1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (C) 2021, Red Hat, Inc. 4 * 5 * Tests for Hyper-V clocksources 6 */ 7#include "test_util.h" 8#include "kvm_util.h" 9#include "processor.h" 10#include "hyperv.h" 11 12struct ms_hyperv_tsc_page { 13 volatile u32 tsc_sequence; 14 u32 reserved1; 15 volatile u64 tsc_scale; 16 volatile s64 tsc_offset; 17} __packed; 18 19/* Simplified mul_u64_u64_shr() */ 20static inline u64 mul_u64_u64_shr64(u64 a, u64 b) 21{ 22 union { 23 u64 ll; 24 struct { 25 u32 low, high; 26 } l; 27 } rm, rn, rh, a0, b0; 28 u64 c; 29 30 a0.ll = a; 31 b0.ll = b; 32 33 rm.ll = (u64)a0.l.low * b0.l.high; 34 rn.ll = (u64)a0.l.high * b0.l.low; 35 rh.ll = (u64)a0.l.high * b0.l.high; 36 37 rh.l.low = c = rm.l.high + rn.l.high + rh.l.low; 38 rh.l.high = (c >> 32) + rh.l.high; 39 40 return rh.ll; 41} 42 43static inline void nop_loop(void) 44{ 45 int i; 46 47 for (i = 0; i < 100000000; i++) 48 asm volatile("nop"); 49} 50 51static inline void check_tsc_msr_rdtsc(void) 52{ 53 u64 tsc_freq, r1, r2, t1, t2; 54 s64 delta_ns; 55 56 tsc_freq = rdmsr(HV_X64_MSR_TSC_FREQUENCY); 57 GUEST_ASSERT(tsc_freq > 0); 58 59 /* For increased accuracy, take mean rdtsc() before and afrer rdmsr() */ 60 r1 = rdtsc(); 61 t1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 62 r1 = (r1 + rdtsc()) / 2; 63 nop_loop(); 64 r2 = rdtsc(); 65 t2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 66 r2 = (r2 + rdtsc()) / 2; 67 68 GUEST_ASSERT(r2 > r1 && t2 > t1); 69 70 /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */ 71 delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq); 72 if (delta_ns < 0) 73 delta_ns = -delta_ns; 74 75 /* 1% tolerance */ 76 GUEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100); 77} 78 79static inline u64 get_tscpage_ts(struct ms_hyperv_tsc_page *tsc_page) 80{ 81 return mul_u64_u64_shr64(rdtsc(), tsc_page->tsc_scale) + tsc_page->tsc_offset; 82} 83 84static inline void check_tsc_msr_tsc_page(struct ms_hyperv_tsc_page *tsc_page) 85{ 86 u64 r1, r2, t1, t2; 87 88 /* Compare TSC page clocksource with HV_X64_MSR_TIME_REF_COUNT */ 89 t1 = get_tscpage_ts(tsc_page); 90 r1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 91 92 /* 10 ms tolerance */ 93 GUEST_ASSERT(r1 >= t1 && r1 - t1 < 100000); 94 nop_loop(); 95 96 t2 = get_tscpage_ts(tsc_page); 97 r2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 98 GUEST_ASSERT(r2 >= t1 && r2 - t2 < 100000); 99} 100 101static void guest_main(struct ms_hyperv_tsc_page *tsc_page, vm_paddr_t tsc_page_gpa) 102{ 103 u64 tsc_scale, tsc_offset; 104 105 /* Set Guest OS id to enable Hyper-V emulation */ 106 GUEST_SYNC(1); 107 wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID); 108 GUEST_SYNC(2); 109 110 check_tsc_msr_rdtsc(); 111 112 GUEST_SYNC(3); 113 114 /* Set up TSC page is disabled state, check that it's clean */ 115 wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa); 116 GUEST_ASSERT(tsc_page->tsc_sequence == 0); 117 GUEST_ASSERT(tsc_page->tsc_scale == 0); 118 GUEST_ASSERT(tsc_page->tsc_offset == 0); 119 120 GUEST_SYNC(4); 121 122 /* Set up TSC page is enabled state */ 123 wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa | 0x1); 124 GUEST_ASSERT(tsc_page->tsc_sequence != 0); 125 126 GUEST_SYNC(5); 127 128 check_tsc_msr_tsc_page(tsc_page); 129 130 GUEST_SYNC(6); 131 132 tsc_offset = tsc_page->tsc_offset; 133 /* Call KVM_SET_CLOCK from userspace, check that TSC page was updated */ 134 135 GUEST_SYNC(7); 136 /* Sanity check TSC page timestamp, it should be close to 0 */ 137 GUEST_ASSERT(get_tscpage_ts(tsc_page) < 100000); 138 139 GUEST_ASSERT(tsc_page->tsc_offset != tsc_offset); 140 141 nop_loop(); 142 143 /* 144 * Enable Re-enlightenment and check that TSC page stays constant across 145 * KVM_SET_CLOCK. 146 */ 147 wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0x1 << 16 | 0xff); 148 wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0x1); 149 tsc_offset = tsc_page->tsc_offset; 150 tsc_scale = tsc_page->tsc_scale; 151 GUEST_SYNC(8); 152 GUEST_ASSERT(tsc_page->tsc_offset == tsc_offset); 153 GUEST_ASSERT(tsc_page->tsc_scale == tsc_scale); 154 155 GUEST_SYNC(9); 156 157 check_tsc_msr_tsc_page(tsc_page); 158 159 /* 160 * Disable re-enlightenment and TSC page, check that KVM doesn't update 161 * it anymore. 162 */ 163 wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0); 164 wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0); 165 wrmsr(HV_X64_MSR_REFERENCE_TSC, 0); 166 memset(tsc_page, 0, sizeof(*tsc_page)); 167 168 GUEST_SYNC(10); 169 GUEST_ASSERT(tsc_page->tsc_sequence == 0); 170 GUEST_ASSERT(tsc_page->tsc_offset == 0); 171 GUEST_ASSERT(tsc_page->tsc_scale == 0); 172 173 GUEST_DONE(); 174} 175 176static void host_check_tsc_msr_rdtsc(struct kvm_vcpu *vcpu) 177{ 178 u64 tsc_freq, r1, r2, t1, t2; 179 s64 delta_ns; 180 181 tsc_freq = vcpu_get_msr(vcpu, HV_X64_MSR_TSC_FREQUENCY); 182 TEST_ASSERT(tsc_freq > 0, "TSC frequency must be nonzero"); 183 184 /* For increased accuracy, take mean rdtsc() before and afrer ioctl */ 185 r1 = rdtsc(); 186 t1 = vcpu_get_msr(vcpu, HV_X64_MSR_TIME_REF_COUNT); 187 r1 = (r1 + rdtsc()) / 2; 188 nop_loop(); 189 r2 = rdtsc(); 190 t2 = vcpu_get_msr(vcpu, HV_X64_MSR_TIME_REF_COUNT); 191 r2 = (r2 + rdtsc()) / 2; 192 193 TEST_ASSERT(t2 > t1, "Time reference MSR is not monotonic (%ld <= %ld)", t1, t2); 194 195 /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */ 196 delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq); 197 if (delta_ns < 0) 198 delta_ns = -delta_ns; 199 200 /* 1% tolerance */ 201 TEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100, 202 "Elapsed time does not match (MSR=%ld, TSC=%ld)", 203 (t2 - t1) * 100, (r2 - r1) * 1000000000 / tsc_freq); 204} 205 206int main(void) 207{ 208 struct kvm_vcpu *vcpu; 209 struct kvm_vm *vm; 210 struct ucall uc; 211 vm_vaddr_t tsc_page_gva; 212 int stage; 213 214 TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_TIME)); 215 TEST_REQUIRE(sys_clocksource_is_based_on_tsc()); 216 217 vm = vm_create_with_one_vcpu(&vcpu, guest_main); 218 219 vcpu_set_hv_cpuid(vcpu); 220 221 tsc_page_gva = vm_vaddr_alloc_page(vm); 222 memset(addr_gva2hva(vm, tsc_page_gva), 0x0, getpagesize()); 223 TEST_ASSERT((addr_gva2gpa(vm, tsc_page_gva) & (getpagesize() - 1)) == 0, 224 "TSC page has to be page aligned"); 225 vcpu_args_set(vcpu, 2, tsc_page_gva, addr_gva2gpa(vm, tsc_page_gva)); 226 227 host_check_tsc_msr_rdtsc(vcpu); 228 229 for (stage = 1;; stage++) { 230 vcpu_run(vcpu); 231 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); 232 233 switch (get_ucall(vcpu, &uc)) { 234 case UCALL_ABORT: 235 REPORT_GUEST_ASSERT(uc); 236 /* NOT REACHED */ 237 case UCALL_SYNC: 238 break; 239 case UCALL_DONE: 240 /* Keep in sync with guest_main() */ 241 TEST_ASSERT(stage == 11, "Testing ended prematurely, stage %d", 242 stage); 243 goto out; 244 default: 245 TEST_FAIL("Unknown ucall %lu", uc.cmd); 246 } 247 248 TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") && 249 uc.args[1] == stage, 250 "Stage %d: Unexpected register values vmexit, got %lx", 251 stage, (ulong)uc.args[1]); 252 253 /* Reset kvmclock triggering TSC page update */ 254 if (stage == 7 || stage == 8 || stage == 10) { 255 struct kvm_clock_data clock = {0}; 256 257 vm_ioctl(vm, KVM_SET_CLOCK, &clock); 258 } 259 } 260 261out: 262 kvm_vm_free(vm); 263} 264