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 12 struct 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() */ 20 static 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 43 static inline void nop_loop(void) 44 { 45 int i; 46 47 for (i = 0; i < 1000000; i++) 48 asm volatile("nop"); 49 } 50 51 static 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 /* First, check MSR-based clocksource */ 60 r1 = rdtsc(); 61 t1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 62 nop_loop(); 63 r2 = rdtsc(); 64 t2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 65 66 GUEST_ASSERT(r2 > r1 && t2 > t1); 67 68 /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */ 69 delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq); 70 if (delta_ns < 0) 71 delta_ns = -delta_ns; 72 73 /* 1% tolerance */ 74 GUEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100); 75 } 76 77 static inline u64 get_tscpage_ts(struct ms_hyperv_tsc_page *tsc_page) 78 { 79 return mul_u64_u64_shr64(rdtsc(), tsc_page->tsc_scale) + tsc_page->tsc_offset; 80 } 81 82 static inline void check_tsc_msr_tsc_page(struct ms_hyperv_tsc_page *tsc_page) 83 { 84 u64 r1, r2, t1, t2; 85 86 /* Compare TSC page clocksource with HV_X64_MSR_TIME_REF_COUNT */ 87 t1 = get_tscpage_ts(tsc_page); 88 r1 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 89 90 /* 10 ms tolerance */ 91 GUEST_ASSERT(r1 >= t1 && r1 - t1 < 100000); 92 nop_loop(); 93 94 t2 = get_tscpage_ts(tsc_page); 95 r2 = rdmsr(HV_X64_MSR_TIME_REF_COUNT); 96 GUEST_ASSERT(r2 >= t1 && r2 - t2 < 100000); 97 } 98 99 static void guest_main(struct ms_hyperv_tsc_page *tsc_page, vm_paddr_t tsc_page_gpa) 100 { 101 u64 tsc_scale, tsc_offset; 102 103 /* Set Guest OS id to enable Hyper-V emulation */ 104 GUEST_SYNC(1); 105 wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48); 106 GUEST_SYNC(2); 107 108 check_tsc_msr_rdtsc(); 109 110 GUEST_SYNC(3); 111 112 /* Set up TSC page is disabled state, check that it's clean */ 113 wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa); 114 GUEST_ASSERT(tsc_page->tsc_sequence == 0); 115 GUEST_ASSERT(tsc_page->tsc_scale == 0); 116 GUEST_ASSERT(tsc_page->tsc_offset == 0); 117 118 GUEST_SYNC(4); 119 120 /* Set up TSC page is enabled state */ 121 wrmsr(HV_X64_MSR_REFERENCE_TSC, tsc_page_gpa | 0x1); 122 GUEST_ASSERT(tsc_page->tsc_sequence != 0); 123 124 GUEST_SYNC(5); 125 126 check_tsc_msr_tsc_page(tsc_page); 127 128 GUEST_SYNC(6); 129 130 tsc_offset = tsc_page->tsc_offset; 131 /* Call KVM_SET_CLOCK from userspace, check that TSC page was updated */ 132 133 GUEST_SYNC(7); 134 /* Sanity check TSC page timestamp, it should be close to 0 */ 135 GUEST_ASSERT(get_tscpage_ts(tsc_page) < 100000); 136 137 GUEST_ASSERT(tsc_page->tsc_offset != tsc_offset); 138 139 nop_loop(); 140 141 /* 142 * Enable Re-enlightenment and check that TSC page stays constant across 143 * KVM_SET_CLOCK. 144 */ 145 wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0x1 << 16 | 0xff); 146 wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0x1); 147 tsc_offset = tsc_page->tsc_offset; 148 tsc_scale = tsc_page->tsc_scale; 149 GUEST_SYNC(8); 150 GUEST_ASSERT(tsc_page->tsc_offset == tsc_offset); 151 GUEST_ASSERT(tsc_page->tsc_scale == tsc_scale); 152 153 GUEST_SYNC(9); 154 155 check_tsc_msr_tsc_page(tsc_page); 156 157 /* 158 * Disable re-enlightenment and TSC page, check that KVM doesn't update 159 * it anymore. 160 */ 161 wrmsr(HV_X64_MSR_REENLIGHTENMENT_CONTROL, 0); 162 wrmsr(HV_X64_MSR_TSC_EMULATION_CONTROL, 0); 163 wrmsr(HV_X64_MSR_REFERENCE_TSC, 0); 164 memset(tsc_page, 0, sizeof(*tsc_page)); 165 166 GUEST_SYNC(10); 167 GUEST_ASSERT(tsc_page->tsc_sequence == 0); 168 GUEST_ASSERT(tsc_page->tsc_offset == 0); 169 GUEST_ASSERT(tsc_page->tsc_scale == 0); 170 171 GUEST_DONE(); 172 } 173 174 #define VCPU_ID 0 175 176 static void host_check_tsc_msr_rdtsc(struct kvm_vm *vm) 177 { 178 u64 tsc_freq, r1, r2, t1, t2; 179 s64 delta_ns; 180 181 tsc_freq = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TSC_FREQUENCY); 182 TEST_ASSERT(tsc_freq > 0, "TSC frequency must be nonzero"); 183 184 /* First, check MSR-based clocksource */ 185 r1 = rdtsc(); 186 t1 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT); 187 nop_loop(); 188 r2 = rdtsc(); 189 t2 = vcpu_get_msr(vm, VCPU_ID, HV_X64_MSR_TIME_REF_COUNT); 190 191 TEST_ASSERT(t2 > t1, "Time reference MSR is not monotonic (%ld <= %ld)", t1, t2); 192 193 /* HV_X64_MSR_TIME_REF_COUNT is in 100ns */ 194 delta_ns = ((t2 - t1) * 100) - ((r2 - r1) * 1000000000 / tsc_freq); 195 if (delta_ns < 0) 196 delta_ns = -delta_ns; 197 198 /* 1% tolerance */ 199 TEST_ASSERT(delta_ns * 100 < (t2 - t1) * 100, 200 "Elapsed time does not match (MSR=%ld, TSC=%ld)", 201 (t2 - t1) * 100, (r2 - r1) * 1000000000 / tsc_freq); 202 } 203 204 int main(void) 205 { 206 struct kvm_vm *vm; 207 struct kvm_run *run; 208 struct ucall uc; 209 vm_vaddr_t tsc_page_gva; 210 int stage; 211 212 vm = vm_create_default(VCPU_ID, 0, guest_main); 213 run = vcpu_state(vm, VCPU_ID); 214 215 vcpu_set_hv_cpuid(vm, VCPU_ID); 216 217 tsc_page_gva = vm_vaddr_alloc_page(vm); 218 memset(addr_gpa2hva(vm, tsc_page_gva), 0x0, getpagesize()); 219 TEST_ASSERT((addr_gva2gpa(vm, tsc_page_gva) & (getpagesize() - 1)) == 0, 220 "TSC page has to be page aligned\n"); 221 vcpu_args_set(vm, VCPU_ID, 2, tsc_page_gva, addr_gva2gpa(vm, tsc_page_gva)); 222 223 host_check_tsc_msr_rdtsc(vm); 224 225 for (stage = 1;; stage++) { 226 _vcpu_run(vm, VCPU_ID); 227 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO, 228 "Stage %d: unexpected exit reason: %u (%s),\n", 229 stage, run->exit_reason, 230 exit_reason_str(run->exit_reason)); 231 232 switch (get_ucall(vm, VCPU_ID, &uc)) { 233 case UCALL_ABORT: 234 TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0], 235 __FILE__, uc.args[1]); 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\n", 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 } 260 261 out: 262 kvm_vm_free(vm); 263 } 264