Reset the segment cache after segment initialization in vmx_vcpu_reset()
to harden KVM against caching stale/uninitialized data.  Without the
recent fix to bypass the cache in kvm_arch_vcpu_put(), the following
scenario is possible:

 - vCPU is just created, and the vCPU thread is preempted before
   SS.AR_BYTES is written in vmx_vcpu_reset().

 - When scheduling out the vCPU task, kvm_arch_vcpu_in_kernel() =>
   vmx_get_cpl() reads and caches '0' for SS.AR_BYTES.

 - vmx_vcpu_reset() => seg_setup() configures SS.AR_BYTES, but doesn't
   invoke vmx_segment_cache_clear() to invalidate the cache.

As a result, KVM retains a stale value in the cache, which can be read,
e.g. via KVM_GET_SREGS.  Usually this is not a problem because the VMX
segment cache is reset on each VM-Exit, but if the userspace VMM (e.g KVM
selftests) reads and writes system registers just after the vCPU was
created, _without_ modifying SS.AR_BYTES, userspace will write back the
stale '0' value and ultimately will trigger a VM-Entry failure due to
incorrect SS segment type.

Invalidating the cache after writing the VMCS doesn't address the general
issue of cache accesses from IRQ context being unsafe, but it does prevent
KVM from clobbering the VMCS, i.e. mitigates the harm done _if_ KVM has a
bug that results in an unsafe cache access.
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Fixes: 2fb92db1 ("KVM: VMX: Cache vmcs segment fields")
[sean: rework changelog to account for previous patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241009175002.1118178-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Massage the documentation for KVM_X86_QUIRK_SLOT_ZAP_ALL to call out that
it applies to moved memslots as well as deleted memslots, to avoid KVM's
"fast zap" terminology (which has no meaning for userspace), and to reword
the documented targeted zap behavior to specifically say that KVM _may_
zap a subset of all SPTEs.  As evidenced by the fix to zap non-leafs SPTEs
with gPTEs, formally documenting KVM's exact internal behavior is risky
and unnecessary.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241009192345.1148353-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Add a lockdep assertion in kvm_unmap_gfn_range() to ensure that either
mmu_invalidate_in_progress is elevated, or that the range is being zapped
due to memslot removal (loosely detected by slots_lock being held).
Zapping SPTEs without mmu_invalidate_{in_progress,seq} protection is unsafe
as KVM's page fault path snapshots state before acquiring mmu_lock, and
thus can create SPTEs with stale information if vCPUs aren't forced to
retry faults (due to seeing an in-progress or past MMU invalidation).

Memslot removal is a special case, as the memslot is retrieved outside of
mmu_invalidate_seq, i.e. doesn't use the "standard" protections, and
instead relies on SRCU synchronization to ensure any in-flight page faults
are fully resolved before zapping SPTEs.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20241009192345.1148353-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

When performing a targeted zap on memslot removal, zap only MMU pages that
shadow guest PTEs, as zapping all SPs that "match" the gfn is inexact and
unnecessary.  Furthermore, for_each_gfn_valid_sp() arguably shouldn't
exist, because it doesn't do what most people would it expect it to do.
The "round gfn for level" adjustment that is done for direct SPs (no gPTE)
means that the exact gfn comparison will not get a match, even when a SP
does "cover" a gfn, or was even created specifically for a gfn.

For memslot deletion specifically, KVM's behavior will vary significantly
based on the size and alignment of a memslot, and in weird ways.  E.g. for
a 4KiB memslot, KVM will zap more SPs if the slot is 1GiB aligned than if
it's only 4KiB aligned.  And as described below, zapping SPs in the
aligned case overzaps for direct MMUs, as odds are good the upper-level
SPs are serving other memslots.

To iterate over all potentially-relevant gfns, KVM would need to make a
pass over the hash table for each level, with the gfn used for lookup
rounded for said level.  And then check that the SP is of the correct
level, too, e.g. to avoid over-zapping.

But even then, KVM would massively overzap, as processing every level is
all but guaranteed to zap SPs that serve other memslots, especially if the
memslot being removed is relatively small.  KVM could mitigate that issue
by processing only levels that can be possible guest huge pages, i.e. are
less likely to be re-used for other memslot, but while somewhat logical,
that's quite arbitrary and would be a bit of a mess to implement.

So, zap only SPs with gPTEs, as the resulting behavior is easy to describe,
is predictable, and is explicitly minimal, i.e. KVM only zaps SPs that
absolutely must be zapped.

Cc: Yan Zhao <yan.y.zhao@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Message-ID: <20241009192345.1148353-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

AMD SEV-SNP and Intel TDX have limited access to MTRR: either it is not
advertised in CPUID or it cannot be programmed (on TDX, due to #VE on
CR0.CD clear).

This results in guests using uncached mappings where it shouldn't and
pmd/pud_set_huge() failures due to non-uniform memory type reported by
mtrr_type_lookup().

Override MTRR state, making it WB by default as the kernel does for
Hyper-V guests.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: Binbin Wu <binbin.wu@intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Message-ID: <20241015095818.357915-1-kirill.shutemov@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The last use of kvm_vcpu_gfn_to_pfn_atomic was removed by commit
1bbc60d0 ("KVM: x86/mmu: Remove MMU auditing")

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Message-ID: <20241001141354.18009-3-linux@treblig.org>
[Adjust Documentation/virt/kvm/locking.rst. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The last use of kvm_vcpu_gfn_to_pfn was removed by commit
b1624f99 ("KVM: Remove kvm_vcpu_gfn_to_page() and kvm_vcpu_gpa_to_page()")

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Message-ID: <20241001141354.18009-2-linux@treblig.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Merge tag 'kvmarm-fixes-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.12, take #1

- Fix pKVM error path on init, making sure we do not change critical
  system registers as we're about to fail

- Make sure that the host's vector length is at capped by a value
  common to all CPUs

- Fix kvm_has_feat*() handling of "negative" features, as the current
  code is pretty broken

- Promote Joey to the status of official reviewer, while James steps
  down -- hopefully only temporarly

Guard them with CONFIG_KVM_X86_COMMON rather than the two vendor modules.
In practice this has no functional change, because CONFIG_KVM_X86_COMMON
is set if and only if at least one vendor-specific module is being built.
However, it is cleaner to specify CONFIG_KVM_X86_COMMON for functions that
are used in kvm.ko.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 590b09b1 ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Fixes: 6d55a942 ("x86/reboot: Unconditionally define cpu_emergency_virt_cb typedef")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

kvm.ko is nothing but library code shared by kvm-intel.ko and kvm-amd.ko.
It provides no functionality on its own and it is unnecessary unless one
of the vendor-specific module is compiled.  In particular, /dev/kvm is
not created until one of kvm-intel.ko or kvm-amd.ko is loaded.

Use CONFIG_KVM to decide if it is built-in or a module, but use the
vendor-specific modules for the actual decision on whether to build it.

This also fixes a build failure when CONFIG_KVM_INTEL and CONFIG_KVM_AMD
are both disabled.  The cpu_emergency_register_virt_callback() function
is called from kvm.ko, but it is only defined if at least one of
CONFIG_KVM_INTEL and CONFIG_KVM_AMD is provided.

Fixes: 590b09b1 ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

As was tried in commit 4e103134 ("KVM: x86/mmu: Zap only the relevant
pages when removing a memslot"), all shadow pages, i.e. non-leaf SPTEs,
need to be zapped.  All of the accounting for a shadow page is tied to the
memslot, i.e. the shadow page holds a reference to the memslot, for all
intents and purposes.  Deleting the memslot without removing all relevant
shadow pages, as is done when KVM_X86_QUIRK_SLOT_ZAP_ALL is disabled,
results in NULL pointer derefs when tearing down the VM.

Reintroduce from that commit the code that walks the whole memslot when
there are active shadow MMU pages.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Oliver reports that the kvm_has_feat() helper is not behaviing as
expected for negative feature. On investigation, the main issue
seems to be caused by the following construct:

 #define get_idreg_field(kvm, id, fld)				\
 	(id##_##fld##_SIGNED ?					\
	 get_idreg_field_signed(kvm, id, fld) :			\
	 get_idreg_field_unsigned(kvm, id, fld))

where one side of the expression evaluates as something signed,
and the other as something unsigned. In retrospect, this is totally
braindead, as the compiler converts this into an unsigned expression.
When compared to something that is 0, the test is simply elided.

Epic fail. Similar issue exists in the expand_field_sign() macro.

The correct way to handle this is to chose between signed and unsigned
comparisons, so that both sides of the ternary expression are of the
same type (bool).

In order to keep the code readable (sort of), we introduce new
comparison primitives taking an operator as a parameter, and
rewrite the kvm_has_feat*() helpers in terms of these primitives.

Fixes: c62d7a23 ("KVM: arm64: Add feature checking helpers")
Reported-by: Oliver Upton <oliver.upton@linux.dev>
Tested-by: Oliver Upton <oliver.upton@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241002204239.2051637-1-maz@kernel.orgSigned-off-by: Marc Zyngier <maz@kernel.org>

The recent addition of support for testing with the x86 specific quirk
KVM_X86_QUIRK_SLOT_ZAP_ALL disabled in the generic memslot tests broke the
build of the KVM selftests for all other architectures:

In file included from include/kvm_util.h:8,
                 from include/memstress.h:13,
                 from memslot_modification_stress_test.c:21:
memslot_modification_stress_test.c: In function ‘main’:
memslot_modification_stress_test.c:176:38: error: ‘KVM_X86_QUIRK_SLOT_ZAP_ALL’ undeclared (first use in this function)
  176 |                                      KVM_X86_QUIRK_SLOT_ZAP_ALL);
      |                                      ^~~~~~~~~~~~~~~~~~~~~~~~~~

Add __x86_64__ guard defines to avoid building the relevant code on other
architectures.

Fixes: 61de4c34 ("KVM: selftests: Test memslot move in memslot_perf_test with quirk disabled")
Fixes: 218f6415 ("KVM: selftests: Allow slot modification stress test with quirk disabled")
Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Message-ID: <20240930-kvm-build-breakage-v1-1-866fad3cc164@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

It has been a while since James had any significant bandwidth to
review KVM/arm64 patches. But in the meantime, Joey has stepped up
and did a really good job reviewing some terrifying patch series.

Having talked with the interested parties, it appears that James
is unlikely to have time for KVM in the near future, and that Joey
is willing to take more responsibilities.

So let's appoint Joey as an official reviewer, and give James some
breathing space, as well as my personal thanks. I'm sure he will
be back one way or another!

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Zenghui Yu <yuzenghui@huawei.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Joey Gouly <joey.gouly@arm.com>
Acked-by: Zenghui Yu <yuzenghui@huawei.com>
Link: https://lore.kernel.org/r/20240927104956.1223658-1-maz@kernel.orgSigned-off-by: Marc Zyngier <maz@kernel.org>

When pKVM saves and restores the host floating point state on a SVE system,
it programs the vector length in ZCR_EL2.LEN to be whatever the maximum VL
for the PE is. But it uses a buffer allocated with kvm_host_sve_max_vl, the
maximum VL shared by all PEs in the system. This means that if we run on a
system where the maximum VLs are not consistent, we will overflow the buffer
on PEs which support larger VLs.

Since the host will not currently attempt to make use of non-shared VLs, fix
this by explicitly setting the EL2 VL to be the maximum shared VL when we
save and restore. This will enforce the limit on host VL usage. Should we
wish to support asymmetric VLs, this code will need to be updated along with
the required changes for the host:

  https://lore.kernel.org/r/20240730-kvm-arm64-fix-pkvm-sve-vl-v6-0-cae8a2e0bd66@kernel.org

Fixes: b5b99556 ("KVM: arm64: Eagerly restore host fpsimd/sve state in pKVM")
Signed-off-by: Mark Brown <broonie@kernel.org>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240912-kvm-arm64-limit-guest-vl-v2-1-dd2c29cb2ac9@kernel.org
[maz: added punctuation to the commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>

On an error, hyp_vcpu will be accessed while this memory has already
been relinquished to the host and unmapped from the hypervisor. Protect
the CPTR assignment with an early return.

Fixes: b5b99556 ("KVM: arm64: Eagerly restore host fpsimd/sve state in pKVM")
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/r/20240919110500.2345927-1-vdonnefort@google.comSigned-off-by: Marc Zyngier <maz@kernel.org>

The cpu_emergency_register_virt_callback() function is used
unconditionally by the x86 kvm code, but it is declared (and defined)
conditionally:

  #if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
  void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback);
  ...

leading to a build error when neither KVM_INTEL nor KVM_AMD support is
enabled:

  arch/x86/kvm/x86.c: In function ‘kvm_arch_enable_virtualization’:
  arch/x86/kvm/x86.c:12517:9: error: implicit declaration of function ‘cpu_emergency_register_virt_callback’ [-Wimplicit-function-declaration]
  12517 |         cpu_emergency_register_virt_callback(kvm_x86_ops.emergency_disable_virtualization_cpu);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  arch/x86/kvm/x86.c: In function ‘kvm_arch_disable_virtualization’:
  arch/x86/kvm/x86.c:12522:9: error: implicit declaration of function ‘cpu_emergency_unregister_virt_callback’ [-Wimplicit-function-declaration]
  12522 |         cpu_emergency_unregister_virt_callback(kvm_x86_ops.emergency_disable_virtualization_cpu);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix the build by defining empty helper functions the same way the old
cpu_emergency_disable_virtualization() function was dealt with for the
same situation.

Maybe we could instead have made the call sites conditional, since the
callers (kvm_arch_{en,dis}able_virtualization()) have an empty weak
fallback.  I'll leave that to the kvm people to argue about, this at
least gets the build going for that particular config.

Fixes: 590b09b1 ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Chao Gao <chao.gao@intel.com>
Cc: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull mailbox updates from Jassi Brar:

 - fix kconfig dependencies (mhu-v3, omap2+)

 - use devie name instead of genereic imx_mu_chan as interrupt name
   (imx)

 - enable sa8255p and qcs8300 ipc controllers (qcom)

 - Fix timeout during suspend mode (bcm2835)

 - convert to use use of_property_match_string (mailbox)

 - enable mt8188 (mediatek)

 - use devm_clk_get_enabled helpers (spreadtrum)

 - fix device-id typo (rockchip)

* tag 'mailbox-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jassibrar/mailbox:
  mailbox, remoteproc: omap2+: fix compile testing
  dt-bindings: mailbox: qcom-ipcc: Document QCS8300 IPCC
  dt-bindings: mailbox: qcom-ipcc: document the support for SA8255p
  dt-bindings: mailbox: mtk,adsp-mbox: Add compatible for MT8188
  mailbox: Use of_property_match_string() instead of open-coding
  mailbox: bcm2835: Fix timeout during suspend mode
  mailbox: sprd: Use devm_clk_get_enabled() helpers
  mailbox: rockchip: fix a typo in module autoloading
  mailbox: imx: use device name in interrupt name
  mailbox: ARM_MHU_V3 should depend on ARM64

Merge tag 'i2c-for-6.12-rc1-additional_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:

 - fix DesignWare driver ENABLE-ABORT sequence, ensuring ABORT can
   always be sent when needed

 - check for PCLK in the SynQuacer controller as an optional clock,
   allowing ACPI to directly provide the clock rate

 - KEBA driver Kconfig dependency fix

 - fix XIIC driver power suspend sequence

* tag 'i2c-for-6.12-rc1-additional_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: xiic: Fix pm_runtime_set_suspended() with runtime pm enabled
  i2c: keba: I2C_KEBA should depend on KEBA_CP500
  i2c: synquacer: Deal with optional PCLK correctly
  i2c: designware: fix controller is holding SCL low while ENABLE bit is disabled

Pull dma-mapping fix from Christoph Hellwig:

 - handle chained SGLs in the new tracing code (Christoph Hellwig)

* tag 'dma-mapping-6.12-2024-09-29' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: fix DMA API tracing for chained scatterlists

Pull more SCSI updates from James Bottomley:
 "These are mostly minor updates.

  There are two drivers (lpfc and mpi3mr) which missed the initial
  pull and a core change to retry a start/stop unit which affect
  suspend/resume"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (32 commits)
  scsi: lpfc: Update lpfc version to 14.4.0.5
  scsi: lpfc: Support loopback tests with VMID enabled
  scsi: lpfc: Revise TRACE_EVENT log flag severities from KERN_ERR to KERN_WARNING
  scsi: lpfc: Ensure DA_ID handling completion before deleting an NPIV instance
  scsi: lpfc: Fix kref imbalance on fabric ndlps from dev_loss_tmo handler
  scsi: lpfc: Restrict support for 32 byte CDBs to specific HBAs
  scsi: lpfc: Update phba link state conditional before sending CMF_SYNC_WQE
  scsi: lpfc: Add ELS_RSP cmd to the list of WQEs to flush in lpfc_els_flush_cmd()
  scsi: mpi3mr: Update driver version to 8.12.0.0.50
  scsi: mpi3mr: Improve wait logic while controller transitions to READY state
  scsi: mpi3mr: Update MPI Headers to revision 34
  scsi: mpi3mr: Use firmware-provided timestamp update interval
  scsi: mpi3mr: Enhance the Enable Controller retry logic
  scsi: sd: Fix off-by-one error in sd_read_block_characteristics()
  scsi: pm8001: Do not overwrite PCI queue mapping
  scsi: scsi_debug: Remove a useless memset()
  scsi: pmcraid: Convert comma to semicolon
  scsi: sd: Retry START STOP UNIT commands
  scsi: mpi3mr: A performance fix
  scsi: ufs: qcom: Update MODE_MAX cfg_bw value
  ...

Pull more bcachefs updates from Kent Overstreet:
 "Assorted minor syzbot fixes, and for bigger stuff:

  Fix two disk accounting rewrite bugs:

   - Disk accounting keys use the version field of bkey so that journal
     replay can tell which updates have been applied to the btree.

     This is set in the transaction commit path, after we've gotten our
     journal reservation (and our time ordering), but the
     BCH_TRANS_COMMIT_skip_accounting_apply flag that journal replay
     uses was incorrectly skipping this for new updates generated prior
     to journal replay.

     This fixes the underlying cause of an assertion pop in
     disk_accounting_read.

   - A couple of fixes for disk accounting + device removal.

     Checking if acocunting replicas entries were marked in the
     superblock was being done at the wrong point, when deltas in the
     journal could still zero them out, and then additionally we'd try
     to add a missing replicas entry to the superblock without checking
     if it referred to an invalid (removed) device.

  A whole slew of repair fixes:

   - fix infinite loop in propagate_key_to_snapshot_leaves(), this fixes
     an infinite loop when repairing a filesystem with many snapshots

   - fix incorrect transaction restart handling leading to occasional
     "fsck counted ..." warnings

   - fix warning in __bch2_fsck_err() for bkey fsck errors

   - check_inode() in fsck now correctly checks if the filesystem was
     clean

   - there shouldn't be pending logged ops if the fs was clean, we now
     check for this

   - remove_backpointer() doesn't remove a dirent that doesn't actually
     point to the inode

   - many more fsck errors are AUTOFIX"

* tag 'bcachefs-2024-09-28' of git://evilpiepirate.org/bcachefs: (35 commits)
  bcachefs: check_subvol_path() now prints subvol root inode
  bcachefs: remove_backpointer() now checks if dirent points to inode
  bcachefs: dirent_points_to_inode() now warns on mismatch
  bcachefs: Fix lost wake up
  bcachefs: Check for logged ops when clean
  bcachefs: BCH_FS_clean_recovery
  bcachefs: Convert disk accounting BUG_ON() to WARN_ON()
  bcachefs: Fix BCH_TRANS_COMMIT_skip_accounting_apply
  bcachefs: Check for accounting keys with bversion=0
  bcachefs: rename version -> bversion
  bcachefs: Don't delete unlinked inodes before logged op resume
  bcachefs: Fix BCH_SB_ERRS() so we can reorder
  bcachefs: Fix fsck warnings from bkey validation
  bcachefs: Move transaction commit path validation to as late as possible
  bcachefs: Fix disk accounting attempting to mark invalid replicas entry
  bcachefs: Fix unlocked access to c->disk_sb.sb in bch2_replicas_entry_validate()
  bcachefs: Fix accounting read + device removal
  bcachefs: bch_accounting_mode
  bcachefs: fix transaction restart handling in check_extents(), check_dirents()
  bcachefs: kill inode_walker_entry.seen_this_pos
  ...

Pull x86 fixes from Ingo Molnar:
 "Fix TDX MMIO #VE fault handling, and add two new Intel model numbers
  for 'Pantherlake' and 'Diamond Rapids'"

* tag 'x86-urgent-2024-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add two Intel CPU model numbers
  x86/tdx: Fix "in-kernel MMIO" check

Pull locking updates from Ingo Molnar:
 "lockdep:
    - Fix potential deadlock between lockdep and RCU (Zhiguo Niu)
    - Use str_plural() to address Coccinelle warning (Thorsten Blum)
    - Add debuggability enhancement (Luis Claudio R. Goncalves)

  static keys & calls:
    - Fix static_key_slow_dec() yet again (Peter Zijlstra)
    - Handle module init failure correctly in static_call_del_module()
      (Thomas Gleixner)
    - Replace pointless WARN_ON() in static_call_module_notify() (Thomas
      Gleixner)

  <linux/cleanup.h>:
    - Add usage and style documentation (Dan Williams)

  rwsems:
    - Move is_rwsem_reader_owned() and rwsem_owner() under
      CONFIG_DEBUG_RWSEMS (Waiman Long)

  atomic ops, x86:
    - Redeclare x86_32 arch_atomic64_{add,sub}() as void (Uros Bizjak)
    - Introduce the read64_nonatomic macro to x86_32 with cx8 (Uros
      Bizjak)"
Signed-off-by: Ingo Molnar <mingo@kernel.org>

* tag 'locking-urgent-2024-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Move is_rwsem_reader_owned() and rwsem_owner() under CONFIG_DEBUG_RWSEMS
  jump_label: Fix static_key_slow_dec() yet again
  static_call: Replace pointless WARN_ON() in static_call_module_notify()
  static_call: Handle module init failure correctly in static_call_del_module()
  locking/lockdep: Simplify character output in seq_line()
  lockdep: fix deadlock issue between lockdep and rcu
  lockdep: Use str_plural() to fix Coccinelle warning
  cleanup: Add usage and style documentation
  lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug
  locking/atomic/x86: Redeclare x86_32 arch_atomic64_{add,sub}() as void
  locking/atomic/x86: Introduce the read64_nonatomic macro to x86_32 with cx8

Pull coccinelle updates from Julia Lawall:
 "Extend string_choices.cocci to use more available helpers

  Ten patches from Hongbo Li extending string_choices.cocci with the
  complete set of functions offered by include/linux/string_choices.h.

  One patch from myself reducing the number of redundant cases that are
  checked by Coccinelle, giving a small performance improvement"

* tag 'cocci-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
  Reduce Coccinelle choices in string_choices.cocci
  coccinelle: Remove unnecessary parentheses for only one possible change.
  coccinelle: Add rules to find str_yes_no() replacements
  coccinelle: Add rules to find str_on_off() replacements
  coccinelle: Add rules to find str_write_read() replacements
  coccinelle: Add rules to find str_read_write() replacements
  coccinelle: Add rules to find str_enable{d}_disable{d}() replacements
  coccinelle: Add rules to find str_lo{w}_hi{gh}() replacements
  coccinelle: Add rules to find str_hi{gh}_lo{w}() replacements
  coccinelle: Add rules to find str_false_true() replacements
  coccinelle: Add rules to find str_true_false() replacements

Merge tag 'linux_kselftest-next-6.12-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fix from Shuah Khan:
 "One urgent fix to vDSO as automated testing is failing due to this
  bug"

* tag 'linux_kselftest-next-6.12-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: vDSO: align stack for O2-optimized memcpy

Merge all pending locking commits into a single branch.
Signed-off-by: Ingo Molnar <mingo@kernel.org>

The isomorphism neg_if_exp negates the test of a ?: conditional,
making it unnecessary to have an explicit case for a negated test
with the branches inverted.

At the same time, we can disable neg_if_exp in cases where a
different API function may be more suitable for a negated test.

Finally, in the non-patch cases, E matches an expression with
parentheses around it, so there is no need to mention ()
explicitly in the pattern.  The () are still needed in the patch
cases, because we want to drop them, if they are present.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

The parentheses are only needed if there is a disjunction, ie a
set of possible changes. If there is only one pattern, we can
remove these parentheses. Just like the format:

  -  x
  +  y

not:

  (
  -  x
  +  y
  )
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_yes_no()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_on_off()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_write_read()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_read_write()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_enable{d}_
disable{d}() to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_lo{w}_hi{gh}()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As other rules done, we add rules for str_hi{gh}_lo{w}()
to check the relative opportunities.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

As done with str_true_false(), add checks for str_false_true()
opportunities. A simple test can find over 9 cases currently
exist in the tree.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

After str_true_false() has been introduced in the tree,
we can add rules for finding places where str_true_false()
can be used. A simple test can find over 10 locations.
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Pull x86 kvm updates from Paolo Bonzini:
 "x86:

   - KVM currently invalidates the entirety of the page tables, not just
     those for the memslot being touched, when a memslot is moved or
     deleted.

     This does not traditionally have particularly noticeable overhead,
     but Intel's TDX will require the guest to re-accept private pages
     if they are dropped from the secure EPT, which is a non starter.

     Actually, the only reason why this is not already being done is a
     bug which was never fully investigated and caused VM instability
     with assigned GeForce GPUs, so allow userspace to opt into the new
     behavior.

   - Advertise AVX10.1 to userspace (effectively prep work for the
     "real" AVX10 functionality that is on the horizon)

   - Rework common MSR handling code to suppress errors on userspace
     accesses to unsupported-but-advertised MSRs

     This will allow removing (almost?) all of KVM's exemptions for
     userspace access to MSRs that shouldn't exist based on the vCPU
     model (the actual cleanup is non-trivial future work)

   - Rework KVM's handling of x2APIC ICR, again, because AMD (x2AVIC)
     splits the 64-bit value into the legacy ICR and ICR2 storage,
     whereas Intel (APICv) stores the entire 64-bit value at the ICR
     offset

   - Fix a bug where KVM would fail to exit to userspace if one was
     triggered by a fastpath exit handler

   - Add fastpath handling of HLT VM-Exit to expedite re-entering the
     guest when there's already a pending wake event at the time of the
     exit

   - Fix a WARN caused by RSM entering a nested guest from SMM with
     invalid guest state, by forcing the vCPU out of guest mode prior to
     signalling SHUTDOWN (the SHUTDOWN hits the VM altogether, not the
     nested guest)

   - Overhaul the "unprotect and retry" logic to more precisely identify
     cases where retrying is actually helpful, and to harden all retry
     paths against putting the guest into an infinite retry loop

   - Add support for yielding, e.g. to honor NEED_RESCHED, when zapping
     rmaps in the shadow MMU

   - Refactor pieces of the shadow MMU related to aging SPTEs in
     prepartion for adding multi generation LRU support in KVM

   - Don't stuff the RSB after VM-Exit when RETPOLINE=y and AutoIBRS is
     enabled, i.e. when the CPU has already flushed the RSB

   - Trace the per-CPU host save area as a VMCB pointer to improve
     readability and cleanup the retrieval of the SEV-ES host save area

   - Remove unnecessary accounting of temporary nested VMCB related
     allocations

   - Set FINAL/PAGE in the page fault error code for EPT violations if
     and only if the GVA is valid. If the GVA is NOT valid, there is no
     guest-side page table walk and so stuffing paging related metadata
     is nonsensical

   - Fix a bug where KVM would incorrectly synthesize a nested VM-Exit
     instead of emulating posted interrupt delivery to L2

   - Add a lockdep assertion to detect unsafe accesses of vmcs12
     structures

   - Harden eVMCS loading against an impossible NULL pointer deref
     (really truly should be impossible)

   - Minor SGX fix and a cleanup

   - Misc cleanups

  Generic:

   - Register KVM's cpuhp and syscore callbacks when enabling
     virtualization in hardware, as the sole purpose of said callbacks
     is to disable and re-enable virtualization as needed

   - Enable virtualization when KVM is loaded, not right before the
     first VM is created

     Together with the previous change, this simplifies a lot the logic
     of the callbacks, because their very existence implies
     virtualization is enabled

   - Fix a bug that results in KVM prematurely exiting to userspace for
     coalesced MMIO/PIO in many cases, clean up the related code, and
     add a testcase

   - Fix a bug in kvm_clear_guest() where it would trigger a buffer
     overflow _if_ the gpa+len crosses a page boundary, which thankfully
     is guaranteed to not happen in the current code base. Add WARNs in
     more helpers that read/write guest memory to detect similar bugs

  Selftests:

   - Fix a goof that caused some Hyper-V tests to be skipped when run on
     bare metal, i.e. NOT in a VM

   - Add a regression test for KVM's handling of SHUTDOWN for an SEV-ES
     guest

   - Explicitly include one-off assets in .gitignore. Past Sean was
     completely wrong about not being able to detect missing .gitignore
     entries

   - Verify userspace single-stepping works when KVM happens to handle a
     VM-Exit in its fastpath

   - Misc cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
  Documentation: KVM: fix warning in "make htmldocs"
  s390: Enable KVM_S390_UCONTROL config in debug_defconfig
  selftests: kvm: s390: Add VM run test case
  KVM: SVM: let alternatives handle the cases when RSB filling is required
  KVM: VMX: Set PFERR_GUEST_{FINAL,PAGE}_MASK if and only if the GVA is valid
  KVM: x86/mmu: Use KVM_PAGES_PER_HPAGE() instead of an open coded equivalent
  KVM: x86/mmu: Add KVM_RMAP_MANY to replace open coded '1' and '1ul' literals
  KVM: x86/mmu: Fold mmu_spte_age() into kvm_rmap_age_gfn_range()
  KVM: x86/mmu: Morph kvm_handle_gfn_range() into an aging specific helper
  KVM: x86/mmu: Honor NEED_RESCHED when zapping rmaps and blocking is allowed
  KVM: x86/mmu: Add a helper to walk and zap rmaps for a memslot
  KVM: x86/mmu: Plumb a @can_yield parameter into __walk_slot_rmaps()
  KVM: x86/mmu: Move walk_slot_rmaps() up near for_each_slot_rmap_range()
  KVM: x86/mmu: WARN on MMIO cache hit when emulating write-protected gfn
  KVM: x86/mmu: Detect if unprotect will do anything based on invalid_list
  KVM: x86/mmu: Subsume kvm_mmu_unprotect_page() into the and_retry() version
  KVM: x86: Rename reexecute_instruction()=>kvm_unprotect_and_retry_on_failure()
  KVM: x86: Update retry protection fields when forcing retry on emulation failure
  KVM: x86: Apply retry protection to "unprotect on failure" path
  KVM: x86: Check EMULTYPE_WRITE_PF_TO_SP before unprotecting gfn
  ...