From c04ec04c0d15a51aa33660be175ed978beb8de0c Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Thu, 13 Oct 2022 11:58:49 +0200 Subject: [PATCH] KVM: selftests: Test Hyper-V invariant TSC control Add a test for the newly introduced Hyper-V invariant TSC control feature: - HV_X64_MSR_TSC_INVARIANT_CONTROL is not available without HV_ACCESS_TSC_INVARIANT CPUID bit set and available with it. - BIT(0) of HV_X64_MSR_TSC_INVARIANT_CONTROL controls the filtering of architectural invariant TSC (CPUID.80000007H:EDX[8]) bit. Signed-off-by: Vitaly Kuznetsov Reviewed-by: Sean Christopherson Message-Id: <20221013095849.705943-8-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- .../testing/selftests/kvm/include/x86_64/hyperv.h | 3 ++ .../selftests/kvm/include/x86_64/processor.h | 1 + .../testing/selftests/kvm/x86_64/hyperv_features.c | 47 ++++++++++++++++++++++ 3 files changed, 51 insertions(+) diff --git a/tools/testing/selftests/kvm/include/x86_64/hyperv.h b/tools/testing/selftests/kvm/include/x86_64/hyperv.h index ab455c4efc66..28eb99046475 100644 --- a/tools/testing/selftests/kvm/include/x86_64/hyperv.h +++ b/tools/testing/selftests/kvm/include/x86_64/hyperv.h @@ -335,4 +335,7 @@ struct hyperv_test_pages { struct hyperv_test_pages *vcpu_alloc_hyperv_test_pages(struct kvm_vm *vm, vm_vaddr_t *p_hv_pages_gva); +/* HV_X64_MSR_TSC_INVARIANT_CONTROL bits */ +#define HV_INVARIANT_TSC_EXPOSED BIT_ULL(0) + #endif /* !SELFTEST_KVM_HYPERV_H */ diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index b1a31de7108a..2a5f47d51388 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -137,6 +137,7 @@ struct kvm_x86_cpu_feature { #define X86_FEATURE_GBPAGES KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 26) #define X86_FEATURE_RDTSCP KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 27) #define X86_FEATURE_LM KVM_X86_CPU_FEATURE(0x80000001, 0, EDX, 29) +#define X86_FEATURE_INVTSC KVM_X86_CPU_FEATURE(0x80000007, 0, EDX, 8) #define X86_FEATURE_RDPRU KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 4) #define X86_FEATURE_AMD_IBPB KVM_X86_CPU_FEATURE(0x80000008, 0, EBX, 12) #define X86_FEATURE_NPT KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 0) diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_features.c b/tools/testing/selftests/kvm/x86_64/hyperv_features.c index b00240963974..258267df8e2a 100644 --- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c +++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c @@ -63,6 +63,16 @@ static void guest_msr(struct msr_data *msr) if (msr->write) GUEST_ASSERT_3(msr_val == msr->write_val, msr->idx, msr_val, msr->write_val); + + /* Invariant TSC bit appears when TSC invariant control MSR is written to */ + if (msr->idx == HV_X64_MSR_TSC_INVARIANT_CONTROL) { + if (!this_cpu_has(HV_ACCESS_TSC_INVARIANT)) + GUEST_ASSERT(this_cpu_has(X86_FEATURE_INVTSC)); + else + GUEST_ASSERT(this_cpu_has(X86_FEATURE_INVTSC) == + !!(msr_val & HV_INVARIANT_TSC_EXPOSED)); + } + done: GUEST_DONE(); } @@ -118,6 +128,7 @@ static void guest_test_msrs_access(void) int stage = 0; vm_vaddr_t msr_gva; struct msr_data *msr; + bool has_invtsc = kvm_cpu_has(X86_FEATURE_INVTSC); while (true) { vm = vm_create_with_one_vcpu(&vcpu, guest_msr); @@ -435,6 +446,42 @@ static void guest_test_msrs_access(void) break; case 44: + /* MSR is not available when CPUID feature bit is unset */ + if (!has_invtsc) + continue; + msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL; + msr->write = false; + msr->fault_expected = true; + break; + case 45: + /* MSR is vailable when CPUID feature bit is set */ + if (!has_invtsc) + continue; + vcpu_set_cpuid_feature(vcpu, HV_ACCESS_TSC_INVARIANT); + msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL; + msr->write = false; + msr->fault_expected = false; + break; + case 46: + /* Writing bits other than 0 is forbidden */ + if (!has_invtsc) + continue; + msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL; + msr->write = true; + msr->write_val = 0xdeadbeef; + msr->fault_expected = true; + break; + case 47: + /* Setting bit 0 enables the feature */ + if (!has_invtsc) + continue; + msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL; + msr->write = true; + msr->write_val = 1; + msr->fault_expected = false; + break; + + default: kvm_vm_free(vm); return; } -- 2.11.0