1 /*
2 * mmio_warning_test
3 *
4 * Copyright (C) 2019, Google LLC.
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2.
7 *
8 * Test that we don't get a kernel warning when we call KVM_RUN after a
9 * triple fault occurs. To get the triple fault to occur we call KVM_RUN
10 * on a VCPU that hasn't been properly setup.
11 *
12 */
13
14 #define _GNU_SOURCE
15 #include <fcntl.h>
16 #include <kvm_util.h>
17 #include <linux/kvm.h>
18 #include <processor.h>
19 #include <pthread.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <sys/ioctl.h>
24 #include <sys/mman.h>
25 #include <sys/stat.h>
26 #include <sys/types.h>
27 #include <sys/wait.h>
28 #include <test_util.h>
29 #include <unistd.h>
30
31 #define NTHREAD 4
32 #define NPROCESS 5
33
34 struct thread_context {
35 int kvmcpu;
36 struct kvm_run *run;
37 };
38
thr(void * arg)39 void *thr(void *arg)
40 {
41 struct thread_context *tc = (struct thread_context *)arg;
42 int res;
43 int kvmcpu = tc->kvmcpu;
44 struct kvm_run *run = tc->run;
45
46 res = ioctl(kvmcpu, KVM_RUN, 0);
47 printf("ret1=%d exit_reason=%d suberror=%d\n",
48 res, run->exit_reason, run->internal.suberror);
49
50 return 0;
51 }
52
test(void)53 void test(void)
54 {
55 int i, kvm, kvmvm, kvmcpu;
56 pthread_t th[NTHREAD];
57 struct kvm_run *run;
58 struct thread_context tc;
59
60 kvm = open("/dev/kvm", O_RDWR);
61 TEST_ASSERT(kvm != -1, "failed to open /dev/kvm");
62 kvmvm = ioctl(kvm, KVM_CREATE_VM, 0);
63 TEST_ASSERT(kvmvm != -1, "KVM_CREATE_VM failed");
64 kvmcpu = ioctl(kvmvm, KVM_CREATE_VCPU, 0);
65 TEST_ASSERT(kvmcpu != -1, "KVM_CREATE_VCPU failed");
66 run = (struct kvm_run *)mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED,
67 kvmcpu, 0);
68 tc.kvmcpu = kvmcpu;
69 tc.run = run;
70 srand(getpid());
71 for (i = 0; i < NTHREAD; i++) {
72 pthread_create(&th[i], NULL, thr, (void *)(uintptr_t)&tc);
73 usleep(rand() % 10000);
74 }
75 for (i = 0; i < NTHREAD; i++)
76 pthread_join(th[i], NULL);
77 }
78
get_warnings_count(void)79 int get_warnings_count(void)
80 {
81 int warnings;
82 FILE *f;
83
84 f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
85 fscanf(f, "%d", &warnings);
86 fclose(f);
87
88 return warnings;
89 }
90
main(void)91 int main(void)
92 {
93 int warnings_before, warnings_after;
94
95 if (!is_intel_cpu()) {
96 printf("Must be run on an Intel CPU, skipping test\n");
97 exit(KSFT_SKIP);
98 }
99
100 if (vm_is_unrestricted_guest(NULL)) {
101 printf("Unrestricted guest must be disabled, skipping test\n");
102 exit(KSFT_SKIP);
103 }
104
105 warnings_before = get_warnings_count();
106
107 for (int i = 0; i < NPROCESS; ++i) {
108 int status;
109 int pid = fork();
110
111 if (pid < 0)
112 exit(1);
113 if (pid == 0) {
114 test();
115 exit(0);
116 }
117 while (waitpid(pid, &status, __WALL) != pid)
118 ;
119 }
120
121 warnings_after = get_warnings_count();
122 TEST_ASSERT(warnings_before == warnings_after,
123 "Warnings found in kernel. Run 'dmesg' to inspect them.");
124
125 return 0;
126 }
127