linux-stable.git/arch/x86/kernel/apic, branch master

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2026-06-25T17:21:13+00:00

Pull kvm fixes from Paolo Bonzini:
 "s390:

   - Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
     unrelated capabilities

   - Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
     memory corruption in some scenarios

   - A bunch of misc gmap fixes (locking, behaviour under memory
     pressure)

   - Fix CMMA dirty tracking

  x86:

   - Tidy up some WARN_ON() and BUG_ON(), replacing them with
     WARN_ON_ONCE() or KVM_BUG_ON(). All of these have obviously never
     triggered, or somebody would have been annoyed earlier, but still...

   - Fix missing interrupt due to stale CR8 intercept

   - Add a statistic that can come in handy to debug leaks as well as
     the vulnerability to a class of recently-discovered issues

   - Do not ask arch/x86/kernel to export
     default_cpu_present_to_apicid() just for KVM"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
  x86/apic: KVM: Use cpu_physical_id() to get APIC ID of running vCPU for AVIC
  KVM: x86/mmu: Expose number of shadow MMU shadow pages as a stat
  KVM: x86: Unconditionally recompute CR8 intercept on PPR update
  KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode
  KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails
  KVM: x86: WARN and fail kvm_set_irq() if a PIC or I/O APIC vector is invalid
  KVM: x86: Bug the VM, not the kernel, if the ISR count {under,over}flows
  KVM: x86/mmu: Bug the VM, not the host kernel, if KVM write-protects upper SPTEs
  KVM: x86: Replace BUG_ON() with WARN_ON_ONCE() on "bad" nested GPA translation
  KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned()
  KVM: s390: Return failure in case of failure in kvm_s390_set_cmma_bits()
  KVM: s390: selftests: Fix cmma selftest
  KVM: s390: Fix cmma dirty tracking
  KVM: s390: Fix locking in kvm_s390_set_mem_control()
  KVM: s390: Fix handle_{sske,pfmf} under memory pressure
  KVM: s390: Fix code typo in gmap_protect_asce_top_level()
  KVM: s390: Do not set special large pages dirty
  KVM: s390: Fix dat_peek_cmma() overflow
  s390/mm: Fix handling of _PAGE_UNUSED pte bit
  KVM: s390: Fix typo in UCONTROL documentation
  ...

x86/apic: KVM: Use cpu_physical_id() to get APIC ID of running vCPU for AVIC

2026-06-24T11:52:24+00:00

Use cpu_physical_id() instead of default_cpu_present_to_apicid() when
getting the APIC ID of the pCPU on which a vCPU is running/loaded, as the
kernel has gone way off the rails if a vCPU is loaded on a pCPU that has
been physically removed from the system.  Even if the impossible were to
happen, the absolutely worst case scenario is that hardware will ring the
AIVC doorbell on the wrong pCPU, i.e. a severely broken system will
experience mild performance issues.

Kill off KVM's superfluous kvm_cpu_get_apicid() wrapper along with the
for-KVM export of default_cpu_present_to_apicid(), as they existed purely
for the wonky AVIC usage.

Cc: Kai Huang 
Cc: Yosry Ahmed 
Signed-off-by: Sean Christopherson 
Acked-by: Naveen N Rao (AMD) 
Reviewed-by: Kai Huang 
Reviewed-by: Yosry Ahmed 
Message-ID: <20260612185459.591892-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini

Merge tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

2026-06-15T09:55:17+00:00

Pull x86 cpuid updates from Ingo Molnar:

 - CPUID API updates (Ahmed S. Darwish):
    - Introduce a centralized CPUID parser
    - Introduce a centralized CPUID data model
    - Introduce 
    - Rename cpuid_leaf()/cpuid_subleaf() APIs
    - treewide: Explicitly include the x86 CPUID headers

 - Update to x86-cpuid-db v3.1 (Maciej Wieczor-Retman)

 - Continued removal of pre-i586 support and related simplifications
   (Ingo Molnar)

 - Add Intel CPU model number for rugged Panther Lake (Tony Luck)

 - Misc fixes, updates and cleanups by Arnd Bergmann, Chao Gao, Lukas
   Bulwahn, Sohil Mehta, Maciej Wieczor-Retman.

* tag 'x86-cpu-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (25 commits)
  x86/cpu: Make CONFIG_X86_CX8 unconditional
  x86/cpu: Remove unused !CONFIG_X86_TSC code
  x86/cpuid: Update bitfields to x86-cpuid-db v3.1
  tools/x86/kcpuid: Update bitfields to x86-cpuid-db v3.1
  x86/cpu: Make CONFIG_X86_TSC unconditional
  MAINTAINERS: Drop obsolete FPU EMULATOR section
  x86/cpu: Fix a F00F bug warning and clean up surrounding code
  x86/cpu: Add Intel CPU model number for rugged Panther Lake
  x86/cpuid: Introduce a centralized CPUID parser
  x86/cpu: Introduce a centralized CPUID data model
  x86/cpuid: Introduce 
  x86/cpuid: Rename cpuid_leaf()/cpuid_subleaf() APIs
  x86/cpu: Do not include the CPUID API header in asm/processor.h
  Documentation: core-api/cpu_hotplug: Remove stale cpu0_hotplug docs
  x86/cpu, cpufreq: Remove AMD ELAN support
  x86/fpu: Remove the math-emu/ FPU emulation library
  x86/fpu: Remove the 'no387' boot option
  x86/fpu: Remove MATH_EMULATION and related glue code
  treewide: Explicitly include the x86 CPUID headers
  x86/cpu: Remove the CONFIG_X86_INVD_BUG quirk
  ...

x86/irq: Move IOAPIC misrouted and PIC/APIC error counts into irq_stats

2026-05-26T14:21:12+00:00

The special treatment of these counts is just adding extra code for no real
value. The irq_stats mechanism allows to suppress output of counters, which
should never happen by default and provides a mechanism to enable them for
the rare case that they occur.

Move the IOAPIC misrouted and the PIC/APIC error counts into irq_stats,
mark them suppressed by default and update the sites which increment them.

This changes the output format of 'ERR' and 'MIS' in case there are events
to the regular per CPU display format and otherwise suppresses them
completely.

As a side effect this removes the arch_cpu_stat() mechanism from proc/stat
which was only there to account for the error interrupts on x86 and missed
to take the misrouted ones into account.

Signed-off-by: Thomas Gleixner 
Tested-by: Michael Kelley 
Reviewed-by: Radu Rendec 
Link: https://patch.msgid.link/20260517194931.361942103@kernel.org

x86/irq: Suppress unlikely interrupt stats by default

2026-05-26T14:21:12+00:00

Unlikely interrupt counters like the spurious vector and the synthetic APIC
ICR read retry show up in /proc/interrupts with all counts 0 most of the
time.

As these are events which should never happen, suppress them by default and
enable them for output when they actually happen.

This requires a seperate bitmap as the description array is marked
__ro_after_init. With that bitmap in place it becomes RO data.

Signed-off-by: Thomas Gleixner 
Tested-by: Michael Kelley 
Reviewed-by: Radu Rendec 
Link: https://patch.msgid.link/20260517194931.276486277@kernel.org

x86/irq: Make irqstats array based

2026-05-26T14:21:12+00:00

Having the x86 specific interrupt statistics as a data structure with
individual members instead of an array is just stupid as it requires
endless copy and paste in arch_show_interrupts() and arch_irq_stat_cpu(),
where the latter does not even take the latest interrupt additions into
account. The resulting #ifdef orgy is just disgusting.

Convert it to an array of counters, which does not make a difference in the
actual interrupt hotpath increment as the array index is constant and
therefore not any different than the member based access.

But in arch_show_interrupts() and arch_irq_stat_cpu() this just turns into
a loop, which reduces the text size by ~2k (~12%):

   text	   data	    bss	    dec	    hex	filename
  19643	  15250	    904	  35797	   8bd5	../build/arch/x86/kernel/irq.o
  17355	  15250	    904	  33509	   82e5	../build/arch/x86/kernel/irq.o

Adding a new vector or software counter only requires to update the table
and everything just works. Using the core provided emit function which
speeds up 0 outputs makes it significantly faster.

Signed-off-by: Thomas Gleixner 
Tested-by: Michael Kelley 
Reviewed-by: Radu Rendec 
Link: https://patch.msgid.link/20260517194931.196070643@kernel.org

treewide: Explicitly include the x86 CPUID headers

2026-05-06T12:29:59+00:00

Modify all CPUID call sites which implicitly include any of the CPUID
headers to explicitly include them instead.

For KVM's reverse_cpuid.h, just include  since it
references the CPUID_EAX..EDX symbols without using the CPUID APIs.

Note, this allows removing the inclusion of  from within
 next.  That allows the CPUID API headers to include
 without introducing a circular dependency.

Signed-off-by: Ahmed S. Darwish 
Signed-off-by: Borislav Petkov (AMD) 
Link: https://lore.kernel.org/20260327021645.555257-1-darwi@linutronix.de

Merge tag 'x86-cleanups-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-04-14T21:03:27+00:00

Pull x86 cleanups from Ingo Molnar:

 - Consolidate AMD and Hygon cases in parse_topology() (Wei Wang)

 - asm constraints cleanups in __iowrite32_copy() (Uros Bizjak)

 - Drop AMD Extended Interrupt LVT macros (Naveen N Rao)

 - Don't use REALLY_SLOW_IO for delays (Juergen Gross)

 - paravirt cleanups (Juergen Gross)

 - FPU code cleanups (Borislav Petkov)

 - split-lock handling code cleanups (Borislav Petkov, Ronan Pigott)

* tag 'x86-cleanups-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Correct the comment explaining what xfeatures_in_use() does
  x86/split_lock: Don't warn about unknown split_lock_detect parameter
  x86/fpu: Correct misspelled xfeaures_to_write local var
  x86/apic: Drop AMD Extended Interrupt LVT macros
  x86/cpu/topology: Consolidate AMD and Hygon cases in parse_topology()
  block/floppy: Don't use REALLY_SLOW_IO for delays
  x86/paravirt: Replace io_delay() hook with a bool
  x86/irqflags: Preemptively move include paravirt.h directive where it belongs
  x86/split_lock: Restructure the unwieldy switch-case in sld_state_show()
  x86/local: Remove trailing semicolon from _ASM_XADD in local_add_return()
  x86/asm: Use inout "+" asm onstraint modifiers in __iowrite32_copy()

Merge branch 'timers/urgent' into timers/core

2026-04-11T05:58:33+00:00

to resolve the conflict with urgent fixes.

x86/apic: Drop AMD Extended Interrupt LVT macros

2026-04-03T22:56:40+00:00

AMD defines Extended Interrupt Local Vector Table (EILVT) registers to allow
for additional interrupt sources. While the APIC registers for those are
unique to AMD, the format of those registers follows the standard LVT
registers. Drop EILVT-specific macros in favor of the standard APIC
LVT macros.

Drop unused APIC_EILVT_NR_AMD_K8 and APIC_EILVT_LVTOFF while at it.

No functional change.

  [ bp: Merge the two cleanup patches into one. ]

Signed-off-by: Naveen N Rao (AMD) 
Signed-off-by: Borislav Petkov (AMD) 
Tested-by: Manali Shukla 
Link: https://patch.msgid.link/b98d69037c0102d2ccd082a941888a689cd214c9.1775019269.git.naveen@kernel.org