1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * svm_vmcall_test
4 *
5 * Copyright © 2021 Amazon.com, Inc. or its affiliates.
6 *
7 * Xen shared_info / pvclock testing
8 */
9
10 #include "test_util.h"
11 #include "kvm_util.h"
12 #include "processor.h"
13
14 #include <stdint.h>
15 #include <time.h>
16 #include <sched.h>
17 #include <signal.h>
18 #include <pthread.h>
19
20 #define NR_TEST_VCPUS 20
21
22 static struct kvm_vm *vm;
23 pthread_spinlock_t create_lock;
24
25 #define TEST_TSC_KHZ 2345678UL
26 #define TEST_TSC_OFFSET 200000000
27
28 uint64_t tsc_sync;
guest_code(void)29 static void guest_code(void)
30 {
31 uint64_t start_tsc, local_tsc, tmp;
32
33 start_tsc = rdtsc();
34 do {
35 tmp = READ_ONCE(tsc_sync);
36 local_tsc = rdtsc();
37 WRITE_ONCE(tsc_sync, local_tsc);
38 if (unlikely(local_tsc < tmp))
39 GUEST_SYNC_ARGS(0, local_tsc, tmp, 0, 0);
40
41 } while (local_tsc - start_tsc < 5000 * TEST_TSC_KHZ);
42
43 GUEST_DONE();
44 }
45
46
run_vcpu(void * _cpu_nr)47 static void *run_vcpu(void *_cpu_nr)
48 {
49 unsigned long vcpu_id = (unsigned long)_cpu_nr;
50 unsigned long failures = 0;
51 static bool first_cpu_done;
52 struct kvm_vcpu *vcpu;
53
54 /* The kernel is fine, but vm_vcpu_add() needs locking */
55 pthread_spin_lock(&create_lock);
56
57 vcpu = vm_vcpu_add(vm, vcpu_id, guest_code);
58
59 if (!first_cpu_done) {
60 first_cpu_done = true;
61 vcpu_set_msr(vcpu, MSR_IA32_TSC, TEST_TSC_OFFSET);
62 }
63
64 pthread_spin_unlock(&create_lock);
65
66 for (;;) {
67 volatile struct kvm_run *run = vcpu->run;
68 struct ucall uc;
69
70 vcpu_run(vcpu);
71 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
72 "Got exit_reason other than KVM_EXIT_IO: %u (%s)\n",
73 run->exit_reason,
74 exit_reason_str(run->exit_reason));
75
76 switch (get_ucall(vcpu, &uc)) {
77 case UCALL_DONE:
78 goto out;
79
80 case UCALL_SYNC:
81 printf("Guest %d sync %lx %lx %ld\n", vcpu->id,
82 uc.args[2], uc.args[3], uc.args[2] - uc.args[3]);
83 failures++;
84 break;
85
86 default:
87 TEST_FAIL("Unknown ucall %lu", uc.cmd);
88 }
89 }
90 out:
91 return (void *)failures;
92 }
93
main(int argc,char * argv[])94 int main(int argc, char *argv[])
95 {
96 TEST_REQUIRE(kvm_has_cap(KVM_CAP_VM_TSC_CONTROL));
97
98 vm = vm_create(NR_TEST_VCPUS);
99 vm_ioctl(vm, KVM_SET_TSC_KHZ, (void *) TEST_TSC_KHZ);
100
101 pthread_spin_init(&create_lock, PTHREAD_PROCESS_PRIVATE);
102 pthread_t cpu_threads[NR_TEST_VCPUS];
103 unsigned long cpu;
104 for (cpu = 0; cpu < NR_TEST_VCPUS; cpu++)
105 pthread_create(&cpu_threads[cpu], NULL, run_vcpu, (void *)cpu);
106
107 unsigned long failures = 0;
108 for (cpu = 0; cpu < NR_TEST_VCPUS; cpu++) {
109 void *this_cpu_failures;
110 pthread_join(cpu_threads[cpu], &this_cpu_failures);
111 failures += (unsigned long)this_cpu_failures;
112 }
113
114 TEST_ASSERT(!failures, "TSC sync failed");
115 pthread_spin_destroy(&create_lock);
116 kvm_vm_free(vm);
117 return 0;
118 }
119