sync_regs_test has never actually checked the sregs and events halves of the kvm_run sync region. compare_sregs() and compare_vcpu_events() have had empty bodies since the test was written, so the checks run after every KVM_RUN only ever compared the general purpose registers, and the events half was never written to at all, hence the standing TODO in set_and_verify_various().
Patch 1 fills in both comparison helpers. Patch 2 exercises the events half by masking NMIs through the sync region and verifying KVM applies it. To confirm the new checks catch something rather than merely passing, the same faults were injected before and after the series on an AMD host: fault injected before after sregs.cr4 mismatch ignored caught sregs.cs.dpl mismatch ignored caught events.interrupt.shadow mismatch ignored caught KVM_SYNC_X86_EVENTS left clean n/a caught Every corruption goes unnoticed before the series and is reported after it, e.g. x86/sync_regs_test.c:128: left->cr4 == right->cr4 Register cr4 values did not match: 0x41221, 0x41220 Unmodified, the test passes 20/20 consecutive runs with the series applied, each patch builds and passes on its own, and the remaining x86 selftests are unchanged either way (61 passed, 24 skipped, with set_sregs_test failing identically before and after for unrelated reasons). Hemanth Selam (2): KVM: selftests: Actually compare sregs and events in sync_regs_test KVM: selftests: Verify the events half of the sync regs region .../selftests/kvm/x86/sync_regs_test.c | 100 +++++++++++++++++- 1 file changed, 98 insertions(+), 2 deletions(-) -- 2.43.7
