258 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * arch_timer.c - Tests the arch timer IRQ functionality4 *5 * The guest's main thread configures the timer interrupt and waits6 * for it to fire, with a timeout equal to the timer period.7 * It asserts that the timeout doesn't exceed the timer period plus8 * a user configurable error margin(default to 100us)9 *10 * On the other hand, upon receipt of an interrupt, the guest's interrupt11 * handler validates the interrupt by checking if the architectural state12 * is in compliance with the specifications.13 *14 * The test provides command-line options to configure the timer's15 * period (-p), number of vCPUs (-n), iterations per stage (-i) and timer16 * interrupt arrival error margin (-e). To stress-test the timer stack17 * even more, an option to migrate the vCPUs across pCPUs (-m), at a18 * 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 31struct 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 40struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];41struct test_vcpu_shared_data vcpu_shared_data[KVM_MAX_VCPUS];42 43static pthread_t pt_vcpu_run[KVM_MAX_VCPUS];44static unsigned long *vcpu_done_map;45static pthread_mutex_t vcpu_done_map_lock;46 47static 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 81static 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 98static 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 120static 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 145static 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 180static 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 199static 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 237err:238 test_print_help(argv[0]);239 return false;240}241 242int 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