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 static struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
80 static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];
81 static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
82
83 static int vtimer_irq, ptimer_irq;
84
85 static unsigned long *vcpu_done_map;
86 static pthread_mutex_t vcpu_done_map_lock;
87
88 static void
guest_configure_timer_action(struct test_vcpu_shared_data * shared_data)89 guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
90 {
91 switch (shared_data->guest_stage) {
92 case GUEST_STAGE_VTIMER_CVAL:
93 timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
94 shared_data->xcnt = timer_get_cntct(VIRTUAL);
95 timer_set_ctl(VIRTUAL, CTL_ENABLE);
96 break;
97 case GUEST_STAGE_VTIMER_TVAL:
98 timer_set_next_tval_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_PTIMER_CVAL:
103 timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
104 shared_data->xcnt = timer_get_cntct(PHYSICAL);
105 timer_set_ctl(PHYSICAL, CTL_ENABLE);
106 break;
107 case GUEST_STAGE_PTIMER_TVAL:
108 timer_set_next_tval_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 default:
113 GUEST_ASSERT(0);
114 }
115 }
116
guest_validate_irq(unsigned int intid,struct test_vcpu_shared_data * shared_data)117 static void guest_validate_irq(unsigned int intid,
118 struct test_vcpu_shared_data *shared_data)
119 {
120 enum guest_stage stage = shared_data->guest_stage;
121 uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
122 unsigned long xctl = 0;
123 unsigned int timer_irq = 0;
124
125 if (stage == GUEST_STAGE_VTIMER_CVAL ||
126 stage == GUEST_STAGE_VTIMER_TVAL) {
127 xctl = timer_get_ctl(VIRTUAL);
128 timer_set_ctl(VIRTUAL, CTL_IMASK);
129 xcnt = timer_get_cntct(VIRTUAL);
130 cval = timer_get_cval(VIRTUAL);
131 timer_irq = vtimer_irq;
132 } else if (stage == GUEST_STAGE_PTIMER_CVAL ||
133 stage == GUEST_STAGE_PTIMER_TVAL) {
134 xctl = timer_get_ctl(PHYSICAL);
135 timer_set_ctl(PHYSICAL, CTL_IMASK);
136 xcnt = timer_get_cntct(PHYSICAL);
137 cval = timer_get_cval(PHYSICAL);
138 timer_irq = ptimer_irq;
139 } else {
140 GUEST_ASSERT(0);
141 }
142
143 xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
144
145 /* Make sure we are dealing with the correct timer IRQ */
146 GUEST_ASSERT_2(intid == timer_irq, intid, timer_irq);
147
148 /* Basic 'timer condition met' check */
149 GUEST_ASSERT_3(xcnt >= cval, xcnt, cval, xcnt_diff_us);
150 GUEST_ASSERT_1(xctl & CTL_ISTATUS, xctl);
151 }
152
guest_irq_handler(struct ex_regs * regs)153 static void guest_irq_handler(struct ex_regs *regs)
154 {
155 unsigned int intid = gic_get_and_ack_irq();
156 uint32_t cpu = guest_get_vcpuid();
157 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
158
159 guest_validate_irq(intid, shared_data);
160
161 WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
162
163 gic_set_eoi(intid);
164 }
165
guest_run_stage(struct test_vcpu_shared_data * shared_data,enum guest_stage stage)166 static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
167 enum guest_stage stage)
168 {
169 uint32_t irq_iter, config_iter;
170
171 shared_data->guest_stage = stage;
172 shared_data->nr_iter = 0;
173
174 for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
175 /* Setup the next interrupt */
176 guest_configure_timer_action(shared_data);
177
178 /* Setup a timeout for the interrupt to arrive */
179 udelay(msecs_to_usecs(test_args.timer_period_ms) +
180 TIMER_TEST_ERR_MARGIN_US);
181
182 irq_iter = READ_ONCE(shared_data->nr_iter);
183 GUEST_ASSERT_2(config_iter + 1 == irq_iter,
184 config_iter + 1, irq_iter);
185 }
186 }
187
guest_code(void)188 static void guest_code(void)
189 {
190 uint32_t cpu = guest_get_vcpuid();
191 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
192
193 local_irq_disable();
194
195 gic_init(GIC_V3, test_args.nr_vcpus,
196 (void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
197
198 timer_set_ctl(VIRTUAL, CTL_IMASK);
199 timer_set_ctl(PHYSICAL, CTL_IMASK);
200
201 gic_irq_enable(vtimer_irq);
202 gic_irq_enable(ptimer_irq);
203 local_irq_enable();
204
205 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
206 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
207 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
208 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
209
210 GUEST_DONE();
211 }
212
test_vcpu_run(void * arg)213 static void *test_vcpu_run(void *arg)
214 {
215 unsigned int vcpu_idx = (unsigned long)arg;
216 struct ucall uc;
217 struct kvm_vcpu *vcpu = vcpus[vcpu_idx];
218 struct kvm_vm *vm = vcpu->vm;
219 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpu_idx];
220
221 vcpu_run(vcpu);
222
223 /* Currently, any exit from guest is an indication of completion */
224 pthread_mutex_lock(&vcpu_done_map_lock);
225 __set_bit(vcpu_idx, vcpu_done_map);
226 pthread_mutex_unlock(&vcpu_done_map_lock);
227
228 switch (get_ucall(vcpu, &uc)) {
229 case UCALL_SYNC:
230 case UCALL_DONE:
231 break;
232 case UCALL_ABORT:
233 sync_global_from_guest(vm, *shared_data);
234 REPORT_GUEST_ASSERT_N(uc, "values: %lu, %lu; %lu, vcpu %u; stage; %u; iter: %u",
235 GUEST_ASSERT_ARG(uc, 0),
236 GUEST_ASSERT_ARG(uc, 1),
237 GUEST_ASSERT_ARG(uc, 2),
238 vcpu_idx,
239 shared_data->guest_stage,
240 shared_data->nr_iter);
241 break;
242 default:
243 TEST_FAIL("Unexpected guest exit\n");
244 }
245
246 return NULL;
247 }
248
test_get_pcpu(void)249 static uint32_t test_get_pcpu(void)
250 {
251 uint32_t pcpu;
252 unsigned int nproc_conf;
253 cpu_set_t online_cpuset;
254
255 nproc_conf = get_nprocs_conf();
256 sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset);
257
258 /* Randomly find an available pCPU to place a vCPU on */
259 do {
260 pcpu = rand() % nproc_conf;
261 } while (!CPU_ISSET(pcpu, &online_cpuset));
262
263 return pcpu;
264 }
265
test_migrate_vcpu(unsigned int vcpu_idx)266 static int test_migrate_vcpu(unsigned int vcpu_idx)
267 {
268 int ret;
269 cpu_set_t cpuset;
270 uint32_t new_pcpu = test_get_pcpu();
271
272 CPU_ZERO(&cpuset);
273 CPU_SET(new_pcpu, &cpuset);
274
275 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu);
276
277 ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx],
278 sizeof(cpuset), &cpuset);
279
280 /* Allow the error where the vCPU thread is already finished */
281 TEST_ASSERT(ret == 0 || ret == ESRCH,
282 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d\n",
283 vcpu_idx, new_pcpu, ret);
284
285 return ret;
286 }
287
test_vcpu_migration(void * arg)288 static void *test_vcpu_migration(void *arg)
289 {
290 unsigned int i, n_done;
291 bool vcpu_done;
292
293 do {
294 usleep(msecs_to_usecs(test_args.migration_freq_ms));
295
296 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) {
297 pthread_mutex_lock(&vcpu_done_map_lock);
298 vcpu_done = test_bit(i, vcpu_done_map);
299 pthread_mutex_unlock(&vcpu_done_map_lock);
300
301 if (vcpu_done) {
302 n_done++;
303 continue;
304 }
305
306 test_migrate_vcpu(i);
307 }
308 } while (test_args.nr_vcpus != n_done);
309
310 return NULL;
311 }
312
test_run(struct kvm_vm * vm)313 static void test_run(struct kvm_vm *vm)
314 {
315 pthread_t pt_vcpu_migration;
316 unsigned int i;
317 int ret;
318
319 pthread_mutex_init(&vcpu_done_map_lock, NULL);
320 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus);
321 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap\n");
322
323 for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++) {
324 ret = pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run,
325 (void *)(unsigned long)i);
326 TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread\n", i);
327 }
328
329 /* Spawn a thread to control the vCPU migrations */
330 if (test_args.migration_freq_ms) {
331 srand(time(NULL));
332
333 ret = pthread_create(&pt_vcpu_migration, NULL,
334 test_vcpu_migration, NULL);
335 TEST_ASSERT(!ret, "Failed to create the migration pthread\n");
336 }
337
338
339 for (i = 0; i < test_args.nr_vcpus; i++)
340 pthread_join(pt_vcpu_run[i], NULL);
341
342 if (test_args.migration_freq_ms)
343 pthread_join(pt_vcpu_migration, NULL);
344
345 bitmap_free(vcpu_done_map);
346 }
347
test_init_timer_irq(struct kvm_vm * vm)348 static void test_init_timer_irq(struct kvm_vm *vm)
349 {
350 /* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
351 vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
352 KVM_ARM_VCPU_TIMER_IRQ_PTIMER, &ptimer_irq);
353 vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
354 KVM_ARM_VCPU_TIMER_IRQ_VTIMER, &vtimer_irq);
355
356 sync_global_to_guest(vm, ptimer_irq);
357 sync_global_to_guest(vm, vtimer_irq);
358
359 pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
360 }
361
362 static int gic_fd;
363
test_vm_create(void)364 static struct kvm_vm *test_vm_create(void)
365 {
366 struct kvm_vm *vm;
367 unsigned int i;
368 int nr_vcpus = test_args.nr_vcpus;
369
370 vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
371
372 vm_init_descriptor_tables(vm);
373 vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
374
375 for (i = 0; i < nr_vcpus; i++)
376 vcpu_init_descriptor_tables(vcpus[i]);
377
378 test_init_timer_irq(vm);
379 gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
380 __TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
381
382 /* Make all the test's cmdline args visible to the guest */
383 sync_global_to_guest(vm, test_args);
384
385 return vm;
386 }
387
test_vm_cleanup(struct kvm_vm * vm)388 static void test_vm_cleanup(struct kvm_vm *vm)
389 {
390 close(gic_fd);
391 kvm_vm_free(vm);
392 }
393
test_print_help(char * name)394 static void test_print_help(char *name)
395 {
396 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
397 name);
398 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
399 NR_VCPUS_DEF, KVM_MAX_VCPUS);
400 pr_info("\t-i: Number of iterations per stage (default: %u)\n",
401 NR_TEST_ITERS_DEF);
402 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
403 TIMER_TEST_PERIOD_MS_DEF);
404 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
405 TIMER_TEST_MIGRATION_FREQ_MS);
406 pr_info("\t-h: print this help screen\n");
407 }
408
parse_args(int argc,char * argv[])409 static bool parse_args(int argc, char *argv[])
410 {
411 int opt;
412
413 while ((opt = getopt(argc, argv, "hn:i:p:m:")) != -1) {
414 switch (opt) {
415 case 'n':
416 test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg);
417 if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
418 pr_info("Max allowed vCPUs: %u\n",
419 KVM_MAX_VCPUS);
420 goto err;
421 }
422 break;
423 case 'i':
424 test_args.nr_iter = atoi_positive("Number of iterations", optarg);
425 break;
426 case 'p':
427 test_args.timer_period_ms = atoi_positive("Periodicity", optarg);
428 break;
429 case 'm':
430 test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
431 break;
432 case 'h':
433 default:
434 goto err;
435 }
436 }
437
438 return true;
439
440 err:
441 test_print_help(argv[0]);
442 return false;
443 }
444
main(int argc,char * argv[])445 int main(int argc, char *argv[])
446 {
447 struct kvm_vm *vm;
448
449 if (!parse_args(argc, argv))
450 exit(KSFT_SKIP);
451
452 __TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2,
453 "At least two physical CPUs needed for vCPU migration");
454
455 vm = test_vm_create();
456 test_run(vm);
457 test_vm_cleanup(vm);
458
459 return 0;
460 }
461