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 memory offset, 1G */ 30 #define DEFAULT_GUEST_TEST_MEM 0x40000000 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 /* 42 * Guest/Host shared variables. Ensure addr_gva2hva() and/or 43 * sync_global_to/from_guest() are used when accessing from 44 * the host. READ/WRITE_ONCE() should also be used with anything 45 * that may change. 46 */ 47 static uint64_t host_page_size; 48 static uint64_t guest_page_size; 49 static uint64_t guest_num_pages; 50 static uint64_t random_array[TEST_PAGES_PER_LOOP]; 51 static uint64_t iteration; 52 53 /* 54 * Guest physical memory offset of the testing memory slot. 55 * This will be set to the topmost valid physical address minus 56 * the test memory size. 57 */ 58 static uint64_t guest_test_phys_mem; 59 60 /* 61 * Guest virtual memory offset of the testing memory slot. 62 * Must not conflict with identity mapped test code. 63 */ 64 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; 65 66 /* 67 * Continuously write to the first 8 bytes of a random pages within 68 * the testing memory region. 69 */ 70 static void guest_code(void) 71 { 72 int i; 73 74 while (true) { 75 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { 76 uint64_t addr = guest_test_virt_mem; 77 addr += (READ_ONCE(random_array[i]) % guest_num_pages) 78 * guest_page_size; 79 addr &= ~(host_page_size - 1); 80 *(uint64_t *)addr = READ_ONCE(iteration); 81 } 82 83 /* Tell the host that we need more random numbers */ 84 GUEST_SYNC(1); 85 } 86 } 87 88 /* Host variables */ 89 static bool host_quit; 90 91 /* Points to the test VM memory region on which we track dirty logs */ 92 static void *host_test_mem; 93 static uint64_t host_num_pages; 94 95 /* For statistics only */ 96 static uint64_t host_dirty_count; 97 static uint64_t host_clear_count; 98 static uint64_t host_track_next_count; 99 100 /* 101 * We use this bitmap to track some pages that should have its dirty 102 * bit set in the _next_ iteration. For example, if we detected the 103 * page value changed to current iteration but at the same time the 104 * page bit is cleared in the latest bitmap, then the system must 105 * report that write in the next get dirty log call. 106 */ 107 static unsigned long *host_bmap_track; 108 109 static void generate_random_array(uint64_t *guest_array, uint64_t size) 110 { 111 uint64_t i; 112 113 for (i = 0; i < size; i++) 114 guest_array[i] = random(); 115 } 116 117 static void *vcpu_worker(void *data) 118 { 119 int ret; 120 struct kvm_vm *vm = data; 121 uint64_t *guest_array; 122 uint64_t pages_count = 0; 123 struct kvm_run *run; 124 struct ucall uc; 125 126 run = vcpu_state(vm, VCPU_ID); 127 128 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 129 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 130 131 while (!READ_ONCE(host_quit)) { 132 /* Let the guest dirty the random pages */ 133 ret = _vcpu_run(vm, VCPU_ID); 134 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 135 if (get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) { 136 pages_count += TEST_PAGES_PER_LOOP; 137 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 138 } else { 139 TEST_ASSERT(false, 140 "Invalid guest sync status: " 141 "exit_reason=%s\n", 142 exit_reason_str(run->exit_reason)); 143 } 144 } 145 146 DEBUG("Dirtied %"PRIu64" pages\n", pages_count); 147 148 return NULL; 149 } 150 151 static void vm_dirty_log_verify(unsigned long *bmap) 152 { 153 uint64_t page; 154 uint64_t *value_ptr; 155 uint64_t step = host_page_size >= guest_page_size ? 1 : 156 guest_page_size / host_page_size; 157 158 for (page = 0; page < host_num_pages; page += step) { 159 value_ptr = host_test_mem + page * host_page_size; 160 161 /* If this is a special page that we were tracking... */ 162 if (test_and_clear_bit(page, host_bmap_track)) { 163 host_track_next_count++; 164 TEST_ASSERT(test_bit(page, bmap), 165 "Page %"PRIu64" should have its dirty bit " 166 "set in this iteration but it is missing", 167 page); 168 } 169 170 if (test_bit(page, bmap)) { 171 host_dirty_count++; 172 /* 173 * If the bit is set, the value written onto 174 * the corresponding page should be either the 175 * previous iteration number or the current one. 176 */ 177 TEST_ASSERT(*value_ptr == iteration || 178 *value_ptr == iteration - 1, 179 "Set page %"PRIu64" value %"PRIu64 180 " incorrect (iteration=%"PRIu64")", 181 page, *value_ptr, iteration); 182 } else { 183 host_clear_count++; 184 /* 185 * If cleared, the value written can be any 186 * value smaller or equals to the iteration 187 * number. Note that the value can be exactly 188 * (iteration-1) if that write can happen 189 * like this: 190 * 191 * (1) increase loop count to "iteration-1" 192 * (2) write to page P happens (with value 193 * "iteration-1") 194 * (3) get dirty log for "iteration-1"; we'll 195 * see that page P bit is set (dirtied), 196 * and not set the bit in host_bmap_track 197 * (4) increase loop count to "iteration" 198 * (which is current iteration) 199 * (5) get dirty log for current iteration, 200 * we'll see that page P is cleared, with 201 * value "iteration-1". 202 */ 203 TEST_ASSERT(*value_ptr <= iteration, 204 "Clear page %"PRIu64" value %"PRIu64 205 " incorrect (iteration=%"PRIu64")", 206 page, *value_ptr, iteration); 207 if (*value_ptr == iteration) { 208 /* 209 * This page is _just_ modified; it 210 * should report its dirtyness in the 211 * next run 212 */ 213 set_bit(page, host_bmap_track); 214 } 215 } 216 } 217 } 218 219 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 220 uint64_t extra_mem_pages, void *guest_code, 221 unsigned long type) 222 { 223 struct kvm_vm *vm; 224 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; 225 226 vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, 227 O_RDWR, type); 228 kvm_vm_elf_load(vm, program_invocation_name, 0, 0); 229 #ifdef __x86_64__ 230 vm_create_irqchip(vm); 231 #endif 232 vm_vcpu_add_default(vm, vcpuid, guest_code); 233 return vm; 234 } 235 236 static void run_test(enum vm_guest_mode mode, unsigned long iterations, 237 unsigned long interval, uint64_t phys_offset) 238 { 239 unsigned int guest_pa_bits, guest_page_shift; 240 pthread_t vcpu_thread; 241 struct kvm_vm *vm; 242 uint64_t max_gfn; 243 unsigned long *bmap; 244 unsigned long type = 0; 245 246 switch (mode) { 247 case VM_MODE_P52V48_4K: 248 guest_pa_bits = 52; 249 guest_page_shift = 12; 250 break; 251 case VM_MODE_P52V48_64K: 252 guest_pa_bits = 52; 253 guest_page_shift = 16; 254 break; 255 case VM_MODE_P48V48_4K: 256 guest_pa_bits = 48; 257 guest_page_shift = 12; 258 break; 259 case VM_MODE_P48V48_64K: 260 guest_pa_bits = 48; 261 guest_page_shift = 16; 262 break; 263 case VM_MODE_P40V48_4K: 264 guest_pa_bits = 40; 265 guest_page_shift = 12; 266 break; 267 case VM_MODE_P40V48_64K: 268 guest_pa_bits = 40; 269 guest_page_shift = 16; 270 break; 271 default: 272 TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode); 273 } 274 275 DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 276 277 #ifdef __x86_64__ 278 /* 279 * FIXME 280 * The x86_64 kvm selftests framework currently only supports a 281 * single PML4 which restricts the number of physical address 282 * bits we can change to 39. 283 */ 284 guest_pa_bits = 39; 285 #endif 286 #ifdef __aarch64__ 287 if (guest_pa_bits != 40) 288 type = KVM_VM_TYPE_ARM_IPA_SIZE(guest_pa_bits); 289 #endif 290 max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1; 291 guest_page_size = (1ul << guest_page_shift); 292 /* 293 * A little more than 1G of guest page sized pages. Cover the 294 * case where the size is not aligned to 64 pages. 295 */ 296 guest_num_pages = (1ul << (30 - guest_page_shift)) + 16; 297 host_page_size = getpagesize(); 298 host_num_pages = (guest_num_pages * guest_page_size) / host_page_size + 299 !!((guest_num_pages * guest_page_size) % host_page_size); 300 301 if (!phys_offset) { 302 guest_test_phys_mem = (max_gfn - guest_num_pages) * guest_page_size; 303 guest_test_phys_mem &= ~(host_page_size - 1); 304 } else { 305 guest_test_phys_mem = phys_offset; 306 } 307 308 DEBUG("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 309 310 bmap = bitmap_alloc(host_num_pages); 311 host_bmap_track = bitmap_alloc(host_num_pages); 312 313 vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code, type); 314 315 #ifdef USE_CLEAR_DIRTY_LOG 316 struct kvm_enable_cap cap = {}; 317 318 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 319 cap.args[0] = 1; 320 vm_enable_cap(vm, &cap); 321 #endif 322 323 /* Add an extra memory slot for testing dirty logging */ 324 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 325 guest_test_phys_mem, 326 TEST_MEM_SLOT_INDEX, 327 guest_num_pages, 328 KVM_MEM_LOG_DIRTY_PAGES); 329 330 /* Do mapping for the dirty track memory slot */ 331 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, 332 guest_num_pages * guest_page_size, 0); 333 334 /* Cache the HVA pointer of the region */ 335 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 336 337 #ifdef __x86_64__ 338 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); 339 #endif 340 #ifdef __aarch64__ 341 ucall_init(vm, UCALL_MMIO, NULL); 342 #endif 343 344 /* Export the shared variables to the guest */ 345 sync_global_to_guest(vm, host_page_size); 346 sync_global_to_guest(vm, guest_page_size); 347 sync_global_to_guest(vm, guest_test_virt_mem); 348 sync_global_to_guest(vm, guest_num_pages); 349 350 /* Start the iterations */ 351 iteration = 1; 352 sync_global_to_guest(vm, iteration); 353 host_quit = false; 354 host_dirty_count = 0; 355 host_clear_count = 0; 356 host_track_next_count = 0; 357 358 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); 359 360 while (iteration < iterations) { 361 /* Give the vcpu thread some time to dirty some pages */ 362 usleep(interval * 1000); 363 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); 364 #ifdef USE_CLEAR_DIRTY_LOG 365 kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0, 366 host_num_pages); 367 #endif 368 vm_dirty_log_verify(bmap); 369 iteration++; 370 sync_global_to_guest(vm, iteration); 371 } 372 373 /* Tell the vcpu thread to quit */ 374 host_quit = true; 375 pthread_join(vcpu_thread, NULL); 376 377 DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 378 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 379 host_track_next_count); 380 381 free(bmap); 382 free(host_bmap_track); 383 ucall_uninit(vm); 384 kvm_vm_free(vm); 385 } 386 387 struct vm_guest_mode_params { 388 bool supported; 389 bool enabled; 390 }; 391 struct vm_guest_mode_params vm_guest_mode_params[NUM_VM_MODES]; 392 393 #define vm_guest_mode_params_init(mode, supported, enabled) \ 394 ({ \ 395 vm_guest_mode_params[mode] = (struct vm_guest_mode_params){ supported, enabled }; \ 396 }) 397 398 static void help(char *name) 399 { 400 int i; 401 402 puts(""); 403 printf("usage: %s [-h] [-i iterations] [-I interval] " 404 "[-p offset] [-m mode]\n", name); 405 puts(""); 406 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 407 TEST_HOST_LOOP_N); 408 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 409 TEST_HOST_LOOP_INTERVAL); 410 printf(" -p: specify guest physical test memory offset\n" 411 " Warning: a low offset can conflict with the loaded test code.\n"); 412 printf(" -m: specify the guest mode ID to test " 413 "(default: test all supported modes)\n" 414 " This option may be used multiple times.\n" 415 " Guest mode IDs:\n"); 416 for (i = 0; i < NUM_VM_MODES; ++i) { 417 printf(" %d: %s%s\n", i, vm_guest_mode_string(i), 418 vm_guest_mode_params[i].supported ? " (supported)" : ""); 419 } 420 puts(""); 421 exit(0); 422 } 423 424 int main(int argc, char *argv[]) 425 { 426 unsigned long iterations = TEST_HOST_LOOP_N; 427 unsigned long interval = TEST_HOST_LOOP_INTERVAL; 428 bool mode_selected = false; 429 uint64_t phys_offset = 0; 430 unsigned int mode; 431 int opt, i; 432 #ifdef __aarch64__ 433 unsigned int host_ipa_limit; 434 #endif 435 436 #ifdef USE_CLEAR_DIRTY_LOG 437 if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) { 438 fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n"); 439 exit(KSFT_SKIP); 440 } 441 #endif 442 443 #ifdef __x86_64__ 444 vm_guest_mode_params_init(VM_MODE_P52V48_4K, true, true); 445 #endif 446 #ifdef __aarch64__ 447 vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); 448 vm_guest_mode_params_init(VM_MODE_P40V48_64K, true, true); 449 450 host_ipa_limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); 451 if (host_ipa_limit >= 52) 452 vm_guest_mode_params_init(VM_MODE_P52V48_64K, true, true); 453 if (host_ipa_limit >= 48) { 454 vm_guest_mode_params_init(VM_MODE_P48V48_4K, true, true); 455 vm_guest_mode_params_init(VM_MODE_P48V48_64K, true, true); 456 } 457 #endif 458 459 while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) { 460 switch (opt) { 461 case 'i': 462 iterations = strtol(optarg, NULL, 10); 463 break; 464 case 'I': 465 interval = strtol(optarg, NULL, 10); 466 break; 467 case 'p': 468 phys_offset = strtoull(optarg, NULL, 0); 469 break; 470 case 'm': 471 if (!mode_selected) { 472 for (i = 0; i < NUM_VM_MODES; ++i) 473 vm_guest_mode_params[i].enabled = false; 474 mode_selected = true; 475 } 476 mode = strtoul(optarg, NULL, 10); 477 TEST_ASSERT(mode < NUM_VM_MODES, 478 "Guest mode ID %d too big", mode); 479 vm_guest_mode_params[mode].enabled = true; 480 break; 481 case 'h': 482 default: 483 help(argv[0]); 484 break; 485 } 486 } 487 488 TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); 489 TEST_ASSERT(interval > 0, "Interval must be greater than zero"); 490 491 DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 492 iterations, interval); 493 494 srandom(time(0)); 495 496 for (i = 0; i < NUM_VM_MODES; ++i) { 497 if (!vm_guest_mode_params[i].enabled) 498 continue; 499 TEST_ASSERT(vm_guest_mode_params[i].supported, 500 "Guest mode ID %d (%s) not supported.", 501 i, vm_guest_mode_string(i)); 502 run_test(i, iterations, interval, phys_offset); 503 } 504 505 return 0; 506 } 507