1907ce0f7SPaolo Bonzini #include "libcflat.h" 2907ce0f7SPaolo Bonzini #include "smp.h" 3907ce0f7SPaolo Bonzini #include "atomic.h" 4907ce0f7SPaolo Bonzini #include "processor.h" 5907ce0f7SPaolo Bonzini #include "hyperv.h" 6907ce0f7SPaolo Bonzini #include "vm.h" 75aca024eSPaolo Bonzini #include "alloc_page.h" 8907ce0f7SPaolo Bonzini 9907ce0f7SPaolo Bonzini #define MAX_CPU 4 10907ce0f7SPaolo Bonzini #define TICKS_PER_SEC (1000000000 / 100) 11907ce0f7SPaolo Bonzini 12907ce0f7SPaolo Bonzini struct hv_reference_tsc_page *hv_clock; 13907ce0f7SPaolo Bonzini 14907ce0f7SPaolo Bonzini /* 15907ce0f7SPaolo Bonzini * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction, 16907ce0f7SPaolo Bonzini * yielding a 64-bit result. 17907ce0f7SPaolo Bonzini */ 18907ce0f7SPaolo Bonzini static inline u64 scale_delta(u64 delta, u64 mul_frac) 19907ce0f7SPaolo Bonzini { 20907ce0f7SPaolo Bonzini u64 product, unused; 21907ce0f7SPaolo Bonzini 22907ce0f7SPaolo Bonzini __asm__ ( 2345276b58SThomas Petazzoni "mulq %3" 24907ce0f7SPaolo Bonzini : "=d" (product), "=a" (unused) : "1" (delta), "rm" ((u64)mul_frac) ); 25907ce0f7SPaolo Bonzini 26907ce0f7SPaolo Bonzini return product; 27907ce0f7SPaolo Bonzini } 28907ce0f7SPaolo Bonzini 29907ce0f7SPaolo Bonzini static u64 hvclock_tsc_to_ticks(struct hv_reference_tsc_page *shadow, uint64_t tsc) 30907ce0f7SPaolo Bonzini { 31907ce0f7SPaolo Bonzini u64 delta = tsc; 32907ce0f7SPaolo Bonzini return scale_delta(delta, shadow->tsc_scale) + shadow->tsc_offset; 33907ce0f7SPaolo Bonzini } 34907ce0f7SPaolo Bonzini 35907ce0f7SPaolo Bonzini /* 36907ce0f7SPaolo Bonzini * Reads a consistent set of time-base values from hypervisor, 37907ce0f7SPaolo Bonzini * into a shadow data area. 38907ce0f7SPaolo Bonzini */ 39907ce0f7SPaolo Bonzini static void hvclock_get_time_values(struct hv_reference_tsc_page *shadow, 40907ce0f7SPaolo Bonzini struct hv_reference_tsc_page *page) 41907ce0f7SPaolo Bonzini { 42907ce0f7SPaolo Bonzini int seq; 43907ce0f7SPaolo Bonzini do { 44907ce0f7SPaolo Bonzini seq = page->tsc_sequence; 45907ce0f7SPaolo Bonzini rmb(); /* fetch version before data */ 46907ce0f7SPaolo Bonzini *shadow = *page; 47907ce0f7SPaolo Bonzini rmb(); /* test version after fetching data */ 48907ce0f7SPaolo Bonzini } while (shadow->tsc_sequence != seq); 49907ce0f7SPaolo Bonzini } 50907ce0f7SPaolo Bonzini 51*db4898e8SThomas Huth static uint64_t hv_clock_read(void) 52907ce0f7SPaolo Bonzini { 53907ce0f7SPaolo Bonzini struct hv_reference_tsc_page shadow; 54907ce0f7SPaolo Bonzini 55907ce0f7SPaolo Bonzini hvclock_get_time_values(&shadow, hv_clock); 56907ce0f7SPaolo Bonzini return hvclock_tsc_to_ticks(&shadow, rdtsc()); 57907ce0f7SPaolo Bonzini } 58907ce0f7SPaolo Bonzini 59907ce0f7SPaolo Bonzini bool ok[MAX_CPU]; 60907ce0f7SPaolo Bonzini uint64_t loops[MAX_CPU]; 61907ce0f7SPaolo Bonzini 62907ce0f7SPaolo Bonzini #define iabs(x) ((x) < 0 ? -(x) : (x)) 63907ce0f7SPaolo Bonzini 64907ce0f7SPaolo Bonzini static void hv_clock_test(void *data) 65907ce0f7SPaolo Bonzini { 66907ce0f7SPaolo Bonzini int i = smp_id(); 67907ce0f7SPaolo Bonzini uint64_t t = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 68907ce0f7SPaolo Bonzini uint64_t end = t + 3 * TICKS_PER_SEC; 69907ce0f7SPaolo Bonzini uint64_t msr_sample = t + TICKS_PER_SEC; 70907ce0f7SPaolo Bonzini int min_delta = 123456, max_delta = -123456; 71907ce0f7SPaolo Bonzini bool got_drift = false; 72907ce0f7SPaolo Bonzini bool got_warp = false; 73907ce0f7SPaolo Bonzini 74907ce0f7SPaolo Bonzini ok[i] = true; 75907ce0f7SPaolo Bonzini do { 76907ce0f7SPaolo Bonzini uint64_t now = hv_clock_read(); 77907ce0f7SPaolo Bonzini int delta = rdmsr(HV_X64_MSR_TIME_REF_COUNT) - now; 78907ce0f7SPaolo Bonzini 79907ce0f7SPaolo Bonzini min_delta = delta < min_delta ? delta : min_delta; 80907ce0f7SPaolo Bonzini if (t < msr_sample) { 81907ce0f7SPaolo Bonzini max_delta = delta > max_delta ? delta: max_delta; 82907ce0f7SPaolo Bonzini } else if (delta < 0 || delta > max_delta * 3 / 2) { 83907ce0f7SPaolo Bonzini printf("suspecting drift on CPU %d? delta = %d, acceptable [0, %d)\n", smp_id(), 84907ce0f7SPaolo Bonzini delta, max_delta); 85907ce0f7SPaolo Bonzini ok[i] = false; 86907ce0f7SPaolo Bonzini got_drift = true; 87907ce0f7SPaolo Bonzini max_delta *= 2; 88907ce0f7SPaolo Bonzini } 89907ce0f7SPaolo Bonzini 90907ce0f7SPaolo Bonzini if (now < t && !got_warp) { 91907ce0f7SPaolo Bonzini printf("warp on CPU %d!\n", smp_id()); 92907ce0f7SPaolo Bonzini ok[i] = false; 93907ce0f7SPaolo Bonzini got_warp = true; 94907ce0f7SPaolo Bonzini break; 95907ce0f7SPaolo Bonzini } 96907ce0f7SPaolo Bonzini t = now; 97907ce0f7SPaolo Bonzini } while(t < end); 98907ce0f7SPaolo Bonzini 99907ce0f7SPaolo Bonzini if (!got_drift) 100907ce0f7SPaolo Bonzini printf("delta on CPU %d was %d...%d\n", smp_id(), min_delta, max_delta); 101907ce0f7SPaolo Bonzini barrier(); 102907ce0f7SPaolo Bonzini } 103907ce0f7SPaolo Bonzini 104907ce0f7SPaolo Bonzini static void check_test(int ncpus) 105907ce0f7SPaolo Bonzini { 106907ce0f7SPaolo Bonzini int i; 107907ce0f7SPaolo Bonzini bool pass; 108907ce0f7SPaolo Bonzini 109eb8445a9SAndrew Jones on_cpus(hv_clock_test, NULL); 110907ce0f7SPaolo Bonzini 111907ce0f7SPaolo Bonzini pass = true; 112907ce0f7SPaolo Bonzini for (i = ncpus - 1; i >= 0; i--) 113907ce0f7SPaolo Bonzini pass &= ok[i]; 114907ce0f7SPaolo Bonzini 115907ce0f7SPaolo Bonzini report("TSC reference precision test", pass); 116907ce0f7SPaolo Bonzini } 117907ce0f7SPaolo Bonzini 118907ce0f7SPaolo Bonzini static void hv_perf_test(void *data) 119907ce0f7SPaolo Bonzini { 120907ce0f7SPaolo Bonzini uint64_t t = hv_clock_read(); 121907ce0f7SPaolo Bonzini uint64_t end = t + 1000000000 / 100; 122907ce0f7SPaolo Bonzini uint64_t local_loops = 0; 123907ce0f7SPaolo Bonzini 124907ce0f7SPaolo Bonzini do { 125907ce0f7SPaolo Bonzini t = hv_clock_read(); 126907ce0f7SPaolo Bonzini local_loops++; 127907ce0f7SPaolo Bonzini } while(t < end); 128907ce0f7SPaolo Bonzini 129907ce0f7SPaolo Bonzini loops[smp_id()] = local_loops; 130907ce0f7SPaolo Bonzini } 131907ce0f7SPaolo Bonzini 132907ce0f7SPaolo Bonzini static void perf_test(int ncpus) 133907ce0f7SPaolo Bonzini { 134907ce0f7SPaolo Bonzini int i; 135907ce0f7SPaolo Bonzini uint64_t total_loops; 136907ce0f7SPaolo Bonzini 137eb8445a9SAndrew Jones on_cpus(hv_perf_test, NULL); 138907ce0f7SPaolo Bonzini 139907ce0f7SPaolo Bonzini total_loops = 0; 140907ce0f7SPaolo Bonzini for (i = ncpus - 1; i >= 0; i--) 141907ce0f7SPaolo Bonzini total_loops += loops[i]; 142907ce0f7SPaolo Bonzini printf("iterations/sec: %" PRId64"\n", total_loops / ncpus); 143907ce0f7SPaolo Bonzini } 144907ce0f7SPaolo Bonzini 145907ce0f7SPaolo Bonzini int main(int ac, char **av) 146907ce0f7SPaolo Bonzini { 147907ce0f7SPaolo Bonzini int nerr = 0; 148907ce0f7SPaolo Bonzini int ncpus; 149907ce0f7SPaolo Bonzini struct hv_reference_tsc_page shadow; 150907ce0f7SPaolo Bonzini uint64_t tsc1, t1, tsc2, t2; 151907ce0f7SPaolo Bonzini uint64_t ref1, ref2; 152907ce0f7SPaolo Bonzini 153907ce0f7SPaolo Bonzini setup_vm(); 154907ce0f7SPaolo Bonzini smp_init(); 155907ce0f7SPaolo Bonzini 156eb8445a9SAndrew Jones ncpus = cpu_count(); 157eb8445a9SAndrew Jones if (ncpus > MAX_CPU) 158eb8445a9SAndrew Jones report_abort("number cpus exceeds %d", MAX_CPU); 159eb8445a9SAndrew Jones 160907ce0f7SPaolo Bonzini hv_clock = alloc_page(); 161907ce0f7SPaolo Bonzini wrmsr(HV_X64_MSR_REFERENCE_TSC, (u64)(uintptr_t)hv_clock | 1); 162907ce0f7SPaolo Bonzini report("MSR value after enabling", 163907ce0f7SPaolo Bonzini rdmsr(HV_X64_MSR_REFERENCE_TSC) == ((u64)(uintptr_t)hv_clock | 1)); 164907ce0f7SPaolo Bonzini 165907ce0f7SPaolo Bonzini hvclock_get_time_values(&shadow, hv_clock); 166907ce0f7SPaolo Bonzini if (shadow.tsc_sequence == 0 || shadow.tsc_sequence == 0xFFFFFFFF) { 167907ce0f7SPaolo Bonzini printf("Reference TSC page not available\n"); 168907ce0f7SPaolo Bonzini exit(1); 169907ce0f7SPaolo Bonzini } 170907ce0f7SPaolo Bonzini 171907ce0f7SPaolo Bonzini printf("scale: %" PRIx64" offset: %" PRId64"\n", shadow.tsc_scale, shadow.tsc_offset); 172907ce0f7SPaolo Bonzini ref1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 173907ce0f7SPaolo Bonzini tsc1 = rdtsc(); 174907ce0f7SPaolo Bonzini t1 = hvclock_tsc_to_ticks(&shadow, tsc1); 175907ce0f7SPaolo Bonzini printf("refcnt %" PRId64", TSC %" PRIx64", TSC reference %" PRId64"\n", 176907ce0f7SPaolo Bonzini ref1, tsc1, t1); 177907ce0f7SPaolo Bonzini 178907ce0f7SPaolo Bonzini do 179907ce0f7SPaolo Bonzini ref2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 180907ce0f7SPaolo Bonzini while (ref2 < ref1 + 2 * TICKS_PER_SEC); 181907ce0f7SPaolo Bonzini 182907ce0f7SPaolo Bonzini tsc2 = rdtsc(); 183907ce0f7SPaolo Bonzini t2 = hvclock_tsc_to_ticks(&shadow, tsc2); 184907ce0f7SPaolo Bonzini printf("refcnt %" PRId64" (delta %" PRId64"), TSC %" PRIx64", " 185907ce0f7SPaolo Bonzini "TSC reference %" PRId64" (delta %" PRId64")\n", 186907ce0f7SPaolo Bonzini ref2, ref2 - ref1, tsc2, t2, t2 - t1); 187907ce0f7SPaolo Bonzini 188907ce0f7SPaolo Bonzini check_test(ncpus); 189907ce0f7SPaolo Bonzini perf_test(ncpus); 190907ce0f7SPaolo Bonzini 191907ce0f7SPaolo Bonzini wrmsr(HV_X64_MSR_REFERENCE_TSC, 0LL); 192907ce0f7SPaolo Bonzini report("MSR value after disabling", rdmsr(HV_X64_MSR_REFERENCE_TSC) == 0); 193907ce0f7SPaolo Bonzini 194907ce0f7SPaolo Bonzini return nerr > 0 ? 1 : 0; 195907ce0f7SPaolo Bonzini } 196