<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm64/include/uapi, branch v6.15.10</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>Merge branch 'kvm-arm64/pv-cpuid' into kvmarm/next</title>
<updated>2025-03-19T21:53:16+00:00</updated>
<author>
<name>Oliver Upton</name>
<email>oliver.upton@linux.dev</email>
</author>
<published>2025-03-19T21:53:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d300b0168ea8fd5022a1413bd37ab63f4e5a7d4d'/>
<id>d300b0168ea8fd5022a1413bd37ab63f4e5a7d4d</id>
<content type='text'>
* kvm-arm64/pv-cpuid:
  : Paravirtualized implementation ID, courtesy of Shameer Kolothum
  :
  : Big-little has historically been a pain in the ass to virtualize. The
  : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim
  : of vCPU scheduling. This can be particularly annoying when the guest
  : needs to know the underlying implementation to mitigate errata.
  :
  : "Hyperscalers" face a similar scheduling problem, where VMs may freely
  : migrate between hosts in a pool of heterogenous hardware. And yes, our
  : server-class friends are equally riddled with errata too.
  :
  : In absence of an architected solution to this wart on the ecosystem,
  : introduce support for paravirtualizing the implementation exposed
  : to a VM, allowing the VMM to describe the pool of implementations that a
  : VM may be exposed to due to scheduling/migration.
  :
  : Userspace is expected to intercept and handle these hypercalls using the
  : SMCCC filter UAPI, should it choose to do so.
  smccc: kvm_guest: Fix kernel builds for 32 bit arm
  KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2
  smccc/kvm_guest: Enable errata based on implementation CPUs
  arm64: Make  _midr_in_range_list() an exported function
  KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
  KVM: arm64: Specify hypercall ABI for retrieving target implementations
  arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* kvm-arm64/pv-cpuid:
  : Paravirtualized implementation ID, courtesy of Shameer Kolothum
  :
  : Big-little has historically been a pain in the ass to virtualize. The
  : implementation ID (MIDR, REVIDR, AIDR) of a vCPU can change at the whim
  : of vCPU scheduling. This can be particularly annoying when the guest
  : needs to know the underlying implementation to mitigate errata.
  :
  : "Hyperscalers" face a similar scheduling problem, where VMs may freely
  : migrate between hosts in a pool of heterogenous hardware. And yes, our
  : server-class friends are equally riddled with errata too.
  :
  : In absence of an architected solution to this wart on the ecosystem,
  : introduce support for paravirtualizing the implementation exposed
  : to a VM, allowing the VMM to describe the pool of implementations that a
  : VM may be exposed to due to scheduling/migration.
  :
  : Userspace is expected to intercept and handle these hypercalls using the
  : SMCCC filter UAPI, should it choose to do so.
  smccc: kvm_guest: Fix kernel builds for 32 bit arm
  KVM: selftests: Add test for KVM_REG_ARM_VENDOR_HYP_BMAP_2
  smccc/kvm_guest: Enable errata based on implementation CPUs
  arm64: Make  _midr_in_range_list() an exported function
  KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2
  KVM: arm64: Specify hypercall ABI for retrieving target implementations
  arm64: Modify _midr_range() functions to read MIDR/REVIDR internally

Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'kvm-arm64/nv-idregs' into kvmarm/next</title>
<updated>2025-03-19T21:52:26+00:00</updated>
<author>
<name>Oliver Upton</name>
<email>oliver.upton@linux.dev</email>
</author>
<published>2025-03-19T21:52:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=13f64f6d215ca229a615ef26cf452e38e22f4cdb'/>
<id>13f64f6d215ca229a615ef26cf452e38e22f4cdb</id>
<content type='text'>
* kvm-arm64/nv-idregs:
  : Changes to exposure of NV features, courtesy of Marc Zyngier
  :
  : Apply NV-specific feature restrictions at reset rather than at the point
  : of KVM_RUN. This makes the true feature set visible to userspace, a
  : necessary step towards save/restore support or NV VMs.
  :
  : Add an additional vCPU feature flag for selecting the E2H0 flavor of NV,
  : such that the VHE-ness of the VM can be applied to the feature set.
  KVM: arm64: selftests: Test that TGRAN*_2 fields are writable
  KVM: arm64: Allow userspace to write ID_AA64MMFR0_EL1.TGRAN*_2
  KVM: arm64: Advertise FEAT_ECV when possible
  KVM: arm64: Make ID_AA64MMFR4_EL1.NV_frac writable
  KVM: arm64: Allow userspace to limit NV support to nVHE
  KVM: arm64: Move NV-specific capping to idreg sanitisation
  KVM: arm64: Enforce NV limits on a per-idregs basis
  KVM: arm64: Make ID_REG_LIMIT_FIELD_ENUM() more widely available
  KVM: arm64: Consolidate idreg callbacks
  KVM: arm64: Advertise NV2 in the boot messages
  KVM: arm64: Mark HCR.EL2.{NV*,AT} RES0 when ID_AA64MMFR4_EL1.NV_frac is 0
  KVM: arm64: Mark HCR.EL2.E2H RES0 when ID_AA64MMFR1_EL1.VH is zero
  KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace
  arm64: cpufeature: Handle NV_frac as a synonym of NV2

Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* kvm-arm64/nv-idregs:
  : Changes to exposure of NV features, courtesy of Marc Zyngier
  :
  : Apply NV-specific feature restrictions at reset rather than at the point
  : of KVM_RUN. This makes the true feature set visible to userspace, a
  : necessary step towards save/restore support or NV VMs.
  :
  : Add an additional vCPU feature flag for selecting the E2H0 flavor of NV,
  : such that the VHE-ness of the VM can be applied to the feature set.
  KVM: arm64: selftests: Test that TGRAN*_2 fields are writable
  KVM: arm64: Allow userspace to write ID_AA64MMFR0_EL1.TGRAN*_2
  KVM: arm64: Advertise FEAT_ECV when possible
  KVM: arm64: Make ID_AA64MMFR4_EL1.NV_frac writable
  KVM: arm64: Allow userspace to limit NV support to nVHE
  KVM: arm64: Move NV-specific capping to idreg sanitisation
  KVM: arm64: Enforce NV limits on a per-idregs basis
  KVM: arm64: Make ID_REG_LIMIT_FIELD_ENUM() more widely available
  KVM: arm64: Consolidate idreg callbacks
  KVM: arm64: Advertise NV2 in the boot messages
  KVM: arm64: Mark HCR.EL2.{NV*,AT} RES0 when ID_AA64MMFR4_EL1.NV_frac is 0
  KVM: arm64: Mark HCR.EL2.E2H RES0 when ID_AA64MMFR1_EL1.VH is zero
  KVM: arm64: Hide ID_AA64MMFR2_EL1.NV from guest and userspace
  arm64: cpufeature: Handle NV_frac as a synonym of NV2

Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm64: nv: Allow userland to set VGIC maintenance IRQ</title>
<updated>2025-03-03T22:57:10+00:00</updated>
<author>
<name>Andre Przywara</name>
<email>andre.przywara@arm.com</email>
</author>
<published>2025-02-25T17:29:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=faf7714a47a25c626ec7fdbd8e85c6bfcd565fdc'/>
<id>faf7714a47a25c626ec7fdbd8e85c6bfcd565fdc</id>
<content type='text'>
The VGIC maintenance IRQ signals various conditions about the LRs, when
the GIC's virtualization extension is used.
So far we didn't need it, but nested virtualization needs to know about
this interrupt, so add a userland interface to setup the IRQ number.
The architecture mandates that it must be a PPI, on top of that this code
only exports a per-device option, so the PPI is the same on all VCPUs.

Signed-off-by: Andre Przywara &lt;andre.przywara@arm.com&gt;
[added some bits of documentation]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20250225172930.1850838-16-maz@kernel.org
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The VGIC maintenance IRQ signals various conditions about the LRs, when
the GIC's virtualization extension is used.
So far we didn't need it, but nested virtualization needs to know about
this interrupt, so add a userland interface to setup the IRQ number.
The architecture mandates that it must be a PPI, on top of that this code
only exports a per-device option, so the PPI is the same on all VCPUs.

Signed-off-by: Andre Przywara &lt;andre.przywara@arm.com&gt;
[added some bits of documentation]
Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Link: https://lore.kernel.org/r/20250225172930.1850838-16-maz@kernel.org
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm64: Introduce KVM_REG_ARM_VENDOR_HYP_BMAP_2</title>
<updated>2025-02-26T21:30:36+00:00</updated>
<author>
<name>Shameer Kolothum</name>
<email>shameerali.kolothum.thodi@huawei.com</email>
</author>
<published>2025-02-21T14:02:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=c0000e58c74eed0702b8271e8475378c3c17cf0f'/>
<id>c0000e58c74eed0702b8271e8475378c3c17cf0f</id>
<content type='text'>
The vendor_hyp_bmap bitmap holds the information about the Vendor Hyp
services available to the user space and can be get/set using
{G, S}ET_ONE_REG interfaces. This is done using the pseudo-firmware
bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP.

At present, this bitmap is a 64 bit one and since the function numbers
for newly added DISCOVER_IPML_* hypercalls are 64-65, introduce
another pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP_2.

Reviewed-by: Sebastian Ott &lt;sebott@redhat.com&gt;
Signed-off-by: Shameer Kolothum &lt;shameerali.kolothum.thodi@huawei.com&gt;
Link: https://lore.kernel.org/r/20250221140229.12588-4-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The vendor_hyp_bmap bitmap holds the information about the Vendor Hyp
services available to the user space and can be get/set using
{G, S}ET_ONE_REG interfaces. This is done using the pseudo-firmware
bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP.

At present, this bitmap is a 64 bit one and since the function numbers
for newly added DISCOVER_IPML_* hypercalls are 64-65, introduce
another pseudo-firmware bitmap register KVM_REG_ARM_VENDOR_HYP_BMAP_2.

Reviewed-by: Sebastian Ott &lt;sebott@redhat.com&gt;
Signed-off-by: Shameer Kolothum &lt;shameerali.kolothum.thodi@huawei.com&gt;
Link: https://lore.kernel.org/r/20250221140229.12588-4-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: arm64: Allow userspace to limit NV support to nVHE</title>
<updated>2025-02-24T19:30:17+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>maz@kernel.org</email>
</author>
<published>2025-02-20T13:49:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f83c41fb3dddbf47881249335a9718d2cdce0bd0'/>
<id>f83c41fb3dddbf47881249335a9718d2cdce0bd0</id>
<content type='text'>
NV is hard. No kidding.

In order to make things simpler, we have established that NV would
support two mutually exclusive configurations:

- VHE-only, and supporting recursive virtualisation

- nVHE-only, and not supporting recursive virtualisation

For that purpose, introduce a new vcpu feature flag that denotes
the second configuration. We use this flag to limit the idregs
further.

Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Reviewed-by: Joey Gouly &lt;joey.gouly@arm.com&gt;
Link: https://lore.kernel.org/r/20250220134907.554085-11-maz@kernel.org
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
NV is hard. No kidding.

In order to make things simpler, we have established that NV would
support two mutually exclusive configurations:

- VHE-only, and supporting recursive virtualisation

- nVHE-only, and not supporting recursive virtualisation

For that purpose, introduce a new vcpu feature flag that denotes
the second configuration. We use this flag to limit the idregs
further.

Signed-off-by: Marc Zyngier &lt;maz@kernel.org&gt;
Reviewed-by: Joey Gouly &lt;joey.gouly@arm.com&gt;
Link: https://lore.kernel.org/r/20250220134907.554085-11-maz@kernel.org
Signed-off-by: Oliver Upton &lt;oliver.upton@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2025-01-25T17:55:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-01-25T17:55:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=0f8e26b38d7ac72b3ad764944a25dd5808f37a6e'/>
<id>0f8e26b38d7ac72b3ad764944a25dd5808f37a6e</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "Loongarch:

   - Clear LLBCTL if secondary mmu mapping changes

   - Add hypercall service support for usermode VMM

  x86:

   - Add a comment to kvm_mmu_do_page_fault() to explain why KVM
     performs a direct call to kvm_tdp_page_fault() when RETPOLINE is
     enabled

   - Ensure that all SEV code is compiled out when disabled in Kconfig,
     even if building with less brilliant compilers

   - Remove a redundant TLB flush on AMD processors when guest CR4.PGE
     changes

   - Use str_enabled_disabled() to replace open coded strings

   - Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's
     APICv cache prior to every VM-Enter

   - Overhaul KVM's CPUID feature infrastructure to track all vCPU
     capabilities instead of just those where KVM needs to manage state
     and/or explicitly enable the feature in hardware. Along the way,
     refactor the code to make it easier to add features, and to make it
     more self-documenting how KVM is handling each feature

   - Rework KVM's handling of VM-Exits during event vectoring; this
     plugs holes where KVM unintentionally puts the vCPU into infinite
     loops in some scenarios (e.g. if emulation is triggered by the
     exit), and brings parity between VMX and SVM

   - Add pending request and interrupt injection information to the
     kvm_exit and kvm_entry tracepoints respectively

   - Fix a relatively benign flaw where KVM would end up redoing RDPKRU
     when loading guest/host PKRU, due to a refactoring of the kernel
     helpers that didn't account for KVM's pre-checking of the need to
     do WRPKRU

   - Make the completion of hypercalls go through the complete_hypercall
     function pointer argument, no matter if the hypercall exits to
     userspace or not.

     Previously, the code assumed that KVM_HC_MAP_GPA_RANGE specifically
     went to userspace, and all the others did not; the new code need
     not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
     all whether there was an exit to userspace or not

   - As part of enabling TDX virtual machines, support support
     separation of private/shared EPT into separate roots.

     When TDX will be enabled, operations on private pages will need to
     go through the privileged TDX Module via SEAMCALLs; as a result,
     they are limited and relatively slow compared to reading a PTE.

     The patches included in 6.14 allow KVM to keep a mirror of the
     private EPT in host memory, and define entries in kvm_x86_ops to
     operate on external page tables such as the TDX private EPT

   - The recently introduced conversion of the NX-page reclamation
     kthread to vhost_task moved the task under the main process. The
     task is created as soon as KVM_CREATE_VM was invoked and this, of
     course, broke userspace that didn't expect to see any child task of
     the VM process until it started creating its own userspace threads.

     In particular crosvm refuses to fork() if procfs shows any child
     task, so unbreak it by creating the task lazily. This is arguably a
     userspace bug, as there can be other kinds of legitimate worker
     tasks and they wouldn't impede fork(); but it's not like userspace
     has a way to distinguish kernel worker tasks right now. Should they
     show as "Kthread: 1" in proc/.../status?

  x86 - Intel:

   - Fix a bug where KVM updates hardware's APICv cache of the highest
     ISR bit while L2 is active, while ultimately results in a
     hardware-accelerated L1 EOI effectively being lost

   - Honor event priority when emulating Posted Interrupt delivery
     during nested VM-Enter by queueing KVM_REQ_EVENT instead of
     immediately handling the interrupt

   - Rework KVM's processing of the Page-Modification Logging buffer to
     reap entries in the same order they were created, i.e. to mark gfns
     dirty in the same order that hardware marked the page/PTE dirty

   - Misc cleanups

  Generic:

   - Cleanup and harden kvm_set_memory_region(); add proper lockdep
     assertions when setting memory regions and add a dedicated API for
     setting KVM-internal memory regions. The API can then explicitly
     disallow all flags for KVM-internal memory regions

   - Explicitly verify the target vCPU is online in kvm_get_vcpu() to
     fix a bug where KVM would return a pointer to a vCPU prior to it
     being fully online, and give kvm_for_each_vcpu() similar treatment
     to fix a similar flaw

   - Wait for a vCPU to come online prior to executing a vCPU ioctl, to
     fix a bug where userspace could coerce KVM into handling the ioctl
     on a vCPU that isn't yet onlined

   - Gracefully handle xarray insertion failures; even though such
     failures are impossible in practice after xa_reserve(), reserving
     an entry is always followed by xa_store() which does not know (or
     differentiate) whether there was an xa_reserve() before or not

  RISC-V:

   - Zabha, Svvptc, and Ziccrse extension support for guests. None of
     them require anything in KVM except for detecting them and marking
     them as supported; Zabha adds byte and halfword atomic operations,
     while the others are markers for specific operation of the TLB and
     of LL/SC instructions respectively

   - Virtualize SBI system suspend extension for Guest/VM

   - Support firmware counters which can be used by the guests to
     collect statistics about traps that occur in the host

  Selftests:

   - Rework vcpu_get_reg() to return a value instead of using an
     out-param, and update all affected arch code accordingly

   - Convert the max_guest_memory_test into a more generic
     mmu_stress_test. The basic gist of the "conversion" is to have the
     test do mprotect() on guest memory while vCPUs are accessing said
     memory, e.g. to verify KVM and mmu_notifiers are working as
     intended

   - Play nice with treewrite builds of unsupported architectures, e.g.
     arm (32-bit), as KVM selftests' Makefile doesn't do anything to
     ensure the target architecture is actually one KVM selftests
     supports

   - Use the kernel's $(ARCH) definition instead of the target triple
     for arch specific directories, e.g. arm64 instead of aarch64,
     mainly so as not to be different from the rest of the kernel

   - Ensure that format strings for logging statements are checked by
     the compiler even when the logging statement itself is disabled

   - Attempt to whack the last LLC references/misses mole in the Intel
     PMU counters test by adding a data load and doing CLFLUSH{OPT} on
     the data instead of the code being executed. It seems that modern
     Intel CPUs have learned new code prefetching tricks that bypass the
     PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that
     events are counting correctly without actually knowing what the
     events count given the underlying hardware; this can happen if
     Intel reuses a formerly microarchitecture-specific event encoding
     as an architectural event, as was the case for Top-Down Slots"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (151 commits)
  kvm: defer huge page recovery vhost task to later
  KVM: x86/mmu: Return RET_PF* instead of 1 in kvm_mmu_page_fault()
  KVM: Disallow all flags for KVM-internal memslots
  KVM: x86: Drop double-underscores from __kvm_set_memory_region()
  KVM: Add a dedicated API for setting KVM-internal memslots
  KVM: Assert slots_lock is held when setting memory regions
  KVM: Open code kvm_set_memory_region() into its sole caller (ioctl() API)
  LoongArch: KVM: Add hypercall service support for usermode VMM
  LoongArch: KVM: Clear LLBCTL if secondary mmu mapping is changed
  KVM: SVM: Use str_enabled_disabled() helper in svm_hardware_setup()
  KVM: VMX: read the PML log in the same order as it was written
  KVM: VMX: refactor PML terminology
  KVM: VMX: Fix comment of handle_vmx_instruction()
  KVM: VMX: Reinstate __exit attribute for vmx_exit()
  KVM: SVM: Use str_enabled_disabled() helper in sev_hardware_setup()
  KVM: x86: Avoid double RDPKRU when loading host/guest PKRU
  KVM: x86: Use LVT_TIMER instead of an open coded literal
  RISC-V: KVM: Add new exit statstics for redirected traps
  RISC-V: KVM: Update firmware counters for various events
  RISC-V: KVM: Redirect instruction access fault trap to guest
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kvm updates from Paolo Bonzini:
 "Loongarch:

   - Clear LLBCTL if secondary mmu mapping changes

   - Add hypercall service support for usermode VMM

  x86:

   - Add a comment to kvm_mmu_do_page_fault() to explain why KVM
     performs a direct call to kvm_tdp_page_fault() when RETPOLINE is
     enabled

   - Ensure that all SEV code is compiled out when disabled in Kconfig,
     even if building with less brilliant compilers

   - Remove a redundant TLB flush on AMD processors when guest CR4.PGE
     changes

   - Use str_enabled_disabled() to replace open coded strings

   - Drop kvm_x86_ops.hwapic_irr_update() as KVM updates hardware's
     APICv cache prior to every VM-Enter

   - Overhaul KVM's CPUID feature infrastructure to track all vCPU
     capabilities instead of just those where KVM needs to manage state
     and/or explicitly enable the feature in hardware. Along the way,
     refactor the code to make it easier to add features, and to make it
     more self-documenting how KVM is handling each feature

   - Rework KVM's handling of VM-Exits during event vectoring; this
     plugs holes where KVM unintentionally puts the vCPU into infinite
     loops in some scenarios (e.g. if emulation is triggered by the
     exit), and brings parity between VMX and SVM

   - Add pending request and interrupt injection information to the
     kvm_exit and kvm_entry tracepoints respectively

   - Fix a relatively benign flaw where KVM would end up redoing RDPKRU
     when loading guest/host PKRU, due to a refactoring of the kernel
     helpers that didn't account for KVM's pre-checking of the need to
     do WRPKRU

   - Make the completion of hypercalls go through the complete_hypercall
     function pointer argument, no matter if the hypercall exits to
     userspace or not.

     Previously, the code assumed that KVM_HC_MAP_GPA_RANGE specifically
     went to userspace, and all the others did not; the new code need
     not special case KVM_HC_MAP_GPA_RANGE and in fact does not care at
     all whether there was an exit to userspace or not

   - As part of enabling TDX virtual machines, support support
     separation of private/shared EPT into separate roots.

     When TDX will be enabled, operations on private pages will need to
     go through the privileged TDX Module via SEAMCALLs; as a result,
     they are limited and relatively slow compared to reading a PTE.

     The patches included in 6.14 allow KVM to keep a mirror of the
     private EPT in host memory, and define entries in kvm_x86_ops to
     operate on external page tables such as the TDX private EPT

   - The recently introduced conversion of the NX-page reclamation
     kthread to vhost_task moved the task under the main process. The
     task is created as soon as KVM_CREATE_VM was invoked and this, of
     course, broke userspace that didn't expect to see any child task of
     the VM process until it started creating its own userspace threads.

     In particular crosvm refuses to fork() if procfs shows any child
     task, so unbreak it by creating the task lazily. This is arguably a
     userspace bug, as there can be other kinds of legitimate worker
     tasks and they wouldn't impede fork(); but it's not like userspace
     has a way to distinguish kernel worker tasks right now. Should they
     show as "Kthread: 1" in proc/.../status?

  x86 - Intel:

   - Fix a bug where KVM updates hardware's APICv cache of the highest
     ISR bit while L2 is active, while ultimately results in a
     hardware-accelerated L1 EOI effectively being lost

   - Honor event priority when emulating Posted Interrupt delivery
     during nested VM-Enter by queueing KVM_REQ_EVENT instead of
     immediately handling the interrupt

   - Rework KVM's processing of the Page-Modification Logging buffer to
     reap entries in the same order they were created, i.e. to mark gfns
     dirty in the same order that hardware marked the page/PTE dirty

   - Misc cleanups

  Generic:

   - Cleanup and harden kvm_set_memory_region(); add proper lockdep
     assertions when setting memory regions and add a dedicated API for
     setting KVM-internal memory regions. The API can then explicitly
     disallow all flags for KVM-internal memory regions

   - Explicitly verify the target vCPU is online in kvm_get_vcpu() to
     fix a bug where KVM would return a pointer to a vCPU prior to it
     being fully online, and give kvm_for_each_vcpu() similar treatment
     to fix a similar flaw

   - Wait for a vCPU to come online prior to executing a vCPU ioctl, to
     fix a bug where userspace could coerce KVM into handling the ioctl
     on a vCPU that isn't yet onlined

   - Gracefully handle xarray insertion failures; even though such
     failures are impossible in practice after xa_reserve(), reserving
     an entry is always followed by xa_store() which does not know (or
     differentiate) whether there was an xa_reserve() before or not

  RISC-V:

   - Zabha, Svvptc, and Ziccrse extension support for guests. None of
     them require anything in KVM except for detecting them and marking
     them as supported; Zabha adds byte and halfword atomic operations,
     while the others are markers for specific operation of the TLB and
     of LL/SC instructions respectively

   - Virtualize SBI system suspend extension for Guest/VM

   - Support firmware counters which can be used by the guests to
     collect statistics about traps that occur in the host

  Selftests:

   - Rework vcpu_get_reg() to return a value instead of using an
     out-param, and update all affected arch code accordingly

   - Convert the max_guest_memory_test into a more generic
     mmu_stress_test. The basic gist of the "conversion" is to have the
     test do mprotect() on guest memory while vCPUs are accessing said
     memory, e.g. to verify KVM and mmu_notifiers are working as
     intended

   - Play nice with treewrite builds of unsupported architectures, e.g.
     arm (32-bit), as KVM selftests' Makefile doesn't do anything to
     ensure the target architecture is actually one KVM selftests
     supports

   - Use the kernel's $(ARCH) definition instead of the target triple
     for arch specific directories, e.g. arm64 instead of aarch64,
     mainly so as not to be different from the rest of the kernel

   - Ensure that format strings for logging statements are checked by
     the compiler even when the logging statement itself is disabled

   - Attempt to whack the last LLC references/misses mole in the Intel
     PMU counters test by adding a data load and doing CLFLUSH{OPT} on
     the data instead of the code being executed. It seems that modern
     Intel CPUs have learned new code prefetching tricks that bypass the
     PMU counters

   - Fix a flaw in the Intel PMU counters test where it asserts that
     events are counting correctly without actually knowing what the
     events count given the underlying hardware; this can happen if
     Intel reuses a formerly microarchitecture-specific event encoding
     as an architectural event, as was the case for Top-Down Slots"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (151 commits)
  kvm: defer huge page recovery vhost task to later
  KVM: x86/mmu: Return RET_PF* instead of 1 in kvm_mmu_page_fault()
  KVM: Disallow all flags for KVM-internal memslots
  KVM: x86: Drop double-underscores from __kvm_set_memory_region()
  KVM: Add a dedicated API for setting KVM-internal memslots
  KVM: Assert slots_lock is held when setting memory regions
  KVM: Open code kvm_set_memory_region() into its sole caller (ioctl() API)
  LoongArch: KVM: Add hypercall service support for usermode VMM
  LoongArch: KVM: Clear LLBCTL if secondary mmu mapping is changed
  KVM: SVM: Use str_enabled_disabled() helper in svm_hardware_setup()
  KVM: VMX: read the PML log in the same order as it was written
  KVM: VMX: refactor PML terminology
  KVM: VMX: Fix comment of handle_vmx_instruction()
  KVM: VMX: Reinstate __exit attribute for vmx_exit()
  KVM: SVM: Use str_enabled_disabled() helper in sev_hardware_setup()
  KVM: x86: Avoid double RDPKRU when loading host/guest PKRU
  KVM: x86: Use LVT_TIMER instead of an open coded literal
  RISC-V: KVM: Add new exit statstics for redirected traps
  RISC-V: KVM: Update firmware counters for various events
  RISC-V: KVM: Redirect instruction access fault trap to guest
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64/hwcap: Describe 2024 dpISA extensions to userspace</title>
<updated>2025-01-08T13:41:06+00:00</updated>
<author>
<name>Mark Brown</name>
<email>broonie@kernel.org</email>
</author>
<published>2025-01-07T22:59:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=819935464cb2f72fff8dfbbf95cf2726d4a66388'/>
<id>819935464cb2f72fff8dfbbf95cf2726d4a66388</id>
<content type='text'>
The 2024 dpISA introduces a number of architecture features all of which
only add new instructions so only require the addition of hwcaps and ID
register visibility.

Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-3-7578da51fc3d@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The 2024 dpISA introduces a number of architecture features all of which
only add new instructions so only require the addition of hwcaps and ID
register visibility.

Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20250107-arm64-2024-dpisa-v5-3-7578da51fc3d@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: Move KVM_REG_SIZE() definition to common uAPI header</title>
<updated>2024-12-17T16:49:48+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2024-11-28T00:55:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=915d2f0718a42ee0b334be34cc53664a865a5928'/>
<id>915d2f0718a42ee0b334be34cc53664a865a5928</id>
<content type='text'>
Define KVM_REG_SIZE() in the common kvm.h header, and delete the arm64 and
RISC-V versions.  As evidenced by the surrounding definitions, all aspects
of the register size encoding are generic, i.e. RISC-V should have moved
arm64's definition to common code instead of copy+pasting.

Acked-by: Anup Patel &lt;anup@brainfault.org&gt;
Reviewed-by: Andrew Jones &lt;ajones@ventanamicro.com&gt;
Reviewed-by: Muhammad Usama Anjum &lt;usama.anjum@collabora.com&gt;
Link: https://lore.kernel.org/r/20241128005547.4077116-2-seanjc@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Define KVM_REG_SIZE() in the common kvm.h header, and delete the arm64 and
RISC-V versions.  As evidenced by the surrounding definitions, all aspects
of the register size encoding are generic, i.e. RISC-V should have moved
arm64's definition to common code instead of copy+pasting.

Acked-by: Anup Patel &lt;anup@brainfault.org&gt;
Reviewed-by: Andrew Jones &lt;ajones@ventanamicro.com&gt;
Reviewed-by: Muhammad Usama Anjum &lt;usama.anjum@collabora.com&gt;
Link: https://lore.kernel.org/r/20241128005547.4077116-2-seanjc@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm</title>
<updated>2024-11-24T00:00:50+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-24T00:00:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=9f16d5e6f220661f73b36a4be1b21575651d8833'/>
<id>9f16d5e6f220661f73b36a4be1b21575651d8833</id>
<content type='text'>
Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu-&gt;pid accesses outside of vcpu-&gt;mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kvm updates from Paolo Bonzini:
 "The biggest change here is eliminating the awful idea that KVM had of
  essentially guessing which pfns are refcounted pages.

  The reason to do so was that KVM needs to map both non-refcounted
  pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP
  VMAs that contain refcounted pages.

  However, the result was security issues in the past, and more recently
  the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by
  struct page but is not refcounted. In particular this broke virtio-gpu
  blob resources (which directly map host graphics buffers into the
  guest as "vram" for the virtio-gpu device) with the amdgpu driver,
  because amdgpu allocates non-compound higher order pages and the tail
  pages could not be mapped into KVM.

  This requires adjusting all uses of struct page in the
  per-architecture code, to always work on the pfn whenever possible.
  The large series that did this, from David Stevens and Sean
  Christopherson, also cleaned up substantially the set of functions
  that provided arch code with the pfn for a host virtual addresses.

  The previous maze of twisty little passages, all different, is
  replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the
  non-__ versions of these two, and kvm_prefetch_pages) saving almost
  200 lines of code.

  ARM:

   - Support for stage-1 permission indirection (FEAT_S1PIE) and
     permission overlays (FEAT_S1POE), including nested virt + the
     emulated page table walker

   - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This
     call was introduced in PSCIv1.3 as a mechanism to request
     hibernation, similar to the S4 state in ACPI

   - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As
     part of it, introduce trivial initialization of the host's MPAM
     context so KVM can use the corresponding traps

   - PMU support under nested virtualization, honoring the guest
     hypervisor's trap configuration and event filtering when running a
     nested guest

   - Fixes to vgic ITS serialization where stale device/interrupt table
     entries are not zeroed when the mapping is invalidated by the VM

   - Avoid emulated MMIO completion if userspace has requested
     synchronous external abort injection

   - Various fixes and cleanups affecting pKVM, vCPU initialization, and
     selftests

  LoongArch:

   - Add iocsr and mmio bus simulation in kernel.

   - Add in-kernel interrupt controller emulation.

   - Add support for virtualization extensions to the eiointc irqchip.

  PPC:

   - Drop lingering and utterly obsolete references to PPC970 KVM, which
     was removed 10 years ago.

   - Fix incorrect documentation references to non-existing ioctls

  RISC-V:

   - Accelerate KVM RISC-V when running as a guest

   - Perf support to collect KVM guest statistics from host side

  s390:

   - New selftests: more ucontrol selftests and CPU model sanity checks

   - Support for the gen17 CPU model

   - List registers supported by KVM_GET/SET_ONE_REG in the
     documentation

  x86:

   - Cleanup KVM's handling of Accessed and Dirty bits to dedup code,
     improve documentation, harden against unexpected changes.

     Even if the hardware A/D tracking is disabled, it is possible to
     use the hardware-defined A/D bits to track if a PFN is Accessed
     and/or Dirty, and that removes a lot of special cases.

   - Elide TLB flushes when aging secondary PTEs, as has been done in
     x86's primary MMU for over 10 years.

   - Recover huge pages in-place in the TDP MMU when dirty page logging
     is toggled off, instead of zapping them and waiting until the page
     is re-accessed to create a huge mapping. This reduces vCPU jitter.

   - Batch TLB flushes when dirty page logging is toggled off. This
     reduces the time it takes to disable dirty logging by ~3x.

   - Remove the shrinker that was (poorly) attempting to reclaim shadow
     page tables in low-memory situations.

   - Clean up and optimize KVM's handling of writes to
     MSR_IA32_APICBASE.

   - Advertise CPUIDs for new instructions in Clearwater Forest

   - Quirk KVM's misguided behavior of initialized certain feature MSRs
     to their maximum supported feature set, which can result in KVM
     creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to
     a non-zero value results in the vCPU having invalid state if
     userspace hides PDCM from the guest, which in turn can lead to
     save/restore failures.

   - Fix KVM's handling of non-canonical checks for vCPUs that support
     LA57 to better follow the "architecture", in quotes because the
     actual behavior is poorly documented. E.g. most MSR writes and
     descriptor table loads ignore CR4.LA57 and operate purely on
     whether the CPU supports LA57.

   - Bypass the register cache when querying CPL from kvm_sched_out(),
     as filling the cache from IRQ context is generally unsafe; harden
     the cache accessors to try to prevent similar issues from occuring
     in the future. The issue that triggered this change was already
     fixed in 6.12, but was still kinda latent.

   - Advertise AMD_IBPB_RET to userspace, and fix a related bug where
     KVM over-advertises SPEC_CTRL when trying to support cross-vendor
     VMs.

   - Minor cleanups

   - Switch hugepage recovery thread to use vhost_task.

     These kthreads can consume significant amounts of CPU time on
     behalf of a VM or in response to how the VM behaves (for example
     how it accesses its memory); therefore KVM tried to place the
     thread in the VM's cgroups and charge the CPU time consumed by that
     work to the VM's container.

     However the kthreads did not process SIGSTOP/SIGCONT, and therefore
     cgroups which had KVM instances inside could not complete freezing.

     Fix this by replacing the kthread with a PF_USER_WORKER thread, via
     the vhost_task abstraction. Another 100+ lines removed, with
     generally better behavior too like having these threads properly
     parented in the process tree.

   - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that
     didn't really work; there was really nothing to work around anyway:
     the broken patch was meant to fix nested virtualization, but the
     PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the
     erratum.

   - Fix 6.12 regression where CONFIG_KVM will be built as a module even
     if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is
     'y'.

  x86 selftests:

   - x86 selftests can now use AVX.

  Documentation:

   - Use rST internal links

   - Reorganize the introduction to the API document

  Generic:

   - Protect vcpu-&gt;pid accesses outside of vcpu-&gt;mutex with a rwlock
     instead of RCU, so that running a vCPU on a different task doesn't
     encounter long due to having to wait for all CPUs become quiescent.

     In general both reads and writes are rare, but userspace that
     supports confidential computing is introducing the use of "helper"
     vCPUs that may jump from one host processor to another. Those will
     be very happy to trigger a synchronize_rcu(), and the effect on
     performance is quite the disaster"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits)
  KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD
  KVM: x86: add back X86_LOCAL_APIC dependency
  Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()"
  KVM: x86: switch hugepage recovery thread to vhost_task
  KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR
  x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest
  Documentation: KVM: fix malformed table
  irqchip/loongson-eiointc: Add virt extension support
  LoongArch: KVM: Add irqfd support
  LoongArch: KVM: Add PCHPIC user mode read and write functions
  LoongArch: KVM: Add PCHPIC read and write functions
  LoongArch: KVM: Add PCHPIC device support
  LoongArch: KVM: Add EIOINTC user mode read and write functions
  LoongArch: KVM: Add EIOINTC read and write functions
  LoongArch: KVM: Add EIOINTC device support
  LoongArch: KVM: Add IPI user mode read and write function
  LoongArch: KVM: Add IPI read and write function
  LoongArch: KVM: Add IPI device support
  LoongArch: KVM: Add iocsr and mmio bus simulation in kernel
  KVM: arm64: Pass on SVE mapping failures
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'for-next/gcs', 'for-next/probes', 'for-next/asm-offsets', 'for-next/tlb', 'for-next/misc', 'for-next/mte', 'for-next/sysreg', 'for-next/stacktrace', 'for-next/hwcap3', 'for-next/kselftest', 'for-next/crc32', 'for-next/guest-cca', 'for-next/haft' and 'for-next/scs', remote-tracking branch 'arm64/for-next/perf' into for-next/core</title>
<updated>2024-11-14T12:07:16+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2024-11-14T12:07:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5a4332062e9e71de8e78dc1b389d21e0dd44848b'/>
<id>5a4332062e9e71de8e78dc1b389d21e0dd44848b</id>
<content type='text'>
* arm64/for-next/perf:
  perf: Switch back to struct platform_driver::remove()
  perf: arm_pmuv3: Add support for Samsung Mongoose PMU
  dt-bindings: arm: pmu: Add Samsung Mongoose core compatible
  perf/dwc_pcie: Fix typos in event names
  perf/dwc_pcie: Add support for Ampere SoCs
  ARM: pmuv3: Add missing write_pmuacr()
  perf/marvell: Marvell PEM performance monitor support
  perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control
  perf/dwc_pcie: Convert the events with mixed case to lowercase
  perf/cxlpmu: Support missing events in 3.1 spec
  perf: imx_perf: add support for i.MX91 platform
  dt-bindings: perf: fsl-imx-ddr: Add i.MX91 compatible
  drivers perf: remove unused field pmu_node

* for-next/gcs: (42 commits)
  : arm64 Guarded Control Stack user-space support
  kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c
  arm64/gcs: Fix outdated ptrace documentation
  kselftest/arm64: Ensure stable names for GCS stress test results
  kselftest/arm64: Validate that GCS push and write permissions work
  kselftest/arm64: Enable GCS for the FP stress tests
  kselftest/arm64: Add a GCS stress test
  kselftest/arm64: Add GCS signal tests
  kselftest/arm64: Add test coverage for GCS mode locking
  kselftest/arm64: Add a GCS test program built with the system libc
  kselftest/arm64: Add very basic GCS test program
  kselftest/arm64: Always run signals tests with GCS enabled
  kselftest/arm64: Allow signals tests to specify an expected si_code
  kselftest/arm64: Add framework support for GCS to signal handling tests
  kselftest/arm64: Add GCS as a detected feature in the signal tests
  kselftest/arm64: Verify the GCS hwcap
  arm64: Add Kconfig for Guarded Control Stack (GCS)
  arm64/ptrace: Expose GCS via ptrace and core files
  arm64/signal: Expose GCS state in signal frames
  arm64/signal: Set up and restore the GCS context for signal handlers
  arm64/mm: Implement map_shadow_stack()
  ...

* for-next/probes:
  : Various arm64 uprobes/kprobes cleanups
  arm64: insn: Simulate nop instruction for better uprobe performance
  arm64: probes: Remove probe_opcode_t
  arm64: probes: Cleanup kprobes endianness conversions
  arm64: probes: Move kprobes-specific fields
  arm64: probes: Fix uprobes for big-endian kernels
  arm64: probes: Fix simulate_ldr*_literal()
  arm64: probes: Remove broken LDR (literal) uprobe support

* for-next/asm-offsets:
  : arm64 asm-offsets.c cleanup (remove unused offsets)
  arm64: asm-offsets: remove PREEMPT_DISABLE_OFFSET
  arm64: asm-offsets: remove DMA_{TO,FROM}_DEVICE
  arm64: asm-offsets: remove VM_EXEC and PAGE_SZ
  arm64: asm-offsets: remove MM_CONTEXT_ID
  arm64: asm-offsets: remove COMPAT_{RT_,SIGFRAME_REGS_OFFSET
  arm64: asm-offsets: remove VMA_VM_*
  arm64: asm-offsets: remove TSK_ACTIVE_MM

* for-next/tlb:
  : TLB flushing optimisations
  arm64: optimize flush tlb kernel range
  arm64: tlbflush: add __flush_tlb_range_limit_excess()

* for-next/misc:
  : Miscellaneous patches
  arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
  arm64/ptrace: Clarify documentation of VL configuration via ptrace
  acpi/arm64: remove unnecessary cast
  arm64/mm: Change protval as 'pteval_t' in map_range()
  arm64: uprobes: Optimize cache flushes for xol slot
  acpi/arm64: Adjust error handling procedure in gtdt_parse_timer_block()
  arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG
  arm64/ptdump: Test both PTE_TABLE_BIT and PTE_VALID for block mappings
  arm64/mm: Sanity check PTE address before runtime P4D/PUD folding
  arm64/mm: Drop setting PTE_TYPE_PAGE in pte_mkcont()
  ACPI: GTDT: Tighten the check for the array of platform timer structures
  arm64/fpsimd: Fix a typo
  arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers
  arm64: Return early when break handler is found on linked-list
  arm64/mm: Re-organize arch_make_huge_pte()
  arm64/mm: Drop _PROT_SECT_DEFAULT
  arm64: Add command-line override for ID_AA64MMFR0_EL1.ECV
  arm64: head: Drop SWAPPER_TABLE_SHIFT
  arm64: cpufeature: add POE to cpucap_is_possible()
  arm64/mm: Change pgattr_change_is_safe() arguments as pteval_t

* for-next/mte:
  : Various MTE improvements
  selftests: arm64: add hugetlb mte tests
  hugetlb: arm64: add mte support

* for-next/sysreg:
  : arm64 sysreg updates
  arm64/sysreg: Update ID_AA64MMFR1_EL1 to DDI0601 2024-09

* for-next/stacktrace:
  : arm64 stacktrace improvements
  arm64: preserve pt_regs::stackframe during exec*()
  arm64: stacktrace: unwind exception boundaries
  arm64: stacktrace: split unwind_consume_stack()
  arm64: stacktrace: report recovered PCs
  arm64: stacktrace: report source of unwind data
  arm64: stacktrace: move dump_backtrace() to kunwind_stack_walk()
  arm64: use a common struct frame_record
  arm64: pt_regs: swap 'unused' and 'pmr' fields
  arm64: pt_regs: rename "pmr_save" -&gt; "pmr"
  arm64: pt_regs: remove stale big-endian layout
  arm64: pt_regs: assert pt_regs is a multiple of 16 bytes

* for-next/hwcap3:
  : Add AT_HWCAP3 support for arm64 (also wire up AT_HWCAP4)
  arm64: Support AT_HWCAP3
  binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4

* for-next/kselftest: (30 commits)
  : arm64 kselftest fixes/cleanups
  kselftest/arm64: Try harder to generate different keys during PAC tests
  kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()
  kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
  kselftest/arm64: Add FPMR coverage to fp-ptrace
  kselftest/arm64: Expand the set of ZA writes fp-ptrace does
  kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
  kselftest/arm64: Enable build of PAC tests with LLVM=1
  kselftest/arm64: Check that SVCR is 0 in signal handlers
  kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests
  kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
  kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests
  kselftest/arm64: Fix build with stricter assemblers
  kselftest/arm64: Test signal handler state modification in fp-stress
  kselftest/arm64: Provide a SIGUSR1 handler in the kernel mode FP stress test
  kselftest/arm64: Implement irritators for ZA and ZT
  kselftest/arm64: Remove unused ADRs from irritator handlers
  kselftest/arm64: Correct misleading comments on fp-stress irritators
  kselftest/arm64: Poll less often while waiting for fp-stress children
  kselftest/arm64: Increase frequency of signal delivery in fp-stress
  kselftest/arm64: Fix encoding for SVE B16B16 test
  ...

* for-next/crc32:
  : Optimise CRC32 using PMULL instructions
  arm64/crc32: Implement 4-way interleave using PMULL
  arm64/crc32: Reorganize bit/byte ordering macros
  arm64/lib: Handle CRC-32 alternative in C code

* for-next/guest-cca:
  : Support for running Linux as a guest in Arm CCA
  arm64: Document Arm Confidential Compute
  virt: arm-cca-guest: TSM_REPORT support for realms
  arm64: Enable memory encrypt for Realms
  arm64: mm: Avoid TLBI when marking pages as valid
  arm64: Enforce bounce buffers for realm DMA
  efi: arm64: Map Device with Prot Shared
  arm64: rsi: Map unprotected MMIO as decrypted
  arm64: rsi: Add support for checking whether an MMIO is protected
  arm64: realm: Query IPA size from the RMM
  arm64: Detect if in a realm and set RIPAS RAM
  arm64: rsi: Add RSI definitions

* for-next/haft:
  : Support for arm64 FEAT_HAFT
  arm64: pgtable: Warn unexpected pmdp_test_and_clear_young()
  arm64: Enable ARCH_HAS_NONLEAF_PMD_YOUNG
  arm64: Add support for FEAT_HAFT
  arm64: setup: name 'tcr2' register
  arm64/sysreg: Update ID_AA64MMFR1_EL1 register

* for-next/scs:
  : Dynamic shadow call stack fixes
  arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux()
  arm64/scs: Deal with 64-bit relative offsets in FDE frames
  arm64/scs: Fix handling of DWARF augmentation data in CIE/FDE frames
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* arm64/for-next/perf:
  perf: Switch back to struct platform_driver::remove()
  perf: arm_pmuv3: Add support for Samsung Mongoose PMU
  dt-bindings: arm: pmu: Add Samsung Mongoose core compatible
  perf/dwc_pcie: Fix typos in event names
  perf/dwc_pcie: Add support for Ampere SoCs
  ARM: pmuv3: Add missing write_pmuacr()
  perf/marvell: Marvell PEM performance monitor support
  perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control
  perf/dwc_pcie: Convert the events with mixed case to lowercase
  perf/cxlpmu: Support missing events in 3.1 spec
  perf: imx_perf: add support for i.MX91 platform
  dt-bindings: perf: fsl-imx-ddr: Add i.MX91 compatible
  drivers perf: remove unused field pmu_node

* for-next/gcs: (42 commits)
  : arm64 Guarded Control Stack user-space support
  kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c
  arm64/gcs: Fix outdated ptrace documentation
  kselftest/arm64: Ensure stable names for GCS stress test results
  kselftest/arm64: Validate that GCS push and write permissions work
  kselftest/arm64: Enable GCS for the FP stress tests
  kselftest/arm64: Add a GCS stress test
  kselftest/arm64: Add GCS signal tests
  kselftest/arm64: Add test coverage for GCS mode locking
  kselftest/arm64: Add a GCS test program built with the system libc
  kselftest/arm64: Add very basic GCS test program
  kselftest/arm64: Always run signals tests with GCS enabled
  kselftest/arm64: Allow signals tests to specify an expected si_code
  kselftest/arm64: Add framework support for GCS to signal handling tests
  kselftest/arm64: Add GCS as a detected feature in the signal tests
  kselftest/arm64: Verify the GCS hwcap
  arm64: Add Kconfig for Guarded Control Stack (GCS)
  arm64/ptrace: Expose GCS via ptrace and core files
  arm64/signal: Expose GCS state in signal frames
  arm64/signal: Set up and restore the GCS context for signal handlers
  arm64/mm: Implement map_shadow_stack()
  ...

* for-next/probes:
  : Various arm64 uprobes/kprobes cleanups
  arm64: insn: Simulate nop instruction for better uprobe performance
  arm64: probes: Remove probe_opcode_t
  arm64: probes: Cleanup kprobes endianness conversions
  arm64: probes: Move kprobes-specific fields
  arm64: probes: Fix uprobes for big-endian kernels
  arm64: probes: Fix simulate_ldr*_literal()
  arm64: probes: Remove broken LDR (literal) uprobe support

* for-next/asm-offsets:
  : arm64 asm-offsets.c cleanup (remove unused offsets)
  arm64: asm-offsets: remove PREEMPT_DISABLE_OFFSET
  arm64: asm-offsets: remove DMA_{TO,FROM}_DEVICE
  arm64: asm-offsets: remove VM_EXEC and PAGE_SZ
  arm64: asm-offsets: remove MM_CONTEXT_ID
  arm64: asm-offsets: remove COMPAT_{RT_,SIGFRAME_REGS_OFFSET
  arm64: asm-offsets: remove VMA_VM_*
  arm64: asm-offsets: remove TSK_ACTIVE_MM

* for-next/tlb:
  : TLB flushing optimisations
  arm64: optimize flush tlb kernel range
  arm64: tlbflush: add __flush_tlb_range_limit_excess()

* for-next/misc:
  : Miscellaneous patches
  arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
  arm64/ptrace: Clarify documentation of VL configuration via ptrace
  acpi/arm64: remove unnecessary cast
  arm64/mm: Change protval as 'pteval_t' in map_range()
  arm64: uprobes: Optimize cache flushes for xol slot
  acpi/arm64: Adjust error handling procedure in gtdt_parse_timer_block()
  arm64: fix .data.rel.ro size assertion when CONFIG_LTO_CLANG
  arm64/ptdump: Test both PTE_TABLE_BIT and PTE_VALID for block mappings
  arm64/mm: Sanity check PTE address before runtime P4D/PUD folding
  arm64/mm: Drop setting PTE_TYPE_PAGE in pte_mkcont()
  ACPI: GTDT: Tighten the check for the array of platform timer structures
  arm64/fpsimd: Fix a typo
  arm64: Expose ID_AA64ISAR1_EL1.XS to sanitised feature consumers
  arm64: Return early when break handler is found on linked-list
  arm64/mm: Re-organize arch_make_huge_pte()
  arm64/mm: Drop _PROT_SECT_DEFAULT
  arm64: Add command-line override for ID_AA64MMFR0_EL1.ECV
  arm64: head: Drop SWAPPER_TABLE_SHIFT
  arm64: cpufeature: add POE to cpucap_is_possible()
  arm64/mm: Change pgattr_change_is_safe() arguments as pteval_t

* for-next/mte:
  : Various MTE improvements
  selftests: arm64: add hugetlb mte tests
  hugetlb: arm64: add mte support

* for-next/sysreg:
  : arm64 sysreg updates
  arm64/sysreg: Update ID_AA64MMFR1_EL1 to DDI0601 2024-09

* for-next/stacktrace:
  : arm64 stacktrace improvements
  arm64: preserve pt_regs::stackframe during exec*()
  arm64: stacktrace: unwind exception boundaries
  arm64: stacktrace: split unwind_consume_stack()
  arm64: stacktrace: report recovered PCs
  arm64: stacktrace: report source of unwind data
  arm64: stacktrace: move dump_backtrace() to kunwind_stack_walk()
  arm64: use a common struct frame_record
  arm64: pt_regs: swap 'unused' and 'pmr' fields
  arm64: pt_regs: rename "pmr_save" -&gt; "pmr"
  arm64: pt_regs: remove stale big-endian layout
  arm64: pt_regs: assert pt_regs is a multiple of 16 bytes

* for-next/hwcap3:
  : Add AT_HWCAP3 support for arm64 (also wire up AT_HWCAP4)
  arm64: Support AT_HWCAP3
  binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4

* for-next/kselftest: (30 commits)
  : arm64 kselftest fixes/cleanups
  kselftest/arm64: Try harder to generate different keys during PAC tests
  kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()
  kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
  kselftest/arm64: Add FPMR coverage to fp-ptrace
  kselftest/arm64: Expand the set of ZA writes fp-ptrace does
  kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
  kselftest/arm64: Enabl