1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2021, Google LLC.
4 *
5 * Tests for adjusting the KVM clock from userspace
6 */
7 #include <asm/kvm_para.h>
8 #include <asm/pvclock.h>
9 #include <asm/pvclock-abi.h>
10 #include <stdint.h>
11 #include <string.h>
12 #include <sys/stat.h>
13 #include <time.h>
14
15 #include "test_util.h"
16 #include "kvm_util.h"
17 #include "processor.h"
18
19 struct test_case {
20 uint64_t kvmclock_base;
21 int64_t realtime_offset;
22 };
23
24 static struct test_case test_cases[] = {
25 { .kvmclock_base = 0 },
26 { .kvmclock_base = 180 * NSEC_PER_SEC },
27 { .kvmclock_base = 0, .realtime_offset = -180 * NSEC_PER_SEC },
28 { .kvmclock_base = 0, .realtime_offset = 180 * NSEC_PER_SEC },
29 };
30
31 #define GUEST_SYNC_CLOCK(__stage, __val) \
32 GUEST_SYNC_ARGS(__stage, __val, 0, 0, 0)
33
34 static void guest_main(vm_paddr_t pvti_pa, struct pvclock_vcpu_time_info *pvti)
35 {
36 int i;
37
38 wrmsr(MSR_KVM_SYSTEM_TIME_NEW, pvti_pa | KVM_MSR_ENABLED);
39 for (i = 0; i < ARRAY_SIZE(test_cases); i++)
40 GUEST_SYNC_CLOCK(i, __pvclock_read_cycles(pvti, rdtsc()));
41 }
42
43 #define EXPECTED_FLAGS (KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC)
44
45 static inline void assert_flags(struct kvm_clock_data *data)
46 {
47 TEST_ASSERT((data->flags & EXPECTED_FLAGS) == EXPECTED_FLAGS,
48 "unexpected clock data flags: %x (want set: %x)",
49 data->flags, EXPECTED_FLAGS);
50 }
51
52 static void handle_sync(struct ucall *uc, struct kvm_clock_data *start,
53 struct kvm_clock_data *end)
54 {
55 uint64_t obs, exp_lo, exp_hi;
56
57 obs = uc->args[2];
58 exp_lo = start->clock;
59 exp_hi = end->clock;
60
61 assert_flags(start);
62 assert_flags(end);
63
64 TEST_ASSERT(exp_lo <= obs && obs <= exp_hi,
65 "unexpected kvm-clock value: %"PRIu64" expected range: [%"PRIu64", %"PRIu64"]",
66 obs, exp_lo, exp_hi);
67
68 pr_info("kvm-clock value: %"PRIu64" expected range [%"PRIu64", %"PRIu64"]\n",
69 obs, exp_lo, exp_hi);
70 }
71
72 static void handle_abort(struct ucall *uc)
73 {
74 REPORT_GUEST_ASSERT(*uc);
75 }
76
77 static void setup_clock(struct kvm_vm *vm, struct test_case *test_case)
78 {
79 struct kvm_clock_data data;
80
81 memset(&data, 0, sizeof(data));
82
83 data.clock = test_case->kvmclock_base;
84 if (test_case->realtime_offset) {
85 struct timespec ts;
86 int r;
87
88 data.flags |= KVM_CLOCK_REALTIME;
89 do {
90 r = clock_gettime(CLOCK_REALTIME, &ts);
91 if (!r)
92 break;
93 } while (errno == EINTR);
94
95 TEST_ASSERT(!r, "clock_gettime() failed: %d", r);
96
97 data.realtime = ts.tv_sec * NSEC_PER_SEC;
98 data.realtime += ts.tv_nsec;
99 data.realtime += test_case->realtime_offset;
100 }
101
102 vm_ioctl(vm, KVM_SET_CLOCK, &data);
103 }
104
105 static void enter_guest(struct kvm_vcpu *vcpu)
106 {
107 struct kvm_clock_data start, end;
108 struct kvm_vm *vm = vcpu->vm;
109 struct ucall uc;
110 int i;
111
112 for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
113 setup_clock(vm, &test_cases[i]);
114
115 vm_ioctl(vm, KVM_GET_CLOCK, &start);
116
117 vcpu_run(vcpu);
118 vm_ioctl(vm, KVM_GET_CLOCK, &end);
119
120 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
121
122 switch (get_ucall(vcpu, &uc)) {
123 case UCALL_SYNC:
124 handle_sync(&uc, &start, &end);
125 break;
126 case UCALL_ABORT:
127 handle_abort(&uc);
128 return;
129 default:
130 TEST_ASSERT(0, "unhandled ucall: %ld", uc.cmd);
131 }
132 }
133 }
134
135 int main(void)
136 {
137 struct kvm_vcpu *vcpu;
138 vm_vaddr_t pvti_gva;
139 vm_paddr_t pvti_gpa;
140 struct kvm_vm *vm;
141 int flags;
142
143 flags = kvm_check_cap(KVM_CAP_ADJUST_CLOCK);
144 TEST_REQUIRE(flags & KVM_CLOCK_REALTIME);
145
146 TEST_REQUIRE(sys_clocksource_is_based_on_tsc());
147
148 vm = vm_create_with_one_vcpu(&vcpu, guest_main);
149
150 pvti_gva = vm_vaddr_alloc(vm, getpagesize(), 0x10000);
151 pvti_gpa = addr_gva2gpa(vm, pvti_gva);
152 vcpu_args_set(vcpu, 2, pvti_gpa, pvti_gva);
153
154 enter_guest(vcpu);
155 kvm_vm_free(vm);
156 }
157
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