[PATCH v2 0/2] KVM: x86: Fix max_irr reporting when PIR is empty despite PID.ON

[Chenyi Qiang <chenyi.qiang@intel.com>]

Fix a race in the PIR-to-IRR synchronization path where PID.ON is set
but PIR is empty, causing __kvm_apic_update_irr() to report max_irr as
-1 even though there are pending interrupts in the IRR.  This triggers a
spurious WARNING in vmx_check_nested_events() during nested VM stress
tests.

v2:
  - Move the fix from vmx_sync_pir_to_irr() to __kvm_apic_update_irr()
    as suggested by Paolo along with some commit message changes. [Paolo]
  - Add Cc: stable, Suggested-by, Reviewed-by tags.
  - Carry Sean's cleanup patch for variable renames and expanded
    comments. [Sean]

v1: https://lore.kernel.org/kvm/20260428070349.1633238-1-chenyi.qiang@intel.com/

Chenyi Qiang (1):
  KVM: x86: Always report highest IRR from __kvm_apic_update_irr()

Sean Christopherson (1):
  KVM: x86: Fix misleading variable names and add more comments for
    PIR=>IRR flow

 arch/x86/kvm/lapic.c   | 24 +++++++++++++-----------
 arch/x86/kvm/vmx/vmx.c | 40 ++++++++++++++++++++++++++++++++--------
 2 files changed, 45 insertions(+), 19 deletions(-)

-- 
2.43.5