1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright © 2021 Amazon.com, Inc. or its affiliates.
4 */
5
6 #include "test_util.h"
7 #include "kvm_util.h"
8 #include "processor.h"
9
10 #include <stdint.h>
11 #include <time.h>
12 #include <sched.h>
13 #include <signal.h>
14 #include <pthread.h>
15
16 #define NR_TEST_VCPUS 20
17
18 static struct kvm_vm *vm;
19 pthread_spinlock_t create_lock;
20
21 #define TEST_TSC_KHZ 2345678UL
22 #define TEST_TSC_OFFSET 200000000
23
24 uint64_t tsc_sync;
guest_code(void)25 static void guest_code(void)
26 {
27 uint64_t start_tsc, local_tsc, tmp;
28
29 start_tsc = rdtsc();
30 do {
31 tmp = READ_ONCE(tsc_sync);
32 local_tsc = rdtsc();
33 WRITE_ONCE(tsc_sync, local_tsc);
34 if (unlikely(local_tsc < tmp))
35 GUEST_SYNC_ARGS(0, local_tsc, tmp, 0, 0);
36
37 } while (local_tsc - start_tsc < 5000 * TEST_TSC_KHZ);
38
39 GUEST_DONE();
40 }
41
42
run_vcpu(void * _cpu_nr)43 static void *run_vcpu(void *_cpu_nr)
44 {
45 unsigned long vcpu_id = (unsigned long)_cpu_nr;
46 unsigned long failures = 0;
47 static bool first_cpu_done;
48 struct kvm_vcpu *vcpu;
49
50 /* The kernel is fine, but vm_vcpu_add() needs locking */
51 pthread_spin_lock(&create_lock);
52
53 vcpu = vm_vcpu_add(vm, vcpu_id, guest_code);
54
55 if (!first_cpu_done) {
56 first_cpu_done = true;
57 vcpu_set_msr(vcpu, MSR_IA32_TSC, TEST_TSC_OFFSET);
58 }
59
60 pthread_spin_unlock(&create_lock);
61
62 for (;;) {
63 struct ucall uc;
64
65 vcpu_run(vcpu);
66 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
67
68 switch (get_ucall(vcpu, &uc)) {
69 case UCALL_DONE:
70 goto out;
71
72 case UCALL_SYNC:
73 printf("Guest %d sync %lx %lx %ld\n", vcpu->id,
74 uc.args[2], uc.args[3], uc.args[2] - uc.args[3]);
75 failures++;
76 break;
77
78 default:
79 TEST_FAIL("Unknown ucall %lu", uc.cmd);
80 }
81 }
82 out:
83 return (void *)failures;
84 }
85
main(int argc,char * argv[])86 int main(int argc, char *argv[])
87 {
88 TEST_REQUIRE(kvm_has_cap(KVM_CAP_VM_TSC_CONTROL));
89
90 vm = vm_create(NR_TEST_VCPUS);
91 vm_ioctl(vm, KVM_SET_TSC_KHZ, (void *) TEST_TSC_KHZ);
92
93 pthread_spin_init(&create_lock, PTHREAD_PROCESS_PRIVATE);
94 pthread_t cpu_threads[NR_TEST_VCPUS];
95 unsigned long cpu;
96 for (cpu = 0; cpu < NR_TEST_VCPUS; cpu++)
97 pthread_create(&cpu_threads[cpu], NULL, run_vcpu, (void *)cpu);
98
99 unsigned long failures = 0;
100 for (cpu = 0; cpu < NR_TEST_VCPUS; cpu++) {
101 void *this_cpu_failures;
102 pthread_join(cpu_threads[cpu], &this_cpu_failures);
103 failures += (unsigned long)this_cpu_failures;
104 }
105
106 TEST_ASSERT(!failures, "TSC sync failed");
107 pthread_spin_destroy(&create_lock);
108 kvm_vm_free(vm);
109 return 0;
110 }
111