1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * arch_timer.c - Tests the aarch64 timer IRQ functionality
4 *
5 * The test validates both the virtual and physical timer IRQs using
6 * CVAL and TVAL registers. This consitutes the four stages in the test.
7 * The guest's main thread configures the timer interrupt for a stage
8 * and waits for it to fire, with a timeout equal to the timer period.
9 * It asserts that the timeout doesn't exceed the timer period.
10 *
11 * On the other hand, upon receipt of an interrupt, the guest's interrupt
12 * handler validates the interrupt by checking if the architectural state
13 * is in compliance with the specifications.
14 *
15 * The test provides command-line options to configure the timer's
16 * period (-p), number of vCPUs (-n), and iterations per stage (-i).
17 * To stress-test the timer stack even more, an option to migrate the
18 * vCPUs across pCPUs (-m), at a particular rate, is also provided.
19 *
20 * Copyright (c) 2021, Google LLC.
21 */
22
23 #define _GNU_SOURCE
24
25 #include <stdlib.h>
26 #include <pthread.h>
27 #include <linux/kvm.h>
28 #include <linux/sizes.h>
29 #include <linux/bitmap.h>
30 #include <sys/sysinfo.h>
31
32 #include "kvm_util.h"
33 #include "processor.h"
34 #include "delay.h"
35 #include "arch_timer.h"
36 #include "gic.h"
37 #include "vgic.h"
38
39 #define NR_VCPUS_DEF 4
40 #define NR_TEST_ITERS_DEF 5
41 #define TIMER_TEST_PERIOD_MS_DEF 10
42 #define TIMER_TEST_ERR_MARGIN_US 100
43 #define TIMER_TEST_MIGRATION_FREQ_MS 2
44
45 struct test_args {
46 int nr_vcpus;
47 int nr_iter;
48 int timer_period_ms;
49 int migration_freq_ms;
50 };
51
52 static struct test_args test_args = {
53 .nr_vcpus = NR_VCPUS_DEF,
54 .nr_iter = NR_TEST_ITERS_DEF,
55 .timer_period_ms = TIMER_TEST_PERIOD_MS_DEF,
56 .migration_freq_ms = TIMER_TEST_MIGRATION_FREQ_MS,
57 };
58
59 #define msecs_to_usecs(msec) ((msec) * 1000LL)
60
61 #define GICD_BASE_GPA 0x8000000ULL
62 #define GICR_BASE_GPA 0x80A0000ULL
63
64 enum guest_stage {
65 GUEST_STAGE_VTIMER_CVAL = 1,
66 GUEST_STAGE_VTIMER_TVAL,
67 GUEST_STAGE_PTIMER_CVAL,
68 GUEST_STAGE_PTIMER_TVAL,
69 GUEST_STAGE_MAX,
70 };
71
72 /* Shared variables between host and guest */
73 struct test_vcpu_shared_data {
74 int nr_iter;
75 enum guest_stage guest_stage;
76 uint64_t xcnt;
77 };
78
79 struct test_vcpu {
80 uint32_t vcpuid;
81 pthread_t pt_vcpu_run;
82 struct kvm_vm *vm;
83 };
84
85 static struct test_vcpu test_vcpu[KVM_MAX_VCPUS];
86 static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
87
88 static int vtimer_irq, ptimer_irq;
89
90 static unsigned long *vcpu_done_map;
91 static pthread_mutex_t vcpu_done_map_lock;
92
93 static void
guest_configure_timer_action(struct test_vcpu_shared_data * shared_data)94 guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
95 {
96 switch (shared_data->guest_stage) {
97 case GUEST_STAGE_VTIMER_CVAL:
98 timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
99 shared_data->xcnt = timer_get_cntct(VIRTUAL);
100 timer_set_ctl(VIRTUAL, CTL_ENABLE);
101 break;
102 case GUEST_STAGE_VTIMER_TVAL:
103 timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
104 shared_data->xcnt = timer_get_cntct(VIRTUAL);
105 timer_set_ctl(VIRTUAL, CTL_ENABLE);
106 break;
107 case GUEST_STAGE_PTIMER_CVAL:
108 timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
109 shared_data->xcnt = timer_get_cntct(PHYSICAL);
110 timer_set_ctl(PHYSICAL, CTL_ENABLE);
111 break;
112 case GUEST_STAGE_PTIMER_TVAL:
113 timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
114 shared_data->xcnt = timer_get_cntct(PHYSICAL);
115 timer_set_ctl(PHYSICAL, CTL_ENABLE);
116 break;
117 default:
118 GUEST_ASSERT(0);
119 }
120 }
121
guest_validate_irq(unsigned int intid,struct test_vcpu_shared_data * shared_data)122 static void guest_validate_irq(unsigned int intid,
123 struct test_vcpu_shared_data *shared_data)
124 {
125 enum guest_stage stage = shared_data->guest_stage;
126 uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
127 unsigned long xctl = 0;
128 unsigned int timer_irq = 0;
129
130 if (stage == GUEST_STAGE_VTIMER_CVAL ||
131 stage == GUEST_STAGE_VTIMER_TVAL) {
132 xctl = timer_get_ctl(VIRTUAL);
133 timer_set_ctl(VIRTUAL, CTL_IMASK);
134 xcnt = timer_get_cntct(VIRTUAL);
135 cval = timer_get_cval(VIRTUAL);
136 timer_irq = vtimer_irq;
137 } else if (stage == GUEST_STAGE_PTIMER_CVAL ||
138 stage == GUEST_STAGE_PTIMER_TVAL) {
139 xctl = timer_get_ctl(PHYSICAL);
140 timer_set_ctl(PHYSICAL, CTL_IMASK);
141 xcnt = timer_get_cntct(PHYSICAL);
142 cval = timer_get_cval(PHYSICAL);
143 timer_irq = ptimer_irq;
144 } else {
145 GUEST_ASSERT(0);
146 }
147
148 xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
149
150 /* Make sure we are dealing with the correct timer IRQ */
151 GUEST_ASSERT_2(intid == timer_irq, intid, timer_irq);
152
153 /* Basic 'timer condition met' check */
154 GUEST_ASSERT_3(xcnt >= cval, xcnt, cval, xcnt_diff_us);
155 GUEST_ASSERT_1(xctl & CTL_ISTATUS, xctl);
156 }
157
guest_irq_handler(struct ex_regs * regs)158 static void guest_irq_handler(struct ex_regs *regs)
159 {
160 unsigned int intid = gic_get_and_ack_irq();
161 uint32_t cpu = guest_get_vcpuid();
162 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
163
164 guest_validate_irq(intid, shared_data);
165
166 WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
167
168 gic_set_eoi(intid);
169 }
170
guest_run_stage(struct test_vcpu_shared_data * shared_data,enum guest_stage stage)171 static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
172 enum guest_stage stage)
173 {
174 uint32_t irq_iter, config_iter;
175
176 shared_data->guest_stage = stage;
177 shared_data->nr_iter = 0;
178
179 for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
180 /* Setup the next interrupt */
181 guest_configure_timer_action(shared_data);
182
183 /* Setup a timeout for the interrupt to arrive */
184 udelay(msecs_to_usecs(test_args.timer_period_ms) +
185 TIMER_TEST_ERR_MARGIN_US);
186
187 irq_iter = READ_ONCE(shared_data->nr_iter);
188 GUEST_ASSERT_2(config_iter + 1 == irq_iter,
189 config_iter + 1, irq_iter);
190 }
191 }
192
guest_code(void)193 static void guest_code(void)
194 {
195 uint32_t cpu = guest_get_vcpuid();
196 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
197
198 local_irq_disable();
199
200 gic_init(GIC_V3, test_args.nr_vcpus,
201 (void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
202
203 timer_set_ctl(VIRTUAL, CTL_IMASK);
204 timer_set_ctl(PHYSICAL, CTL_IMASK);
205
206 gic_irq_enable(vtimer_irq);
207 gic_irq_enable(ptimer_irq);
208 local_irq_enable();
209
210 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
211 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
212 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
213 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
214
215 GUEST_DONE();
216 }
217
test_vcpu_run(void * arg)218 static void *test_vcpu_run(void *arg)
219 {
220 struct ucall uc;
221 struct test_vcpu *vcpu = arg;
222 struct kvm_vm *vm = vcpu->vm;
223 uint32_t vcpuid = vcpu->vcpuid;
224 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpuid];
225
226 vcpu_run(vm, vcpuid);
227
228 /* Currently, any exit from guest is an indication of completion */
229 pthread_mutex_lock(&vcpu_done_map_lock);
230 set_bit(vcpuid, vcpu_done_map);
231 pthread_mutex_unlock(&vcpu_done_map_lock);
232
233 switch (get_ucall(vm, vcpuid, &uc)) {
234 case UCALL_SYNC:
235 case UCALL_DONE:
236 break;
237 case UCALL_ABORT:
238 sync_global_from_guest(vm, *shared_data);
239 TEST_FAIL("%s at %s:%ld\n\tvalues: %lu, %lu; %lu, vcpu: %u; stage: %u; iter: %u",
240 (const char *)uc.args[0], __FILE__, uc.args[1],
241 uc.args[2], uc.args[3], uc.args[4], vcpuid,
242 shared_data->guest_stage, shared_data->nr_iter);
243 break;
244 default:
245 TEST_FAIL("Unexpected guest exit\n");
246 }
247
248 return NULL;
249 }
250
test_get_pcpu(void)251 static uint32_t test_get_pcpu(void)
252 {
253 uint32_t pcpu;
254 unsigned int nproc_conf;
255 cpu_set_t online_cpuset;
256
257 nproc_conf = get_nprocs_conf();
258 sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset);
259
260 /* Randomly find an available pCPU to place a vCPU on */
261 do {
262 pcpu = rand() % nproc_conf;
263 } while (!CPU_ISSET(pcpu, &online_cpuset));
264
265 return pcpu;
266 }
267
test_migrate_vcpu(struct test_vcpu * vcpu)268 static int test_migrate_vcpu(struct test_vcpu *vcpu)
269 {
270 int ret;
271 cpu_set_t cpuset;
272 uint32_t new_pcpu = test_get_pcpu();
273
274 CPU_ZERO(&cpuset);
275 CPU_SET(new_pcpu, &cpuset);
276
277 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu->vcpuid, new_pcpu);
278
279 ret = pthread_setaffinity_np(vcpu->pt_vcpu_run,
280 sizeof(cpuset), &cpuset);
281
282 /* Allow the error where the vCPU thread is already finished */
283 TEST_ASSERT(ret == 0 || ret == ESRCH,
284 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d\n",
285 vcpu->vcpuid, new_pcpu, ret);
286
287 return ret;
288 }
289
test_vcpu_migration(void * arg)290 static void *test_vcpu_migration(void *arg)
291 {
292 unsigned int i, n_done;
293 bool vcpu_done;
294
295 do {
296 usleep(msecs_to_usecs(test_args.migration_freq_ms));
297
298 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) {
299 pthread_mutex_lock(&vcpu_done_map_lock);
300 vcpu_done = test_bit(i, vcpu_done_map);
301 pthread_mutex_unlock(&vcpu_done_map_lock);
302
303 if (vcpu_done) {
304 n_done++;
305 continue;
306 }
307
308 test_migrate_vcpu(&test_vcpu[i]);
309 }
310 } while (test_args.nr_vcpus != n_done);
311
312 return NULL;
313 }
314
test_run(struct kvm_vm * vm)315 static void test_run(struct kvm_vm *vm)
316 {
317 int i, ret;
318 pthread_t pt_vcpu_migration;
319
320 pthread_mutex_init(&vcpu_done_map_lock, NULL);
321 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus);
322 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap\n");
323
324 for (i = 0; i < test_args.nr_vcpus; i++) {
325 ret = pthread_create(&test_vcpu[i].pt_vcpu_run, NULL,
326 test_vcpu_run, &test_vcpu[i]);
327 TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread\n", i);
328 }
329
330 /* Spawn a thread to control the vCPU migrations */
331 if (test_args.migration_freq_ms) {
332 srand(time(NULL));
333
334 ret = pthread_create(&pt_vcpu_migration, NULL,
335 test_vcpu_migration, NULL);
336 TEST_ASSERT(!ret, "Failed to create the migration pthread\n");
337 }
338
339
340 for (i = 0; i < test_args.nr_vcpus; i++)
341 pthread_join(test_vcpu[i].pt_vcpu_run, NULL);
342
343 if (test_args.migration_freq_ms)
344 pthread_join(pt_vcpu_migration, NULL);
345
346 bitmap_free(vcpu_done_map);
347 }
348
test_init_timer_irq(struct kvm_vm * vm)349 static void test_init_timer_irq(struct kvm_vm *vm)
350 {
351 /* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
352 int vcpu0_fd = vcpu_get_fd(vm, 0);
353
354 kvm_device_access(vcpu0_fd, KVM_ARM_VCPU_TIMER_CTRL,
355 KVM_ARM_VCPU_TIMER_IRQ_PTIMER, &ptimer_irq, false);
356 kvm_device_access(vcpu0_fd, KVM_ARM_VCPU_TIMER_CTRL,
357 KVM_ARM_VCPU_TIMER_IRQ_VTIMER, &vtimer_irq, false);
358
359 sync_global_to_guest(vm, ptimer_irq);
360 sync_global_to_guest(vm, vtimer_irq);
361
362 pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
363 }
364
test_vm_create(void)365 static struct kvm_vm *test_vm_create(void)
366 {
367 struct kvm_vm *vm;
368 unsigned int i;
369 int nr_vcpus = test_args.nr_vcpus;
370
371 vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL);
372
373 vm_init_descriptor_tables(vm);
374 vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
375
376 for (i = 0; i < nr_vcpus; i++) {
377 vcpu_init_descriptor_tables(vm, i);
378
379 test_vcpu[i].vcpuid = i;
380 test_vcpu[i].vm = vm;
381 }
382
383 ucall_init(vm, NULL);
384 test_init_timer_irq(vm);
385 vgic_v3_setup(vm, nr_vcpus, GICD_BASE_GPA, GICR_BASE_GPA);
386
387 /* Make all the test's cmdline args visible to the guest */
388 sync_global_to_guest(vm, test_args);
389
390 return vm;
391 }
392
test_print_help(char * name)393 static void test_print_help(char *name)
394 {
395 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
396 name);
397 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
398 NR_VCPUS_DEF, KVM_MAX_VCPUS);
399 pr_info("\t-i: Number of iterations per stage (default: %u)\n",
400 NR_TEST_ITERS_DEF);
401 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
402 TIMER_TEST_PERIOD_MS_DEF);
403 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
404 TIMER_TEST_MIGRATION_FREQ_MS);
405 pr_info("\t-h: print this help screen\n");
406 }
407
parse_args(int argc,char * argv[])408 static bool parse_args(int argc, char *argv[])
409 {
410 int opt;
411
412 while ((opt = getopt(argc, argv, "hn:i:p:m:")) != -1) {
413 switch (opt) {
414 case 'n':
415 test_args.nr_vcpus = atoi(optarg);
416 if (test_args.nr_vcpus <= 0) {
417 pr_info("Positive value needed for -n\n");
418 goto err;
419 } else if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
420 pr_info("Max allowed vCPUs: %u\n",
421 KVM_MAX_VCPUS);
422 goto err;
423 }
424 break;
425 case 'i':
426 test_args.nr_iter = atoi(optarg);
427 if (test_args.nr_iter <= 0) {
428 pr_info("Positive value needed for -i\n");
429 goto err;
430 }
431 break;
432 case 'p':
433 test_args.timer_period_ms = atoi(optarg);
434 if (test_args.timer_period_ms <= 0) {
435 pr_info("Positive value needed for -p\n");
436 goto err;
437 }
438 break;
439 case 'm':
440 test_args.migration_freq_ms = atoi(optarg);
441 if (test_args.migration_freq_ms < 0) {
442 pr_info("0 or positive value needed for -m\n");
443 goto err;
444 }
445 break;
446 case 'h':
447 default:
448 goto err;
449 }
450 }
451
452 return true;
453
454 err:
455 test_print_help(argv[0]);
456 return false;
457 }
458
main(int argc,char * argv[])459 int main(int argc, char *argv[])
460 {
461 struct kvm_vm *vm;
462
463 /* Tell stdout not to buffer its content */
464 setbuf(stdout, NULL);
465
466 if (!parse_args(argc, argv))
467 exit(KSFT_SKIP);
468
469 if (test_args.migration_freq_ms && get_nprocs() < 2) {
470 print_skip("At least two physical CPUs needed for vCPU migration");
471 exit(KSFT_SKIP);
472 }
473
474 vm = test_vm_create();
475 test_run(vm);
476 kvm_vm_free(vm);
477
478 return 0;
479 }
480