KVM: x86: Add I/O APIC kconfig, delete irq_comm.c

Add CONFIG_KVM_IOAPIC to allow disabling support for KVM's I/O APIC (and PIC
and PIT) emulation, and delete irq_comm.c by moving its contents to other
files.

Vitaly and Kai, I didn't apply your review/ack to the Hyper-V patch, as I ended
up keeping the helper as kvm_hv_synic_set_irq() to fix the tracepoint
inconsistency and the bad changelog.

v2:
 - Keep kvm_hv_synic_set_irq() instead of renaming it kvm_hv_set_sint() to
   stay consistent with kvm_pic_set_irq() and kvm_ioapic_set_irq(), and with
   its tracepoint. [Vitaly, Kai]
 - Keep kvm_setup_default_irq_routine() instead of folding it into I/O APIC
   allocation, but rename it to kvm_setup_default_ioapic_and_pic_routing().
   [Paolo].
 - Move a bit more code out of x86.c (this time into i8254.c).
 - Guard more code with CONFIG_KVM_IOAPIC (e.g. struct kvm_pit).
 - Fix a changelog typo. [Kai]
 - Collect Kai's Acked-by. [Kai]

v1: https://lore.kernel.org/all/20250519232808.2745331-1-sean...

Sean Christopherson (18):
  KVM: x86: Trigger I/O APIC route rescan in
    kvm_arch_irq_routing_update()
  KVM: x86: Drop superfluous kvm_set_pic_irq() => kvm_pic_set_irq()
    wrapper
  KVM: x86: Drop superfluous kvm_set_ioapic_irq() =>
    kvm_ioapic_set_irq() wrapper
  KVM: x86: Drop superfluous kvm_hv_set_sint() => kvm_hv_synic_set_irq()
    wrapper
  KVM: x86: Move PIT ioctl helpers to i8254.c
  KVM: x86: Move KVM_{GET,SET}_IRQCHIP ioctl helpers to irq.c
  KVM: x86: Rename irqchip_kernel() to irqchip_full()
  KVM: x86: Move kvm_setup_default_irq_routing() into irq.c
  KVM: x86: Move kvm_{request,free}_irq_source_id() to i8254.c (PIT)
  KVM: x86: Hardcode the PIT IRQ source ID to '2'
  KVM: x86: Don't clear PIT's IRQ line status when destroying PIT
  KVM: x86: Explicitly check for in-kernel PIC when getting ExtINT
  KVM: Move x86-only tracepoints to x86's trace.h
  KVM: x86: Add CONFIG_KVM_IOAPIC to allow disabling in-kernel I/O APIC
  KVM: Squash two CONFIG_HAVE_KVM_IRQCHIP #ifdefs into one
  KVM: selftests: Fall back to split IRQ chip if full in-kernel chip is
    unsupported
  KVM: x86: Move IRQ mask notifier infrastructure to I/O APIC emulation
  KVM: x86: Fold irq_comm.c into irq.c

 arch/x86/include/asm/kvm_host.h            |  22 +-
 arch/x86/kvm/Kconfig                       |  10 +
 arch/x86/kvm/Makefile                      |   7 +-
 arch/x86/kvm/hyperv.c                      |  10 +-
 arch/x86/kvm/hyperv.h                      |   3 +-
 arch/x86/kvm/i8254.c                       |  90 +++-
 arch/x86/kvm/i8254.h                       |  17 +-
 arch/x86/kvm/i8259.c                       |  17 +-
 arch/x86/kvm/ioapic.c                      |  55 ++-
 arch/x86/kvm/ioapic.h                      |  24 +-
 arch/x86/kvm/irq.c                         | 427 ++++++++++++++++++-
 arch/x86/kvm/irq.h                         |  35 +-
 arch/x86/kvm/irq_comm.c                    | 469 ---------------------
 arch/x86/kvm/lapic.c                       |   7 +-
 arch/x86/kvm/trace.h                       |  80 ++++
 arch/x86/kvm/x86.c                         | 164 +------
 include/linux/kvm_host.h                   |   9 +-
 include/trace/events/kvm.h                 |  84 +---
 tools/testing/selftests/kvm/lib/kvm_util.c |  13 +-
 virt/kvm/irqchip.c                         |   2 -
 20 files changed, 746 insertions(+), 799 deletions(-)
 delete mode 100644 arch/x86/kvm/irq_comm.c


base-commit: 61374cc145f4a56377eaf87c7409a97ec7a34041
-- 
2.50.0.rc1.591.g9c95f17f64-goog