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