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 int iteration; 32 static int 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 run = vcpu_state(vm, vcpu_id); 48 49 while (!READ_ONCE(host_quit)) { 50 int current_iteration = READ_ONCE(iteration); 51 52 clock_gettime(CLOCK_MONOTONIC, &start); 53 ret = _vcpu_run(vm, vcpu_id); 54 ts_diff = timespec_elapsed(start); 55 56 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 57 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC, 58 "Invalid guest sync status: exit_reason=%s\n", 59 exit_reason_str(run->exit_reason)); 60 61 pr_debug("Got sync event from vCPU %d\n", vcpu_id); 62 vcpu_last_completed_iteration[vcpu_id] = current_iteration; 63 pr_debug("vCPU %d updated last completed iteration to %d\n", 64 vcpu_id, vcpu_last_completed_iteration[vcpu_id]); 65 66 if (current_iteration) { 67 pages_count += vcpu_args->pages; 68 total = timespec_add(total, ts_diff); 69 pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n", 70 vcpu_id, current_iteration, ts_diff.tv_sec, 71 ts_diff.tv_nsec); 72 } else { 73 pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n", 74 vcpu_id, current_iteration, ts_diff.tv_sec, 75 ts_diff.tv_nsec); 76 } 77 78 while (current_iteration == READ_ONCE(iteration) && 79 !READ_ONCE(host_quit)) {} 80 } 81 82 avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]); 83 pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 84 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id], 85 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec); 86 87 return NULL; 88 } 89 90 struct test_params { 91 unsigned long iterations; 92 uint64_t phys_offset; 93 int wr_fract; 94 bool partition_vcpu_memory_access; 95 enum vm_mem_backing_src_type backing_src; 96 int slots; 97 }; 98 99 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable) 100 { 101 int i; 102 103 for (i = 0; i < slots; i++) { 104 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 105 int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0; 106 107 vm_mem_region_set_flags(vm, slot, flags); 108 } 109 } 110 111 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots) 112 { 113 toggle_dirty_logging(vm, slots, true); 114 } 115 116 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots) 117 { 118 toggle_dirty_logging(vm, slots, false); 119 } 120 121 static void get_dirty_log(struct kvm_vm *vm, int slots, unsigned long *bitmap, 122 uint64_t nr_pages) 123 { 124 uint64_t slot_pages = nr_pages / slots; 125 int i; 126 127 for (i = 0; i < slots; i++) { 128 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 129 unsigned long *slot_bitmap = bitmap + i * slot_pages; 130 131 kvm_vm_get_dirty_log(vm, slot, slot_bitmap); 132 } 133 } 134 135 static void clear_dirty_log(struct kvm_vm *vm, int slots, unsigned long *bitmap, 136 uint64_t nr_pages) 137 { 138 uint64_t slot_pages = nr_pages / slots; 139 int i; 140 141 for (i = 0; i < slots; i++) { 142 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 143 unsigned long *slot_bitmap = bitmap + i * slot_pages; 144 145 kvm_vm_clear_dirty_log(vm, slot, slot_bitmap, 0, slot_pages); 146 } 147 } 148 149 static void run_test(enum vm_guest_mode mode, void *arg) 150 { 151 struct test_params *p = arg; 152 pthread_t *vcpu_threads; 153 struct kvm_vm *vm; 154 unsigned long *bmap; 155 uint64_t guest_num_pages; 156 uint64_t host_num_pages; 157 int vcpu_id; 158 struct timespec start; 159 struct timespec ts_diff; 160 struct timespec get_dirty_log_total = (struct timespec){0}; 161 struct timespec vcpu_dirty_total = (struct timespec){0}; 162 struct timespec avg; 163 struct kvm_enable_cap cap = {}; 164 struct timespec clear_dirty_log_total = (struct timespec){0}; 165 166 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 167 p->slots, p->backing_src); 168 169 perf_test_args.wr_fract = p->wr_fract; 170 171 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); 172 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 173 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 174 bmap = bitmap_zalloc(host_num_pages); 175 176 if (dirty_log_manual_caps) { 177 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 178 cap.args[0] = dirty_log_manual_caps; 179 vm_enable_cap(vm, &cap); 180 } 181 182 vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads)); 183 TEST_ASSERT(vcpu_threads, "Memory allocation failed"); 184 185 perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size, 186 p->partition_vcpu_memory_access); 187 188 sync_global_to_guest(vm, perf_test_args); 189 190 /* Start the iterations */ 191 iteration = 0; 192 host_quit = false; 193 194 clock_gettime(CLOCK_MONOTONIC, &start); 195 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 196 vcpu_last_completed_iteration[vcpu_id] = -1; 197 198 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker, 199 &perf_test_args.vcpu_args[vcpu_id]); 200 } 201 202 /* Allow the vCPUs to populate memory */ 203 pr_debug("Starting iteration %d - Populating\n", iteration); 204 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 205 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != 206 iteration) 207 ; 208 } 209 210 ts_diff = timespec_elapsed(start); 211 pr_info("Populate memory time: %ld.%.9lds\n", 212 ts_diff.tv_sec, ts_diff.tv_nsec); 213 214 /* Enable dirty logging */ 215 clock_gettime(CLOCK_MONOTONIC, &start); 216 enable_dirty_logging(vm, p->slots); 217 ts_diff = timespec_elapsed(start); 218 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", 219 ts_diff.tv_sec, ts_diff.tv_nsec); 220 221 while (iteration < p->iterations) { 222 /* 223 * Incrementing the iteration number will start the vCPUs 224 * dirtying memory again. 225 */ 226 clock_gettime(CLOCK_MONOTONIC, &start); 227 iteration++; 228 229 pr_debug("Starting iteration %d\n", iteration); 230 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 231 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) 232 != iteration) 233 ; 234 } 235 236 ts_diff = timespec_elapsed(start); 237 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff); 238 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n", 239 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 240 241 clock_gettime(CLOCK_MONOTONIC, &start); 242 get_dirty_log(vm, p->slots, bmap, host_num_pages); 243 ts_diff = timespec_elapsed(start); 244 get_dirty_log_total = timespec_add(get_dirty_log_total, 245 ts_diff); 246 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n", 247 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 248 249 if (dirty_log_manual_caps) { 250 clock_gettime(CLOCK_MONOTONIC, &start); 251 clear_dirty_log(vm, p->slots, bmap, host_num_pages); 252 ts_diff = timespec_elapsed(start); 253 clear_dirty_log_total = timespec_add(clear_dirty_log_total, 254 ts_diff); 255 pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n", 256 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 257 } 258 } 259 260 /* Disable dirty logging */ 261 clock_gettime(CLOCK_MONOTONIC, &start); 262 disable_dirty_logging(vm, p->slots); 263 ts_diff = timespec_elapsed(start); 264 pr_info("Disabling dirty logging time: %ld.%.9lds\n", 265 ts_diff.tv_sec, ts_diff.tv_nsec); 266 267 /* Tell the vcpu thread to quit */ 268 host_quit = true; 269 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) 270 pthread_join(vcpu_threads[vcpu_id], NULL); 271 272 avg = timespec_div(get_dirty_log_total, p->iterations); 273 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 274 p->iterations, get_dirty_log_total.tv_sec, 275 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 276 277 if (dirty_log_manual_caps) { 278 avg = timespec_div(clear_dirty_log_total, p->iterations); 279 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 280 p->iterations, clear_dirty_log_total.tv_sec, 281 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 282 } 283 284 free(bmap); 285 free(vcpu_threads); 286 perf_test_destroy_vm(vm); 287 } 288 289 static void help(char *name) 290 { 291 puts(""); 292 printf("usage: %s [-h] [-i iterations] [-p offset] " 293 "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" 294 "[-x memslots]\n", name); 295 puts(""); 296 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 297 TEST_HOST_LOOP_N); 298 printf(" -p: specify guest physical test memory offset\n" 299 " Warning: a low offset can conflict with the loaded test code.\n"); 300 guest_modes_help(); 301 printf(" -b: specify the size of the memory region which should be\n" 302 " dirtied by each vCPU. e.g. 10M or 3G.\n" 303 " (default: 1G)\n"); 304 printf(" -f: specify the fraction of pages which should be written to\n" 305 " as opposed to simply read, in the form\n" 306 " 1/<fraction of pages to write>.\n" 307 " (default: 1 i.e. all pages are written to.)\n"); 308 printf(" -v: specify the number of vCPUs to run.\n"); 309 printf(" -o: Overlap guest memory accesses instead of partitioning\n" 310 " them into a separate region of memory for each vCPU.\n"); 311 printf(" -s: specify the type of memory that should be used to\n" 312 " back the guest data region.\n\n"); 313 printf(" -x: Split the memory region into this number of memslots.\n" 314 " (default: 1)"); 315 backing_src_help(); 316 puts(""); 317 exit(0); 318 } 319 320 int main(int argc, char *argv[]) 321 { 322 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 323 struct test_params p = { 324 .iterations = TEST_HOST_LOOP_N, 325 .wr_fract = 1, 326 .partition_vcpu_memory_access = true, 327 .backing_src = VM_MEM_SRC_ANONYMOUS, 328 .slots = 1, 329 }; 330 int opt; 331 332 dirty_log_manual_caps = 333 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 334 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 335 KVM_DIRTY_LOG_INITIALLY_SET); 336 337 guest_modes_append_default(); 338 339 while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:x:")) != -1) { 340 switch (opt) { 341 case 'i': 342 p.iterations = atoi(optarg); 343 break; 344 case 'p': 345 p.phys_offset = strtoull(optarg, NULL, 0); 346 break; 347 case 'm': 348 guest_modes_cmdline(optarg); 349 break; 350 case 'b': 351 guest_percpu_mem_size = parse_size(optarg); 352 break; 353 case 'f': 354 p.wr_fract = atoi(optarg); 355 TEST_ASSERT(p.wr_fract >= 1, 356 "Write fraction cannot be less than one"); 357 break; 358 case 'v': 359 nr_vcpus = atoi(optarg); 360 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, 361 "Invalid number of vcpus, must be between 1 and %d", max_vcpus); 362 break; 363 case 'o': 364 p.partition_vcpu_memory_access = false; 365 break; 366 case 's': 367 p.backing_src = parse_backing_src_type(optarg); 368 break; 369 case 'x': 370 p.slots = atoi(optarg); 371 break; 372 case 'h': 373 default: 374 help(argv[0]); 375 break; 376 } 377 } 378 379 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); 380 381 pr_info("Test iterations: %"PRIu64"\n", p.iterations); 382 383 for_each_guest_mode(run_test, &p); 384 385 return 0; 386 } 387