[PATCH v5 0/6] KVM: x86: Fix IOAPIC remote_irr and irr_delivered handling

[Hao Zhang <hao_zhang_kdev@163.com>]

From: Hao Zhang <zhanghao1@kylinos.cn>

Fix several cases where KVM updates IOAPIC interrupt state incorrectly.

The first fix avoids setting remote_irr when level-triggered interrupt
delivery fails, which can leave the pin blocked waiting for an EOI that
will never arrive.  The remaining fixes clean up irr_delivered handling
for edge-triggered interrupts, which affects the IOAPIC state exposed to
userspace through KVM_GET_IRQCHIP.

Changes in v5:
- Updated patch 1 changelog to explain the Fixes tag history and added
  Kai's Reviewed-by.
- Split selftest changes for the irr_delivered fixes into separate
  patches.
- Dropped the Fixes tag from the duplicate-edge patch, as the exact
  historical commit is unclear.

Hao Zhang (6):
  KVM: x86: ioapic: Update remote_irr only after successful delivery
  KVM: selftests: Verify failed IOAPIC delivery preserves state
  KVM: x86: ioapic: Preserve irr_delivered for duplicate edge interrupts
  KVM: selftests: Verify duplicate edge preserves IOAPIC state
  KVM: x86: ioapic: Clear irr_delivered on level-triggered RTE
  KVM: selftests: Verify edge-to-level clears IOAPIC state

 arch/x86/kvm/ioapic.c                              |  15 +-
 tools/testing/selftests/kvm/Makefile.kvm           |   1 +
 .../testing/selftests/kvm/x86/ioapic_state_test.c  | 190 +++++++++++++++++++++
 3 files changed, 203 insertions(+), 3 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/x86/ioapic_state_test.c


base-commit: c21bb4193868a8de71fc4693fa741e195fdf5d86

-- 
2.15.0