projects/linux·blob master · refs

246 lines · 6.5 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * arch_timer.c - Tests the arch timer IRQ functionality
4 *
5 * The guest's main thread configures the timer interrupt and waits
6 * for it to fire, with a timeout equal to the timer period.
7 * It asserts that the timeout doesn't exceed the timer period plus
8 * a user configurable error margin(default to 100us)
9 *
10 * On the other hand, upon receipt of an interrupt, the guest's interrupt
11 * handler validates the interrupt by checking if the architectural state
12 * is in compliance with the specifications.
13 *
14 * The test provides command-line options to configure the timer's
15 * period (-p), number of vCPUs (-n), iterations per stage (-i) and timer
16 * interrupt arrival error margin (-e). To stress-test the timer stack
17 * even more, an option to migrate the vCPUs across pCPUs (-m), at a
18 * particular rate, is also provided.
19 *
20 * Copyright (c) 2021, Google LLC.
21 */
22#include <stdlib.h>
23#include <pthread.h>
24#include <linux/sizes.h>
25#include <linux/bitmap.h>
26#include <sys/sysinfo.h>
27
28#include "timer_test.h"
29#include "ucall_common.h"
30
31struct test_args test_args = {
32 .nr_vcpus = NR_VCPUS_DEF,
33 .nr_iter = NR_TEST_ITERS_DEF,
34 .timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
35 .migration_freq_ms = TIMER_TEST_MIGRATION_FREQ_MS,
36 .timer_err_margin_us = TIMER_TEST_ERR_MARGIN_US,
37 .reserved = 1,
38};
39
40struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
41struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
42
43static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];
44static unsigned long *vcpu_done_map;
45static pthread_mutex_t vcpu_done_map_lock;
46
47static void *test_vcpu_run(void *arg)
48{
49 unsigned int vcpu_idx = (unsigned long)arg;
50 struct ucall uc;
51 struct kvm_vcpu *vcpu = vcpus[vcpu_idx];
52 struct kvm_vm *vm = vcpu->vm;
53 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpu_idx];
54
55 vcpu_run(vcpu);
56
57 /* Currently, any exit from guest is an indication of completion */
58 pthread_mutex_lock(&vcpu_done_map_lock);
59 __set_bit(vcpu_idx, vcpu_done_map);
60 pthread_mutex_unlock(&vcpu_done_map_lock);
61
62 switch (get_ucall(vcpu, &uc)) {
63 case UCALL_SYNC:
64 case UCALL_DONE:
65 break;
66 case UCALL_ABORT:
67 sync_global_from_guest(vm, *shared_data);
68 fprintf(stderr, "Guest assert failed, vcpu %u; stage; %u; iter: %u\n",
69 vcpu_idx, shared_data->guest_stage, shared_data->nr_iter);
70 REPORT_GUEST_ASSERT(uc);
71 break;
72 default:
73 TEST_FAIL("Unexpected guest exit");
74 }
75
76 pr_info("PASS(vCPU-%d).\n", vcpu_idx);
77
78 return NULL;
79}
80
81static u32 test_get_pcpu(void)
82{
83 u32 pcpu;
84 unsigned int nproc_conf;
85 cpu_set_t online_cpuset;
86
87 nproc_conf = get_nprocs_conf();
88 kvm_sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset);
89
90 /* Randomly find an available pCPU to place a vCPU on */
91 do {
92 pcpu = rand() % nproc_conf;
93 } while (!CPU_ISSET(pcpu, &online_cpuset));
94
95 return pcpu;
96}
97
98static int test_migrate_vcpu(unsigned int vcpu_idx)
99{
100 int ret;
101 u32 new_pcpu = test_get_pcpu();
102
103 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu);
104
105 ret = __pin_task_to_cpu(pt_vcpu_run[vcpu_idx], new_pcpu);
106
107 /* Allow the error where the vCPU thread is already finished */
108 TEST_ASSERT(ret == 0 || ret == ESRCH,
109 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d",
110 vcpu_idx, new_pcpu, ret);
111
112 return ret;
113}
114
115static void *test_vcpu_migration(void *arg)
116{
117 unsigned int i, n_done;
118 bool vcpu_done;
119
120 do {
121 usleep(msecs_to_usecs(test_args.migration_freq_ms));
122
123 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) {
124 pthread_mutex_lock(&vcpu_done_map_lock);
125 vcpu_done = test_bit(i, vcpu_done_map);
126 pthread_mutex_unlock(&vcpu_done_map_lock);
127
128 if (vcpu_done) {
129 n_done++;
130 continue;
131 }
132
133 test_migrate_vcpu(i);
134 }
135 } while (test_args.nr_vcpus != n_done);
136
137 return NULL;
138}
139
140static void test_run(struct kvm_vm *vm)
141{
142 pthread_t pt_vcpu_migration;
143 unsigned int i;
144
145 pthread_mutex_init(&vcpu_done_map_lock, NULL);
146 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus);
147 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap");
148
149 for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++)
150 kvm_pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run,
151 (void *)(unsigned long)i);
152
153 /* Spawn a thread to control the vCPU migrations */
154 if (test_args.migration_freq_ms) {
155 srand(time(NULL));
156
157 kvm_pthread_create(&pt_vcpu_migration, NULL, test_vcpu_migration, NULL);
158 }
159
160 for (i = 0; i < test_args.nr_vcpus; i++)
161 kvm_pthread_join(pt_vcpu_run[i], NULL);
162
163 if (test_args.migration_freq_ms)
164 kvm_pthread_join(pt_vcpu_migration, NULL);
165
166 bitmap_free(vcpu_done_map);
167}
168
169static void test_print_help(char *name)
170{
171 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n"
172 "\t\t [-m migration_freq_ms] [-o counter_offset]\n"
173 "\t\t [-e timer_err_margin_us]\n", name);
174 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
175 NR_VCPUS_DEF, KVM_MAX_VCPUS);
176 pr_info("\t-i: Number of iterations per stage (default: %u)\n",
177 NR_TEST_ITERS_DEF);
178 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
179 TIMER_TEST_PERIOD_MS_DEF);
180 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
181 TIMER_TEST_MIGRATION_FREQ_MS);
182 pr_info("\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n");
183 pr_info("\t-e: Interrupt arrival error margin (in us) of the guest timer (default: %u)\n",
184 TIMER_TEST_ERR_MARGIN_US);
185 pr_info("\t-h: print this help screen\n");
186}
187
188static bool parse_args(int argc, char *argv[])
189{
190 int opt;
191
192 while ((opt = getopt(argc, argv, "hn:i:p:m:o:e:")) != -1) {
193 switch (opt) {
194 case 'n':
195 test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg);
196 if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
197 pr_info("Max allowed vCPUs: %u\n",
198 KVM_MAX_VCPUS);
199 goto err;
200 }
201 break;
202 case 'i':
203 test_args.nr_iter = atoi_positive("Number of iterations", optarg);
204 break;
205 case 'p':
206 test_args.timer_period_ms = atoi_positive("Periodicity", optarg);
207 break;
208 case 'm':
209 test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
210 break;
211 case 'e':
212 test_args.timer_err_margin_us = atoi_non_negative("Error Margin", optarg);
213 break;
214 case 'o':
215 test_args.counter_offset = strtol(optarg, NULL, 0);
216 test_args.reserved = 0;
217 break;
218 case 'h':
219 default:
220 goto err;
221 }
222 }
223
224 return true;
225
226err:
227 test_print_help(argv[0]);
228 return false;
229}
230
231int main(int argc, char *argv[])
232{
233 struct kvm_vm *vm;
234
235 if (!parse_args(argc, argv))
236 exit(KSFT_SKIP);
237
238 __TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2,
239 "At least two physical CPUs needed for vCPU migration");
240
241 vm = test_vm_create();
242 test_run(vm);
243 test_vm_cleanup(vm);
244
245 return 0;
246}