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127 lines · 2.6 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2021, Google LLC.
4 *
5 * Tests for adjusting the system counter from userspace
6 */
7#include <asm/kvm_para.h>
8#include <stdint.h>
9#include <string.h>
10#include <sys/stat.h>
11#include <time.h>
12
13#include "test_util.h"
14#include "kvm_util.h"
15#include "processor.h"
16
17#ifdef __x86_64__
18
19struct test_case {
20 u64 tsc_offset;
21};
22
23static struct test_case test_cases[] = {
24 { 0 },
25 { 180 * NSEC_PER_SEC },
26 { -180 * NSEC_PER_SEC },
27};
28
29static void check_preconditions(struct kvm_vcpu *vcpu)
30{
31 __TEST_REQUIRE(!__vcpu_has_device_attr(vcpu, KVM_VCPU_TSC_CTRL,
32 KVM_VCPU_TSC_OFFSET),
33 "KVM_VCPU_TSC_OFFSET not supported; skipping test");
34}
35
36static void setup_system_counter(struct kvm_vcpu *vcpu, struct test_case *test)
37{
38 vcpu_device_attr_set(vcpu, KVM_VCPU_TSC_CTRL, KVM_VCPU_TSC_OFFSET,
39 &test->tsc_offset);
40}
41
42static u64 guest_read_system_counter(struct test_case *test)
43{
44 return rdtsc();
45}
46
47static u64 host_read_guest_system_counter(struct test_case *test)
48{
49 return rdtsc() + test->tsc_offset;
50}
51
52#else /* __x86_64__ */
53
54#error test not implemented for this architecture!
55
56#endif
57
58#define GUEST_SYNC_CLOCK(__stage, __val) \
59 GUEST_SYNC_ARGS(__stage, __val, 0, 0, 0)
60
61static void guest_main(void)
62{
63 int i;
64
65 for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
66 struct test_case *test = &test_cases[i];
67
68 GUEST_SYNC_CLOCK(i, guest_read_system_counter(test));
69 }
70}
71
72static void handle_sync(struct ucall *uc, u64 start, u64 end)
73{
74 u64 obs = uc->args[2];
75
76 TEST_ASSERT(start <= obs && obs <= end,
77 "unexpected system counter value: %"PRIu64" expected range: [%"PRIu64", %"PRIu64"]",
78 obs, start, end);
79
80 pr_info("system counter value: %"PRIu64" expected range [%"PRIu64", %"PRIu64"]\n",
81 obs, start, end);
82}
83
84static void handle_abort(struct ucall *uc)
85{
86 REPORT_GUEST_ASSERT(*uc);
87}
88
89static void enter_guest(struct kvm_vcpu *vcpu)
90{
91 u64 start, end;
92 struct ucall uc;
93 int i;
94
95 for (i = 0; i < ARRAY_SIZE(test_cases); i++) {
96 struct test_case *test = &test_cases[i];
97
98 setup_system_counter(vcpu, test);
99 start = host_read_guest_system_counter(test);
100 vcpu_run(vcpu);
101 end = host_read_guest_system_counter(test);
102
103 switch (get_ucall(vcpu, &uc)) {
104 case UCALL_SYNC:
105 handle_sync(&uc, start, end);
106 break;
107 case UCALL_ABORT:
108 handle_abort(&uc);
109 return;
110 default:
111 TEST_ASSERT(0, "unhandled ucall %ld",
112 get_ucall(vcpu, &uc));
113 }
114 }
115}
116
117int main(void)
118{
119 struct kvm_vcpu *vcpu;
120 struct kvm_vm *vm;
121
122 vm = vm_create_with_one_vcpu(&vcpu, guest_main);
123 check_preconditions(vcpu);
124
125 enter_guest(vcpu);
126 kvm_vm_free(vm);
127}