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 <vkuznets@xxxxxxxxxx>
---
.../selftests/kvm/include/x86_64/hyperv.h | 3 +
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/x86_64/hyperv_features.c | 58 +++++++++++++++++--
3 files changed, 58 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86_64/hyperv.h b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
index 843748dde1ff..8368d65afbe4 100644
--- a/tools/testing/selftests/kvm/include/x86_64/hyperv.h
+++ b/tools/testing/selftests/kvm/include/x86_64/hyperv.h
@@ -232,4 +232,7 @@
/* hypercall options */
#define HV_HYPERCALL_FAST_BIT BIT(16)
+/* 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 0cbc71b7af50..8d106380b0af 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -128,6 +128,7 @@ 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 d4bd18bc580d..18b44450dfb8 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_features.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_features.c
@@ -46,20 +46,33 @@ struct hcall_data {
static void guest_msr(struct msr_data *msr)
{
- uint64_t ignored;
+ uint64_t msr_val = 0;
uint8_t vector;
GUEST_ASSERT(msr->idx);
- if (!msr->write)
- vector = rdmsr_safe(msr->idx, &ignored);
- else
+ if (!msr->write) {
+ vector = rdmsr_safe(msr->idx, &msr_val);
+ } else {
vector = wrmsr_safe(msr->idx, msr->write_val);
+ if (!vector)
+ msr_val = msr->write_val;
+ }
if (msr->fault_expected)
GUEST_ASSERT_2(vector == GP_VECTOR, msr->idx, vector);
else
GUEST_ASSERT_2(!vector, msr->idx, vector);
+
+ /* 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));
+ }
+
GUEST_DONE();
}
@@ -114,6 +127,7 @@ 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);
@@ -425,6 +439,42 @@ 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 = 0;
+ msr->fault_expected = 1;
+ 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 = 0;
+ msr->fault_expected = 0;
+ break;
+ case 46:
+ /* Writing bits other than 0 is forbidden */
+ if (!has_invtsc)
+ continue;
+ msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+ msr->write = 1;
+ msr->write_val = 0xdeadbeef;
+ msr->fault_expected = 1;
+ break;
+ case 47:
+ /* Setting bit 0 enables the feature */
+ if (!has_invtsc)
+ continue;
+ msr->idx = HV_X64_MSR_TSC_INVARIANT_CONTROL;
+ msr->write = 1;
+ msr->write_val = 1;
+ msr->fault_expected = 0;
+ break;
+
+ default:
kvm_vm_free(vm);
return;
}
--
2.37.2
