1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * KVM dirty page logging performance test 4 * 5 * Based on dirty_log_test.c 6 * 7 * Copyright (C) 2018, Red Hat, Inc. 8 * Copyright (C) 2020, Google, Inc. 9 */ 10 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <time.h> 14 #include <pthread.h> 15 #include <linux/bitmap.h> 16 17 #include "kvm_util.h" 18 #include "test_util.h" 19 #include "perf_test_util.h" 20 #include "guest_modes.h" 21 22 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/ 23 #define TEST_HOST_LOOP_N 2UL 24 25 static int nr_vcpus = 1; 26 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE; 27 28 /* Host variables */ 29 static u64 dirty_log_manual_caps; 30 static bool host_quit; 31 static uint64_t iteration; 32 static uint64_t vcpu_last_completed_iteration[KVM_MAX_VCPUS]; 33 34 static void *vcpu_worker(void *data) 35 { 36 int ret; 37 struct kvm_vm *vm = perf_test_args.vm; 38 uint64_t pages_count = 0; 39 struct kvm_run *run; 40 struct timespec start; 41 struct timespec ts_diff; 42 struct timespec total = (struct timespec){0}; 43 struct timespec avg; 44 struct perf_test_vcpu_args *vcpu_args = (struct perf_test_vcpu_args *)data; 45 int vcpu_id = vcpu_args->vcpu_id; 46 47 vcpu_args_set(vm, vcpu_id, 1, vcpu_id); 48 run = vcpu_state(vm, vcpu_id); 49 50 while (!READ_ONCE(host_quit)) { 51 uint64_t current_iteration = READ_ONCE(iteration); 52 53 clock_gettime(CLOCK_MONOTONIC, &start); 54 ret = _vcpu_run(vm, vcpu_id); 55 ts_diff = timespec_diff_now(start); 56 57 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 58 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC, 59 "Invalid guest sync status: exit_reason=%s\n", 60 exit_reason_str(run->exit_reason)); 61 62 pr_debug("Got sync event from vCPU %d\n", vcpu_id); 63 vcpu_last_completed_iteration[vcpu_id] = current_iteration; 64 pr_debug("vCPU %d updated last completed iteration to %lu\n", 65 vcpu_id, vcpu_last_completed_iteration[vcpu_id]); 66 67 if (current_iteration) { 68 pages_count += vcpu_args->pages; 69 total = timespec_add(total, ts_diff); 70 pr_debug("vCPU %d iteration %lu dirty memory time: %ld.%.9lds\n", 71 vcpu_id, current_iteration, ts_diff.tv_sec, 72 ts_diff.tv_nsec); 73 } else { 74 pr_debug("vCPU %d iteration %lu populate memory time: %ld.%.9lds\n", 75 vcpu_id, current_iteration, ts_diff.tv_sec, 76 ts_diff.tv_nsec); 77 } 78 79 while (current_iteration == READ_ONCE(iteration) && 80 !READ_ONCE(host_quit)) {} 81 } 82 83 avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]); 84 pr_debug("\nvCPU %d dirtied 0x%lx pages over %lu iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 85 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id], 86 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec); 87 88 return NULL; 89 } 90 91 struct test_params { 92 unsigned long iterations; 93 uint64_t phys_offset; 94 int wr_fract; 95 }; 96 97 static void run_test(enum vm_guest_mode mode, void *arg) 98 { 99 struct test_params *p = arg; 100 pthread_t *vcpu_threads; 101 struct kvm_vm *vm; 102 unsigned long *bmap; 103 uint64_t guest_num_pages; 104 uint64_t host_num_pages; 105 int vcpu_id; 106 struct timespec start; 107 struct timespec ts_diff; 108 struct timespec get_dirty_log_total = (struct timespec){0}; 109 struct timespec vcpu_dirty_total = (struct timespec){0}; 110 struct timespec avg; 111 struct kvm_enable_cap cap = {}; 112 struct timespec clear_dirty_log_total = (struct timespec){0}; 113 114 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size); 115 116 perf_test_args.wr_fract = p->wr_fract; 117 118 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); 119 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 120 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 121 bmap = bitmap_alloc(host_num_pages); 122 123 if (dirty_log_manual_caps) { 124 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 125 cap.args[0] = dirty_log_manual_caps; 126 vm_enable_cap(vm, &cap); 127 } 128 129 vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads)); 130 TEST_ASSERT(vcpu_threads, "Memory allocation failed"); 131 132 perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size); 133 134 sync_global_to_guest(vm, perf_test_args); 135 136 /* Start the iterations */ 137 iteration = 0; 138 host_quit = false; 139 140 clock_gettime(CLOCK_MONOTONIC, &start); 141 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 142 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker, 143 &perf_test_args.vcpu_args[vcpu_id]); 144 } 145 146 /* Allow the vCPU to populate memory */ 147 pr_debug("Starting iteration %lu - Populating\n", iteration); 148 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration) 149 pr_debug("Waiting for vcpu_last_completed_iteration == %lu\n", 150 iteration); 151 152 ts_diff = timespec_diff_now(start); 153 pr_info("Populate memory time: %ld.%.9lds\n", 154 ts_diff.tv_sec, ts_diff.tv_nsec); 155 156 /* Enable dirty logging */ 157 clock_gettime(CLOCK_MONOTONIC, &start); 158 vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX, 159 KVM_MEM_LOG_DIRTY_PAGES); 160 ts_diff = timespec_diff_now(start); 161 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", 162 ts_diff.tv_sec, ts_diff.tv_nsec); 163 164 while (iteration < p->iterations) { 165 /* 166 * Incrementing the iteration number will start the vCPUs 167 * dirtying memory again. 168 */ 169 clock_gettime(CLOCK_MONOTONIC, &start); 170 iteration++; 171 172 pr_debug("Starting iteration %lu\n", iteration); 173 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 174 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration) 175 pr_debug("Waiting for vCPU %d vcpu_last_completed_iteration == %lu\n", 176 vcpu_id, iteration); 177 } 178 179 ts_diff = timespec_diff_now(start); 180 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff); 181 pr_info("Iteration %lu dirty memory time: %ld.%.9lds\n", 182 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 183 184 clock_gettime(CLOCK_MONOTONIC, &start); 185 kvm_vm_get_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap); 186 187 ts_diff = timespec_diff_now(start); 188 get_dirty_log_total = timespec_add(get_dirty_log_total, 189 ts_diff); 190 pr_info("Iteration %lu get dirty log time: %ld.%.9lds\n", 191 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 192 193 if (dirty_log_manual_caps) { 194 clock_gettime(CLOCK_MONOTONIC, &start); 195 kvm_vm_clear_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap, 0, 196 host_num_pages); 197 198 ts_diff = timespec_diff_now(start); 199 clear_dirty_log_total = timespec_add(clear_dirty_log_total, 200 ts_diff); 201 pr_info("Iteration %lu clear dirty log time: %ld.%.9lds\n", 202 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 203 } 204 } 205 206 /* Tell the vcpu thread to quit */ 207 host_quit = true; 208 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) 209 pthread_join(vcpu_threads[vcpu_id], NULL); 210 211 /* Disable dirty logging */ 212 clock_gettime(CLOCK_MONOTONIC, &start); 213 vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX, 0); 214 ts_diff = timespec_diff_now(start); 215 pr_info("Disabling dirty logging time: %ld.%.9lds\n", 216 ts_diff.tv_sec, ts_diff.tv_nsec); 217 218 avg = timespec_div(get_dirty_log_total, p->iterations); 219 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 220 p->iterations, get_dirty_log_total.tv_sec, 221 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 222 223 if (dirty_log_manual_caps) { 224 avg = timespec_div(clear_dirty_log_total, p->iterations); 225 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 226 p->iterations, clear_dirty_log_total.tv_sec, 227 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 228 } 229 230 free(bmap); 231 free(vcpu_threads); 232 perf_test_destroy_vm(vm); 233 } 234 235 static void help(char *name) 236 { 237 puts(""); 238 printf("usage: %s [-h] [-i iterations] [-p offset] " 239 "[-m mode] [-b vcpu bytes] [-v vcpus]\n", name); 240 puts(""); 241 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 242 TEST_HOST_LOOP_N); 243 printf(" -p: specify guest physical test memory offset\n" 244 " Warning: a low offset can conflict with the loaded test code.\n"); 245 guest_modes_help(); 246 printf(" -b: specify the size of the memory region which should be\n" 247 " dirtied by each vCPU. e.g. 10M or 3G.\n" 248 " (default: 1G)\n"); 249 printf(" -f: specify the fraction of pages which should be written to\n" 250 " as opposed to simply read, in the form\n" 251 " 1/<fraction of pages to write>.\n" 252 " (default: 1 i.e. all pages are written to.)\n"); 253 printf(" -v: specify the number of vCPUs to run.\n"); 254 puts(""); 255 exit(0); 256 } 257 258 int main(int argc, char *argv[]) 259 { 260 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 261 struct test_params p = { 262 .iterations = TEST_HOST_LOOP_N, 263 .wr_fract = 1, 264 }; 265 int opt; 266 267 dirty_log_manual_caps = 268 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 269 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 270 KVM_DIRTY_LOG_INITIALLY_SET); 271 272 guest_modes_append_default(); 273 274 while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:")) != -1) { 275 switch (opt) { 276 case 'i': 277 p.iterations = strtol(optarg, NULL, 10); 278 break; 279 case 'p': 280 p.phys_offset = strtoull(optarg, NULL, 0); 281 break; 282 case 'm': 283 guest_modes_cmdline(optarg); 284 break; 285 case 'b': 286 guest_percpu_mem_size = parse_size(optarg); 287 break; 288 case 'f': 289 p.wr_fract = atoi(optarg); 290 TEST_ASSERT(p.wr_fract >= 1, 291 "Write fraction cannot be less than one"); 292 break; 293 case 'v': 294 nr_vcpus = atoi(optarg); 295 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, 296 "Invalid number of vcpus, must be between 1 and %d", max_vcpus); 297 break; 298 case 'h': 299 default: 300 help(argv[0]); 301 break; 302 } 303 } 304 305 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); 306 307 pr_info("Test iterations: %"PRIu64"\n", p.iterations); 308 309 for_each_guest_mode(run_test, &p); 310 311 return 0; 312 } 313