<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/x86/include/uapi, branch v6.14</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<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.tavy.me/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>KVM: x86: Add a VM type define for TDX</title>
<updated>2024-12-23T13:28:55+00:00</updated>
<author>
<name>Rick Edgecombe</name>
<email>rick.p.edgecombe@intel.com</email>
</author>
<published>2024-07-18T21:12:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9364789567f9b49279b138f7d124f0c6db1d6589'/>
<id>9364789567f9b49279b138f7d124f0c6db1d6589</id>
<content type='text'>
Add a VM type define for TDX.

Future changes will need to lay the ground work for TDX support by
making some behavior conditional on the VM being a TDX guest.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Message-ID: &lt;20240718211230.1492011-4-rick.p.edgecombe@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a VM type define for TDX.

Future changes will need to lay the ground work for TDX support by
making some behavior conditional on the VM being a TDX guest.

Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Message-ID: &lt;20240718211230.1492011-4-rick.p.edgecombe@intel.com&gt;
Signed-off-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>platform/x86/amd/hsmp: Add support for HSMP protocol version 7 messages</title>
<updated>2024-12-02T17:20:14+00:00</updated>
<author>
<name>Suma Hegde</name>
<email>suma.hegde@amd.com</email>
</author>
<published>2024-11-18T10:27:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=836d0d7107e53e6479b60d32fb73bd5f7813e5d1'/>
<id>836d0d7107e53e6479b60d32fb73bd5f7813e5d1</id>
<content type='text'>
Following new HSMP messages are available on family 0x1A, model 0x00-0x1F
platforms with protocol version 7. Add support for them in the driver.
- SetXgmiPstateRange(26h)
- CpuRailIsoFreqPolicy(27h)
- DfcEnable(28h)
- GetRaplUnit(30h)
- GetRaplCoreCounter(31h)
- GetRaplPackageCounter(32h)

Also update HSMP message PwrEfficiencyModeSelection-21h. This message is
updated to include GET option in recent firmware.

Signed-off-by: Suma Hegde &lt;suma.hegde@amd.com&gt;
Reviewed-by: Naveen Krishna Chatradhi &lt;naveenkrishna.chatradhi@amd.com&gt;
Link: https://lore.kernel.org/r/20241118102752.11703-1-suma.hegde@amd.com
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Following new HSMP messages are available on family 0x1A, model 0x00-0x1F
platforms with protocol version 7. Add support for them in the driver.
- SetXgmiPstateRange(26h)
- CpuRailIsoFreqPolicy(27h)
- DfcEnable(28h)
- GetRaplUnit(30h)
- GetRaplCoreCounter(31h)
- GetRaplPackageCounter(32h)

Also update HSMP message PwrEfficiencyModeSelection-21h. This message is
updated to include GET option in recent firmware.

Signed-off-by: Suma Hegde &lt;suma.hegde@amd.com&gt;
Reviewed-by: Naveen Krishna Chatradhi &lt;naveenkrishna.chatradhi@amd.com&gt;
Link: https://lore.kernel.org/r/20241118102752.11703-1-suma.hegde@amd.com
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.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.tavy.me/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 tag 'platform-drivers-x86-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86</title>
<updated>2024-11-20T22:07:55+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-20T22:07:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fcb3ad4366b9c810cbb9da34c076a9a52d8aa1e0'/>
<id>fcb3ad4366b9c810cbb9da34c076a9a52d8aa1e0</id>
<content type='text'>
Pull x86 platform driver updates from Ilpo Järvinen:

 - alienware WMAX thermal interface support

 - Split ACPI and platform device based amd/hsmp drivers

 - AMD X3D frequency/cache mode switching support

 - asus thermal policy fixes

 - Disable C1 auto-demotion in suspend to allow entering the deepest
   C-states

 - Fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1

 - Replace intel_scu_ipc "workaround" with 32-bit IO

 - Correct *_show() function error handling in panasonic-laptop

 - Gemini Lake P2SB devfn correction

 - think-lmi Admin/System certificate authentication support

 - Disable WMI devices for shutdown, refactoring continues

 - Vexia EDU ATLA 10 tablet support

 - Surface Pro 9 5G (Arm/QCOM) support

 - Misc cleanups / refactoring / improvements

* tag 'platform-drivers-x86-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (69 commits)
  platform/x86: p2sb: Cache correct PCI bar for P2SB on Gemini Lake
  platform/x86: panasonic-laptop: Return errno correctly in show callback
  Documentation: alienware-wmi: Describe THERMAL_INFORMATION operation 0x02
  alienware-wmi: create_thermal_profile() no longer brute-forces IDs
  alienware-wmi: Adds support to Alienware x17 R2
  alienware-wmi: extends the list of supported models
  alienware-wmi: order alienware_quirks[] alphabetically
  platform/x86/intel/pmt: allow user offset for PMT callbacks
  platform/x86/amd/hsmp: Change the error type
  platform/x86/amd/hsmp: Add new error code and error logs
  platform/x86/amd: amd_3d_vcache: Add sysfs ABI documentation
  platform/x86/amd: amd_3d_vcache: Add AMD 3D V-Cache optimizer driver
  intel-hid: fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1
  platform/x86/amd/hsmp: mark hsmp_msg_desc_table[] as maybe_unused
  platform/x86: asus-wmi: Use platform_profile_cycle()
  platform/x86: asus-wmi: Fix inconsistent use of thermal policies
  platform/x86: hp: hp-bioscfg: remove redundant if statement
  MAINTAINERS: Update ISHTP ECLITE maintainer entry
  platform/x86: x86-android-tablets: Add support for Vexia EDU ATLA 10 tablet
  platform/x86: x86-android-tablets: Add support for getting i2c_adapter by PCI parent devname()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 platform driver updates from Ilpo Järvinen:

 - alienware WMAX thermal interface support

 - Split ACPI and platform device based amd/hsmp drivers

 - AMD X3D frequency/cache mode switching support

 - asus thermal policy fixes

 - Disable C1 auto-demotion in suspend to allow entering the deepest
   C-states

 - Fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1

 - Replace intel_scu_ipc "workaround" with 32-bit IO

 - Correct *_show() function error handling in panasonic-laptop

 - Gemini Lake P2SB devfn correction

 - think-lmi Admin/System certificate authentication support

 - Disable WMI devices for shutdown, refactoring continues

 - Vexia EDU ATLA 10 tablet support

 - Surface Pro 9 5G (Arm/QCOM) support

 - Misc cleanups / refactoring / improvements

* tag 'platform-drivers-x86-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (69 commits)
  platform/x86: p2sb: Cache correct PCI bar for P2SB on Gemini Lake
  platform/x86: panasonic-laptop: Return errno correctly in show callback
  Documentation: alienware-wmi: Describe THERMAL_INFORMATION operation 0x02
  alienware-wmi: create_thermal_profile() no longer brute-forces IDs
  alienware-wmi: Adds support to Alienware x17 R2
  alienware-wmi: extends the list of supported models
  alienware-wmi: order alienware_quirks[] alphabetically
  platform/x86/intel/pmt: allow user offset for PMT callbacks
  platform/x86/amd/hsmp: Change the error type
  platform/x86/amd/hsmp: Add new error code and error logs
  platform/x86/amd: amd_3d_vcache: Add sysfs ABI documentation
  platform/x86/amd: amd_3d_vcache: Add AMD 3D V-Cache optimizer driver
  intel-hid: fix volume buttons on Thinkpad X12 Detachable Tablet Gen 1
  platform/x86/amd/hsmp: mark hsmp_msg_desc_table[] as maybe_unused
  platform/x86: asus-wmi: Use platform_profile_cycle()
  platform/x86: asus-wmi: Fix inconsistent use of thermal policies
  platform/x86: hp: hp-bioscfg: remove redundant if statement
  MAINTAINERS: Update ISHTP ECLITE maintainer entry
  platform/x86: x86-android-tablets: Add support for Vexia EDU ATLA 10 tablet
  platform/x86: x86-android-tablets: Add support for getting i2c_adapter by PCI parent devname()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'ras_core_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-11-19T20:04:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-19T20:04:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c1f2ffe207a23b52d58923b1b34c2fd3d1b30494'/>
<id>c1f2ffe207a23b52d58923b1b34c2fd3d1b30494</id>
<content type='text'>
Pull RAS updates from Borislav Petkov:

 - Log and handle twp new AMD-specific MCA registers: SYND1 and SYND2
   and report the Field Replaceable Unit text info reported through them

 - Add support for handling variable-sized SMCA BERT records

 - Add the capability for reporting vendor-specific RAS error info
   without adding vendor-specific fields to struct mce

 - Cleanups

* tag 'ras_core_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/mce_amd: Add support for FRU text in MCA
  x86/mce/apei: Handle variable SMCA BERT record size
  x86/MCE/AMD: Add support for new MCA_SYND{1,2} registers
  tracing: Add __print_dynamic_array() helper
  x86/mce: Add wrapper for struct mce to export vendor specific info
  x86/mce/intel: Use MCG_BANKCNT_MASK instead of 0xff
  x86/mce/mcelog: Use xchg() to get and clear the flags
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull RAS updates from Borislav Petkov:

 - Log and handle twp new AMD-specific MCA registers: SYND1 and SYND2
   and report the Field Replaceable Unit text info reported through them

 - Add support for handling variable-sized SMCA BERT records

 - Add the capability for reporting vendor-specific RAS error info
   without adding vendor-specific fields to struct mce

 - Cleanups

* tag 'ras_core_for_v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  EDAC/mce_amd: Add support for FRU text in MCA
  x86/mce/apei: Handle variable SMCA BERT record size
  x86/MCE/AMD: Add support for new MCA_SYND{1,2} registers
  tracing: Add __print_dynamic_array() helper
  x86/mce: Add wrapper for struct mce to export vendor specific info
  x86/mce/intel: Use MCG_BANKCNT_MASK instead of 0xff
  x86/mce/mcelog: Use xchg() to get and clear the flags
</pre>
</div>
</content>
</entry>
<entry>
<title>platform/x86/amd/hsmp: mark hsmp_msg_desc_table[] as maybe_unused</title>
<updated>2024-11-12T10:15:36+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2024-10-28T16:35:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0d5e2d9b8fcb58116df2a201c54af60c1ac50bf2'/>
<id>0d5e2d9b8fcb58116df2a201c54af60c1ac50bf2</id>
<content type='text'>
After the file got split, there are now W=1 warnings for users that
include it without referencing hsmp_msg_desc_table:

In file included from arch/x86/include/asm/amd_hsmp.h:6,
                 from drivers/platform/x86/amd/hsmp/plat.c:12:
arch/x86/include/uapi/asm/amd_hsmp.h:91:35: error: 'hsmp_msg_desc_table' defined but not used [-Werror=unused-const-variable=]
   91 | static const struct hsmp_msg_desc hsmp_msg_desc_table[] = {
      |                                   ^~~~~~~~~~~~~~~~~~~

Mark it as __attribute__((maybe_unused)) to shut up the warning but
keep it in the file in case it is used from userland. The __maybe_unused
shorthand unfortunately isn't available in userspace, so this has to
be the long form.

While it is not envisioned a normal userspace program could benefit
from having this table as part of UAPI, it seems there is non-zero
chance this array is used by some userspace tests so it is retained for
now (see the Link below).

Fixes: e47c018a0ee6 ("platform/x86/amd/hsmp: Move platform device specific code to plat.c")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lore.kernel.org/platform-driver-x86/CAPhsuW7mDRswhVjYf+4iinO+sph_rQ1JykEof+apoiSOVwOXXQ@mail.gmail.com/
Link: https://lore.kernel.org/r/20241028163553.2452486-1-arnd@kernel.org
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After the file got split, there are now W=1 warnings for users that
include it without referencing hsmp_msg_desc_table:

In file included from arch/x86/include/asm/amd_hsmp.h:6,
                 from drivers/platform/x86/amd/hsmp/plat.c:12:
arch/x86/include/uapi/asm/amd_hsmp.h:91:35: error: 'hsmp_msg_desc_table' defined but not used [-Werror=unused-const-variable=]
   91 | static const struct hsmp_msg_desc hsmp_msg_desc_table[] = {
      |                                   ^~~~~~~~~~~~~~~~~~~

Mark it as __attribute__((maybe_unused)) to shut up the warning but
keep it in the file in case it is used from userland. The __maybe_unused
shorthand unfortunately isn't available in userspace, so this has to
be the long form.

While it is not envisioned a normal userspace program could benefit
from having this table as part of UAPI, it seems there is non-zero
chance this array is used by some userspace tests so it is retained for
now (see the Link below).

Fixes: e47c018a0ee6 ("platform/x86/amd/hsmp: Move platform device specific code to plat.c")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lore.kernel.org/platform-driver-x86/CAPhsuW7mDRswhVjYf+4iinO+sph_rQ1JykEof+apoiSOVwOXXQ@mail.gmail.com/
Link: https://lore.kernel.org/r/20241028163553.2452486-1-arnd@kernel.org
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration</title>
<updated>2024-11-01T16:22:31+00:00</updated>
<author>
<name>Sean Christopherson</name>
<email>seanjc@google.com</email>
</author>
<published>2024-08-02T18:55:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dcb988cdac85bad177de86fbf409524eda4f9467'/>
<id>dcb988cdac85bad177de86fbf409524eda4f9467</id>
<content type='text'>
Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore.  E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.

Link: https://lore.kernel.org/r/20240802185511.305849-4-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>
Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore.  E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.

Link: https://lore.kernel.org/r/20240802185511.305849-4-seanjc@google.com
Signed-off-by: Sean Christopherson &lt;seanjc@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/MCE/AMD: Add support for new MCA_SYND{1,2} registers</title>
<updated>2024-10-31T09:36:07+00:00</updated>
<author>
<name>Avadhut Naik</name>
<email>avadhut.naik@amd.com</email>
</author>
<published>2024-10-22T19:36:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d4fca1358ea9096f2f6ed942e2cb3a820073dfc1'/>
<id>d4fca1358ea9096f2f6ed942e2cb3a820073dfc1</id>
<content type='text'>
Starting with Zen4, AMD's Scalable MCA systems incorporate two new registers:
MCA_SYND1 and MCA_SYND2.

These registers will include supplemental error information in addition to the
existing MCA_SYND register. The data within these registers is considered
valid if MCA_STATUS[SyndV] is set.

Userspace error decoding tools like rasdaemon gather related hardware error
information through the tracepoints.

Therefore, export these two registers through the mce_record tracepoint so
that tools like rasdaemon can parse them and output the supplemental error
information like FRU text contained in them.

  [ bp: Massage. ]

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Avadhut Naik &lt;avadhut.naik@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Qiuxu Zhuo &lt;qiuxu.zhuo@intel.com&gt;
Link: https://lore.kernel.org/r/20241022194158.110073-4-avadhut.naik@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Starting with Zen4, AMD's Scalable MCA systems incorporate two new registers:
MCA_SYND1 and MCA_SYND2.

These registers will include supplemental error information in addition to the
existing MCA_SYND register. The data within these registers is considered
valid if MCA_STATUS[SyndV] is set.

Userspace error decoding tools like rasdaemon gather related hardware error
information through the tracepoints.

Therefore, export these two registers through the mce_record tracepoint so
that tools like rasdaemon can parse them and output the supplemental error
information like FRU text contained in them.

  [ bp: Massage. ]

Signed-off-by: Yazen Ghannam &lt;yazen.ghannam@amd.com&gt;
Signed-off-by: Avadhut Naik &lt;avadhut.naik@amd.com&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Qiuxu Zhuo &lt;qiuxu.zhuo@intel.com&gt;
Link: https://lore.kernel.org/r/20241022194158.110073-4-avadhut.naik@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>mman: Add map_shadow_stack() flags</title>
<updated>2024-10-04T11:04:33+00:00</updated>
<author>
<name>Mark Brown</name>
<email>broonie@kernel.org</email>
</author>
<published>2024-10-01T22:58:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3630e82ab6bd2642f0fc03b574783ccf2fb0c955'/>
<id>3630e82ab6bd2642f0fc03b574783ccf2fb0c955</id>
<content type='text'>
In preparation for adding arm64 GCS support make the map_shadow_stack()
SHADOW_STACK_SET_TOKEN flag generic and add _SET_MARKER. The existing
flag indicates that a token usable for stack switch should be added to
the top of the newly mapped GCS region while the new flag indicates that
a top of stack marker suitable for use by unwinders should be added
above that.

For arm64 the top of stack marker is all bits 0.

Reviewed-by: Thiago Jung Bauermann &lt;thiago.bauermann@linaro.org&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Yury Khrustalev &lt;yury.khrustalev@arm.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-5-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation for adding arm64 GCS support make the map_shadow_stack()
SHADOW_STACK_SET_TOKEN flag generic and add _SET_MARKER. The existing
flag indicates that a token usable for stack switch should be added to
the top of the newly mapped GCS region while the new flag indicates that
a top of stack marker suitable for use by unwinders should be added
above that.

For arm64 the top of stack marker is all bits 0.

Reviewed-by: Thiago Jung Bauermann &lt;thiago.bauermann@linaro.org&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Yury Khrustalev &lt;yury.khrustalev@arm.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-5-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
