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}