Add a flag to kvm_run, KVM_RUN_NEEDS_COMPLETION, that is set by KVM to inform userspace that KVM_RUN needs to be re-invoked prior to state save/restore. The current approach of relying on KVM developers to update documentation, and on VMM developers to read said documentation, is brittle and error prone. Note, this series is *very* lightly tested (borderline RFC). Sean Christopherson (5): KVM: x86: Document that KVM_EXIT_HYPERCALL requires completion KVM: Clear vcpu->run->flags at start of KVM_RUN for all architectures KVM: Add a common kvm_run flag to communicate an exit needs completion KVM: selftests: Provide separate helper for KVM_RUN with immediate_exit KVM: selftests: Rely on KVM_RUN_NEEDS_COMPLETION to complete userspace exits Documentation/virt/kvm/api.rst | 77 ++++++++++++------- arch/arm64/kvm/arm.c | 1 - arch/arm64/kvm/handle_exit.c | 2 +- arch/powerpc/kvm/book3s_emulate.c | 1 + arch/powerpc/kvm/book3s_hv.c | 5 +- arch/powerpc/kvm/book3s_pr.c | 2 + arch/powerpc/kvm/booke.c | 1 + arch/x86/include/uapi/asm/kvm.h | 7 +- arch/x86/kvm/x86.c | 3 +- include/uapi/linux/kvm.h | 3 + .../testing/selftests/kvm/include/kvm_util.h | 13 +++- tools/testing/selftests/kvm/lib/kvm_util.c | 6 +- .../testing/selftests/kvm/lib/ucall_common.c | 2 +- .../testing/selftests/kvm/lib/x86/processor.c | 8 +- .../kvm/x86/nested_exceptions_test.c | 3 +- .../kvm/x86/triple_fault_event_test.c | 3 +- virt/kvm/kvm_main.c | 4 + 17 files changed, 90 insertions(+), 51 deletions(-) base-commit: 10b2c8a67c4b8ec15f9d07d177f63b563418e948 -- 2.47.1.613.gc27f4b7a9f-goog