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 #define _GNU_SOURCE
23
24 #include <stdlib.h>
25 #include <pthread.h>
26 #include <linux/kvm.h>
27 #include <linux/sizes.h>
28 #include <linux/bitmap.h>
29 #include <sys/sysinfo.h>
30
31 #include "kvm_util.h"
32 #include "processor.h"
33 #include "delay.h"
34 #include "arch_timer.h"
35 #include "gic.h"
36 #include "vgic.h"
37
38 #define NR_VCPUS_DEF 4
39 #define NR_TEST_ITERS_DEF 5
40 #define TIMER_TEST_PERIOD_MS_DEF 10
41 #define TIMER_TEST_ERR_MARGIN_US 100
42 #define TIMER_TEST_MIGRATION_FREQ_MS 2
43
44 struct test_args {
45 int nr_vcpus;
46 int nr_iter;
47 int timer_period_ms;
48 int migration_freq_ms;
49 struct kvm_arm_counter_offset offset;
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 .offset = { .reserved = 1 },
58 };
59
60 #define msecs_to_usecs(msec) ((msec) * 1000LL)
61
62 #define GICD_BASE_GPA 0x8000000ULL
63 #define GICR_BASE_GPA 0x80A0000ULL
64
65 enum guest_stage {
66 GUEST_STAGE_VTIMER_CVAL = 1,
67 GUEST_STAGE_VTIMER_TVAL,
68 GUEST_STAGE_PTIMER_CVAL,
69 GUEST_STAGE_PTIMER_TVAL,
70 GUEST_STAGE_MAX,
71 };
72
73 /* Shared variables between host and guest */
74 struct test_vcpu_shared_data {
75 int nr_iter;
76 enum guest_stage guest_stage;
77 uint64_t xcnt;
78 };
79
80 static struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
81 static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];
82 static struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];
83
84 static int vtimer_irq, ptimer_irq;
85
86 static unsigned long *vcpu_done_map;
87 static pthread_mutex_t vcpu_done_map_lock;
88
89 static void
guest_configure_timer_action(struct test_vcpu_shared_data * shared_data)90 guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
91 {
92 switch (shared_data->guest_stage) {
93 case GUEST_STAGE_VTIMER_CVAL:
94 timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
95 shared_data->xcnt = timer_get_cntct(VIRTUAL);
96 timer_set_ctl(VIRTUAL, CTL_ENABLE);
97 break;
98 case GUEST_STAGE_VTIMER_TVAL:
99 timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
100 shared_data->xcnt = timer_get_cntct(VIRTUAL);
101 timer_set_ctl(VIRTUAL, CTL_ENABLE);
102 break;
103 case GUEST_STAGE_PTIMER_CVAL:
104 timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
105 shared_data->xcnt = timer_get_cntct(PHYSICAL);
106 timer_set_ctl(PHYSICAL, CTL_ENABLE);
107 break;
108 case GUEST_STAGE_PTIMER_TVAL:
109 timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
110 shared_data->xcnt = timer_get_cntct(PHYSICAL);
111 timer_set_ctl(PHYSICAL, CTL_ENABLE);
112 break;
113 default:
114 GUEST_ASSERT(0);
115 }
116 }
117
guest_validate_irq(unsigned int intid,struct test_vcpu_shared_data * shared_data)118 static void guest_validate_irq(unsigned int intid,
119 struct test_vcpu_shared_data *shared_data)
120 {
121 enum guest_stage stage = shared_data->guest_stage;
122 uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
123 unsigned long xctl = 0;
124 unsigned int timer_irq = 0;
125 unsigned int accessor;
126
127 if (intid == IAR_SPURIOUS)
128 return;
129
130 switch (stage) {
131 case GUEST_STAGE_VTIMER_CVAL:
132 case GUEST_STAGE_VTIMER_TVAL:
133 accessor = VIRTUAL;
134 timer_irq = vtimer_irq;
135 break;
136 case GUEST_STAGE_PTIMER_CVAL:
137 case GUEST_STAGE_PTIMER_TVAL:
138 accessor = PHYSICAL;
139 timer_irq = ptimer_irq;
140 break;
141 default:
142 GUEST_ASSERT(0);
143 return;
144 }
145
146 xctl = timer_get_ctl(accessor);
147 if ((xctl & CTL_IMASK) || !(xctl & CTL_ENABLE))
148 return;
149
150 timer_set_ctl(accessor, CTL_IMASK);
151 xcnt = timer_get_cntct(accessor);
152 cval = timer_get_cval(accessor);
153
154 xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);
155
156 /* Make sure we are dealing with the correct timer IRQ */
157 GUEST_ASSERT_EQ(intid, timer_irq);
158
159 /* Basic 'timer condition met' check */
160 __GUEST_ASSERT(xcnt >= cval,
161 "xcnt = 0x%llx, cval = 0x%llx, xcnt_diff_us = 0x%llx",
162 xcnt, cval, xcnt_diff_us);
163 __GUEST_ASSERT(xctl & CTL_ISTATUS, "xcnt = 0x%llx", xcnt);
164
165 WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
166 }
167
guest_irq_handler(struct ex_regs * regs)168 static void guest_irq_handler(struct ex_regs *regs)
169 {
170 unsigned int intid = gic_get_and_ack_irq();
171 uint32_t cpu = guest_get_vcpuid();
172 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
173
174 guest_validate_irq(intid, shared_data);
175
176 gic_set_eoi(intid);
177 }
178
guest_run_stage(struct test_vcpu_shared_data * shared_data,enum guest_stage stage)179 static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
180 enum guest_stage stage)
181 {
182 uint32_t irq_iter, config_iter;
183
184 shared_data->guest_stage = stage;
185 shared_data->nr_iter = 0;
186
187 for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
188 /* Setup the next interrupt */
189 guest_configure_timer_action(shared_data);
190
191 /* Setup a timeout for the interrupt to arrive */
192 udelay(msecs_to_usecs(test_args.timer_period_ms) +
193 TIMER_TEST_ERR_MARGIN_US);
194
195 irq_iter = READ_ONCE(shared_data->nr_iter);
196 GUEST_ASSERT_EQ(config_iter + 1, irq_iter);
197 }
198 }
199
guest_code(void)200 static void guest_code(void)
201 {
202 uint32_t cpu = guest_get_vcpuid();
203 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];
204
205 local_irq_disable();
206
207 gic_init(GIC_V3, test_args.nr_vcpus,
208 (void *)GICD_BASE_GPA, (void *)GICR_BASE_GPA);
209
210 timer_set_ctl(VIRTUAL, CTL_IMASK);
211 timer_set_ctl(PHYSICAL, CTL_IMASK);
212
213 gic_irq_enable(vtimer_irq);
214 gic_irq_enable(ptimer_irq);
215 local_irq_enable();
216
217 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
218 guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
219 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
220 guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);
221
222 GUEST_DONE();
223 }
224
test_vcpu_run(void * arg)225 static void *test_vcpu_run(void *arg)
226 {
227 unsigned int vcpu_idx = (unsigned long)arg;
228 struct ucall uc;
229 struct kvm_vcpu *vcpu = vcpus[vcpu_idx];
230 struct kvm_vm *vm = vcpu->vm;
231 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpu_idx];
232
233 vcpu_run(vcpu);
234
235 /* Currently, any exit from guest is an indication of completion */
236 pthread_mutex_lock(&vcpu_done_map_lock);
237 __set_bit(vcpu_idx, vcpu_done_map);
238 pthread_mutex_unlock(&vcpu_done_map_lock);
239
240 switch (get_ucall(vcpu, &uc)) {
241 case UCALL_SYNC:
242 case UCALL_DONE:
243 break;
244 case UCALL_ABORT:
245 sync_global_from_guest(vm, *shared_data);
246 fprintf(stderr, "Guest assert failed, vcpu %u; stage; %u; iter: %u\n",
247 vcpu_idx, shared_data->guest_stage, shared_data->nr_iter);
248 REPORT_GUEST_ASSERT(uc);
249 break;
250 default:
251 TEST_FAIL("Unexpected guest exit\n");
252 }
253
254 return NULL;
255 }
256
test_get_pcpu(void)257 static uint32_t test_get_pcpu(void)
258 {
259 uint32_t pcpu;
260 unsigned int nproc_conf;
261 cpu_set_t online_cpuset;
262
263 nproc_conf = get_nprocs_conf();
264 sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset);
265
266 /* Randomly find an available pCPU to place a vCPU on */
267 do {
268 pcpu = rand() % nproc_conf;
269 } while (!CPU_ISSET(pcpu, &online_cpuset));
270
271 return pcpu;
272 }
273
test_migrate_vcpu(unsigned int vcpu_idx)274 static int test_migrate_vcpu(unsigned int vcpu_idx)
275 {
276 int ret;
277 cpu_set_t cpuset;
278 uint32_t new_pcpu = test_get_pcpu();
279
280 CPU_ZERO(&cpuset);
281 CPU_SET(new_pcpu, &cpuset);
282
283 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu);
284
285 ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx],
286 sizeof(cpuset), &cpuset);
287
288 /* Allow the error where the vCPU thread is already finished */
289 TEST_ASSERT(ret == 0 || ret == ESRCH,
290 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d\n",
291 vcpu_idx, new_pcpu, ret);
292
293 return ret;
294 }
295
test_vcpu_migration(void * arg)296 static void *test_vcpu_migration(void *arg)
297 {
298 unsigned int i, n_done;
299 bool vcpu_done;
300
301 do {
302 usleep(msecs_to_usecs(test_args.migration_freq_ms));
303
304 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) {
305 pthread_mutex_lock(&vcpu_done_map_lock);
306 vcpu_done = test_bit(i, vcpu_done_map);
307 pthread_mutex_unlock(&vcpu_done_map_lock);
308
309 if (vcpu_done) {
310 n_done++;
311 continue;
312 }
313
314 test_migrate_vcpu(i);
315 }
316 } while (test_args.nr_vcpus != n_done);
317
318 return NULL;
319 }
320
test_run(struct kvm_vm * vm)321 static void test_run(struct kvm_vm *vm)
322 {
323 pthread_t pt_vcpu_migration;
324 unsigned int i;
325 int ret;
326
327 pthread_mutex_init(&vcpu_done_map_lock, NULL);
328 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus);
329 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap\n");
330
331 for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++) {
332 ret = pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run,
333 (void *)(unsigned long)i);
334 TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread\n", i);
335 }
336
337 /* Spawn a thread to control the vCPU migrations */
338 if (test_args.migration_freq_ms) {
339 srand(time(NULL));
340
341 ret = pthread_create(&pt_vcpu_migration, NULL,
342 test_vcpu_migration, NULL);
343 TEST_ASSERT(!ret, "Failed to create the migration pthread\n");
344 }
345
346
347 for (i = 0; i < test_args.nr_vcpus; i++)
348 pthread_join(pt_vcpu_run[i], NULL);
349
350 if (test_args.migration_freq_ms)
351 pthread_join(pt_vcpu_migration, NULL);
352
353 bitmap_free(vcpu_done_map);
354 }
355
test_init_timer_irq(struct kvm_vm * vm)356 static void test_init_timer_irq(struct kvm_vm *vm)
357 {
358 /* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
359 vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
360 KVM_ARM_VCPU_TIMER_IRQ_PTIMER, &ptimer_irq);
361 vcpu_device_attr_get(vcpus[0], KVM_ARM_VCPU_TIMER_CTRL,
362 KVM_ARM_VCPU_TIMER_IRQ_VTIMER, &vtimer_irq);
363
364 sync_global_to_guest(vm, ptimer_irq);
365 sync_global_to_guest(vm, vtimer_irq);
366
367 pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
368 }
369
370 static int gic_fd;
371
test_vm_create(void)372 static struct kvm_vm *test_vm_create(void)
373 {
374 struct kvm_vm *vm;
375 unsigned int i;
376 int nr_vcpus = test_args.nr_vcpus;
377
378 vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);
379
380 vm_init_descriptor_tables(vm);
381 vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);
382
383 if (!test_args.offset.reserved) {
384 if (kvm_has_cap(KVM_CAP_COUNTER_OFFSET))
385 vm_ioctl(vm, KVM_ARM_SET_COUNTER_OFFSET, &test_args.offset);
386 else
387 TEST_FAIL("no support for global offset\n");
388 }
389
390 for (i = 0; i < nr_vcpus; i++)
391 vcpu_init_descriptor_tables(vcpus[i]);
392
393 test_init_timer_irq(vm);
394 gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
395 __TEST_REQUIRE(gic_fd >= 0, "Failed to create vgic-v3");
396
397 /* Make all the test's cmdline args visible to the guest */
398 sync_global_to_guest(vm, test_args);
399
400 return vm;
401 }
402
test_vm_cleanup(struct kvm_vm * vm)403 static void test_vm_cleanup(struct kvm_vm *vm)
404 {
405 close(gic_fd);
406 kvm_vm_free(vm);
407 }
408
test_print_help(char * name)409 static void test_print_help(char *name)
410 {
411 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n",
412 name);
413 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n",
414 NR_VCPUS_DEF, KVM_MAX_VCPUS);
415 pr_info("\t-i: Number of iterations per stage (default: %u)\n",
416 NR_TEST_ITERS_DEF);
417 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n",
418 TIMER_TEST_PERIOD_MS_DEF);
419 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n",
420 TIMER_TEST_MIGRATION_FREQ_MS);
421 pr_info("\t-o: Counter offset (in counter cycles, default: 0)\n");
422 pr_info("\t-h: print this help screen\n");
423 }
424
parse_args(int argc,char * argv[])425 static bool parse_args(int argc, char *argv[])
426 {
427 int opt;
428
429 while ((opt = getopt(argc, argv, "hn:i:p:m:o:")) != -1) {
430 switch (opt) {
431 case 'n':
432 test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg);
433 if (test_args.nr_vcpus > KVM_MAX_VCPUS) {
434 pr_info("Max allowed vCPUs: %u\n",
435 KVM_MAX_VCPUS);
436 goto err;
437 }
438 break;
439 case 'i':
440 test_args.nr_iter = atoi_positive("Number of iterations", optarg);
441 break;
442 case 'p':
443 test_args.timer_period_ms = atoi_positive("Periodicity", optarg);
444 break;
445 case 'm':
446 test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg);
447 break;
448 case 'o':
449 test_args.offset.counter_offset = strtol(optarg, NULL, 0);
450 test_args.offset.reserved = 0;
451 break;
452 case 'h':
453 default:
454 goto err;
455 }
456 }
457
458 return true;
459
460 err:
461 test_print_help(argv[0]);
462 return false;
463 }
464
main(int argc,char * argv[])465 int main(int argc, char *argv[])
466 {
467 struct kvm_vm *vm;
468
469 if (!parse_args(argc, argv))
470 exit(KSFT_SKIP);
471
472 __TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2,
473 "At least two physical CPUs needed for vCPU migration");
474
475 vm = test_vm_create();
476 test_run(vm);
477 test_vm_cleanup(vm);
478
479 return 0;
480 }
481