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 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 } 117 118 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 } 167 168 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 } 178 179 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 } 199 200 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 } 224 225 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 } 256 257 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 } 273 274 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 } 295 296 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 } 320 321 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 } 355 356 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; 371 372 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 } 402 403 static void test_vm_cleanup(struct kvm_vm *vm) 404 { 405 close(gic_fd); 406 kvm_vm_free(vm); 407 } 408 409 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 } 424 425 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 } 464 465 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