorithms, supported_policies, total_size, used_space, and version.
These attributes describe the PLPKS, and not the secure boot variables
(secvars).

Create /sys/firmware/plpks directory and move the PLPKS config inside this
directory. For backwards compatibility, create a soft link from the secvar
sysfs directory to this config and emit a warning stating that the older
sysfs path has been deprecated. Separate out the plpks specific
documentation from secvar.

Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260127145228.48320-3-ssrish@linux.ibm.com
2026-01-30 09:27:26 +05:30
Srish Srinivasan
88372ad4b0 pseries/plpks: fix kernel-doc comment inconsistencies
Fix issues with comments for all the applicable functions to be
consistent with kernel-doc format. Move them before the function
definition as opposed to the function prototype.

Signed-off-by: Srish Srinivasan <ssrish@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260127145228.48320-2-ssrish@linux.ibm.com
2026-01-30 09:27:26 +05:30
Miquel Sabaté Solà
4acc549e80 powerpc: kgdb: Remove OUTBUFMAX constant
This constant was introduced in commit 17ce452f7e ("kgdb, powerpc:
arch specific powerpc kgdb support"), but it is no longer used anywhere
in the source tree.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250915141808.146695-1-mikisabate@gmail.com
2026-01-29 09:06:01 +05:30
Rohan McLure
641d47d4c9 powerpc/mm: support page table check
On creation and clearing of a page table mapping, instrument such calls by
invoking page_table_check_pte_set and page_table_check_pte_clear
respectively.  These calls serve as a sanity check against illegal
mappings.

Enable ARCH_SUPPORTS_PAGE_TABLE_CHECK on powerpc, except when HUGETLB_PAGE
is enabled (powerpc has some weirdness in how it implements
set_huge_pte_at(), which may require some further work).

See also:

riscv support in commit 3fee229a8e ("riscv/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
arm64 in commit 42b2547137 ("arm64/mm: enable
ARCH_SUPPORTS_PAGE_TABLE_CHECK")
x86_64 in commit d283d422c6 ("x86: mm: add x86_64 support for page table
check")

[ajd@linux.ibm.com: rebase, add additional instrumentation, misc fixes]
Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-12-755bc151a50b@linux.ibm.com
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26 20:02:36 -08:00
Rohan McLure
2360f523a4 powerpc/mm: use set_pte_at_unchecked() for internal usages
In the new set_ptes() API, set_pte_at() (a special case of set_ptes()) is
intended to be instrumented by the page table check facility.  There are
however several other routines that constitute the API for setting page
table entries, including set_pmd_at() among others.  Such routines are
themselves implemented in terms of set_ptes_at().

A future patch providing support for page table checking on powerpc must
take care to avoid duplicate calls to page_table_check_p{te,md,ud}_set(). 
Allow for assignment of pte entries without instrumentation through the
set_pte_at_unchecked() routine introduced in this patch.

Cause API-facing routines that call set_pte_at() to instead call
set_pte_at_unchecked(), which will remain uninstrumented by page table
check.  set_ptes() is itself implemented by calls to __set_pte_at(), so
this eliminates redundant code.

[ajd@linux.ibm.com: don't change to unchecked for early boot/kernel mappings]
Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-11-755bc151a50b@linux.ibm.com
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26 20:02:36 -08:00
Rohan McLure
2f5e576598 powerpc/mm: implement *_user_accessible_page() for ptes
Page table checking depends on architectures providing an implementation
of p{te,md,ud}_user_accessible_page.  With refactorisations made on
powerpc/mm, the pte_access_permitted() and similar methods verify whether
a userland page is accessible with the required permissions.

Since page table checking is the only user of
p{te,md,ud}_user_accessible_page(), implement these for all platforms,
using some of the same preliminary checks taken by pte_access_permitted()
on that platform.

Since commit 8e9bd41e4c ("powerpc/nohash: Replace pte_user() by
pte_read()") pte_user() is no longer required to be present on all
platforms as it may be equivalent to or implied by pte_read().  Hence
implementations of pte_user_accessible_page() are specialised.

[ajd@linux.ibm.com: rebase and clean up]
Link: https://lkml.kernel.org/r/20251219-pgtable_check_v18rebase-v18-10-755bc151a50b@linux.ibm.com
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: "Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: Guo Weikang <guoweikang.kernel@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Cc: Thomas Huth <thuth@redhat.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26 20:02:35 -08:00
Mike Rapoport (Microsoft)
9fac145b6d mm, arch: consolidate hugetlb CMA reservation
Every architecture that supports hugetlb_cma command line parameter
reserves CMA areas for hugetlb during setup_arch().

This obfuscates the ordering of hugetlb CMA initialization with respect to
the rest initialization of the core MM.

Introduce arch_hugetlb_cma_order() callback to allow architectures report
the desired order-per-bit of CMA areas and provide a week implementation
of arch_hugetlb_cma_order() for architectures that don't support hugetlb
with CMA.

Use this callback in hugetlb_cma_reserve() instead if passing the order as
parameter and call hugetlb_cma_reserve() from mm_core_init_early() rather
than have it spread over architecture specific code.

Link: https://lkml.kernel.org/r/20260111082105.290734-28-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26 20:02:19 -08:00
Mike Rapoport (Microsoft)
4267739cab arch, mm: consolidate initialization of SPARSE memory model
Every architecture calls sparse_init() during setup_arch() although the
data structures created by sparse_init() are not used until the
initialization of the core MM.

Beside the code duplication, calling sparse_init() from architecture
specific code causes ordering differences of vmemmap and HVO
initialization on different architectures.

Move the call to sparse_init() from architecture specific code to
free_area_init() to ensure that vmemmap and HVO initialization order is
always the same.

Link: https://lkml.kernel.org/r/20260111082105.290734-25-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26 20:02:18 -08:00
David Hildenbrand
8e38607aa4 treewide: provide a generic clear_user_page() variant
Patch series "mm: folio_zero_user: clear page ranges", v11.

This series adds clearing of contiguous page ranges for hugepages.

The series improves on the current discontiguous clearing approach in two
ways:

  - clear pages in a contiguous fashion.
  - use batched clearing via clear_pages() wherever exposed.

The first is useful because it allows us to make much better use of
hardware prefetchers.

The second, enables advertising the real extent to the processor.  Where
specific instructions support it (ex.  string instructions on x86; "mops"
on arm64 etc), a processor can optimize based on this because, instead of
seeing a sequence of 8-byte stores, or a sequence of 4KB pages, it sees a
larger unit being operated on.

For instance, AMD Zen uarchs (for extents larger than LLC-size) switch to
a mode where they start eliding cacheline allocation.  This is helpful not
just because it results in higher bandwidth, but also because now the
cache is not evicting useful cachelines and replacing them with zeroes.

Demand faulting a 64GB region shows performance improvement:

 $ perf bench mem mmap -p $pg-sz -f demand -s 64GB -l 5

                       baseline              +series
                   (GBps +- %stdev)      (GBps +- %stdev)

   pg-sz=2MB       11.76 +- 1.10%        25.34 +- 1.18% [*]   +115.47%  	preempt=*

   pg-sz=1GB       24.85 +- 2.41%        39.22 +- 2.32%       + 57.82%  	preempt=none|voluntary
   pg-sz=1GB         (similar)           52.73 +- 0.20% [#]   +112.19%  	preempt=full|lazy

 [*] This improvement is because switching to sequential clearing
  allows the hardware prefetchers to do a much better job.

 [#] For pg-sz=1GB a large part of the improvement is because of the
  cacheline elision mentioned above. preempt=full|lazy improves upon
  that because, not needing explicit invocations of cond_resched() to
  ensure reasonable preemption latency, it can clear the full extent
  as a single unit. In comparison the maximum extent used for
  preempt=none|voluntary is PROCESS_PAGES_NON_PREEMPT_BATCH (32MB).

  When provided the full extent the processor forgoes allocating
  cachelines on this path almost entirely.

  (The hope is that eventually, in the fullness of time, the lazy
   preemption model will be able to do the same job that none or
   voluntary models are used for, allowing us to do away with
   cond_resched().)

Raghavendra also tested previous version of the series on AMD Genoa and
sees similar improvement [1] with preempt=lazy.

  $ perf bench mem map -p $page-size -f populate -s 64GB -l 10

                    base               patched              change
   pg-sz=2MB       12.731939 GB/sec    26.304263 GB/sec     106.6%
   pg-sz=1GB       26.232423 GB/sec    61.174836 GB/sec     133.2%


This patch (of 8):

Let's drop all variants that effectively map to clear_page() and provide
it in a generic variant instead.

We'll use the macro clear_user_page to indicate whether an architecture
provides it's own variant.

Also, clear_user_page() is only called from the generic variant of
clear_user_highpage(), so define it only if the architecture does not
provide a clear_user_highpage().  And, for simplicity define it in
linux/highmem.h.

Note that for parisc, clear_page() and clear_user_page() map to
clear_page_asm(), so we can just get rid of the custom clear_user_page()
implementation.  There is a clear_user_page_asm() function on parisc, that
seems to be unused.  Not sure what's up with that.

Link: https://lkml.kernel.org/r/20260107072009.1615991-1-ankur.a.arora@oracle.com
Link: https://lkml.kernel.org/r/20260107072009.1615991-2-ankur.a.arora@oracle.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Co-developed-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ankur Arora <ankur.a.arora@oracle.com>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzessutek Wilk <konrad.wilk@oracle.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Li Zhe <lizhe.67@bytedance.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:39 -08:00
Kevin Brodsky
313a05a15a powerpc/mm: replace batch->active with is_lazy_mmu_mode_active()
A per-CPU batch struct is activated when entering lazy MMU mode; its
lifetime is the same as the lazy MMU section (it is deactivated when
leaving the mode).  Preemption is disabled in that interval to ensure that
the per-CPU reference remains valid.

The generic lazy_mmu layer now tracks whether a task is in lazy MMU mode. 
We can therefore use the generic helper is_lazy_mmu_mode_active() to tell
whether a batch struct is active instead of tracking it explicitly.

Link: https://lkml.kernel.org/r/20251215150323.2218608-12-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:34 -08:00
Kevin Brodsky
7303ecbfe4 mm: introduce CONFIG_ARCH_HAS_LAZY_MMU_MODE
Architectures currently opt in for implementing lazy_mmu helpers by
defining __HAVE_ARCH_ENTER_LAZY_MMU_MODE.

In preparation for introducing a generic lazy_mmu layer that will require
storage in task_struct, let's switch to a cleaner approach: instead of
defining a macro, select a CONFIG option.

This patch introduces CONFIG_ARCH_HAS_LAZY_MMU_MODE and has each arch
select it when it implements lazy_mmu helpers. 
__HAVE_ARCH_ENTER_LAZY_MMU_MODE is removed and <linux/pgtable.h> relies on
the new CONFIG instead.

On x86, lazy_mmu helpers are only implemented if PARAVIRT_XXL is selected.
This creates some complications in arch/x86/boot/, because a few files
manually undefine PARAVIRT* options.  As a result <asm/paravirt.h> does
not define the lazy_mmu helpers, but this breaks the build as
<linux/pgtable.h> only defines them if !CONFIG_ARCH_HAS_LAZY_MMU_MODE. 
There does not seem to be a clean way out of this - let's just undefine
that new CONFIG too.

Link: https://lkml.kernel.org/r/20251215150323.2218608-7-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>	[sparc]
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:33 -08:00
Kevin Brodsky
c3f0778ffe powerpc/mm: implement arch_flush_lazy_mmu_mode()
Upcoming changes to the lazy_mmu API will cause arch_flush_lazy_mmu_mode()
to be called when leaving a nested lazy_mmu section.

Move the relevant logic from arch_leave_lazy_mmu_mode() to
arch_flush_lazy_mmu_mode() and have the former call the latter.  The
radix_enabled() check is required in both as arch_flush_lazy_mmu_mode()
will be called directly from the generic layer in a subsequent patch.

Note: the additional this_cpu_ptr() and radix_enabled() calls on the
arch_leave_lazy_mmu_mode() path will be removed in a subsequent patch.

Link: https://lkml.kernel.org/r/20251215150323.2218608-4-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:32 -08:00
Alexander Gordeev
58852f24f9 powerpc/64s: do not re-activate batched TLB flush
Patch series "Nesting support for lazy MMU mode", v6.

When the lazy MMU mode was introduced eons ago, it wasn't made clear
whether such a sequence was legal:

	arch_enter_lazy_mmu_mode()
	...
		arch_enter_lazy_mmu_mode()
		...
		arch_leave_lazy_mmu_mode()
	...
	arch_leave_lazy_mmu_mode()

It seems fair to say that nested calls to
arch_{enter,leave}_lazy_mmu_mode() were not expected, and most
architectures never explicitly supported it.

Nesting does in fact occur in certain configurations, and avoiding it has
proved difficult.  This series therefore enables lazy_mmu sections to
nest, on all architectures.

Nesting is handled using a counter in task_struct (patch 8), like other
stateless APIs such as pagefault_{disable,enable}().  This is fully
handled in a new generic layer in <linux/pgtable.h>; the arch_* API
remains unchanged.  A new pair of calls, lazy_mmu_mode_{pause,resume}(),
is also introduced to allow functions that are called with the lazy MMU
mode enabled to temporarily pause it, regardless of nesting.

An arch now opts in to using the lazy MMU mode by selecting
CONFIG_ARCH_LAZY_MMU; this is more appropriate now that we have a generic
API, especially with state conditionally added to task_struct.


This patch (of 14):

Since commit b9ef323ea1 ("powerpc/64s: Disable preemption in hash lazy
mmu mode") a task can not be preempted while in lazy MMU mode.  Therefore,
the batch re-activation code is never called, so remove it.

Link: https://lkml.kernel.org/r/20251215150323.2218608-1-kevin.brodsky@arm.com
Link: https://lkml.kernel.org/r/20251215150323.2218608-2-kevin.brodsky@arm.com
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Juegren Gross <jgross@suse.com>
Cc: levi.yun <yeoreum.yun@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand (Red Hat) <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-20 19:24:32 -08:00
Thomas Weißschuh
759a1f9737 powerpc/vdso: Provide clock_getres_time64()
For consistency with __vdso_clock_gettime64() there should also be a
64-bit variant of clock_getres(). This will allow the extension of
CONFIG_COMPAT_32BIT_TIME to the vDSO and finally the removal of 32-bit
time types from the kernel and UAPI.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/20260114-vdso-powerpc-align-v1-1-acf09373d568@linutronix.de
2026-01-14 14:57:39 +01:00
Juergen Gross
e6b2aa6d40 sched: Move clock related paravirt code to kernel/sched
Paravirt clock related functions are available in multiple archs.

In order to share the common parts, move the common static keys
to kernel/sched/ and remove them from the arch specific files.

Make a common paravirt_steal_clock() implementation available in
kernel/sched/cputime.c, guarding it with a new config option
CONFIG_HAVE_PV_STEAL_CLOCK_GEN, which can be selected by an arch
in case it wants to use that common variant.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260105110520.21356-7-jgross@suse.com
2026-01-12 15:39:14 +01:00
Juergen Gross
68b10fd40d paravirt: Remove asm/paravirt_api_clock.h
All architectures supporting CONFIG_PARAVIRT share the same contents
of asm/paravirt_api_clock.h:

  #include <asm/paravirt.h>

So remove all incarnations of asm/paravirt_api_clock.h and remove the
only place where it is included, as there asm/paravirt.h is included
anyway.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> # powerpc, scheduler bits
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260105110520.21356-6-jgross@suse.com
2026-01-12 15:34:33 +01:00
Narayana Murty N
815a8d2feb powerpc/eeh: fix recursive pci_lock_rescan_remove locking in EEH event handling
The recent commit 1010b4c012 ("powerpc/eeh: Make EEH driver device
hotplug safe") restructured the EEH driver to improve synchronization
with the PCI hotplug layer.

However, it inadvertently moved pci_lock_rescan_remove() outside its
intended scope in eeh_handle_normal_event(), leading to broken PCI
error reporting and improper EEH event triggering. Specifically,
eeh_handle_normal_event() acquired pci_lock_rescan_remove() before
calling eeh_pe_bus_get(), but eeh_pe_bus_get() itself attempts to
acquire the same lock internally, causing nested locking and disrupting
normal EEH event handling paths.

This patch adds a boolean parameter do_lock to _eeh_pe_bus_get(),
with two public wrappers:
    eeh_pe_bus_get() with locking enabled.
    eeh_pe_bus_get_nolock() that skips locking.

Callers that already hold pci_lock_rescan_remove() now use
eeh_pe_bus_get_nolock() to avoid recursive lock acquisition.

Additionally, pci_lock_rescan_remove() calls are restored to the correct
position—after eeh_pe_bus_get() and immediately before iterating affected
PEs and devices. This ensures EEH-triggered PCI removes occur under proper
bus rescan locking without recursive lock contention.

The eeh_pe_loc_get() function has been split into two functions:
    eeh_pe_loc_get(struct eeh_pe *pe) which retrieves the loc for given PE.
    eeh_pe_loc_get_bus(struct pci_bus *bus) which retrieves the location
    code for given bus.

This resolves lockdep warnings such as:
<snip>
[   84.964298] [    T928] ============================================
[   84.964304] [    T928] WARNING: possible recursive locking detected
[   84.964311] [    T928] 6.18.0-rc3 #51 Not tainted
[   84.964315] [    T928] --------------------------------------------
[   84.964320] [    T928] eehd/928 is trying to acquire lock:
[   84.964324] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964342] [    T928]
                       but task is already holding lock:
[   84.964347] [    T928] c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964357] [    T928]
                       other info that might help us debug this:
[   84.964363] [    T928]  Possible unsafe locking scenario:

[   84.964367] [    T928]        CPU0
[   84.964370] [    T928]        ----
[   84.964373] [    T928]   lock(pci_rescan_remove_lock);
[   84.964378] [    T928]   lock(pci_rescan_remove_lock);
[   84.964383] [    T928]
                       *** DEADLOCK ***

[   84.964388] [    T928]  May be due to missing lock nesting notation

[   84.964393] [    T928] 1 lock held by eehd/928:
[   84.964397] [    T928]  #0: c000000003b29d58 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pci_lock_rescan_remove+0x28/0x40
[   84.964408] [    T928]
                       stack backtrace:
[   84.964414] [    T928] CPU: 2 UID: 0 PID: 928 Comm: eehd Not tainted 6.18.0-rc3 #51 VOLUNTARY
[   84.964417] [    T928] Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_022) hv:phyp pSeries
[   84.964419] [    T928] Call Trace:
[   84.964420] [    T928] [c0000011a7157990] [c000000001705de4] dump_stack_lvl+0xc8/0x130 (unreliable)
[   84.964424] [    T928] [c0000011a71579d0] [c0000000002f66e0] print_deadlock_bug+0x430/0x440
[   84.964428] [    T928] [c0000011a7157a70] [c0000000002fd0c0] __lock_acquire+0x1530/0x2d80
[   84.964431] [    T928] [c0000011a7157ba0] [c0000000002fea54] lock_acquire+0x144/0x410
[   84.964433] [    T928] [c0000011a7157cb0] [c0000011a7157cb0] __mutex_lock+0xf4/0x1050
[   84.964436] [    T928] [c0000011a7157e00] [c000000000de21d8] pci_lock_rescan_remove+0x28/0x40
[   84.964439] [    T928] [c0000011a7157e20] [c00000000004ed98] eeh_pe_bus_get+0x48/0xc0
[   84.964442] [    T928] [c0000011a7157e50] [c000000000050434] eeh_handle_normal_event+0x64/0xa60
[   84.964446] [    T928] [c0000011a7157f30] [c000000000051de8] eeh_event_handler+0xf8/0x190
[   84.964450] [    T928] [c0000011a7157f90] [c0000000002747ac] kthread+0x16c/0x180
[   84.964453] [    T928] [c0000011a7157fe0] [c00000000000ded8] start_kernel_thread+0x14/0x18
</snip>

Fixes: 1010b4c012 ("powerpc/eeh: Make EEH driver device hotplug safe")
Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20251210142559.8874-1-nnmlinux@linux.ibm.com
2026-01-08 17:56:53 +05:30
Christophe Leroy
861574d51b powerpc/uaccess: Implement masked user access
Masked user access avoids the address/size verification by access_ok().
Allthough its main purpose is to skip the speculation in the
verification of user address and size hence avoid the need of spec
mitigation, it also has the advantage of reducing the amount of
instructions required so it even benefits to platforms that don't
need speculation mitigation, especially when the size of the copy is
not know at build time.

So implement masked user access on powerpc. The only requirement is
to have memory gap that faults between the top user space and the
real start of kernel area.

On 64 bits platforms the address space is divided that way:

	0xffffffffffffffff	+------------------+
				|                  |
				|   kernel space   |
 		 		|                  |
	0xc000000000000000	+------------------+  <== PAGE_OFFSET
				|//////////////////|
				|//////////////////|
	0x8000000000000000	|//////////////////|
				|//////////////////|
				|//////////////////|
	0x0010000000000000	+------------------+  <== TASK_SIZE_MAX
				|                  |
				|    user space    |
				|                  |
	0x0000000000000000	+------------------+

Kernel is always above 0x8000000000000000 and user always
below, with a gap in-between. It leads to a 3 instructions sequence:

 150:	7c 69 fe 76 	sradi   r9,r3,63
 154:	79 29 00 40 	clrldi  r9,r9,1
 158:	7c 63 48 78 	andc    r3,r3,r9

This sequence leaves r3 unmodified when it is below 0x8000000000000000
and clamps it to 0x8000000000000000 if it is above.

On 32 bits it is more tricky. In theory user space can go up to
0xbfffffff while kernel will usually start at 0xc0000000. So a gap
needs to be added in-between. Allthough in theory a single 4k page
would suffice, it is easier and more efficient to enforce a 128k gap
below kernel, as it simplifies the masking.

e500 has the isel instruction which allows selecting one value or
the other without branch and that instruction is not speculative, so
use it. Allthough GCC usually generates code using that instruction,
it is safer to use inline assembly to be sure. The result is:

  14:	3d 20 bf fe 	lis     r9,-16386
  18:	7c 03 48 40 	cmplw   r3,r9
  1c:	7c 69 18 5e 	iselgt  r3,r9,r3

On other ones, when kernel space is over 0x80000000 and user space
is below, the logic in mask_user_address_simple() leads to a
3 instruction sequence:

  64:	7c 69 fe 70 	srawi   r9,r3,31
  68:	55 29 00 7e 	clrlwi  r9,r9,1
  6c:	7c 63 48 78 	andc    r3,r3,r9

This is the default on powerpc 8xx.

When the limit between user space and kernel space is not 0x80000000,
mask_user_address_32() is used and a 6 instructions sequence is
generated:

  24:	54 69 7c 7e 	srwi    r9,r3,17
  28:	21 29 57 ff 	subfic  r9,r9,22527
  2c:	7d 29 fe 70 	srawi   r9,r9,31
  30:	75 2a b0 00 	andis.  r10,r9,45056
  34:	7c 63 48 78 	andc    r3,r3,r9
  38:	7c 63 53 78 	or      r3,r3,r10

The constraint is that TASK_SIZE be aligned to 128K in order to get
the most optimal number of instructions.

When CONFIG_PPC_BARRIER_NOSPEC is not defined, fallback on the
test-based masking as it is quicker than the 6 instructions sequence
but not quicker than the 3 instructions sequences above.

As an exemple, allthough barrier_nospec() voids on the 8xx, this
change has the following impact on strncpy_from_user(): the length of
the function is reduced from 488 to 340 bytes:

Start of the function with the patch:

00000000 <strncpy_from_user>:
   0:	7c ab 2b 79 	mr.     r11,r5
   4:	40 81 01 40 	ble     144 <strncpy_from_user+0x144>
   8:	7c 89 fe 70 	srawi   r9,r4,31
   c:	55 29 00 7e 	clrlwi  r9,r9,1
  10:	7c 84 48 78 	andc    r4,r4,r9
  14:	3d 20 dc 00 	lis     r9,-9216
  18:	7d 3a c3 a6 	mtspr   794,r9
  1c:	2f 8b 00 03 	cmpwi   cr7,r11,3
  20:	40 9d 00 b4 	ble     cr7,d4 <strncpy_from_user+0xd4>
...

Start of the function without the patch:

00000000 <strncpy_from_user>:
   0:	7c a0 2b 79 	mr.     r0,r5
   4:	40 81 01 10 	ble     114 <strncpy_from_user+0x114>
   8:	2f 84 00 00 	cmpwi   cr7,r4,0
   c:	41 9c 01 30 	blt     cr7,13c <strncpy_from_user+0x13c>
  10:	3d 20 80 00 	lis     r9,-32768
  14:	7d 24 48 50 	subf    r9,r4,r9
  18:	7f 80 48 40 	cmplw   cr7,r0,r9
  1c:	7c 05 03 78 	mr      r5,r0
  20:	41 9d 01 00 	bgt     cr7,120 <strncpy_from_user+0x120>
  24:	3d 20 80 00 	lis     r9,-32768
  28:	7d 25 48 50 	subf    r9,r5,r9
  2c:	7f 84 48 40 	cmplw   cr7,r4,r9
  30:	38 e0 ff f2 	li      r7,-14
  34:	41 9d 00 e4 	bgt     cr7,118 <strncpy_from_user+0x118>
  38:	94 21 ff e0 	stwu    r1,-32(r1)
  3c:	3d 20 dc 00 	lis     r9,-9216
  40:	7d 3a c3 a6 	mtspr   794,r9
  44:	2b 85 00 03 	cmplwi  cr7,r5,3
  48:	40 9d 01 6c 	ble     cr7,1b4 <strncpy_from_user+0x1b4>
...
 118:	7c e3 3b 78 	mr      r3,r7
 11c:	4e 80 00 20 	blr
 120:	7d 25 4b 78 	mr      r5,r9
 124:	3d 20 80 00 	lis     r9,-32768
 128:	7d 25 48 50 	subf    r9,r5,r9
 12c:	7f 84 48 40 	cmplw   cr7,r4,r9
 130:	38 e0 ff f2 	li      r7,-14
 134:	41 bd ff e4 	bgt     cr7,118 <strncpy_from_user+0x118>
 138:	4b ff ff 00 	b       38 <strncpy_from_user+0x38>
 13c:	38 e0 ff f2 	li      r7,-14
 140:	4b ff ff d8 	b       118 <strncpy_from_user+0x118>
...

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/8f418183d9125cc0bf23922bc2ef2a1130d8b63a.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:05 +05:30
Christophe Leroy
370d841929 powerpc/32: Automatically adapt TASK_SIZE based on constraints
At the time being, TASK_SIZE can be customized by the user via Kconfig
but it is not possible to check all constraints in Kconfig. Impossible
setups are detected at compile time with BUILD_BUG() but that leads
to build failure when setting crazy values. It is not a problem on its
own because the user will usually either use the default value or set
a well thought value. However build robots generate crazy random
configs that lead to build failures, and build robots see it as a
regression every time a patch adds such a constraint.

So instead of failing the build when the custom TASK_SIZE is too
big, just adjust it to the maximum possible value matching the setup.

Several architectures already calculate TASK_SIZE based on other
parameters and options.

In order to do so, move MODULES_VADDR calculation into task_size_32.h
and ensure that:
- On book3s/32, userspace and module area have their own segments (256M)
- On 8xx, userspace has its own full PGDIR entries (4M)

Then TASK_SIZE is guaranteed to be correct so remove related
BUILD_BUG()s.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/6a2575420770d075cd090b5a316730a2ffafdee4.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:05 +05:30
Christophe Leroy
fb7903771c powerpc/32s: Fix segments setup when TASK_SIZE is not a multiple of 256M
For book3s/32 it is assumed that TASK_SIZE is a multiple of 256 Mbytes,
but Kconfig allows any value for TASK_SIZE.

In all relevant calculations, align TASK_SIZE to the upper 256 Mbytes
boundary.

Also use ASM_CONST() in the definition of TASK_SIZE to ensure it is
seen as an unsigned constant.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/8928d906079e156c59794c41e826a684eaaaebb4.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:04 +05:30
Christophe Leroy
704f430031 powerpc/uaccess: Refactor user_{read/write/}_access_begin()
user_read_access_begin() and user_write_access_begin() and
user_access_begin() are now very similar. Create a common
__user_access_begin() that takes direction as parameter.

In order to avoid a warning with the conditional call of
barrier_nospec() which is sometimes an empty macro, change it to a
do {} while (0).

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/2b4f9d4e521e0b56bf5cb239916b4a178c4d2007.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:04 +05:30
Christophe Leroy
5458989a0e powerpc/uaccess: Remove {allow/prevent}_{read/write/read_write}_{from/to/}_user()
The six following functions have become simple single-line fonctions
that do not have much added value anymore:
- allow_read_from_user()
- allow_write_to_user()
- allow_read_write_user()
- prevent_read_from_user()
- prevent_write_to_user()
- prevent_read_write_user()

Directly call allow_user_access() and prevent_user_access(), it doesn't
reduce the readability and it removes unnecessary middle functions.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/70971f0ba81eab742a120e5bfdeff6b42d08fd98.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:04 +05:30
Christophe Leroy
e3efbfbfaa powerpc/uaccess: Remove unused size and from parameters from allow_access_user()
Since commit 16132529ce ("powerpc/32s: Rework Kernel Userspace
Access Protection") the size parameter is unused on all platforms.

And the 'from' parameter has never been used.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/4552b00707923b71150ee47b925d6eaae1b03261.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:04 +05:30
Christophe Leroy
5fbc09eb0b powerpc/uaccess: Move barrier_nospec() out of allow_read_{from/write}_user()
Commit 74e19ef0ff ("uaccess: Add speculation barrier to
copy_from_user()") added a redundant barrier_nospec() in
copy_from_user(), because powerpc is already calling
barrier_nospec() in allow_read_from_user() and
allow_read_write_user(). But on other architectures that
call to barrier_nospec() was missing. So change powerpc
instead of reverting the above commit and having to fix
other architectures one by one. This is now possible
because barrier_nospec() has also been added in
copy_from_user_iter().

Move barrier_nospec() out of allow_read_from_user() and
allow_read_write_user(). This will also allow reuse of those
functions when implementing masked user access which doesn't
require barrier_nospec().

Don't add it back in raw_copy_from_user() as it is already called
by copy_from_user() and copy_from_user_iter().

Fixes: 74e19ef0ff ("uaccess: Add speculation barrier to copy_from_user()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/f29612105c5fcbc8ceb7303808ddc1a781f0f6b5.1766574657.git.chleroy@kernel.org
2026-01-07 09:31:04 +05:30
Christophe Leroy (CS GROUP)
608328ba5b powerpc/32: Restore disabling of interrupts at interrupt/syscall exit
Commit 2997876c4a ("powerpc/32: Restore clearing of MSR[RI] at
interrupt/syscall exit") delayed clearing of MSR[RI], but missed that
both MSR[RI] and MSR[EE] are cleared at the same time, so the commit
also delayed the disabling of interrupts, leading to unexpected
behaviour.

To fix that, mostly revert the blamed commit and restore the clearing
of MSR[RI] in interrupt_exit_kernel_prepare() instead. For 8xx it
implies adding a synchronising instruction after the mtspr in order to
make sure no instruction counter interrupt (used for perf events) will
fire just after clearing MSR[RI].

Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Closes: https://lore.kernel.org/all/4d0bd05d-6158-1323-3509-744d3fbe8fc7@xenosoft.de/
Reported-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/6b05eb1c-fdef-44e0-91a7-8286825e68f1@roeck-us.net/
Fixes: 2997876c4a ("powerpc/32: Restore clearing of MSR[RI] at interrupt/syscall exit")
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/585ea521b2be99d293b539bbfae148366cfb3687.1766146895.git.chleroy@kernel.org
2025-12-22 18:25:07 +05:30
Linus Torvalds
509d3f4584 Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:

 - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
   fixes a build issue and does some cleanup in ib/sys_info.c

 - "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
   enhances the 64-bit math code on behalf of a PWM driver and beefs up
   the test module for these library functions

 - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
   makes BPF symbol names, sizes, and line numbers available to the GDB
   debugger

 - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
   adds a sysctl which can be used to cause additional info dumping when
   the hung-task and lockup detectors fire

 - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
   adds a general base64 encoder/decoder to lib/ and migrates several
   users away from their private implementations

 - "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
   makes TCP a little faster

 - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
   reworks the KEXEC Handover interfaces in preparation for Live Update
   Orchestrator (LUO), and possibly for other future clients

 - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
   increases the flexibility of KEXEC Handover. Also preparation for LUO

 - "Live Update Orchestrator" (Pasha Tatashin)
   is a major new feature targeted at cloud environments. Quoting the
   cover letter:

      This series introduces the Live Update Orchestrator, a kernel
      subsystem designed to facilitate live kernel updates using a
      kexec-based reboot. This capability is critical for cloud
      environments, allowing hypervisors to be updated with minimal
      downtime for running virtual machines. LUO achieves this by
      preserving the state of selected resources, such as memory,
      devices and their dependencies, across the kernel transition.

      As a key feature, this series includes support for preserving
      memfd file descriptors, which allows critical in-memory data, such
      as guest RAM or any other large memory region, to be maintained in
      RAM across the kexec reboot.

   Mike Rappaport merits a mention here, for his extensive review and
   testing work.

 - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
   moves the kexec and kdump sysfs entries from /sys/kernel/ to
   /sys/kernel/kexec/ and adds back-compatibility symlinks which can
   hopefully be removed one day

 - "kho: fixes for vmalloc restoration" (Mike Rapoport)
   fixes a BUG which was being hit during KHO restoration of vmalloc()
   regions

* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
  calibrate: update header inclusion
  Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
  vmcoreinfo: track and log recoverable hardware errors
  kho: fix restoring of contiguous ranges of order-0 pages
  kho: kho_restore_vmalloc: fix initialization of pages array
  MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
  init: replace simple_strtoul with kstrtoul to improve lpj_setup
  KHO: fix boot failure due to kmemleak access to non-PRESENT pages
  Documentation/ABI: new kexec and kdump sysfs interface
  Documentation/ABI: mark old kexec sysfs deprecated
  kexec: move sysfs entries to /sys/kernel/kexec
  test_kho: always print restore status
  kho: free chunks using free_page() instead of kfree()
  selftests/liveupdate: add kexec test for multiple and empty sessions
  selftests/liveupdate: add simple kexec-based selftest for LUO
  selftests/liveupdate: add userspace API selftests
  docs: add documentation for memfd preservation via LUO
  mm: memfd_luo: allow preserving memfd
  liveupdate: luo_file: add private argument to store runtime state
  mm: shmem: export some functions to internal.h
  ...
2025-12-06 14:01:20 -08:00
Linus Torvalds
a7405aa92f Merge tag 'dma-mapping-6.19-2025-12-05' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping updates from Marek Szyprowski:

 - More DMA mapping API refactoring to physical addresses as the primary
   interface instead of page+offset parameters.

   This time dma_map_ops callbacks are converted to physical addresses,
   what in turn results also in some simplification of architecture
   specific code (Leon Romanovsky and Jason Gunthorpe)

 - Clarify that dma_map_benchmark is not a kernel self-test, but
   standalone tool (Qinxin Xia)

* tag 'dma-mapping-6.19-2025-12-05' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  dma-mapping: remove unused map_page callback
  xen: swiotlb: Convert mapping routine to rely on physical address
  x86: Use physical address for DMA mapping
  sparc: Use physical address DMA mapping
  powerpc: Convert to physical address DMA mapping
  parisc: Convert DMA map_page to map_phys interface
  MIPS/jazzdma: Provide physical address directly
  alpha: Convert mapping routine to rely on physical address
  dma-mapping: remove unused mapping resource callbacks
  xen: swiotlb: Switch to physical address mapping callbacks
  ARM: dma-mapping: Switch to physical address mapping callbacks
  ARM: dma-mapping: Reduce struct page exposure in arch_sync_dma*()
  dma-mapping: convert dummy ops to physical address mapping
  dma-mapping: prepare dma_map_ops to conversion to physical address
  tools/dma: move dma_map_benchmark from selftests to tools/dma
2025-12-06 09:25:05 -08:00
Linus Torvalds
ad952db4a8 Merge tag 'powerpc-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:

 - Restore clearing of MSR[RI] at interrupt/syscall exit on 32-bit

 - Fix unpaired stwcx on interrupt exit on 32-bit

 - Fix race condition leading to double list-add in
   mac_hid_toggle_emumouse()

 - Fix mprotect on book3s 32-bit

 - Fix SLB multihit issue during SLB preload with 64-bit hash MMU

 - Add support for crashkernel CMA reservation

 - Add die_id and die_cpumask for Power10 & later to expose chip
   hemispheres

 - A series of minor fixes and improvements to the hash SLB code

Thanks to Antonio Alvarez Feijoo, Ben Collins, Bhaskar Chowdhury,
Christophe Leroy, Daniel Thompson, Dave Vasilevsky, Donet Tom,
J. Neuschäfer, Kunwu Chan, Long Li, Naresh Kamboju, Nathan Chancellor,
Ritesh Harjani (IBM), Shirisha G, Shrikanth Hegde, Sourabh Jain, Srikar
Dronamraju, Stephen Rothwell, Thomas Zimmermann, Venkat Rao Bagalkote,
and Vishal Chourasia.

* tag 'powerpc-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (32 commits)
  macintosh/via-pmu-backlight: Include <linux/fb.h> and <linux/of.h>
  powerpc/powermac: backlight: Include <linux/of.h>
  powerpc/64s/slb: Add no_slb_preload early cmdline param
  powerpc/64s/slb: Make preload_add return type as void
  powerpc/ptdump: Dump PXX level info for kernel_page_tables
  powerpc/64s/pgtable: Enable directMap counters in meminfo for Hash
  powerpc/64s/hash: Update directMap page counters for Hash
  powerpc/64s/hash: Hash hpt_order should be only available with Hash MMU
  powerpc/64s/hash: Improve hash mmu printk messages
  powerpc/64s/hash: Fix phys_addr_t printf format in htab_initialize()
  powerpc/64s/ptdump: Fix kernel_hash_pagetable dump for ISA v3.00 HPTE format
  powerpc/64s/hash: Restrict stress_hpt_struct memblock region to within RMA limit
  powerpc/64s/slb: Fix SLB multihit issue during SLB preload
  powerpc, mm: Fix mprotect on book3s 32-bit
  powerpc/smp: Expose die_id and die_cpumask
  powerpc/83xx: Add a null pointer check to mcu_gpiochip_add
  arch:powerpc:tools This file was missing shebang line, so added it
  kexec: Include kernel-end even without crashkernel
  powerpc: p2020: Rename wdt@ nodes to watchdog@
  powerpc: 86xx: Rename wdt@ nodes to watchdog@
  ...
2025-12-05 16:18:21 -08:00
Linus Torvalds
ce5cfb0fa2 Merge tag 'iommu-updates-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux
Pull iommu updates from Joerg Roedel:

 - Introduction of the generic IO page-table framework with support for
   Intel and AMD IOMMU formats from Jason.

   This has good potential for unifying more IO page-table
   implementations and making future enhancements more easy. But this
   also needed quite some fixes during development. All known issues
   have been fixed, but my feeling is that there is a higher potential
   than usual that more might be needed.

 - Intel VT-d updates:
    - Use right invalidation hint in qi_desc_iotlb()
    - Reduce the scope of INTEL_IOMMU_FLOPPY_WA

 - ARM-SMMU updates:
    - Qualcomm device-tree binding updates for Kaanapali and Glymur SoCs
      and a new clock for the TBU.
    - Fix error handling if level 1 CD table allocation fails.
    - Permit more than the architectural maximum number of SMRs for
      funky Qualcomm mis-implementations of SMMUv2.

 - Mediatek driver:
    - MT8189 iommu support

 - Move ARM IO-pgtable selftests to kunit

 - Device leak fixes for a couple of drivers

 - Random smaller fixes and improvements

* tag 'iommu-updates-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (81 commits)
  iommupt/vtd: Support mgaw's less than a 4 level walk for first stage
  iommupt/vtd: Allow VT-d to have a larger table top than the vasz requires
  powerpc/pseries/svm: Make mem_encrypt.h self contained
  genpt: Make GENERIC_PT invisible
  iommupt: Avoid a compiler bug with sw_bit
  iommu/arm-smmu-qcom: Enable use of all SMR groups when running bare-metal
  iommupt: Fix unlikely flows in increase_top()
  iommu/amd: Propagate the error code returned by __modify_irte_ga() in modify_irte_ga()
  MAINTAINERS: Update my email address
  iommu/arm-smmu-v3: Fix error check in arm_smmu_alloc_cd_tables
  dt-bindings: iommu: qcom_iommu: Allow 'tbu' clock
  iommu/vt-d: Restore previous domain::aperture_end calculation
  iommu/vt-d: Fix unused invalidation hint in qi_desc_iotlb
  iommu/vt-d: Set INTEL_IOMMU_FLOPPY_WA depend on BLK_DEV_FD
  iommu/tegra: fix device leak on probe_device()
  iommu/sun50i: fix device leak on of_xlate()
  iommu/omap: simplify probe_device() error handling
  iommu/omap: fix device leaks on probe_device()
  iommu/mediatek-v1: add missing larb count sanity check
  iommu/mediatek-v1: fix device leaks on probe()
  ...
2025-12-04 18:05:06 -08:00
Linus Torvalds
1dce50698a Merge tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scoped user access updates from Thomas Gleixner:
 "Scoped user mode access and related changes:

   - Implement the missing u64 user access function on ARM when
     CONFIG_CPU_SPECTRE=n.

     This makes it possible to access a 64bit value in generic code with
     [unsafe_]get_user(). All other architectures and ARM variants
     provide the relevant accessors already.

   - Ensure that ASM GOTO jump label usage in the user mode access
     helpers always goes through a local C scope label indirection
     inside the helpers.

     This is required because compilers are not supporting that a ASM
     GOTO target leaves a auto cleanup scope. GCC silently fails to emit
     the cleanup invocation and CLANG fails the build.

     [ Editor's note: gcc-16 will have fixed the code generation issue
       in commit f68fe3ddda4 ("eh: Invoke cleanups/destructors in asm
       goto jumps [PR122835]"). But we obviously have to deal with clang
       and older versions of gcc, so.. - Linus ]

     This provides generic wrapper macros and the conversion of affected
     architecture code to use them.

   - Scoped user mode access with auto cleanup

     Access to user mode memory can be required in hot code paths, but
     if it has to be done with user controlled pointers, the access is
     shielded with a speculation barrier, so that the CPU cannot
     speculate around the address range check. Those speculation
     barriers impact performance quite significantly.

     This cost can be avoided by "masking" the provided pointer so it is
     guaranteed to be in the valid user memory access range and
     otherwise to point to a guaranteed unpopulated address space. This
     has to be done without branches so it creates an address dependency
     for the access, which the CPU cannot speculate ahead.

     This results in repeating and error prone programming patterns:

       	    if (can_do_masked_user_access())
                      from = masked_user_read_access_begin((from));
              else if (!user_read_access_begin(from, sizeof(*from)))
                      return -EFAULT;
              unsafe_get_user(val, from, Efault);
              user_read_access_end();
              return 0;
        Efault:
              user_read_access_end();
              return -EFAULT;

      which can be replaced with scopes and automatic cleanup:

              scoped_user_read_access(from, Efault)
                      unsafe_get_user(val, from, Efault);
              return 0;
         Efault:
              return -EFAULT;

   - Convert code which implements the above pattern over to
     scope_user.*.access(). This also corrects a couple of imbalanced
     masked_*_begin() instances which are harmless on most
     architectures, but prevent PowerPC from implementing the masking
     optimization.

   - Add a missing speculation barrier in copy_from_user_iter()"

* tag 'core-uaccess-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lib/strn*,uaccess: Use masked_user_{read/write}_access_begin when required
  scm: Convert put_cmsg() to scoped user access
  iov_iter: Add missing speculation barrier to copy_from_user_iter()
  iov_iter: Convert copy_from_user_iter() to masked user access
  select: Convert to scoped user access
  x86/futex: Convert to scoped user access
  futex: Convert to get/put_user_inline()
  uaccess: Provide put/get_user_inline()
  uaccess: Provide scoped user access regions
  arm64: uaccess: Use unsafe wrappers for ASM GOTO
  s390/uaccess: Use unsafe wrappers for ASM GOTO
  riscv/uaccess: Use unsafe wrappers for ASM GOTO
  powerpc/uaccess: Use unsafe wrappers for ASM GOTO
  x86/uaccess: Use unsafe wrappers for ASM GOTO
  uaccess: Provide ASM GOTO safe wrappers for unsafe_*_user()
  ARM: uaccess: Implement missing __get_user_asm_dword()
2025-12-02 08:01:39 -08:00
Jason Gunthorpe
416d9a220e powerpc/pseries/svm: Make mem_encrypt.h self contained
Add the missing forward declarations and includes so it does not have
implicit dependencies. mem_encrypt.h is a public header imported by
drivers. Users should not have to guess what include files are needed.

Resolves a kbuild splat:

   In file included from drivers/iommu/generic_pt/fmt/iommu_amdv1.c:15:
   In file included from drivers/iommu/generic_pt/fmt/iommu_template.h:36:
   In file included from drivers/iommu/generic_pt/fmt/amdv1.h:23:
   In file included from include/linux/mem_encrypt.h:17:
>> arch/powerpc/include/asm/mem_encrypt.h:13:49: warning: declaration of 'struct device' will not be visible outside of this function [-Wvisibility]
      13 | static inline bool force_dma_unencrypted(struct device *dev)

Fixes: 879ced2bab ("iommupt: Add the AMD IOMMU v1 page table format")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511161358.rS5pSb3U-lkp@intel.com/
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2025-11-28 08:40:55 +01:00
Peter Zijlstra
2ace527183 Merge branch 'objtool/core'
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>
2025-11-21 11:21:20 +01:00
Donet Tom
00312419f0 powerpc/64s/slb: Fix SLB multihit issue during SLB preload
On systems using the hash MMU, there is a software SLB preload cache that
mirrors the entries loaded into the hardware SLB buffer. This preload
cache is subject to periodic eviction — typically after every 256 context
switches — to remove old entry.

To optimize performance, the kernel skips switch_mmu_context() in
switch_mm_irqs_off() when the prev and next mm_struct are the same.
However, on hash MMU systems, this can lead to inconsistencies between
the hardware SLB and the software preload cache.

If an SLB entry for a process is evicted from the software cache on one
CPU, and the same process later runs on another CPU without executing
switch_mmu_context(), the hardware SLB may retain stale entries. If the
kernel then attempts to reload that entry, it can trigger an SLB
multi-hit error.

The following timeline shows how stale SLB entries are created and can
cause a multi-hit error when a process moves between CPUs without a
MMU context switch.

CPU 0                                   CPU 1
-----                                    -----
Process P
exec                                    swapper/1
 load_elf_binary
  begin_new_exc
    activate_mm
     switch_mm_irqs_off
      switch_mmu_context
       switch_slb
       /*
        * This invalidates all
        * the entries in the HW
        * and setup the new HW
        * SLB entries as per the
        * preload cache.
        */
context_switch
sched_migrate_task migrates process P to cpu-1

Process swapper/0                       context switch (to process P)
(uses mm_struct of Process P)           switch_mm_irqs_off()
                                         switch_slb
                                           load_slb++
                                            /*
                                            * load_slb becomes 0 here
                                            * and we evict an entry from
                                            * the preload cache with
                                            * preload_age(). We still
                                            * keep HW SLB and preload
                                            * cache in sync, that is
                                            * because all HW SLB entries
                                            * anyways gets evicted in
                                            * switch_slb during SLBIA.
                                            * We then only add those
                                            * entries back in HW SLB,
                                            * which are currently
                                            * present in preload_cache
                                            * (after eviction).
                                            */
                                        load_elf_binary continues...
                                         setup_new_exec()
                                          slb_setup_new_exec()

                                        sched_switch event
                                        sched_migrate_task migrates
                                        process P to cpu-0

context_switch from swapper/0 to Process P
 switch_mm_irqs_off()
  /*
   * Since both prev and next mm struct are same we don't call
   * switch_mmu_context(). This will cause the HW SLB and SW preload
   * cache to go out of sync in preload_new_slb_context. Because there
   * was an SLB entry which was evicted from both HW and preload cache
   * on cpu-1. Now later in preload_new_slb_context(), when we will try
   * to add the same preload entry again, we will add this to the SW
   * preload cache and then will add it to the HW SLB. Since on cpu-0
   * this entry was never invalidated, hence adding this entry to the HW
   * SLB will cause a SLB multi-hit error.
   */
load_elf_binary continues...
 START_THREAD
  start_thread
   preload_new_slb_context
   /*
    * This tries to add a new EA to preload cache which was earlier
    * evicted from both cpu-1 HW SLB and preload cache. This caused the
    * HW SLB of cpu-0 to go out of sync with the SW preload cache. The
    * reason for this was, that when we context switched back on CPU-0,
    * we should have ideally called switch_mmu_context() which will
    * bring the HW SLB entries on CPU-0 in sync with SW preload cache
    * entries by setting up the mmu context properly. But we didn't do
    * that since the prev mm_struct running on cpu-0 was same as the
    * next mm_struct (which is true for swapper / kernel threads). So
    * now when we try to add this new entry into the HW SLB of cpu-0,
    * we hit a SLB multi-hit error.
    */

WARNING: CPU: 0 PID: 1810970 at arch/powerpc/mm/book3s64/slb.c:62
assert_slb_presence+0x2c/0x50(48 results) 02:47:29 [20157/42149]
Modules linked in:
CPU: 0 UID: 0 PID: 1810970 Comm: dd Not tainted 6.16.0-rc3-dirty #12
VOLUNTARY
Hardware name: IBM pSeries (emulated by qemu) POWER8 (architected)
0x4d0200 0xf000004 of:SLOF,HEAD hv:linux,kvm pSeries
NIP:  c00000000015426c LR: c0000000001543b4 CTR: 0000000000000000
REGS: c0000000497c77e0 TRAP: 0700   Not tainted  (6.16.0-rc3-dirty)
MSR:  8000000002823033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE>  CR: 28888482  XER: 00000000
CFAR: c0000000001543b0 IRQMASK: 3
<...>
NIP [c00000000015426c] assert_slb_presence+0x2c/0x50
LR [c0000000001543b4] slb_insert_entry+0x124/0x390
Call Trace:
  0x7fffceb5ffff (unreliable)
  preload_new_slb_context+0x100/0x1a0
  start_thread+0x26c/0x420
  load_elf_binary+0x1b04/0x1c40
  bprm_execve+0x358/0x680
  do_execveat_common+0x1f8/0x240
  sys_execve+0x58/0x70
  system_call_exception+0x114/0x300
  system_call_common+0x160/0x2c4

>From the above analysis, during early exec the hardware SLB is cleared,
and entries from the software preload cache are reloaded into hardware
by switch_slb. However, preload_new_slb_context and slb_setup_new_exec
also attempt to load some of the same entries, which can trigger a
multi-hit. In most cases, these additional preloads simply hit existing
entries and add nothing new. Removing these functions avoids redundant
preloads and eliminates the multi-hit issue. This patch removes these
two functions.

We tested process switching performance using the context_switch
benchmark on POWER9/hash, and observed no regression.

Without this patch: 129041 ops/sec
With this patch:    129341 ops/sec

We also measured SLB faults during boot, and the counts are essentially
the same with and without this patch.

SLB faults without this patch: 19727
SLB faults with this patch:    19786

Fixes: 5434ae7462 ("powerpc/64s/hash: Add a SLB preload cache")
cc: stable@vger.kernel.org
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/0ac694ae683494fe8cadbd911a1a5018d5d3c541.1761834163.git.ritesh.list@gmail.com
2025-11-18 12:35:52 +05:30
Dave Vasilevsky
78fc63ffa7 powerpc, mm: Fix mprotect on book3s 32-bit
On 32-bit book3s with hash-MMUs, tlb_flush() was a no-op. This was
unnoticed because all uses until recently were for unmaps, and thus
handled by __tlb_remove_tlb_entry().

After commit 4a18419f71 ("mm/mprotect: use mmu_gather") in kernel 5.19,
tlb_gather_mmu() started being used for mprotect as well. This caused
mprotect to simply not work on these machines:

  int *ptr = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
                  MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  *ptr = 1; // force HPTE to be created
  mprotect(ptr, 4096, PROT_READ);
  *ptr = 2; // should segfault, but succeeds

Fixed by making tlb_flush() actually flush TLB pages. This finally
agrees with the behaviour of boot3s64's tlb_flush().

Fixes: 4a18419f71 ("mm/mprotect: use mmu_gather")
Cc: stable@vger.kernel.org
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Dave Vasilevsky <dave@vasilevsky.ca>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20251116-vasi-mprotect-g3-v3-1-59a9bd33ba00@vasilevsky.ca
2025-11-18 12:34:17 +05:30
Srikar Dronamraju
fb2ff9fa72 powerpc/smp: Expose die_id and die_cpumask
>From Power10 processors onwards, each chip has 2 hemispheres. For LPARs
running on PowerVM Hypervisor, hypervisor determines the allocation of
CPU groups to each LPAR, resulting in two LPARs with the same number of
CPUs potentially having different numbers of CPUs from each hemisphere.
Additionally, it is not feasible to ascertain the hemisphere based
solely on the CPU number.

Users wishing to assign their workload to all CPUs, or a subset of CPUs
within a specific hemisphere, encounter difficulties in identifying the
cpumask. To address this, it is proposed to expose hemisphere
information as a die in sysfs. This aligns with other architectures
and facilitates the identification of CPUs within the same hemisphere.
Tools such as lstopo can also access this information.

Please note: The hypervisor reveals the locality of the CPUs to
hemispheres only in dedicated mode. Consequently, in systems where
hemisphere information is unavailable, such as shared LPARs, the
die_cpus information in sysfs will mirror package_cpus, with
die_id set to -1.

Without this change.
$ grep . /sys/devices/system/cpu/cpu16/topology/{die*,package*} 2>/dev/null
/sys/devices/system/cpu/cpu16/topology/package_cpus:000000,000000ff,ffff0000
/sys/devices/system/cpu/cpu16/topology/package_cpus_list:16-39

With this change.
$ grep . /sys/devices/system/cpu/cpu16/topology/{die*,package*} 2>/dev/null
/sys/devices/system/cpu/cpu16/topology/die_cpus:000000,00000000,00ff0000
/sys/devices/system/cpu/cpu16/topology/die_cpus_list:16-23
/sys/devices/system/cpu/cpu16/topology/die_id:2
/sys/devices/system/cpu/cpu16/topology/package_cpus:000000,000000ff,ffff0000
/sys/devices/system/cpu/cpu16/topology/package_cpus_list:16-39

snipped lstopo-no-graphics o/p
  Group0 L#0 (total=8747584KB)
    Package L#0 (total=3564096KB CPUModel="POWER10 (architected), altivec supported" CPURevision="2.0 (pvr 0080 0200)")
      NUMANode L#0 (P#0 local=3564096KB total=3564096KB)
      Die L#0 (P#0)
        Core L#0 (P#0)
<snipped>
    Package L#1 (total=5183488KB CPUModel="POWER10 (architected), altivec supported" CPURevision="2.0 (pvr 0080 0200)")
      NUMANode L#1 (P#1 local=5183488KB total=5183488KB)
      Die L#2 (P#2)
        Core L#2 (P#16)
          L3Cache L#4 (size=4096KB linesize=128 ways=16)
            L2Cache L#4 (size=1024KB linesize=128 ways=8)
              L1dCache L#4 (size=32KB linesize=128 ways=8)
                L1iCache L#4 (size=48KB linesize=128 ways=6)
                  PU L#16 (P#16)
                  PU L#17 (P#18)
                  PU L#18 (P#20)
                  PU L#19 (P#22)
          L3Cache L#5 (size=4096KB linesize=128 ways=16)
            L2Cache L#5 (size=1024KB linesize=128 ways=8)
              L1dCache L#5 (size=32KB linesize=128 ways=8)
                L1iCache L#5 (size=48KB linesize=128 ways=6)
                  PU L#20 (P#17)
                  PU L#21 (P#19)
                  PU L#22 (P#21)
                  PU L#23 (P#23)
      Die L#3 (P#3)
        Core L#3 (P#24)
          L3Cache L#6 (size=4096KB linesize=128 ways=16)
            L2Cache L#6 (size=1024KB linesize=128 ways=8)
              L1dCache L#6 (size=32KB linesize=128 ways=8)
                L1iCache L#6 (size=48KB linesize=128 ways=6)
                  PU L#24 (P#24)
                  PU L#25 (P#26)
                  PU L#26 (P#28)
                  PU L#27 (P#30)
          L3Cache L#7 (size=4096KB linesize=128 ways=16)
            L2Cache L#7 (size=1024KB linesize=128 ways=8)
              L1dCache L#7 (size=32KB linesize=128 ways=8)
                L1iCache L#7 (size=48KB linesize=128 ways=6)
                  PU L#28 (P#25)
                  PU L#29 (P#27)
                  PU L#30 (P#29)
                  PU L#31 (P#31)
        Core L#4 (P#32)
          L3Cache L#8 (size=4096KB linesize=128 ways=16)
            L2Cache L#8 (size=1024KB linesize=128 ways=8)
              L1dCache L#8 (size=32KB linesize=128 ways=8)
                L1iCache L#8 (size=48KB linesize=128 ways=6)
                  PU L#32 (P#32)
                  PU L#33 (P#34)
                  PU L#34 (P#36)
                  PU L#35 (P#38)
          L3Cache L#9 (size=4096KB linesize=128 ways=16)
            L2Cache L#9 (size=1024KB linesize=128 ways=8)
              L1dCache L#9 (size=32KB linesize=128 ways=8)
                L1iCache L#9 (size=48KB linesize=128 ways=6)
                  PU L#36 (P#33)
                  PU L#37 (P#35)
                  PU L#38 (P#37)
                  PU L#39 (P#39)
  Group0 L#1 (total=7736896KB)
    Package L#2 (total=5170880KB CPUModel="POWER10 (architected), altivec supported" CPURevision="2.0 (pvr 0080 0200)")
      NUMANode L#2 (P#2 local=5170880KB total=5170880KB)
      Die L#4 (P#4)
<snipped>

Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Srikar Dronamraju <srikar@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20251112074859.814087-1-srikar@linux.ibm.com
2025-11-14 11:12:56 +05:30
Sourabh Jain
adc15829fb crash: let architecture decide crash memory export to iomem_resource
With the generic crashkernel reservation, the kernel emits the following
warning on powerpc:

WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/mem.c:341 add_system_ram_resources+0xfc/0x180
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.17.0-auto-12607-g5472d60c129f #1 VOLUNTARY
Hardware name: IBM,9080-HEX Power11 (architected) 0x820200 0xf000007 of:IBM,FW1110.01 (NH1110_069) hv:phyp pSeries
NIP:  c00000000201de3c LR: c00000000201de34 CTR: 0000000000000000
REGS: c000000127cef8a0 TRAP: 0700   Not tainted (6.17.0-auto-12607-g5472d60c129f)
MSR:  8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 84000840  XER: 20040010
CFAR: c00000000017eed0 IRQMASK: 0
GPR00: c00000000201de34 c000000127cefb40 c0000000016a8100 0000000000000001
GPR04: c00000012005aa00 0000000020000000 c000000002b705c8 0000000000000000
GPR08: 000000007fffffff fffffffffffffff0 c000000002db8100 000000011fffffff
GPR12: c00000000201dd40 c000000002ff0000 c0000000000112bc 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 c0000000015a3808
GPR24: c00000000200468c c000000001699888 0000000000000106 c0000000020d1950
GPR28: c0000000014683f8 0000000081000200 c0000000015c1868 c000000002b9f710
NIP [c00000000201de3c] add_system_ram_resources+0xfc/0x180
LR [c00000000201de34] add_system_ram_resources+0xf4/0x180
Call Trace:
add_system_ram_resources+0xf4/0x180 (unreliable)
do_one_initcall+0x60/0x36c
do_initcalls+0x120/0x220
kernel_init_freeable+0x23c/0x390
kernel_init+0x34/0x26c
ret_from_kernel_user_thread+0x14/0x1c

This warning occurs due to a conflict between crashkernel and System RAM
iomem resources.

The generic crashkernel reservation adds the crashkernel memory range to
/proc/iomem during early initialization. Later, all memblock ranges are
added to /proc/iomem as System RAM. If the crashkernel region overlaps
with any memblock range, it causes a conflict while adding those memblock
regions as iomem resources, triggering the above warning. The conflicting
memblock regions are then omitted from /proc/iomem.

For example, if the following crashkernel region is added to /proc/iomem:
20000000-11fffffff : Crash kernel

then the following memblock regions System RAM regions fail to be inserted:
00000000-7fffffff : System RAM
80000000-257fffffff : System RAM

Fix this by not adding the crashkernel memory to /proc/iomem on powerpc.
Introduce an architecture hook to let each architecture decide whether to
export the crashkernel region to /proc/iomem.

For more info checkout commit c40dd2f766 ("powerpc: Add System RAM
to /proc/iomem") and commit bce074bdbc ("powerpc: insert System RAM
resource to prevent crashkernel conflict")

Note: Before switching to the generic crashkernel reservation, powerpc
never exported the crashkernel region to /proc/iomem.

Link: https://lkml.kernel.org/r/20251016142831.144515-1-sourabhjain@linux.ibm.com
Fixes: e3185ee438 ("powerpc/crash: use generic crashkernel reservation").
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/90937fe0-2e76-4c82-b27e-7b8a7fe3ac69@linux.ibm.com/
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Cc: Baoquan he <bhe@redhat.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-12 10:00:15 -08:00
Sourabh Jain
b4a96ab50f powerpc/kdump: Add support for crashkernel CMA reservation
Commit 35c18f2933 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e0 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation.

Extend crashkernel CMA reservation support to powerpc.

The following changes are made to enable CMA reservation on powerpc:

- Parse and obtain the CMA reservation size along with other crashkernel
  parameters
- Call reserve_crashkernel_cma() to allocate the CMA region for kdump
- Include the CMA-reserved ranges in the usable memory ranges for the
  kdump kernel to use.
- Exclude the CMA-reserved ranges from the crash kernel memory to
  prevent them from being exported through /proc/vmcore.

With the introduction of the CMA crashkernel regions,
crash_exclude_mem_range() needs to be called multiple times to exclude
both crashk_res and crashk_cma_ranges from the crash memory ranges. To
avoid repetitive logic for validating mem_ranges size and handling
reallocation when required, this functionality is moved to a new wrapper
function crash_exclude_mem_range_guarded().

To ensure proper CMA reservation, reserve_crashkernel_cma() is called
after pageblock_order is initialized.

Update kernel-parameters.txt to document CMA support for crashkernel on
powerpc architecture.

Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20251107080334.708028-1-sourabhjain@linux.ibm.com
2025-11-11 14:11:08 +05:30
Thomas Gleixner
5002dd5314 powerpc/uaccess: Use unsafe wrappers for ASM GOTO
ASM GOTO is miscompiled by GCC when it is used inside a auto cleanup scope:

bool foo(u32 __user *p, u32 val)
{
	scoped_guard(pagefault)
		unsafe_put_user(val, p, efault);
	return true;
efault:
	return false;
}

It ends up leaking the pagefault disable counter in the fault path. clang
at least fails the build.

Rename unsafe_*_user() to arch_unsafe_*_user() which makes the generic
uaccess header wrap it with a local label that makes both compilers emit
correct code. Same for the kernel_nofault() variants.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027083745.356628509@linutronix.de
2025-11-03 15:26:09 +01:00
Leon Romanovsky
a10d648d13 powerpc: Convert to physical address DMA mapping
Adapt PowerPC DMA to use physical addresses in order to prepare code
to removal .map_page and .unmap_page.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251015-remove-map-page-v5-10-3bbfe3a25cdf@kernel.org
2025-10-29 10:27:30 +01:00
Linus Torvalds
256e341706 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull x86 kvm updates from Paolo Bonzini:
 "Generic:

   - Rework almost all of KVM's exports to expose symbols only to KVM's
     x86 vendor modules (kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko

  x86:

   - Rework almost all of KVM x86's exports to expose symbols only to
     KVM's vendor modules, i.e. to kvm-{amd,intel}.ko

   - Add support for virtualizing Control-flow Enforcement Technology
     (CET) on Intel (Shadow Stacks and Indirect Branch Tracking) and AMD
     (Shadow Stacks).

     It is worth noting that while SHSTK and IBT can be enabled
     separately in CPUID, it is not really possible to virtualize them
     separately. Therefore, Intel processors will really allow both
     SHSTK and IBT under the hood if either is made visible in the
     guest's CPUID. The alternative would be to intercept
     XSAVES/XRSTORS, which is not feasible for performance reasons

   - Fix a variety of fuzzing WARNs all caused by checking L1 intercepts
     when completing userspace I/O. KVM has already committed to
     allowing L2 to to perform I/O at that point

   - Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 guests, as the
     MSR is supposed to exist for v2 PMUs

   - Allow Centaur CPU leaves (base 0xC000_0000) for Zhaoxin CPUs

   - Add support for the immediate forms of RDMSR and WRMSRNS, sans full
     emulator support (KVM should never need to emulate the MSRs outside
     of forced emulation and other contrived testing scenarios)

   - Clean up the MSR APIs in preparation for CET and FRED
     virtualization, as well as mediated vPMU support

   - Clean up a pile of PMU code in anticipation of adding support for
     mediated vPMUs

   - Reject in-kernel IOAPIC/PIT for TDX VMs, as KVM can't obtain EOI
     vmexits needed to faithfully emulate an I/O APIC for such guests

   - Many cleanups and minor fixes

   - Recover possible NX huge pages within the TDP MMU under read lock
     to reduce guest jitter when restoring NX huge pages

   - Return -EAGAIN during prefault if userspace concurrently
     deletes/moves the relevant memslot, to fix an issue where
     prefaulting could deadlock with the memslot update

  x86 (AMD):

   - Enable AVIC by default for Zen4+ if x2AVIC (and other prereqs) is
     supported

   - Require a minimum GHCB version of 2 when starting SEV-SNP guests
     via KVM_SEV_INIT2 so that invalid GHCB versions result in immediate
     errors instead of latent guest failures

   - Add support for SEV-SNP's CipherText Hiding, an opt-in feature that
     prevents unauthorized CPU accesses from reading the ciphertext of
     SNP guest private memory, e.g. to attempt an offline attack. This
     feature splits the shared SEV-ES/SEV-SNP ASID space into separate
     ranges for SEV-ES and SEV-SNP guests, therefore a new module
     parameter is needed to control the number of ASIDs that can be used
     for VMs with CipherText Hiding vs. how many can be used to run
     SEV-ES guests

   - Add support for Secure TSC for SEV-SNP guests, which prevents the
     untrusted host from tampering with the guest's TSC frequency, while
     still allowing the the VMM to configure the guest's TSC frequency
     prior to launch

   - Validate the XCR0 provided by the guest (via the GHCB) to avoid
     bugs resulting from bogus XCR0 values

   - Save an SEV guest's policy if and only if LAUNCH_START fully
     succeeds to avoid leaving behind stale state (thankfully not
     consumed in KVM)

   - Explicitly reject non-positive effective lengths during SNP's
     LAUNCH_UPDATE instead of subtly relying on guest_memfd to deal with
     them

   - Reload the pre-VMRUN TSC_AUX on #VMEXIT for SEV-ES guests, not the
     host's desired TSC_AUX, to fix a bug where KVM was keeping a
     different vCPU's TSC_AUX in the host MSR until return to userspace

  KVM (Intel):

   - Preparation for FRED support

   - Don't retry in TDX's anti-zero-step mitigation if the target
     memslot is invalid, i.e. is being deleted or moved, to fix a
     deadlock scenario similar to the aforementioned prefaulting case

   - Misc bugfixes and minor cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (142 commits)
  KVM: x86: Export KVM-internal symbols for sub-modules only
  KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks
  KVM: x86: Move kvm_intr_is_single_vcpu() to lapic.c
  KVM: Export KVM-internal symbols for sub-modules only
  KVM: s390/vfio-ap: Use kvm_is_gpa_in_memslot() instead of open coded equivalent
  KVM: VMX: Make CR4.CET a guest owned bit
  KVM: selftests: Verify MSRs are (not) in save/restore list when (un)supported
  KVM: selftests: Add coverage for KVM-defined registers in MSRs test
  KVM: selftests: Add KVM_{G,S}ET_ONE_REG coverage to MSRs test
  KVM: selftests: Extend MSRs test to validate vCPUs without supported features
  KVM: selftests: Add support for MSR_IA32_{S,U}_CET to MSRs test
  KVM: selftests: Add an MSR test to exercise guest/host and read/write
  KVM: x86: Define AMD's #HV, #VC, and #SX exception vectors
  KVM: x86: Define Control Protection Exception (#CP) vector
  KVM: x86: Add human friendly formatting for #XM, and #VE
  KVM: SVM: Enable shadow stack virtualization for SVM
  KVM: SEV: Synchronize MSR_IA32_XSS from the GHCB when it's valid
  KVM: SVM: Pass through shadow stack MSRs as appropriate
  KVM: SVM: Update dump_vmcb with shadow stack save area additions
  KVM: nSVM: Save/load CET Shadow Stack state to/from vmcb12/vmcb02
  ...
2025-10-06 12:37:34 -07:00