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 DEBUG printf 23 24 #define VCPU_ID 1 25 26 /* The memory slot index to track dirty pages */ 27 #define TEST_MEM_SLOT_INDEX 1 28 29 /* Default guest test virtual memory offset */ 30 #define DEFAULT_GUEST_TEST_MEM 0xc0000000 31 32 /* How many pages to dirty for each guest loop */ 33 #define TEST_PAGES_PER_LOOP 1024 34 35 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */ 36 #define TEST_HOST_LOOP_N 32UL 37 38 /* Interval for each host loop (ms) */ 39 #define TEST_HOST_LOOP_INTERVAL 10UL 40 41 /* Dirty bitmaps are always little endian, so we need to swap on big endian */ 42 #if defined(__s390x__) 43 # define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) 44 # define test_bit_le(nr, addr) \ 45 test_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 46 # define set_bit_le(nr, addr) \ 47 set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 48 # define clear_bit_le(nr, addr) \ 49 clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 50 # define test_and_set_bit_le(nr, addr) \ 51 test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 52 # define test_and_clear_bit_le(nr, addr) \ 53 test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 54 #else 55 # define test_bit_le test_bit 56 # define set_bit_le set_bit 57 # define clear_bit_le clear_bit 58 # define test_and_set_bit_le test_and_set_bit 59 # define test_and_clear_bit_le test_and_clear_bit 60 #endif 61 62 /* 63 * Guest/Host shared variables. Ensure addr_gva2hva() and/or 64 * sync_global_to/from_guest() are used when accessing from 65 * the host. READ/WRITE_ONCE() should also be used with anything 66 * that may change. 67 */ 68 static uint64_t host_page_size; 69 static uint64_t guest_page_size; 70 static uint64_t guest_num_pages; 71 static uint64_t random_array[TEST_PAGES_PER_LOOP]; 72 static uint64_t iteration; 73 74 /* 75 * Guest physical memory offset of the testing memory slot. 76 * This will be set to the topmost valid physical address minus 77 * the test memory size. 78 */ 79 static uint64_t guest_test_phys_mem; 80 81 /* 82 * Guest virtual memory offset of the testing memory slot. 83 * Must not conflict with identity mapped test code. 84 */ 85 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; 86 87 /* 88 * Continuously write to the first 8 bytes of a random pages within 89 * the testing memory region. 90 */ 91 static void guest_code(void) 92 { 93 uint64_t addr; 94 int i; 95 96 /* 97 * On s390x, all pages of a 1M segment are initially marked as dirty 98 * when a page of the segment is written to for the very first time. 99 * To compensate this specialty in this test, we need to touch all 100 * pages during the first iteration. 101 */ 102 for (i = 0; i < guest_num_pages; i++) { 103 addr = guest_test_virt_mem + i * guest_page_size; 104 *(uint64_t *)addr = READ_ONCE(iteration); 105 } 106 107 while (true) { 108 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { 109 addr = guest_test_virt_mem; 110 addr += (READ_ONCE(random_array[i]) % guest_num_pages) 111 * guest_page_size; 112 addr &= ~(host_page_size - 1); 113 *(uint64_t *)addr = READ_ONCE(iteration); 114 } 115 116 /* Tell the host that we need more random numbers */ 117 GUEST_SYNC(1); 118 } 119 } 120 121 /* Host variables */ 122 static bool host_quit; 123 124 /* Points to the test VM memory region on which we track dirty logs */ 125 static void *host_test_mem; 126 static uint64_t host_num_pages; 127 128 /* For statistics only */ 129 static uint64_t host_dirty_count; 130 static uint64_t host_clear_count; 131 static uint64_t host_track_next_count; 132 133 /* 134 * We use this bitmap to track some pages that should have its dirty 135 * bit set in the _next_ iteration. For example, if we detected the 136 * page value changed to current iteration but at the same time the 137 * page bit is cleared in the latest bitmap, then the system must 138 * report that write in the next get dirty log call. 139 */ 140 static unsigned long *host_bmap_track; 141 142 static void generate_random_array(uint64_t *guest_array, uint64_t size) 143 { 144 uint64_t i; 145 146 for (i = 0; i < size; i++) 147 guest_array[i] = random(); 148 } 149 150 static void *vcpu_worker(void *data) 151 { 152 int ret; 153 struct kvm_vm *vm = data; 154 uint64_t *guest_array; 155 uint64_t pages_count = 0; 156 struct kvm_run *run; 157 158 run = vcpu_state(vm, VCPU_ID); 159 160 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 161 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 162 163 while (!READ_ONCE(host_quit)) { 164 /* Let the guest dirty the random pages */ 165 ret = _vcpu_run(vm, VCPU_ID); 166 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 167 if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) { 168 pages_count += TEST_PAGES_PER_LOOP; 169 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 170 } else { 171 TEST_ASSERT(false, 172 "Invalid guest sync status: " 173 "exit_reason=%s\n", 174 exit_reason_str(run->exit_reason)); 175 } 176 } 177 178 DEBUG("Dirtied %"PRIu64" pages\n", pages_count); 179 180 return NULL; 181 } 182 183 static void vm_dirty_log_verify(unsigned long *bmap) 184 { 185 uint64_t page; 186 uint64_t *value_ptr; 187 uint64_t step = host_page_size >= guest_page_size ? 1 : 188 guest_page_size / host_page_size; 189 190 for (page = 0; page < host_num_pages; page += step) { 191 value_ptr = host_test_mem + page * host_page_size; 192 193 /* If this is a special page that we were tracking... */ 194 if (test_and_clear_bit_le(page, host_bmap_track)) { 195 host_track_next_count++; 196 TEST_ASSERT(test_bit_le(page, bmap), 197 "Page %"PRIu64" should have its dirty bit " 198 "set in this iteration but it is missing", 199 page); 200 } 201 202 if (test_bit_le(page, bmap)) { 203 host_dirty_count++; 204 /* 205 * If the bit is set, the value written onto 206 * the corresponding page should be either the 207 * previous iteration number or the current one. 208 */ 209 TEST_ASSERT(*value_ptr == iteration || 210 *value_ptr == iteration - 1, 211 "Set page %"PRIu64" value %"PRIu64 212 " incorrect (iteration=%"PRIu64")", 213 page, *value_ptr, iteration); 214 } else { 215 host_clear_count++; 216 /* 217 * If cleared, the value written can be any 218 * value smaller or equals to the iteration 219 * number. Note that the value can be exactly 220 * (iteration-1) if that write can happen 221 * like this: 222 * 223 * (1) increase loop count to "iteration-1" 224 * (2) write to page P happens (with value 225 * "iteration-1") 226 * (3) get dirty log for "iteration-1"; we'll 227 * see that page P bit is set (dirtied), 228 * and not set the bit in host_bmap_track 229 * (4) increase loop count to "iteration" 230 * (which is current iteration) 231 * (5) get dirty log for current iteration, 232 * we'll see that page P is cleared, with 233 * value "iteration-1". 234 */ 235 TEST_ASSERT(*value_ptr <= iteration, 236 "Clear page %"PRIu64" value %"PRIu64 237 " incorrect (iteration=%"PRIu64")", 238 page, *value_ptr, iteration); 239 if (*value_ptr == iteration) { 240 /* 241 * This page is _just_ modified; it 242 * should report its dirtyness in the 243 * next run 244 */ 245 set_bit_le(page, host_bmap_track); 246 } 247 } 248 } 249 } 250 251 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 252 uint64_t extra_mem_pages, void *guest_code, 253 unsigned long type) 254 { 255 struct kvm_vm *vm; 256 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; 257 258 vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, 259 O_RDWR, type); 260 kvm_vm_elf_load(vm, program_invocation_name, 0, 0); 261 #ifdef __x86_64__ 262 vm_create_irqchip(vm); 263 #endif 264 vm_vcpu_add_default(vm, vcpuid, guest_code); 265 return vm; 266 } 267 268 static void run_test(enum vm_guest_mode mode, unsigned long iterations, 269 unsigned long interval, uint64_t phys_offset) 270 { 271 unsigned int guest_pa_bits, guest_page_shift; 272 pthread_t vcpu_thread; 273 struct kvm_vm *vm; 274 uint64_t max_gfn; 275 unsigned long *bmap; 276 unsigned long type = 0; 277 278 switch (mode) { 279 case VM_MODE_P52V48_4K: 280 guest_pa_bits = 52; 281 guest_page_shift = 12; 282 break; 283 case VM_MODE_P52V48_64K: 284 guest_pa_bits = 52; 285 guest_page_shift = 16; 286 break; 287 case VM_MODE_P48V48_4K: 288 guest_pa_bits = 48; 289 guest_page_shift = 12; 290 break; 291 case VM_MODE_P48V48_64K: 292 guest_pa_bits = 48; 293 guest_page_shift = 16; 294 break; 295 case VM_MODE_P40V48_4K: 296 guest_pa_bits = 40; 297 guest_page_shift = 12; 298 break; 299 case VM_MODE_P40V48_64K: 300 guest_pa_bits = 40; 301 guest_page_shift = 16; 302 break; 303 default: 304 TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode); 305 } 306 307 DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 308 309 #ifdef __x86_64__ 310 /* 311 * FIXME 312 * The x86_64 kvm selftests framework currently only supports a 313 * single PML4 which restricts the number of physical address 314 * bits we can change to 39. 315 */ 316 guest_pa_bits = 39; 317 #endif 318 #ifdef __aarch64__ 319 if (guest_pa_bits != 40) 320 type = KVM_VM_TYPE_ARM_IPA_SIZE(guest_pa_bits); 321 #endif 322 max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1; 323 guest_page_size = (1ul << guest_page_shift); 324 /* 325 * A little more than 1G of guest page sized pages. Cover the 326 * case where the size is not aligned to 64 pages. 327 */ 328 guest_num_pages = (1ul << (30 - guest_page_shift)) + 16; 329 #ifdef __s390x__ 330 /* Round up to multiple of 1M (segment size) */ 331 guest_num_pages = (guest_num_pages + 0xff) & ~0xffUL; 332 #endif 333 host_page_size = getpagesize(); 334 host_num_pages = (guest_num_pages * guest_page_size) / host_page_size + 335 !!((guest_num_pages * guest_page_size) % host_page_size); 336 337 if (!phys_offset) { 338 guest_test_phys_mem = (max_gfn - guest_num_pages) * guest_page_size; 339 guest_test_phys_mem &= ~(host_page_size - 1); 340 } else { 341 guest_test_phys_mem = phys_offset; 342 } 343 344 #ifdef __s390x__ 345 /* Align to 1M (segment size) */ 346 guest_test_phys_mem &= ~((1 << 20) - 1); 347 #endif 348 349 DEBUG("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 350 351 bmap = bitmap_alloc(host_num_pages); 352 host_bmap_track = bitmap_alloc(host_num_pages); 353 354 vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code, type); 355 356 #ifdef USE_CLEAR_DIRTY_LOG 357 struct kvm_enable_cap cap = {}; 358 359 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 360 cap.args[0] = 1; 361 vm_enable_cap(vm, &cap); 362 #endif 363 364 /* Add an extra memory slot for testing dirty logging */ 365 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 366 guest_test_phys_mem, 367 TEST_MEM_SLOT_INDEX, 368 guest_num_pages, 369 KVM_MEM_LOG_DIRTY_PAGES); 370 371 /* Do mapping for the dirty track memory slot */ 372 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, 373 guest_num_pages * guest_page_size, 0); 374 375 /* Cache the HVA pointer of the region */ 376 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 377 378 #ifdef __x86_64__ 379 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); 380 #endif 381 #ifdef __aarch64__ 382 ucall_init(vm, NULL); 383 #endif 384 385 /* Export the shared variables to the guest */ 386 sync_global_to_guest(vm, host_page_size); 387 sync_global_to_guest(vm, guest_page_size); 388 sync_global_to_guest(vm, guest_test_virt_mem); 389 sync_global_to_guest(vm, guest_num_pages); 390 391 /* Start the iterations */ 392 iteration = 1; 393 sync_global_to_guest(vm, iteration); 394 host_quit = false; 395 host_dirty_count = 0; 396 host_clear_count = 0; 397 host_track_next_count = 0; 398 399 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); 400 401 while (iteration < iterations) { 402 /* Give the vcpu thread some time to dirty some pages */ 403 usleep(interval * 1000); 404 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); 405 #ifdef USE_CLEAR_DIRTY_LOG 406 kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0, 407 host_num_pages); 408 #endif 409 vm_dirty_log_verify(bmap); 410 iteration++; 411 sync_global_to_guest(vm, iteration); 412 } 413 414 /* Tell the vcpu thread to quit */ 415 host_quit = true; 416 pthread_join(vcpu_thread, NULL); 417 418 DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 419 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 420 host_track_next_count); 421 422 free(bmap); 423 free(host_bmap_track); 424 ucall_uninit(vm); 425 kvm_vm_free(vm); 426 } 427 428 struct vm_guest_mode_params { 429 bool supported; 430 bool enabled; 431 }; 432 struct vm_guest_mode_params vm_guest_mode_params[NUM_VM_MODES]; 433 434 #define vm_guest_mode_params_init(mode, supported, enabled) \ 435 ({ \ 436 vm_guest_mode_params[mode] = (struct vm_guest_mode_params){ supported, enabled }; \ 437 }) 438 439 static void help(char *name) 440 { 441 int i; 442 443 puts(""); 444 printf("usage: %s [-h] [-i iterations] [-I interval] " 445 "[-p offset] [-m mode]\n", name); 446 puts(""); 447 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 448 TEST_HOST_LOOP_N); 449 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 450 TEST_HOST_LOOP_INTERVAL); 451 printf(" -p: specify guest physical test memory offset\n" 452 " Warning: a low offset can conflict with the loaded test code.\n"); 453 printf(" -m: specify the guest mode ID to test " 454 "(default: test all supported modes)\n" 455 " This option may be used multiple times.\n" 456 " Guest mode IDs:\n"); 457 for (i = 0; i < NUM_VM_MODES; ++i) { 458 printf(" %d: %s%s\n", i, vm_guest_mode_string(i), 459 vm_guest_mode_params[i].supported ? " (supported)" : ""); 460 } 461 puts(""); 462 exit(0); 463 } 464 465 int main(int argc, char *argv[]) 466 { 467 unsigned long iterations = TEST_HOST_LOOP_N; 468 unsigned long interval = TEST_HOST_LOOP_INTERVAL; 469 bool mode_selected = false; 470 uint64_t phys_offset = 0; 471 unsigned int mode; 472 int opt, i; 473 #ifdef __aarch64__ 474 unsigned int host_ipa_limit; 475 #endif 476 477 #ifdef USE_CLEAR_DIRTY_LOG 478 if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) { 479 fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n"); 480 exit(KSFT_SKIP); 481 } 482 #endif 483 484 #ifdef __x86_64__ 485 vm_guest_mode_params_init(VM_MODE_P52V48_4K, true, true); 486 #endif 487 #ifdef __aarch64__ 488 vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); 489 vm_guest_mode_params_init(VM_MODE_P40V48_64K, true, true); 490 491 host_ipa_limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); 492 if (host_ipa_limit >= 52) 493 vm_guest_mode_params_init(VM_MODE_P52V48_64K, true, true); 494 if (host_ipa_limit >= 48) { 495 vm_guest_mode_params_init(VM_MODE_P48V48_4K, true, true); 496 vm_guest_mode_params_init(VM_MODE_P48V48_64K, true, true); 497 } 498 #endif 499 #ifdef __s390x__ 500 vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); 501 #endif 502 503 while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) { 504 switch (opt) { 505 case 'i': 506 iterations = strtol(optarg, NULL, 10); 507 break; 508 case 'I': 509 interval = strtol(optarg, NULL, 10); 510 break; 511 case 'p': 512 phys_offset = strtoull(optarg, NULL, 0); 513 break; 514 case 'm': 515 if (!mode_selected) { 516 for (i = 0; i < NUM_VM_MODES; ++i) 517 vm_guest_mode_params[i].enabled = false; 518 mode_selected = true; 519 } 520 mode = strtoul(optarg, NULL, 10); 521 TEST_ASSERT(mode < NUM_VM_MODES, 522 "Guest mode ID %d too big", mode); 523 vm_guest_mode_params[mode].enabled = true; 524 break; 525 case 'h': 526 default: 527 help(argv[0]); 528 break; 529 } 530 } 531 532 TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); 533 TEST_ASSERT(interval > 0, "Interval must be greater than zero"); 534 535 DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 536 iterations, interval); 537 538 srandom(time(0)); 539 540 for (i = 0; i < NUM_VM_MODES; ++i) { 541 if (!vm_guest_mode_params[i].enabled) 542 continue; 543 TEST_ASSERT(vm_guest_mode_params[i].supported, 544 "Guest mode ID %d (%s) not supported.", 545 i, vm_guest_mode_string(i)); 546 run_test(i, iterations, interval, phys_offset); 547 } 548 549 return 0; 550 } 551