Changes since v1: - Drop the allowlist of items which were allowed to change and just allow the exact same CPUID data [Sean, Paolo]. Adjust selftest accordingly. - Drop PATCH1 as the exact same change got merged upstream. Recently, KVM made it illegal to change CPUID after KVM_RUN but unfortunately this change is not fully compatible with existing VMMs. In particular, QEMU reuses vCPU fds for CPU hotplug after unplug and it calls KVM_SET_CPUID2. Relax the requirement by implementing an allowing KVM_SET_CPUID{,2} with the exact same data. Vitaly Kuznetsov (4): KVM: x86: Do runtime CPUID update before updating vcpu->arch.cpuid_entries KVM: x86: Partially allow KVM_SET_CPUID{,2} after KVM_RUN KVM: selftests: Rename 'get_cpuid_test' to 'cpuid_test' KVM: selftests: Test KVM_SET_CPUID2 after KVM_RUN arch/x86/kvm/cpuid.c | 67 ++++++++++++++++--- arch/x86/kvm/x86.c | 19 ------ tools/testing/selftests/kvm/.gitignore | 2 +- tools/testing/selftests/kvm/Makefile | 4 +- .../selftests/kvm/include/x86_64/processor.h | 7 ++ .../selftests/kvm/lib/x86_64/processor.c | 33 +++++++-- .../x86_64/{get_cpuid_test.c => cpuid_test.c} | 30 +++++++++ 7 files changed, 126 insertions(+), 36 deletions(-) rename tools/testing/selftests/kvm/x86_64/{get_cpuid_test.c => cpuid_test.c} (83%) -- 2.34.1