[PATCH 0/2] LoongArch: KVM: Fix PC double advance in MMIO read fast path

Zeng Chi <[email protected]> Thu, 23 Jul 2026 19:03:29 +0800
Newsgroups dev.linux.lists.loongarch,org.kernel.vger.kvm,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
From: Zeng Chi <[email protected]>

This series fixes a bug where the guest PC is advanced twice in the
in-kernel MMIO read fast path, causing the instruction immediately
following the MMIO read to be silently skipped.

Patch 1 removes the redundant update_pc() call in kvm_emu_mmio_read().
Patch 2 adds a KVM selftest that exercises this fast path and verifies
that the PC advances correctly.

Zeng Chi (2):
  LoongArch: KVM: Fix PC double advance in kernel MMIO read fast path
  KVM: LoongArch: selftests: Add in-kernel MMIO read fast path test

 arch/loongarch/kvm/exit.c                     |  1 -
 tools/testing/selftests/kvm/Makefile.kvm      |  3 +-
 .../selftests/kvm/loongarch/mmio_read_test.c  | 89 +++++++++++++++++++
 3 files changed, 91 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/loongarch/mmio_read_test.c

-- 
2.25.1


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