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 struct kvm_vcpu *vcpu = vcpu_args->vcpu; 72 int vcpu_idx = vcpu_args->vcpu_idx; 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 ret; 80 81 run = vcpu->run; 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(vcpu); 88 ts_diff = timespec_elapsed(start); 89 90 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 91 TEST_ASSERT(get_ucall(vcpu, 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_idx); 96 vcpu_last_completed_iteration[vcpu_idx] = current_iteration; 97 pr_debug("vCPU %d updated last completed iteration to %d\n", 98 vcpu_idx, vcpu_last_completed_iteration[vcpu_idx]); 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_idx, 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_idx, 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_idx]); 117 pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 118 vcpu_idx, pages_count, vcpu_last_completed_iteration[vcpu_idx], 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 struct timespec start; 211 struct timespec ts_diff; 212 struct timespec get_dirty_log_total = (struct timespec){0}; 213 struct timespec vcpu_dirty_total = (struct timespec){0}; 214 struct timespec avg; 215 struct timespec clear_dirty_log_total = (struct timespec){0}; 216 int i; 217 218 vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 219 p->slots, p->backing_src, 220 p->partition_vcpu_memory_access); 221 222 perf_test_set_wr_fract(vm, p->wr_fract); 223 224 guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm); 225 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 226 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 227 pages_per_slot = host_num_pages / p->slots; 228 229 bitmaps = alloc_bitmaps(p->slots, pages_per_slot); 230 231 if (dirty_log_manual_caps) 232 vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, 233 dirty_log_manual_caps); 234 235 arch_setup_vm(vm, nr_vcpus); 236 237 /* Start the iterations */ 238 iteration = 0; 239 host_quit = false; 240 241 clock_gettime(CLOCK_MONOTONIC, &start); 242 for (i = 0; i < nr_vcpus; i++) 243 vcpu_last_completed_iteration[i] = -1; 244 245 perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); 246 247 /* Allow the vCPUs to populate memory */ 248 pr_debug("Starting iteration %d - Populating\n", iteration); 249 for (i = 0; i < nr_vcpus; i++) { 250 while (READ_ONCE(vcpu_last_completed_iteration[i]) != 251 iteration) 252 ; 253 } 254 255 ts_diff = timespec_elapsed(start); 256 pr_info("Populate memory time: %ld.%.9lds\n", 257 ts_diff.tv_sec, ts_diff.tv_nsec); 258 259 /* Enable dirty logging */ 260 clock_gettime(CLOCK_MONOTONIC, &start); 261 enable_dirty_logging(vm, p->slots); 262 ts_diff = timespec_elapsed(start); 263 pr_info("Enabling dirty logging time: %ld.%.9lds\n\n", 264 ts_diff.tv_sec, ts_diff.tv_nsec); 265 266 while (iteration < p->iterations) { 267 /* 268 * Incrementing the iteration number will start the vCPUs 269 * dirtying memory again. 270 */ 271 clock_gettime(CLOCK_MONOTONIC, &start); 272 iteration++; 273 274 pr_debug("Starting iteration %d\n", iteration); 275 for (i = 0; i < nr_vcpus; i++) { 276 while (READ_ONCE(vcpu_last_completed_iteration[i]) 277 != iteration) 278 ; 279 } 280 281 ts_diff = timespec_elapsed(start); 282 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff); 283 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n", 284 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 285 286 clock_gettime(CLOCK_MONOTONIC, &start); 287 get_dirty_log(vm, bitmaps, p->slots); 288 ts_diff = timespec_elapsed(start); 289 get_dirty_log_total = timespec_add(get_dirty_log_total, 290 ts_diff); 291 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n", 292 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 293 294 if (dirty_log_manual_caps) { 295 clock_gettime(CLOCK_MONOTONIC, &start); 296 clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot); 297 ts_diff = timespec_elapsed(start); 298 clear_dirty_log_total = timespec_add(clear_dirty_log_total, 299 ts_diff); 300 pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n", 301 iteration, ts_diff.tv_sec, ts_diff.tv_nsec); 302 } 303 } 304 305 /* Disable dirty logging */ 306 clock_gettime(CLOCK_MONOTONIC, &start); 307 disable_dirty_logging(vm, p->slots); 308 ts_diff = timespec_elapsed(start); 309 pr_info("Disabling dirty logging time: %ld.%.9lds\n", 310 ts_diff.tv_sec, ts_diff.tv_nsec); 311 312 /* Tell the vcpu thread to quit */ 313 host_quit = true; 314 perf_test_join_vcpu_threads(nr_vcpus); 315 316 avg = timespec_div(get_dirty_log_total, p->iterations); 317 pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 318 p->iterations, get_dirty_log_total.tv_sec, 319 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 320 321 if (dirty_log_manual_caps) { 322 avg = timespec_div(clear_dirty_log_total, p->iterations); 323 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n", 324 p->iterations, clear_dirty_log_total.tv_sec, 325 clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec); 326 } 327 328 free_bitmaps(bitmaps, p->slots); 329 arch_cleanup_vm(vm); 330 perf_test_destroy_vm(vm); 331 } 332 333 static void help(char *name) 334 { 335 puts(""); 336 printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " 337 "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" 338 "[-x memslots]\n", name); 339 puts(""); 340 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 341 TEST_HOST_LOOP_N); 342 printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n" 343 " makes KVM_GET_DIRTY_LOG clear the dirty log (i.e.\n" 344 " KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is not enabled)\n" 345 " and writes will be tracked as soon as dirty logging is\n" 346 " enabled on the memslot (i.e. KVM_DIRTY_LOG_INITIALLY_SET\n" 347 " is not enabled).\n"); 348 printf(" -p: specify guest physical test memory offset\n" 349 " Warning: a low offset can conflict with the loaded test code.\n"); 350 guest_modes_help(); 351 printf(" -n: Run the vCPUs in nested mode (L2)\n"); 352 printf(" -b: specify the size of the memory region which should be\n" 353 " dirtied by each vCPU. e.g. 10M or 3G.\n" 354 " (default: 1G)\n"); 355 printf(" -f: specify the fraction of pages which should be written to\n" 356 " as opposed to simply read, in the form\n" 357 " 1/<fraction of pages to write>.\n" 358 " (default: 1 i.e. all pages are written to.)\n"); 359 printf(" -v: specify the number of vCPUs to run.\n"); 360 printf(" -o: Overlap guest memory accesses instead of partitioning\n" 361 " them into a separate region of memory for each vCPU.\n"); 362 backing_src_help("-s"); 363 printf(" -x: Split the memory region into this number of memslots.\n" 364 " (default: 1)\n"); 365 puts(""); 366 exit(0); 367 } 368 369 int main(int argc, char *argv[]) 370 { 371 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 372 struct test_params p = { 373 .iterations = TEST_HOST_LOOP_N, 374 .wr_fract = 1, 375 .partition_vcpu_memory_access = true, 376 .backing_src = DEFAULT_VM_MEM_SRC, 377 .slots = 1, 378 }; 379 int opt; 380 381 dirty_log_manual_caps = 382 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 383 dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 384 KVM_DIRTY_LOG_INITIALLY_SET); 385 386 guest_modes_append_default(); 387 388 while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:os:x:")) != -1) { 389 switch (opt) { 390 case 'g': 391 dirty_log_manual_caps = 0; 392 break; 393 case 'i': 394 p.iterations = atoi(optarg); 395 break; 396 case 'p': 397 p.phys_offset = strtoull(optarg, NULL, 0); 398 break; 399 case 'm': 400 guest_modes_cmdline(optarg); 401 break; 402 case 'n': 403 perf_test_args.nested = true; 404 break; 405 case 'b': 406 guest_percpu_mem_size = parse_size(optarg); 407 break; 408 case 'f': 409 p.wr_fract = atoi(optarg); 410 TEST_ASSERT(p.wr_fract >= 1, 411 "Write fraction cannot be less than one"); 412 break; 413 case 'v': 414 nr_vcpus = atoi(optarg); 415 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, 416 "Invalid number of vcpus, must be between 1 and %d", max_vcpus); 417 break; 418 case 'o': 419 p.partition_vcpu_memory_access = false; 420 break; 421 case 's': 422 p.backing_src = parse_backing_src_type(optarg); 423 break; 424 case 'x': 425 p.slots = atoi(optarg); 426 break; 427 case 'h': 428 default: 429 help(argv[0]); 430 break; 431 } 432 } 433 434 TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations"); 435 436 pr_info("Test iterations: %"PRIu64"\n", p.iterations); 437 438 for_each_guest_mode(run_test, &p); 439 440 return 0; 441 } 442