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
19 struct test_case {
20 uint64_t tsc_offset;
21 };
22
23 static struct test_case test_cases[] = {
24 { 0 },
25 { 180 * NSEC_PER_SEC },
26 { -180 * NSEC_PER_SEC },
27 };
28
29 static 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
36 static 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
42 static uint64_t guest_read_system_counter(struct test_case *test)
43 {
44 return rdtsc();
45 }
46
47 static uint64_t 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
61 static 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
72 static void handle_sync(struct ucall *uc, uint64_t start, uint64_t end)
73 {
74 uint64_t 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
84 static void handle_abort(struct ucall *uc)
85 {
86 REPORT_GUEST_ASSERT(*uc);
87 }
88
89 static void enter_guest(struct kvm_vcpu *vcpu)
90 {
91 uint64_t 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
117 int 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 }
128
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.