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 31 struct 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 40 struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; 41 struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS]; 42 43 static pthread_t pt_vcpu_run[KVM_MAX_VCPUS]; 44 static unsigned long *vcpu_done_map; 45 static pthread_mutex_t vcpu_done_map_lock; 46 47 static 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 81 static uint32_t test_get_pcpu(void) 82 { 83 uint32_t pcpu; 84 unsigned int nproc_conf; 85 cpu_set_t online_cpuset; 86 87 nproc_conf = get_nprocs_conf(); 88 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 98 static int test_migrate_vcpu(unsigned int vcpu_idx) 99 { 100 int ret; 101 cpu_set_t cpuset; 102 uint32_t new_pcpu = test_get_pcpu(); 103 104 CPU_ZERO(&cpuset); 105 CPU_SET(new_pcpu, &cpuset); 106 107 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu); 108 109 ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx], 110 sizeof(cpuset), &cpuset); 111 112 /* Allow the error where the vCPU thread is already finished */ 113 TEST_ASSERT(ret == 0 || ret == ESRCH, 114 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d", 115 vcpu_idx, new_pcpu, ret); 116 117 return ret; 118 } 119 120 static void *test_vcpu_migration(void *arg) 121 { 122 unsigned int i, n_done; 123 bool vcpu_done; 124 125 do { 126 usleep(msecs_to_usecs(test_args.migration_freq_ms)); 127 128 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) { 129 pthread_mutex_lock(&vcpu_done_map_lock); 130 vcpu_done = test_bit(i, vcpu_done_map); 131 pthread_mutex_unlock(&vcpu_done_map_lock); 132 133 if (vcpu_done) { 134 n_done++; 135 continue; 136 } 137 138 test_migrate_vcpu(i); 139 } 140 } while (test_args.nr_vcpus != n_done); 141 142 return NULL; 143 } 144 145 static void test_run(struct kvm_vm *vm) 146 { 147 pthread_t pt_vcpu_migration; 148 unsigned int i; 149 int ret; 150 151 pthread_mutex_init(&vcpu_done_map_lock, NULL); 152 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus); 153 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap"); 154 155 for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++) { 156 ret = pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run, 157 (void *)(unsigned long)i); 158 TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread", i); 159 } 160 161 /* Spawn a thread to control the vCPU migrations */ 162 if (test_args.migration_freq_ms) { 163 srand(time(NULL)); 164 165 ret = pthread_create(&pt_vcpu_migration, NULL, 166 test_vcpu_migration, NULL); 167 TEST_ASSERT(!ret, "Failed to create the migration pthread"); 168 } 169 170 171 for (i = 0; i < test_args.nr_vcpus; i++) 172 pthread_join(pt_vcpu_run[i], NULL); 173 174 if (test_args.migration_freq_ms) 175 pthread_join(pt_vcpu_migration, NULL); 176 177 bitmap_free(vcpu_done_map); 178 } 179 180 static void test_print_help(char *name) 181 { 182 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n" 183 "\t\t [-m migration_freq_ms] [-o counter_offset]\n" 184 "\t\t [-e timer_err_margin_us]\n", name); 185 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n", 186 NR_VCPUS_DEF, KVM_MAX_VCPUS); 187 pr_info("\t-i: Number of iterations per stage (default: %u)\n", 188 NR_TEST_ITERS_DEF); 189 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n", 190 TIMER_TEST_PERIOD_MS_DEF); 191 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n", 192 TIMER_TEST_MIGRATION_FREQ_MS); 193 pr_info("\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n"); 194 pr_info("\t-e: Interrupt arrival error margin (in us) of the guest timer (default: %u)\n", 195 TIMER_TEST_ERR_MARGIN_US); 196 pr_info("\t-h: print this help screen\n"); 197 } 198 199 static bool parse_args(int argc, char *argv[]) 200 { 201 int opt; 202 203 while ((opt = getopt(argc, argv, "hn:i:p:m:o:e:")) != -1) { 204 switch (opt) { 205 case 'n': 206 test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg); 207 if (test_args.nr_vcpus > KVM_MAX_VCPUS) { 208 pr_info("Max allowed vCPUs: %u\n", 209 KVM_MAX_VCPUS); 210 goto err; 211 } 212 break; 213 case 'i': 214 test_args.nr_iter = atoi_positive("Number of iterations", optarg); 215 break; 216 case 'p': 217 test_args.timer_period_ms = atoi_positive("Periodicity", optarg); 218 break; 219 case 'm': 220 test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg); 221 break; 222 case 'e': 223 test_args.timer_err_margin_us = atoi_non_negative("Error Margin", optarg); 224 break; 225 case 'o': 226 test_args.counter_offset = strtol(optarg, NULL, 0); 227 test_args.reserved = 0; 228 break; 229 case 'h': 230 default: 231 goto err; 232 } 233 } 234 235 return true; 236 237 err: 238 test_print_help(argv[0]); 239 return false; 240 } 241 242 int main(int argc, char *argv[]) 243 { 244 struct kvm_vm *vm; 245 246 if (!parse_args(argc, argv)) 247 exit(KSFT_SKIP); 248 249 __TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2, 250 "At least two physical CPUs needed for vCPU migration"); 251 252 vm = test_vm_create(); 253 test_run(vm); 254 test_vm_cleanup(vm); 255 256 return 0; 257 } 258