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	uint64_t 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 uint64_t guest_read_system_counter(struct test_case *test)
43{
44	return rdtsc();
45}
46
47static 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
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, 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
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	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
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}
128