diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-07 12:06:02 -0400 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-06-07 12:06:02 -0400 |
| commit | a280e358465b4ac8982dc1eb2deebcb020443b7f (patch) | |
| tree | 2e8ea05740008b6b2761e30069aefabb1710ca2d /tools/testing/selftests/kvm/x86_64 | |
| parent | f2906aa863381afb0015a9eb7fefad885d4e5a56 (diff) | |
| parent | 11d39e8cc43e1c6737af19ca9372e590061b5ad2 (diff) | |
| download | linux-a280e358465b4ac8982dc1eb2deebcb020443b7f.tar.bz2 | |
Merge branch 'kvm-5.19-early-fixes' into HEAD
Diffstat (limited to 'tools/testing/selftests/kvm/x86_64')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/hyperv_clock.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_clock.c b/tools/testing/selftests/kvm/x86_64/hyperv_clock.c index e0b2bb1339b1..3330fb183c68 100644 --- a/tools/testing/selftests/kvm/x86_64/hyperv_clock.c +++ b/tools/testing/selftests/kvm/x86_64/hyperv_clock.c @@ -44,7 +44,7 @@ static inline void nop_loop(void) { int i; - for (i = 0; i < 1000000; i++) + for (i = 0; i < 100000000; i++) asm volatile("nop"); } @@ -56,12 +56,14 @@ static inline void check_tsc_msr_rdtsc(void) tsc_freq = rdmsr(HV_X64_MSR_TSC_FREQUENCY); GUEST_ASSERT(tsc_freq > 0); - /* First, check MSR-based clocksource */ + /* For increased accuracy, take mean rdtsc() before and afrer rdmsr() */ r1 = rdtsc(); t1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); + r1 = (r1 + rdtsc()) / 2; nop_loop(); r2 = rdtsc(); t2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); + r2 = (r2 + rdtsc()) / 2; GUEST_ASSERT(r2 > r1 && t2 > t1); @@ -181,12 +183,14 @@ static void host_check_tsc_msr_rdtsc(struct kvm_vm *vm) tsc_freq = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TSC_FREQUENCY); TEST_ASSERT(tsc_freq > 0, "TSC frequency must be nonzero"); - /* First, check MSR-based clocksource */ + /* For increased accuracy, take mean rdtsc() before and afrer ioctl */ r1 = rdtsc(); t1 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT); + r1 = (r1 + rdtsc()) / 2; nop_loop(); r2 = rdtsc(); t2 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT); + r2 = (r2 + rdtsc()) / 2; TEST_ASSERT(t2 > t1, "Time reference MSR is not monotonic (%ld <= %ld)", t1, t2); |