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 #ifdef __aarch64__ 23 #include "aarch64/vgic.h" 24 25 #define GICD_BASE_GPA 0x8000000ULL 26 #define GICR_BASE_GPA 0x80A0000ULL 27 28 static int gic_fd; 29 30 static void arch_setup_vm(struct kvm_vm *vm, unsigned int nr_vcpus) 31 { 32 /* 33 * The test can still run even if hardware does not support GICv3, as it 34 * is only an optimization to reduce guest exits. 35 */ 36 gic_fd = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA); 37 } 38 39 static void arch_cleanup_vm(struct kvm_vm *vm) 40 { 41 if (gic_fd > 0) 42 close(gic_fd); 43 } 44 45 #else /* __aarch64__ */ 46 47 static void arch_setup_vm(struct kvm_vm *vm, unsigned int nr_vcpus) 48 { 49 } 50 51 static void arch_cleanup_vm(struct kvm_vm *vm) 52 { 53 } 54 55 #endif 56 57 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/ 58 #define TEST_HOST_LOOP_N 2UL 59 60 static int nr_vcpus = 1; 61 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE; 62 63 /* Host variables */ 64 static u64 dirty_log_manual_caps; 65 static bool host_quit; 66 static int iteration; 67 static int vcpu_last_completed_iteration[KVM_MAX_VCPUS]; 68 69 static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args) 70 { 71 int ret; 72 struct kvm_vm *vm = perf_test_args.vm; 73 uint64_t pages_count = 0; 74 struct kvm_run *run; 75 struct timespec start; 76 struct timespec ts_diff; 77 struct timespec total = (struct timespec){0}; 78 struct timespec avg; 79 int vcpu_id = vcpu_args->vcpu_id; 80 81 run = vcpu_state(vm, vcpu_id); 82 83 while (!READ_ONCE(host_quit)) { 84 int current_iteration = READ_ONCE(iteration); 85 86 clock_gettime(CLOCK_MONOTONIC, &start); 87 ret = _vcpu_run(vm, vcpu_id); 88 ts_diff = timespec_elapsed(start); 89 90 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 91 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC, 92 "Invalid guest sync status: exit_reason=%s\n", 93 exit_reason_str(run->exit_reason)); 94 95 pr_debug("Got sync event from vCPU %d\n", vcpu_id); 96 vcpu_last_completed_iteration[vcpu_id] = current_iteration; 97 pr_debug("vCPU %d updated last completed iteration to %d\n", 98 vcpu_id, vcpu_last_completed_iteration[vcpu_id]); 99 100 if (current_iteration) { 101 pages_count += vcpu_args->pages; 102 total = timespec_add(total, ts_diff); 103 pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n", 104 vcpu_id, current_iteration, ts_diff.tv_sec, 105 ts_diff.tv_nsec); 106 } else { 107 pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n", 108 vcpu_id, current_iteration, ts_diff.tv_sec, 109 ts_diff.tv_nsec); 110 } 111 112 while (current_iteration == READ_ONCE(iteration) && 113 !READ_ONCE(host_quit)) {} 114 } 115 116 avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]); 117 pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 118 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id], 119 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec); 120 } 121 122 struct test_params { 123 unsigned long iterations; 124 uint64_t phys_offset; 125 int wr_fract; 126 bool partition_vcpu_memory_access; 127 enum vm_mem_backing_src_type backing_src; 128 int slots; 129 }; 130 131 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable) 132 { 133 int i; 134 135 for (i = 0; i < slots; i++) { 136 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 137 int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0; 138 139 vm_mem_region_set_flags(vm, slot, flags); 140 } 141 } 142 143 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots) 144 { 145 toggle_dirty_logging(vm, slots, true); 146 } 147 148 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots) 149 { 150 toggle_dirty_logging(vm, slots, false); 151 } 152 153 static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots) 154 { 155 int i; 156 157 for (i = 0; i < slots; i++) { 158 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 159 160 kvm_vm_get_dirty_log(vm, slot, bitmaps[i]); 161 } 162 } 163 164 static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], 165 int slots, uint64_t pages_per_slot) 166 { 167 int i; 168 169 for (i = 0; i < slots; i++) { 170 int slot = PERF_TEST_MEM_SLOT_INDEX + i; 171 172 kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot); 173 } 174 } 175 176 static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot) 177 { 178 unsigned long **bitmaps; 179 int i; 180 181 bitmaps = malloc(slots * sizeof(bitmaps[0])); 182 TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array."); 183 184 for (i = 0; i < slots; i++) { 185 bitmaps[i] = bitmap_zalloc(pages_per_slot); 186 TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap."); 187 } 188 189 return bitmaps; 190 } 191 192 static void free_bitmaps(unsigned long *bitmaps[], int slots) 193 { 194 int i; 195 196 for (i = 0; i < slots; i++) 197 free(bitmaps[i]); 198 199 free(bitmaps); 200 } 201 202 static void run_test(enum vm_guest_mode mode, void *arg) 203 { 204 struct test_params *p = arg; 205 struct kvm_vm *vm; 206 unsigned long **bitmaps; 207 uint64_t guest_num_pages; 208 uint64_t host_num_pages; 209 uint64_t pages_per_slot; 210 int vcpu_id; 211 struct timespec start; 212 struct timespec ts_diff; 213 struct timespec get_dirty_log_total = (struct timespec){0}; 214 struct timespec vcpu_dirty_total = (struct timespec){0}; 215 struct timespec avg; 216 struct kvm_enable_cap cap = {}; 217 struct timespec clear_dirty_log_total = (struct timespec){0}; 218 219 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 220 p->slots, p->backing_src, 221 p->partition_vcpu_memory_access); 222 223 perf_test_set_wr_fract(vm, p->wr_fract); 224 225 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); 226 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 227 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 228 pages_per_slot = host_num_pages / p->slots; 229 230 bitmaps = alloc_bitmaps(p->slots, pages_per_slot); 231 232 if (dirty_log_manual_caps) { 233 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 234 cap.args[0] = dirty_log_manual_caps; 235 vm_enable_cap(vm, &cap); 236 } 237 238 arch_setup_vm(vm, nr_vcpus); 239 240 /* Start the iterations */ 241 iteration = 0; 242 host_quit = false; 243 244 clock_gettime(CLOCK_MONOTONIC, &start); 245 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) 246 vcpu_last_completed_iteration[vcpu_id] = -1; 247 248 perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); 249 250 /* Allow the vCPUs to populate memory */ 251 pr_debug("Starting iteration %d - Populating\n", iteration); 252 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 253 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != 254 iteration) 255 ; 256 } 257 258 ts_diff = timespec_elapsed(start); 259 pr_info("Populate memory time: %ld.%.9lds\n", 260 ts_diff.tv_sec, ts_diff.tv_nsec); 261 262 /* Enable dirty logging */ 263 clock_gettime(CLOCK_MONOTONIC, &start); 264 enable_dirty_logging(vm, p->slots); 265 ts_diff = timespec_elapsed(start); 266 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", 267 ts_diff.tv_sec, ts_diff.tv_nsec); 268 269 while (iteration < p->iterations) { 270 /* 271 * Incrementing the iteration number will start the vCPUs 272 * dirtying memory again. 273 */ 274 clock_gettime(CLOCK_MONOTONIC, &start); 275 iteration++; 276 277 pr_debug("Starting iteration %d\n", iteration); 278 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { 279 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) 280 != iteration) 281 ; 282 } 283 284 ts_diff = timespec_elapsed(start); 285 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff); 286 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n", 287 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 288 289 clock_gettime(CLOCK_MONOTONIC, &start); 290 get_dirty_log(vm, bitmaps, p->slots); 291 ts_diff = timespec_elapsed(start); 292 get_dirty_log_total = timespec_add(get_dirty_log_total, 293 ts_diff); 294 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n", 295 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 296 297 if (dirty_log_manual_caps) { 298 clock_gettime(CLOCK_MONOTONIC, &start); 299 clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot); 300 ts_diff = timespec_elapsed(start); 301 clear_dirty_log_total = timespec_add(clear_dirty_log_total, 302 ts_diff); 303 pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n", 304 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 305 } 306 } 307 308 /* Disable dirty logging */ 309 clock_gettime(CLOCK_MONOTONIC, &start); 310 disable_dirty_logging(vm, p->slots); 311 ts_diff = timespec_elapsed(start); 312 pr_info("Disabling dirty logging time: %ld.%.9lds\n", 313 ts_diff.tv_sec, ts_diff.tv_nsec); 314 315 /* Tell the vcpu thread to quit */ 316 host_quit = true; 317 perf_test_join_vcpu_threads(nr_vcpus); 318 319 avg = timespec_div(get_dirty_log_total, p->iterations); 320 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 321 p->iterations, get_dirty_log_total.tv_sec, 322 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 323 324 if (dirty_log_manual_caps) { 325 avg = timespec_div(clear_dirty_log_total, p->iterations); 326 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 327 p->iterations, clear_dirty_log_total.tv_sec, 328 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 329 } 330 331 free_bitmaps(bitmaps, p->slots); 332 arch_cleanup_vm(vm); 333 perf_test_destroy_vm(vm); 334 } 335 336 static void help(char *name) 337 { 338 puts(""); 339 printf("usage: %s [-h] [-i iterations] [-p offset] [-g]" 340 "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" 341 "[-x memslots]\n", name); 342 puts(""); 343 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 344 TEST_HOST_LOOP_N); 345 printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n" 346 " makes KVM_GET_DIRTY_LOG clear the dirty log (i.e.\n" 347 " KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is not enabled)\n" 348 " and writes will be tracked as soon as dirty logging is\n" 349 " enabled on the memslot (i.e. KVM_DIRTY_LOG_INITIALLY_SET\n" 350 " is not enabled).\n"); 351 printf(" -p: specify guest physical test memory offset\n" 352 " Warning: a low offset can conflict with the loaded test code.\n"); 353 guest_modes_help(); 354 printf(" -b: specify the size of the memory region which should be\n" 355 " dirtied by each vCPU. e.g. 10M or 3G.\n" 356 " (default: 1G)\n"); 357 printf(" -f: specify the fraction of pages which should be written to\n" 358 " as opposed to simply read, in the form\n" 359 " 1/<fraction of pages to write>.\n" 360 " (default: 1 i.e. all pages are written to.)\n"); 361 printf(" -v: specify the number of vCPUs to run.\n"); 362 printf(" -o: Overlap guest memory accesses instead of partitioning\n" 363 " them into a separate region of memory for each vCPU.\n"); 364 backing_src_help("-s"); 365 printf(" -x: Split the memory region into this number of memslots.\n" 366 " (default: 1)\n"); 367 puts(""); 368 exit(0); 369 } 370 371 int main(int argc, char *argv[]) 372 { 373 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 374 struct test_params p = { 375 .iterations = TEST_HOST_LOOP_N, 376 .wr_fract = 1, 377 .partition_vcpu_memory_access = true, 378 .backing_src = DEFAULT_VM_MEM_SRC, 379 .slots = 1, 380 }; 381 int opt; 382 383 dirty_log_manual_caps = 384 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 385 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 386 KVM_DIRTY_LOG_INITIALLY_SET); 387 388 guest_modes_append_default(); 389 390 while ((opt = getopt(argc, argv, "ghi:p:m:b:f:v:os:x:")) != -1) { 391 switch (opt) { 392 case 'g': 393 dirty_log_manual_caps = 0; 394 break; 395 case 'i': 396 p.iterations = atoi(optarg); 397 break; 398 case 'p': 399 p.phys_offset = strtoull(optarg, NULL, 0); 400 break; 401 case 'm': 402 guest_modes_cmdline(optarg); 403 break; 404 case 'b': 405 guest_percpu_mem_size = parse_size(optarg); 406 break; 407 case 'f': 408 p.wr_fract = atoi(optarg); 409 TEST_ASSERT(p.wr_fract >= 1, 410 "Write fraction cannot be less than one"); 411 break; 412 case 'v': 413 nr_vcpus = atoi(optarg); 414 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, 415 "Invalid number of vcpus, must be between 1 and %d", max_vcpus); 416 break; 417 case 'o': 418 p.partition_vcpu_memory_access = false; 419 break; 420 case 's': 421 p.backing_src = parse_backing_src_type(optarg); 422 break; 423 case 'x': 424 p.slots = atoi(optarg); 425 break; 426 case 'h': 427 default: 428 help(argv[0]); 429 break; 430 } 431 } 432 433 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); 434 435 pr_info("Test iterations: %"PRIu64"\n", p.iterations); 436 437 for_each_guest_mode(run_test, &p); 438 439 return 0; 440 } 441