Add a new helper, vcpu_clear_cpuid_entry(), to do a RMW operation on the vCPU's CPUID model to clear a given CPUID entry, and use it to clear KVM's paravirt feature instead of operating on kvm_get_supported_cpuid()'s static "cpuid" variable. This also eliminates a user of the soon-be-defunct set_cpuid() helper. Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- .../testing/selftests/kvm/include/x86_64/processor.h | 1 + tools/testing/selftests/kvm/lib/x86_64/processor.c | 11 +++++++++++ tools/testing/selftests/kvm/x86_64/kvm_pv_test.c | 12 +----------- 3 files changed, 13 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 2097822b4b98..65f3a828c903 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -658,6 +658,7 @@ static inline void vcpu_set_cpuid(struct kvm_vcpu *vcpu) void vcpu_set_cpuid_maxphyaddr(struct kvm_vcpu *vcpu, uint8_t maxphyaddr); +void vcpu_clear_cpuid_entry(struct kvm_vcpu *vcpu, uint32_t function); void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu, struct kvm_x86_cpu_feature feature, bool set); diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index cdc35dd765e7..99f72f3b4382 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -770,6 +770,17 @@ void vcpu_set_cpuid_maxphyaddr(struct kvm_vcpu *vcpu, uint8_t maxphyaddr) vcpu_set_cpuid(vcpu); } +void vcpu_clear_cpuid_entry(struct kvm_vcpu *vcpu, uint32_t function) +{ + struct kvm_cpuid_entry2 *entry = vcpu_get_cpuid_entry(vcpu, function); + + entry->eax = 0; + entry->ebx = 0; + entry->ecx = 0; + entry->edx = 0; + vcpu_set_cpuid(vcpu); +} + void vcpu_set_or_clear_cpuid_feature(struct kvm_vcpu *vcpu, struct kvm_x86_cpu_feature feature, bool set) diff --git a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c index e3bb9b803944..7ab61f3f2a20 100644 --- a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c +++ b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c @@ -142,15 +142,6 @@ static void guest_main(void) GUEST_DONE(); } -static void clear_kvm_cpuid_features(struct kvm_cpuid2 *cpuid) -{ - struct kvm_cpuid_entry2 ent = {0}; - - ent.function = KVM_CPUID_FEATURES; - TEST_ASSERT(set_cpuid(cpuid, &ent), - "failed to clear KVM_CPUID_FEATURES leaf"); -} - static void pr_msr(struct ucall *uc) { struct msr_data *msr = (struct msr_data *)uc->args[0]; @@ -209,8 +200,7 @@ int main(void) vcpu_enable_cap(vcpu, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, 1); - clear_kvm_cpuid_features(vcpu->cpuid); - vcpu_set_cpuid(vcpu); + vcpu_clear_cpuid_entry(vcpu, KVM_CPUID_FEATURES); vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vcpu); -- 2.36.1.476.g0c4daa206d-goog