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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2021, Red Hat, Inc.4 *5 * Tests for Hyper-V clocksources6 */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 across145 * 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 update161 * 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