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 23 #define _GNU_SOURCE 24 25 #include <stdlib.h> 26 #include <pthread.h> 27 #include <linux/sizes.h> 28 #include <linux/bitmap.h> 29 #include <sys/sysinfo.h> 30 31 #include "timer_test.h" 32 33 struct test_args test_args = { 34 .nr_vcpus = NR_VCPUS_DEF, 35 .nr_iter = NR_TEST_ITERS_DEF, 36 .timer_period_ms = TIMER_TEST_PERIOD_MS_DEF, 37 .migration_freq_ms = TIMER_TEST_MIGRATION_FREQ_MS, 38 .timer_err_margin_us = TIMER_TEST_ERR_MARGIN_US, 39 .reserved = 1, 40 }; 41 42 struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; 43 struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS]; 44 45 static pthread_t pt_vcpu_run[KVM_MAX_VCPUS]; 46 static unsigned long *vcpu_done_map; 47 static pthread_mutex_t vcpu_done_map_lock; 48 49 static void *test_vcpu_run(void *arg) 50 { 51 unsigned int vcpu_idx = (unsigned long)arg; 52 struct ucall uc; 53 struct kvm_vcpu *vcpu = vcpus[vcpu_idx]; 54 struct kvm_vm *vm = vcpu->vm; 55 struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[vcpu_idx]; 56 57 vcpu_run(vcpu); 58 59 /* Currently, any exit from guest is an indication of completion */ 60 pthread_mutex_lock(&vcpu_done_map_lock); 61 __set_bit(vcpu_idx, vcpu_done_map); 62 pthread_mutex_unlock(&vcpu_done_map_lock); 63 64 switch (get_ucall(vcpu, &uc)) { 65 case UCALL_SYNC: 66 case UCALL_DONE: 67 break; 68 case UCALL_ABORT: 69 sync_global_from_guest(vm, *shared_data); 70 fprintf(stderr, "Guest assert failed, vcpu %u; stage; %u; iter: %u\n", 71 vcpu_idx, shared_data->guest_stage, shared_data->nr_iter); 72 REPORT_GUEST_ASSERT(uc); 73 break; 74 default: 75 TEST_FAIL("Unexpected guest exit"); 76 } 77 78 pr_info("PASS(vCPU-%d).\n", vcpu_idx); 79 80 return NULL; 81 } 82 83 static uint32_t test_get_pcpu(void) 84 { 85 uint32_t pcpu; 86 unsigned int nproc_conf; 87 cpu_set_t online_cpuset; 88 89 nproc_conf = get_nprocs_conf(); 90 sched_getaffinity(0, sizeof(cpu_set_t), &online_cpuset); 91 92 /* Randomly find an available pCPU to place a vCPU on */ 93 do { 94 pcpu = rand() % nproc_conf; 95 } while (!CPU_ISSET(pcpu, &online_cpuset)); 96 97 return pcpu; 98 } 99 100 static int test_migrate_vcpu(unsigned int vcpu_idx) 101 { 102 int ret; 103 cpu_set_t cpuset; 104 uint32_t new_pcpu = test_get_pcpu(); 105 106 CPU_ZERO(&cpuset); 107 CPU_SET(new_pcpu, &cpuset); 108 109 pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu); 110 111 ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx], 112 sizeof(cpuset), &cpuset); 113 114 /* Allow the error where the vCPU thread is already finished */ 115 TEST_ASSERT(ret == 0 || ret == ESRCH, 116 "Failed to migrate the vCPU:%u to pCPU: %u; ret: %d", 117 vcpu_idx, new_pcpu, ret); 118 119 return ret; 120 } 121 122 static void *test_vcpu_migration(void *arg) 123 { 124 unsigned int i, n_done; 125 bool vcpu_done; 126 127 do { 128 usleep(msecs_to_usecs(test_args.migration_freq_ms)); 129 130 for (n_done = 0, i = 0; i < test_args.nr_vcpus; i++) { 131 pthread_mutex_lock(&vcpu_done_map_lock); 132 vcpu_done = test_bit(i, vcpu_done_map); 133 pthread_mutex_unlock(&vcpu_done_map_lock); 134 135 if (vcpu_done) { 136 n_done++; 137 continue; 138 } 139 140 test_migrate_vcpu(i); 141 } 142 } while (test_args.nr_vcpus != n_done); 143 144 return NULL; 145 } 146 147 static void test_run(struct kvm_vm *vm) 148 { 149 pthread_t pt_vcpu_migration; 150 unsigned int i; 151 int ret; 152 153 pthread_mutex_init(&vcpu_done_map_lock, NULL); 154 vcpu_done_map = bitmap_zalloc(test_args.nr_vcpus); 155 TEST_ASSERT(vcpu_done_map, "Failed to allocate vcpu done bitmap"); 156 157 for (i = 0; i < (unsigned long)test_args.nr_vcpus; i++) { 158 ret = pthread_create(&pt_vcpu_run[i], NULL, test_vcpu_run, 159 (void *)(unsigned long)i); 160 TEST_ASSERT(!ret, "Failed to create vCPU-%d pthread", i); 161 } 162 163 /* Spawn a thread to control the vCPU migrations */ 164 if (test_args.migration_freq_ms) { 165 srand(time(NULL)); 166 167 ret = pthread_create(&pt_vcpu_migration, NULL, 168 test_vcpu_migration, NULL); 169 TEST_ASSERT(!ret, "Failed to create the migration pthread"); 170 } 171 172 173 for (i = 0; i < test_args.nr_vcpus; i++) 174 pthread_join(pt_vcpu_run[i], NULL); 175 176 if (test_args.migration_freq_ms) 177 pthread_join(pt_vcpu_migration, NULL); 178 179 bitmap_free(vcpu_done_map); 180 } 181 182 static void test_print_help(char *name) 183 { 184 pr_info("Usage: %s [-h] [-n nr_vcpus] [-i iterations] [-p timer_period_ms]\n" 185 "\t\t [-m migration_freq_ms] [-o counter_offset]\n" 186 "\t\t [-e timer_err_margin_us]\n", name); 187 pr_info("\t-n: Number of vCPUs to configure (default: %u; max: %u)\n", 188 NR_VCPUS_DEF, KVM_MAX_VCPUS); 189 pr_info("\t-i: Number of iterations per stage (default: %u)\n", 190 NR_TEST_ITERS_DEF); 191 pr_info("\t-p: Periodicity (in ms) of the guest timer (default: %u)\n", 192 TIMER_TEST_PERIOD_MS_DEF); 193 pr_info("\t-m: Frequency (in ms) of vCPUs to migrate to different pCPU. 0 to turn off (default: %u)\n", 194 TIMER_TEST_MIGRATION_FREQ_MS); 195 pr_info("\t-o: Counter offset (in counter cycles, default: 0) [aarch64-only]\n"); 196 pr_info("\t-e: Interrupt arrival error margin (in us) of the guest timer (default: %u)\n", 197 TIMER_TEST_ERR_MARGIN_US); 198 pr_info("\t-h: print this help screen\n"); 199 } 200 201 static bool parse_args(int argc, char *argv[]) 202 { 203 int opt; 204 205 while ((opt = getopt(argc, argv, "hn:i:p:m:o:e:")) != -1) { 206 switch (opt) { 207 case 'n': 208 test_args.nr_vcpus = atoi_positive("Number of vCPUs", optarg); 209 if (test_args.nr_vcpus > KVM_MAX_VCPUS) { 210 pr_info("Max allowed vCPUs: %u\n", 211 KVM_MAX_VCPUS); 212 goto err; 213 } 214 break; 215 case 'i': 216 test_args.nr_iter = atoi_positive("Number of iterations", optarg); 217 break; 218 case 'p': 219 test_args.timer_period_ms = atoi_positive("Periodicity", optarg); 220 break; 221 case 'm': 222 test_args.migration_freq_ms = atoi_non_negative("Frequency", optarg); 223 break; 224 case 'e': 225 test_args.timer_err_margin_us = atoi_non_negative("Error Margin", optarg); 226 break; 227 case 'o': 228 test_args.counter_offset = strtol(optarg, NULL, 0); 229 test_args.reserved = 0; 230 break; 231 case 'h': 232 default: 233 goto err; 234 } 235 } 236 237 return true; 238 239 err: 240 test_print_help(argv[0]); 241 return false; 242 } 243 244 int main(int argc, char *argv[]) 245 { 246 struct kvm_vm *vm; 247 248 if (!parse_args(argc, argv)) 249 exit(KSFT_SKIP); 250 251 __TEST_REQUIRE(!test_args.migration_freq_ms || get_nprocs() >= 2, 252 "At least two physical CPUs needed for vCPU migration"); 253 254 vm = test_vm_create(); 255 test_run(vm); 256 test_vm_cleanup(vm); 257 258 return 0; 259 } 260