Pull kvm updates from Paolo Bonzini:
 "ARM64:

   - Add support for 'slot' based PMU events, paired with new UAPI that
     compels the user to select a specific PMU implementation

   - Lazy save/restore of vCPU state for pKVM, along with various fixes
     and cleanups to the management of vCPU state between the untrusted
     host and pKVM hypervisor

   - Disable traps of EL1 registers for nested hypervisors when
     FEAT_NV2p1 is present, guaranteeing that EL2-specific register bits
     are stateful in the EL1 counterpart

   - Leverage FEAT_NV3 to avoid unnecessary ERET/TLBI traps when the
     scope of those instructions remains 'in host' (i.e. L1
     kernel/userspace)

   - Pile of fixes for the management of the VNCR pseudo-TLB, such as
     under-invalidations and races with concurrent TLBIs on other vCPUs

   - Consolidate the non-protected and pKVM view of ICH_VTR_EL2 to a
     runtime-patched constant, allowing the same data to be shared with
     pKVM prior to dropping host privileges

   - Considerable pile of LLM-assisted fixes around the shop but mostly
     in the VGIC, our in-kernel generator of bugs (and sometimes
     interrupts)

  LoongArch:

   - Advertise already-supported capabilities

   - Some bug fixes about timer and MMIO

   - Some hardening about interrupt injection

   - Replace kvm_err() with kvm_pr_unimpl()

   - Add FPU/LSX/LASX test cases for selftests

  RISC-V:

   - Svadu/Zicfiss/Zicfilp FWFT support for Guest

   - Use try_cmpxchg for IMSIC MRIF RMW

   - More arch-specific tracepoints in KVM RISC-V

   - Eager page splitting when enabling dirty logging

   - Optimize hfence request handling for SMP Guests

   - Improve dirty log clearing by skipping zero bits in mask

   - Guard HFENCE range loops against overflow

   - CPU PM notifiers in KVM RISC-V for non-retentive idle states

   - Fix kernel-mode vector context save/restore for Guest

  s390:

   - Fixes for vfio-ap

   - Fixes for the gmap rework

   - Fixes for vsie

   - AI triggered fixes all over

   - diag9c tracing

   - code move preparation for the additional arm64 support

   - enable CONTEXT_ANALYSIS

  x86:

   - Perform spring cleaning on x86.{c,h} and asm/kvm_host.h, by adding
     regs.c (the kvm_cache_regs.h => regs.h is already applied) and
     msrs.{c,h}, and moving relevant code out of x86.c

   - Split kvm_mmu in three parts, respectively to describe the format
     of page tables, walking the guest page tables and building the page
     tables. Always use the same page table walker kvm->arch.gva_walk as
     the entry point to convert a guest's virtual address, where the
     previous code used two different kvm_mmu structs depending on
     whether the walk included nested EPT/NPT or not. Make page fault
     vmexits reuse the permission checking machinery that is used for
     guest page faults. This is both a cleanup and a baby step towards
     supporting XS/XU memory permissions

   - Document some of the "fun" gotchas with the APIC base when creating
     IRQCHIPs on x86

   - Remove a defunct masterclock update from kvm_xen_shared_info_init().
     It could result in incorrect kvmclock due to triggering an
     unnecessary switch to/from masterclock mode

   - Skip Xen runstate time updates if time has effectively gone
     backwards, so that the guest doesn't report 100% steal time for
     a very, very long time

   - Drop KVM's runtime updates of the Xen PV timing CPUID leaf, as KVM
     was updating the wrong sub-leaf, and upstream KVM will soon provide
     all the information needed by userspace to populate the CPUID field
     itself

   - Fix a bug where KVM would walk a newly created rmap without holding
     the rmap lock (or mmu_lock) during aging

   - Fix a bug where aging TDP MMU SPTEs could clobber FROZEN SPTEs

   - Fix a variety of #DB priority bugs

   - Fix a class of races related to enabling Hyper-V emulation on a
     vCPU after the vCPU is visible to the rest of KVM

   - Use static calls for nested virtualization ops

   - Move more KVM-internal code out of x86's kvm_host.h

   - Enumerate support for a variety of Zhaoxin instructions that don't
     require explicit virtualization

   - Fix missing EFER validation bugs, including in the KVM_SET_SREGS*
     path

   - Harden kvm_vcpu_map() against double-mapping and thus leaking
     references

   - Misc fixes and cleanups, e.g. for largely benign syzkaller splats

  x86 (Intel):

   - Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used
     for IPI virtualization when the vCPU is freed, to fix a
     use-after-free where hardware will write to a freed vCPU's PID

   - Service local TLB flushes on a failed nested VM-Enter to fix a bug
     where KVM could miss a TLB on a future, successful VM-Enter with
     the same L2 VPID

   - Cap the maximum value shoved into the VMX Preemption Timer to
     workaround an erratum that affects all existing Intel CPUs that
     support CPUID 0x15

   - Fix VPID virtualization bugs where KVM would fail to flush hardware
     TLBs

   - Harden the TDX "populate" ioctls against bad input, and to prepare
     for supporting in-place private<=>shared conversion

  x86 (AMD):

   - Forcefully invalidate SNP VMSA pages if their backing guest_memfd
     page is zapped/invalidated, e.g. due to a PUNCH_HOLE in response to
     a Page-State Change request

   - Remove a dying VM from the GA Log notifier list before the VM is
     actually destroyed, to fix a potential use-after-free

   - While FOLL_WRITE was needed in the past to trigger CoW unsharing,
     nowadays FOLL_LONGTERM does that already even without FOLL_WRITE,
     and in fact, get_user_pages() actually disallows FOLL_WRITE
     together with FOLL_LONGTERM. So don't pass FOLL_WRITE when
     registering encrypted memory regions, i.e. when pinning SEV/SEV-ES
     guest memory, to fix a regression with file-backed memory
     introduced by KVM's (correct) usage of long-term pins

     (This was reviewed by mm maintainers; for more information, see
     commit ee1a586dd1fa "KVM: SEV: Drop FOLL_WRITE for encrypted region
     registration")

   - Allocate full pages for SEV/SEV-ES {DE,EN}CRYPT ops on SNP-enabled
     hosts to fix a data corruption issue due to the PSP driver
     assigning to-be-written pages to firmware (as required by the SNP
     specs)

   - Unconditionally intercept ICBEP so that KVM generates the correct
     guest RIP when handling an ICEBP-induced TASK_SWITCH #VMEXIT

   - Harden the SNP "populate" ioctls against bad input, and to prepare
     for supporting in-place private<=>shared conversion

  Generic:

   - Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's
     debugfs

   - Add a per-VM bitmap to track which vCPU IDs have been "claimed" but
     for which the vCPU isn't yet online, and use the bitmap to reject
     duplicate IDs before calling into arch code. This allows arch code
     to consume vcpu_id without having to worry about cross-vCPU
     clobbering (at least s390 and x86 have had related bugs)

   - Rework the so called "prepare" and "invalidate" guest_memfd hooks
     to prepare for in-place private<=>shared conversion, and clean up a
     few warts along the way

  Selftests:

   - Automatically allocate a full page for L2 guest stacks on x86
     instead of requiring test-specific L1 guest code to carve out a
     portion of the L1 stack for L2 usage, and to ensure the L2 stack
     also adheres to the x86-64 calling convention ABI

   - Add a selftest to verify {Guest,Host}-Only behavior in x86's
     mediated PMU

   - Clean up nested SVM's handling of GPRs on L2<=>L1 transitions,
     reuse the functionality for nested VMX, and drop the ucall hack
     that was fudging around the lack of GPR switching on nVMX

   - Add a stress test to verify KVM doesn't clobber/drop #PF state,
     e.g. CR2, across save/restore, including when L2 is active

   - Add a test to verify KVM_CREATE_VM accepts exactly what is reported
     by KVM_CAP_VM_TYPES

   - Misc selftests fixes and cleanups

   - Fix several issues with seeding the pRNG, and rework the pRNG APIs
     to that the pRNG can be sanely used in host code, not just guest
     code

   - Add an IRQ test to validate virtual IRQ deliverty for IRQs wired up
     via KVM_IRQFD + KVM_SET_GSI_ROUTING, with optional support for
     triggering IRQs via writes to an assigned VFIO device

   - Add syscall wrappers to assert success on a variety of pthreads and
     CPU affinity APIs

   - Set vCPU pthread affinity as early as possible to reduce contention
     issues that were surfaced by PREEMPT_LAZY, which result in runtimes
     of over a minute on large hosts, versus the expected ~5 seconds

   - Rework the PMU counters test to run each testcase using a single VM
     with many vCPUs for each sub-testcase, instead of using a unique VM
     for each sub-testcase. This cuts the runtime by ~20x

  Miscellaneous:

   - MAINTAINERS updates for vfio-ap, guest_memfd, kvm-x86. Mostly
     representing the status quo more accurately, but also... welcome
     David Hildenbrand as guest_memfd reviewer!"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (413 commits)
  KVM: arm64: Validate GICv5 timer PPIs before claiming ownership
  KVM: arm64: vgic: Reject out-of-range GICv5 PPI IDs
  KVM: arm64: vgic: Prevent speculative SPI array underflow
  KVM: arm64: vgic: Free gic_kvm_info on initialization failure
  KVM: arm64: Avoid mismatched accesses to 'struct kvm_nvhe_init_params'
  s390/vfio-ap: Fix NULL deref in status_show() during queue probe
  s390/vfio-ap: Fix hot-unplug skipped when last AP adapter or domain removed
  s390/vfio-ap: fix potential use of uninitialized apm_filtered bitmap
  s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove
  s390/vfio-ap: Fix required lock not held during update of ap_matrix_mdev object
  s390/vfio-ap: Fix missing lock required to access list of ap_matrix_mdev objects
  s390/vfio-ap: Fix dereference matrix_mdev->kvm without checking for NULL
  s390/vfio-ap: Fix stale do_remove flag across iterations in vfio_ap_mdev_cfg_remove
  RISC-V: KVM: fix vcpu vector context handling for kernel-mode vector
  riscv: vector: allow non-preemptible kernel-mode vector with IRQs off
  riscv: vector: refactor riscv_v_start_kernel_context
  KVM: s390: gmap: Make prefix handling optional
  KVM: s390: gmap: Make CMMA optional
  KVM: s390: gmap: Make storage keys optional
  KVM: s390: Prepare gmap for a second KVM implementation
  ...

KVM x86 misc changes for 7.3

 - Fix VPID virtualization bugs where KVM would fail to flush hardware TLBs.

 - Harden the SNP and TDX "populate" ioctls against bad input, and to prepare
   for supporting in-place private<=>shared conversion.

 - Fix a variety of #DB priority bugs.

 - Fix a class of races related to enabling Hyper-V emulation on a vCPU after
   the vCPU is visible to the rest of KVM.

 - Use static calls for nested virtualization ops.

 - Move more KVM-internal code out of x86's kvm_host.h.

 - Enumerate support for a variety of Zhaoxin instructions that don't require
   explicit virtualization.

 - Fix missing EFER validation bugs, including in the KVM_SET_SREGS* path.

 - Harden kvm_vcpu_map() against double-mapping and thus leaking references.

 - Misc fixes and cleanups, e.g. for largely benign syzkaller splats.

KVM guest_memfd and x86 CoCo changes for 7.3

 - Forcefully invalidate SNP VMSA pages if their backing guest_memfd page is
   zapped/invalidated, e.g. due to a PUNCH_HOLE in response to a Page-State
   Change request.

 - Rework the so called "prepare" and "invalidate" guest_memfd hooks to prepare
   for in-place private<=>shared conversion, and clean up a few warts along the
   way.

KVM arch-neutral and documentation changes for 7.3

 - Remove kvm_debugfs_dir if kvm_init() fails after creating KVM's debugfs.

 - Document some of the "fun" gotchas with the APIC base when creating IRQCHIPs
   on x86.

 - Add a per-VM bitmap to track which vCPU IDs have been "claimed" but for
   which the vCPU isn't yet online, and use the bitmap to reject duplicate IDs
   before calling into arch code.  This allows arch code to consume vcpu_id
   without having to worry about cross-vCPU clobbering (at least s390 and x86
   have had related bugs).

 - Zero a vCPU's entry in VMX's Posted Interrupt Descriptor table used for IPI
   virtualization when the vCPU is freed to fix a use-after-free where hardware
   will write to a freed vCPU's PID.

KVM MAINTAINERS changes for 7.3

 - Add the kvm-x86 tree to KVM x86 entries so that humans and robots alike can
   more easily find in-flight x86 changes.

 - Add a dedicated entry for guest_memfd, with the usual suspects as
   Maintainers, and David Hildenbrand as a Reviewer.

 - Add Sean as a Reviewer for overall KVM.

Extract the gmem function declarations out of kvm_mm.h and into a dedicated
header, guest_memfd.h.  This will allow creating a MAINTAINERS entry for
guest_memfd without having to rely on content pattern matching.

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Link: https://patch.msgid.link/20260731173842.2649391-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

There are a number of places where we open code what linear_page_index()
and linear_page_delta() calculate.

Replace this code with the appropriate functions for consistency.

No functional change intended.

Link: https://lore.kernel.org/20260710-b4-pre-scalable-cow-v2-21-2a5aa403d977@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>	[DRM]
Acked-by: Kai Huang <kai.huang@intel.com> # for sgx
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Pedro Falcato <pfalcato@suse.de> # for mm
Reviewed-by: Ackerley Tng <ackerleytng@google.com>	[guest_memfd]
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: SJ Park <sj@kernel.org>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

If userspace tries to create a vCPU with the same vcpu_id as an existing
one, kvm_vm_ioctl_create_vcpu() checks for that and fails with -EEXIST
only after it already created the vCPU via kvm_arch_vcpu_create(). As a
result, even though this newly created vCPU is destroyed in the failure
path, the fact that it is temporarily created with an invalid vcpu_id
and that there are temporarily two vCPUs with the same vcpu_id is a
potential source of subtle issues.

In particular, this prevents fixing an VMX IPIv issue where a stale entry
left in the VM's PI descriptor table after the vCPU is destroyed in the
failure path.  The right way to fix that issue is to clear that entry when
destroying the vCPU, however right now that would have a nasty side effect:
since the same entry is used for the other, previously created vCPU with
same vcpu_id, clearing it would mean effectively disabling IPIv for that
existing good vCPU.

So to avoid this and similar problems, check for duplicate vcpu_id as
early in the vCPU creation path as possible, before
kvm_arch_vcpu_create() and even before kvm_arch_vcpu_precreate().

Simply moving the existing kvm_get_vcpu_by_id() check earlier doesn't work,
as kvm->lock is dropped and reacquired, i.e. moving kvm_get_vcpu_by_id()
would introduce a race:

  1. vCPU A is being created but not installed in kvm->vcpu_array yet.
  2. vCPU B with the same vcpu_id is being created. It passes the
     duplicated vcpu_id check, since the check doesn't find vCPU A in
     kvm->vcpu_array.
  3. vCPU A is installed in kvm->vcpu_array, vCPU creation succeeds.
  4. vCPU B with the same vcpu_id is installed in kvm->vcpu_array, vCPU
     creation succeeds.

So introduce the bitmap of vcpu_ids used by the VM, in order to safely
check if the given vcpu_id is used and mark is as used before releasing
kvm->lock first time.

Alternatively, KVM could use another Xarray[*] for roughly the same code
complexity, which would minimize KVM's steady state memory footprint at
the cost of higher runtime latency (to allocate and free entries).  Given
that the worst case scenario is 256 bytes per-VM (on x86, which allows up
to 16KiB vCPU IDs), go with the slightly simpler approach until there's a
need to save memory.

Suggested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/kvm/al6eg7C-2sDBEAFD@google.com [*]
Signed-off-by: Dmytro Maluka <dmaluka@chromium.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Link: https://patch.msgid.link/20260729170621.308809-2-dmaluka@chromium.org
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>

Now that all on-stack maps use CLASS(kvm_vcpu_map_local), i.e. now that all
maps are zero-allocated, explicitly put any existing mappings/references
when establishing a new mapping to harden against KVM bugs leaking memory,
but yell loudly as the owner of the map is still ultimately responsible for
the lifecycle of the mapping.

Suggested-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260724004757.131420-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

When calling into arch code to make the underlying memory private, i.e. to
assign memory to the VM in SNP's RMP table, assign/convert *exactly* the
range of memory that can be mapped into the guest for the current page
fault, instead of aggressively converting/assigning the entire folio.  For
SNP, the mapping size in the stage-2 page tables (Nested Page Tables, NPT)
must be at least the size of the corresponding RMP entry, e.g. assigning a
2MiB mapping in the RMP when it can only be mapped at 4KiB granualarity
will ultimate result in another page fault (#NPF for SNP) to "smash" the
RMP down to the correct mapping size.

Assigning the entire folio was necessary back when guest_memfd tracked
preparedness, which was done on a per-folio basis.  At the time, it made
sense to do per-folio tracking/preparation, because tracking per-folio
meant guest_memfd didn't need to add a separate data structure to track
that information, and doing per-folio tracking only works if the entire
folio is prepared (or not).

Now that guest_memfd no longer does preparation tracking (see commit
8622ef05709f ("KVM: guest_memfd: Remove preparation tracking")), in favor
having SNP query the RMP, per-folio preparation, i.e. per-folio conversions
to private, doesn't make any sense.

*If* SNP allowed the RMP size to be greater than the NPT size, then
per-folio conversion could theoretically provide marginal value, as it
would allow KVM to assign a hugepage in the RMP even if it can only be
mapped into the NPT with a smaller page, e.g. because of memslot alignment.
The documentation of that reasoning would be something like this:

  /*
   * If the memory is private from KVM's perspective, and hardware tracks
   * VM-assigned private memory in a dedicated data structure, i.e. not
   * in the stage-2 page tables, then call into arch code to assign the
   * entire folio to the guest.  Assigning the entire folio, e.g. instead
   * of only the memory being mapped into the guest, allows KVM to assign
   * an entire hugepage of memory in the out-of-band structure even if
   * KVM can only map a smaller page size into the MMU, e.g. because the
   * gmem hugepage is spread across multiple memslots.
   */

But even *if* a future SNP implementation supported that behavior, the
value added would be dubious, as having a huge folio that is fully private,
but can only be mapped at a smaller granularity, would be rare.  E.g. maybe
for memory at the top of lower DRAM that has holes for non-RAM assets?

So, convert/assign exactly what guest_memfd allows the caller to map to
simplify the guest_memfd code and provide a (super) minor performance
optimization for SNP.  E.g. once hugepage support comes along, guest_memfd
will only need a single flow to compute "how much memory can be assigned
and at what size".

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://patch.msgid.link/20260723210811.72720-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>