1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * KVM dirty page logging test 4 * 5 * Copyright (C) 2018, Red Hat, Inc. 6 */ 7 8 #define _GNU_SOURCE /* for program_invocation_name */ 9 10 #include <stdio.h> 11 #include <stdlib.h> 12 #include <unistd.h> 13 #include <time.h> 14 #include <pthread.h> 15 #include <linux/bitmap.h> 16 #include <linux/bitops.h> 17 18 #include "test_util.h" 19 #include "kvm_util.h" 20 #include "processor.h" 21 22 #define VCPU_ID 1 23 24 /* The memory slot index to track dirty pages */ 25 #define TEST_MEM_SLOT_INDEX 1 26 27 /* Default guest test virtual memory offset */ 28 #define DEFAULT_GUEST_TEST_MEM 0xc0000000 29 30 /* How many pages to dirty for each guest loop */ 31 #define TEST_PAGES_PER_LOOP 1024 32 33 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */ 34 #define TEST_HOST_LOOP_N 32UL 35 36 /* Interval for each host loop (ms) */ 37 #define TEST_HOST_LOOP_INTERVAL 10UL 38 39 /* Dirty bitmaps are always little endian, so we need to swap on big endian */ 40 #if defined(__s390x__) 41 # define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) 42 # define test_bit_le(nr, addr) \ 43 test_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 44 # define set_bit_le(nr, addr) \ 45 set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 46 # define clear_bit_le(nr, addr) \ 47 clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 48 # define test_and_set_bit_le(nr, addr) \ 49 test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 50 # define test_and_clear_bit_le(nr, addr) \ 51 test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 52 #else 53 # define test_bit_le test_bit 54 # define set_bit_le set_bit 55 # define clear_bit_le clear_bit 56 # define test_and_set_bit_le test_and_set_bit 57 # define test_and_clear_bit_le test_and_clear_bit 58 #endif 59 60 /* 61 * Guest/Host shared variables. Ensure addr_gva2hva() and/or 62 * sync_global_to/from_guest() are used when accessing from 63 * the host. READ/WRITE_ONCE() should also be used with anything 64 * that may change. 65 */ 66 static uint64_t host_page_size; 67 static uint64_t guest_page_size; 68 static uint64_t guest_num_pages; 69 static uint64_t random_array[TEST_PAGES_PER_LOOP]; 70 static uint64_t iteration; 71 72 /* 73 * Guest physical memory offset of the testing memory slot. 74 * This will be set to the topmost valid physical address minus 75 * the test memory size. 76 */ 77 static uint64_t guest_test_phys_mem; 78 79 /* 80 * Guest virtual memory offset of the testing memory slot. 81 * Must not conflict with identity mapped test code. 82 */ 83 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; 84 85 /* 86 * Continuously write to the first 8 bytes of a random pages within 87 * the testing memory region. 88 */ 89 static void guest_code(void) 90 { 91 uint64_t addr; 92 int i; 93 94 /* 95 * On s390x, all pages of a 1M segment are initially marked as dirty 96 * when a page of the segment is written to for the very first time. 97 * To compensate this specialty in this test, we need to touch all 98 * pages during the first iteration. 99 */ 100 for (i = 0; i < guest_num_pages; i++) { 101 addr = guest_test_virt_mem + i * guest_page_size; 102 *(uint64_t *)addr = READ_ONCE(iteration); 103 } 104 105 while (true) { 106 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { 107 addr = guest_test_virt_mem; 108 addr += (READ_ONCE(random_array[i]) % guest_num_pages) 109 * guest_page_size; 110 addr &= ~(host_page_size - 1); 111 *(uint64_t *)addr = READ_ONCE(iteration); 112 } 113 114 /* Tell the host that we need more random numbers */ 115 GUEST_SYNC(1); 116 } 117 } 118 119 /* Host variables */ 120 static bool host_quit; 121 122 /* Points to the test VM memory region on which we track dirty logs */ 123 static void *host_test_mem; 124 static uint64_t host_num_pages; 125 126 /* For statistics only */ 127 static uint64_t host_dirty_count; 128 static uint64_t host_clear_count; 129 static uint64_t host_track_next_count; 130 131 enum log_mode_t { 132 /* Only use KVM_GET_DIRTY_LOG for logging */ 133 LOG_MODE_DIRTY_LOG = 0, 134 135 /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */ 136 LOG_MODE_CLEAR_LOG = 1, 137 138 LOG_MODE_NUM, 139 140 /* Run all supported modes */ 141 LOG_MODE_ALL = LOG_MODE_NUM, 142 }; 143 144 /* Mode of logging to test. Default is to run all supported modes */ 145 static enum log_mode_t host_log_mode_option = LOG_MODE_ALL; 146 /* Logging mode for current run */ 147 static enum log_mode_t host_log_mode; 148 149 static bool clear_log_supported(void) 150 { 151 return kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 152 } 153 154 static void clear_log_create_vm_done(struct kvm_vm *vm) 155 { 156 struct kvm_enable_cap cap = {}; 157 u64 manual_caps; 158 159 manual_caps = kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 160 TEST_ASSERT(manual_caps, "MANUAL_CAPS is zero!"); 161 manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 162 KVM_DIRTY_LOG_INITIALLY_SET); 163 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 164 cap.args[0] = manual_caps; 165 vm_enable_cap(vm, &cap); 166 } 167 168 static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot, 169 void *bitmap, uint32_t num_pages) 170 { 171 kvm_vm_get_dirty_log(vm, slot, bitmap); 172 } 173 174 static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot, 175 void *bitmap, uint32_t num_pages) 176 { 177 kvm_vm_get_dirty_log(vm, slot, bitmap); 178 kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages); 179 } 180 181 struct log_mode { 182 const char *name; 183 /* Return true if this mode is supported, otherwise false */ 184 bool (*supported)(void); 185 /* Hook when the vm creation is done (before vcpu creation) */ 186 void (*create_vm_done)(struct kvm_vm *vm); 187 /* Hook to collect the dirty pages into the bitmap provided */ 188 void (*collect_dirty_pages) (struct kvm_vm *vm, int slot, 189 void *bitmap, uint32_t num_pages); 190 } log_modes[LOG_MODE_NUM] = { 191 { 192 .name = "dirty-log", 193 .collect_dirty_pages = dirty_log_collect_dirty_pages, 194 }, 195 { 196 .name = "clear-log", 197 .supported = clear_log_supported, 198 .create_vm_done = clear_log_create_vm_done, 199 .collect_dirty_pages = clear_log_collect_dirty_pages, 200 }, 201 }; 202 203 /* 204 * We use this bitmap to track some pages that should have its dirty 205 * bit set in the _next_ iteration. For example, if we detected the 206 * page value changed to current iteration but at the same time the 207 * page bit is cleared in the latest bitmap, then the system must 208 * report that write in the next get dirty log call. 209 */ 210 static unsigned long *host_bmap_track; 211 212 static void log_modes_dump(void) 213 { 214 int i; 215 216 printf("all"); 217 for (i = 0; i < LOG_MODE_NUM; i++) 218 printf(", %s", log_modes[i].name); 219 printf("\n"); 220 } 221 222 static bool log_mode_supported(void) 223 { 224 struct log_mode *mode = &log_modes[host_log_mode]; 225 226 if (mode->supported) 227 return mode->supported(); 228 229 return true; 230 } 231 232 static void log_mode_create_vm_done(struct kvm_vm *vm) 233 { 234 struct log_mode *mode = &log_modes[host_log_mode]; 235 236 if (mode->create_vm_done) 237 mode->create_vm_done(vm); 238 } 239 240 static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot, 241 void *bitmap, uint32_t num_pages) 242 { 243 struct log_mode *mode = &log_modes[host_log_mode]; 244 245 TEST_ASSERT(mode->collect_dirty_pages != NULL, 246 "collect_dirty_pages() is required for any log mode!"); 247 mode->collect_dirty_pages(vm, slot, bitmap, num_pages); 248 } 249 250 static void generate_random_array(uint64_t *guest_array, uint64_t size) 251 { 252 uint64_t i; 253 254 for (i = 0; i < size; i++) 255 guest_array[i] = random(); 256 } 257 258 static void *vcpu_worker(void *data) 259 { 260 int ret; 261 struct kvm_vm *vm = data; 262 uint64_t *guest_array; 263 uint64_t pages_count = 0; 264 struct kvm_run *run; 265 266 run = vcpu_state(vm, VCPU_ID); 267 268 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 269 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 270 271 while (!READ_ONCE(host_quit)) { 272 /* Let the guest dirty the random pages */ 273 ret = _vcpu_run(vm, VCPU_ID); 274 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 275 if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) { 276 pages_count += TEST_PAGES_PER_LOOP; 277 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 278 } else { 279 TEST_FAIL("Invalid guest sync status: " 280 "exit_reason=%s\n", 281 exit_reason_str(run->exit_reason)); 282 } 283 } 284 285 pr_info("Dirtied %"PRIu64" pages\n", pages_count); 286 287 return NULL; 288 } 289 290 static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap) 291 { 292 uint64_t step = vm_num_host_pages(mode, 1); 293 uint64_t page; 294 uint64_t *value_ptr; 295 296 for (page = 0; page < host_num_pages; page += step) { 297 value_ptr = host_test_mem + page * host_page_size; 298 299 /* If this is a special page that we were tracking... */ 300 if (test_and_clear_bit_le(page, host_bmap_track)) { 301 host_track_next_count++; 302 TEST_ASSERT(test_bit_le(page, bmap), 303 "Page %"PRIu64" should have its dirty bit " 304 "set in this iteration but it is missing", 305 page); 306 } 307 308 if (test_and_clear_bit_le(page, bmap)) { 309 host_dirty_count++; 310 /* 311 * If the bit is set, the value written onto 312 * the corresponding page should be either the 313 * previous iteration number or the current one. 314 */ 315 TEST_ASSERT(*value_ptr == iteration || 316 *value_ptr == iteration - 1, 317 "Set page %"PRIu64" value %"PRIu64 318 " incorrect (iteration=%"PRIu64")", 319 page, *value_ptr, iteration); 320 } else { 321 host_clear_count++; 322 /* 323 * If cleared, the value written can be any 324 * value smaller or equals to the iteration 325 * number. Note that the value can be exactly 326 * (iteration-1) if that write can happen 327 * like this: 328 * 329 * (1) increase loop count to "iteration-1" 330 * (2) write to page P happens (with value 331 * "iteration-1") 332 * (3) get dirty log for "iteration-1"; we'll 333 * see that page P bit is set (dirtied), 334 * and not set the bit in host_bmap_track 335 * (4) increase loop count to "iteration" 336 * (which is current iteration) 337 * (5) get dirty log for current iteration, 338 * we'll see that page P is cleared, with 339 * value "iteration-1". 340 */ 341 TEST_ASSERT(*value_ptr <= iteration, 342 "Clear page %"PRIu64" value %"PRIu64 343 " incorrect (iteration=%"PRIu64")", 344 page, *value_ptr, iteration); 345 if (*value_ptr == iteration) { 346 /* 347 * This page is _just_ modified; it 348 * should report its dirtyness in the 349 * next run 350 */ 351 set_bit_le(page, host_bmap_track); 352 } 353 } 354 } 355 } 356 357 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 358 uint64_t extra_mem_pages, void *guest_code) 359 { 360 struct kvm_vm *vm; 361 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; 362 363 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 364 365 vm = vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); 366 kvm_vm_elf_load(vm, program_invocation_name, 0, 0); 367 #ifdef __x86_64__ 368 vm_create_irqchip(vm); 369 #endif 370 log_mode_create_vm_done(vm); 371 vm_vcpu_add_default(vm, vcpuid, guest_code); 372 return vm; 373 } 374 375 #define DIRTY_MEM_BITS 30 /* 1G */ 376 #define PAGE_SHIFT_4K 12 377 378 static void run_test(enum vm_guest_mode mode, unsigned long iterations, 379 unsigned long interval, uint64_t phys_offset) 380 { 381 pthread_t vcpu_thread; 382 struct kvm_vm *vm; 383 unsigned long *bmap; 384 385 if (!log_mode_supported()) { 386 print_skip("Log mode '%s' not supported", 387 log_modes[host_log_mode].name); 388 return; 389 } 390 391 /* 392 * We reserve page table for 2 times of extra dirty mem which 393 * will definitely cover the original (1G+) test range. Here 394 * we do the calculation with 4K page size which is the 395 * smallest so the page number will be enough for all archs 396 * (e.g., 64K page size guest will need even less memory for 397 * page tables). 398 */ 399 vm = create_vm(mode, VCPU_ID, 400 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), 401 guest_code); 402 403 guest_page_size = vm_get_page_size(vm); 404 /* 405 * A little more than 1G of guest page sized pages. Cover the 406 * case where the size is not aligned to 64 pages. 407 */ 408 guest_num_pages = (1ul << (DIRTY_MEM_BITS - 409 vm_get_page_shift(vm))) + 3; 410 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 411 412 host_page_size = getpagesize(); 413 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 414 415 if (!phys_offset) { 416 guest_test_phys_mem = (vm_get_max_gfn(vm) - 417 guest_num_pages) * guest_page_size; 418 guest_test_phys_mem &= ~(host_page_size - 1); 419 } else { 420 guest_test_phys_mem = phys_offset; 421 } 422 423 #ifdef __s390x__ 424 /* Align to 1M (segment size) */ 425 guest_test_phys_mem &= ~((1 << 20) - 1); 426 #endif 427 428 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 429 430 bmap = bitmap_alloc(host_num_pages); 431 host_bmap_track = bitmap_alloc(host_num_pages); 432 433 /* Add an extra memory slot for testing dirty logging */ 434 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 435 guest_test_phys_mem, 436 TEST_MEM_SLOT_INDEX, 437 guest_num_pages, 438 KVM_MEM_LOG_DIRTY_PAGES); 439 440 /* Do mapping for the dirty track memory slot */ 441 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages, 0); 442 443 /* Cache the HVA pointer of the region */ 444 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 445 446 #ifdef __x86_64__ 447 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); 448 #endif 449 ucall_init(vm, NULL); 450 451 /* Export the shared variables to the guest */ 452 sync_global_to_guest(vm, host_page_size); 453 sync_global_to_guest(vm, guest_page_size); 454 sync_global_to_guest(vm, guest_test_virt_mem); 455 sync_global_to_guest(vm, guest_num_pages); 456 457 /* Start the iterations */ 458 iteration = 1; 459 sync_global_to_guest(vm, iteration); 460 host_quit = false; 461 host_dirty_count = 0; 462 host_clear_count = 0; 463 host_track_next_count = 0; 464 465 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); 466 467 while (iteration < iterations) { 468 /* Give the vcpu thread some time to dirty some pages */ 469 usleep(interval * 1000); 470 log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX, 471 bmap, host_num_pages); 472 vm_dirty_log_verify(mode, bmap); 473 iteration++; 474 sync_global_to_guest(vm, iteration); 475 } 476 477 /* Tell the vcpu thread to quit */ 478 host_quit = true; 479 pthread_join(vcpu_thread, NULL); 480 481 pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 482 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 483 host_track_next_count); 484 485 free(bmap); 486 free(host_bmap_track); 487 ucall_uninit(vm); 488 kvm_vm_free(vm); 489 } 490 491 struct guest_mode { 492 bool supported; 493 bool enabled; 494 }; 495 static struct guest_mode guest_modes[NUM_VM_MODES]; 496 497 #define guest_mode_init(mode, supported, enabled) ({ \ 498 guest_modes[mode] = (struct guest_mode){ supported, enabled }; \ 499 }) 500 501 static void help(char *name) 502 { 503 int i; 504 505 puts(""); 506 printf("usage: %s [-h] [-i iterations] [-I interval] " 507 "[-p offset] [-m mode]\n", name); 508 puts(""); 509 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 510 TEST_HOST_LOOP_N); 511 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 512 TEST_HOST_LOOP_INTERVAL); 513 printf(" -p: specify guest physical test memory offset\n" 514 " Warning: a low offset can conflict with the loaded test code.\n"); 515 printf(" -M: specify the host logging mode " 516 "(default: run all log modes). Supported modes: \n\t"); 517 log_modes_dump(); 518 printf(" -m: specify the guest mode ID to test " 519 "(default: test all supported modes)\n" 520 " This option may be used multiple times.\n" 521 " Guest mode IDs:\n"); 522 for (i = 0; i < NUM_VM_MODES; ++i) { 523 printf(" %d: %s%s\n", i, vm_guest_mode_string(i), 524 guest_modes[i].supported ? " (supported)" : ""); 525 } 526 puts(""); 527 exit(0); 528 } 529 530 int main(int argc, char *argv[]) 531 { 532 unsigned long iterations = TEST_HOST_LOOP_N; 533 unsigned long interval = TEST_HOST_LOOP_INTERVAL; 534 bool mode_selected = false; 535 uint64_t phys_offset = 0; 536 unsigned int mode; 537 int opt, i, j; 538 539 #ifdef __x86_64__ 540 guest_mode_init(VM_MODE_PXXV48_4K, true, true); 541 #endif 542 #ifdef __aarch64__ 543 guest_mode_init(VM_MODE_P40V48_4K, true, true); 544 guest_mode_init(VM_MODE_P40V48_64K, true, true); 545 546 { 547 unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); 548 549 if (limit >= 52) 550 guest_mode_init(VM_MODE_P52V48_64K, true, true); 551 if (limit >= 48) { 552 guest_mode_init(VM_MODE_P48V48_4K, true, true); 553 guest_mode_init(VM_MODE_P48V48_64K, true, true); 554 } 555 } 556 #endif 557 #ifdef __s390x__ 558 guest_mode_init(VM_MODE_P40V48_4K, true, true); 559 #endif 560 561 while ((opt = getopt(argc, argv, "hi:I:p:m:M:")) != -1) { 562 switch (opt) { 563 case 'i': 564 iterations = strtol(optarg, NULL, 10); 565 break; 566 case 'I': 567 interval = strtol(optarg, NULL, 10); 568 break; 569 case 'p': 570 phys_offset = strtoull(optarg, NULL, 0); 571 break; 572 case 'm': 573 if (!mode_selected) { 574 for (i = 0; i < NUM_VM_MODES; ++i) 575 guest_modes[i].enabled = false; 576 mode_selected = true; 577 } 578 mode = strtoul(optarg, NULL, 10); 579 TEST_ASSERT(mode < NUM_VM_MODES, 580 "Guest mode ID %d too big", mode); 581 guest_modes[mode].enabled = true; 582 break; 583 case 'M': 584 if (!strcmp(optarg, "all")) { 585 host_log_mode_option = LOG_MODE_ALL; 586 break; 587 } 588 for (i = 0; i < LOG_MODE_NUM; i++) { 589 if (!strcmp(optarg, log_modes[i].name)) { 590 pr_info("Setting log mode to: '%s'\n", 591 optarg); 592 host_log_mode_option = i; 593 break; 594 } 595 } 596 if (i == LOG_MODE_NUM) { 597 printf("Log mode '%s' invalid. Please choose " 598 "from: ", optarg); 599 log_modes_dump(); 600 exit(1); 601 } 602 break; 603 case 'h': 604 default: 605 help(argv[0]); 606 break; 607 } 608 } 609 610 TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); 611 TEST_ASSERT(interval > 0, "Interval must be greater than zero"); 612 613 pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 614 iterations, interval); 615 616 srandom(time(0)); 617 618 for (i = 0; i < NUM_VM_MODES; ++i) { 619 if (!guest_modes[i].enabled) 620 continue; 621 TEST_ASSERT(guest_modes[i].supported, 622 "Guest mode ID %d (%s) not supported.", 623 i, vm_guest_mode_string(i)); 624 if (host_log_mode_option == LOG_MODE_ALL) { 625 /* Run each log mode */ 626 for (j = 0; j < LOG_MODE_NUM; j++) { 627 pr_info("Testing Log Mode '%s'\n", 628 log_modes[j].name); 629 host_log_mode = j; 630 run_test(i, iterations, interval, phys_offset); 631 } 632 } else { 633 host_log_mode = host_log_mode_option; 634 run_test(i, iterations, interval, phys_offset); 635 } 636 } 637 638 return 0; 639 } 640