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 /* 132 * We use this bitmap to track some pages that should have its dirty 133 * bit set in the _next_ iteration. For example, if we detected the 134 * page value changed to current iteration but at the same time the 135 * page bit is cleared in the latest bitmap, then the system must 136 * report that write in the next get dirty log call. 137 */ 138 static unsigned long *host_bmap_track; 139 140 static void generate_random_array(uint64_t *guest_array, uint64_t size) 141 { 142 uint64_t i; 143 144 for (i = 0; i < size; i++) 145 guest_array[i] = random(); 146 } 147 148 static void *vcpu_worker(void *data) 149 { 150 int ret; 151 struct kvm_vm *vm = data; 152 uint64_t *guest_array; 153 uint64_t pages_count = 0; 154 struct kvm_run *run; 155 156 run = vcpu_state(vm, VCPU_ID); 157 158 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 159 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 160 161 while (!READ_ONCE(host_quit)) { 162 /* Let the guest dirty the random pages */ 163 ret = _vcpu_run(vm, VCPU_ID); 164 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret); 165 if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) { 166 pages_count += TEST_PAGES_PER_LOOP; 167 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 168 } else { 169 TEST_ASSERT(false, 170 "Invalid guest sync status: " 171 "exit_reason=%s\n", 172 exit_reason_str(run->exit_reason)); 173 } 174 } 175 176 DEBUG("Dirtied %"PRIu64" pages\n", pages_count); 177 178 return NULL; 179 } 180 181 static void vm_dirty_log_verify(unsigned long *bmap) 182 { 183 uint64_t page; 184 uint64_t *value_ptr; 185 uint64_t step = host_page_size >= guest_page_size ? 1 : 186 guest_page_size / host_page_size; 187 188 for (page = 0; page < host_num_pages; page += step) { 189 value_ptr = host_test_mem + page * host_page_size; 190 191 /* If this is a special page that we were tracking... */ 192 if (test_and_clear_bit_le(page, host_bmap_track)) { 193 host_track_next_count++; 194 TEST_ASSERT(test_bit_le(page, bmap), 195 "Page %"PRIu64" should have its dirty bit " 196 "set in this iteration but it is missing", 197 page); 198 } 199 200 if (test_bit_le(page, bmap)) { 201 host_dirty_count++; 202 /* 203 * If the bit is set, the value written onto 204 * the corresponding page should be either the 205 * previous iteration number or the current one. 206 */ 207 TEST_ASSERT(*value_ptr == iteration || 208 *value_ptr == iteration - 1, 209 "Set page %"PRIu64" value %"PRIu64 210 " incorrect (iteration=%"PRIu64")", 211 page, *value_ptr, iteration); 212 } else { 213 host_clear_count++; 214 /* 215 * If cleared, the value written can be any 216 * value smaller or equals to the iteration 217 * number. Note that the value can be exactly 218 * (iteration-1) if that write can happen 219 * like this: 220 * 221 * (1) increase loop count to "iteration-1" 222 * (2) write to page P happens (with value 223 * "iteration-1") 224 * (3) get dirty log for "iteration-1"; we'll 225 * see that page P bit is set (dirtied), 226 * and not set the bit in host_bmap_track 227 * (4) increase loop count to "iteration" 228 * (which is current iteration) 229 * (5) get dirty log for current iteration, 230 * we'll see that page P is cleared, with 231 * value "iteration-1". 232 */ 233 TEST_ASSERT(*value_ptr <= iteration, 234 "Clear page %"PRIu64" value %"PRIu64 235 " incorrect (iteration=%"PRIu64")", 236 page, *value_ptr, iteration); 237 if (*value_ptr == iteration) { 238 /* 239 * This page is _just_ modified; it 240 * should report its dirtyness in the 241 * next run 242 */ 243 set_bit_le(page, host_bmap_track); 244 } 245 } 246 } 247 } 248 249 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 250 uint64_t extra_mem_pages, void *guest_code) 251 { 252 struct kvm_vm *vm; 253 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; 254 255 vm = _vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); 256 kvm_vm_elf_load(vm, program_invocation_name, 0, 0); 257 #ifdef __x86_64__ 258 vm_create_irqchip(vm); 259 #endif 260 vm_vcpu_add_default(vm, vcpuid, guest_code); 261 return vm; 262 } 263 264 #define DIRTY_MEM_BITS 30 /* 1G */ 265 #define PAGE_SHIFT_4K 12 266 267 static void run_test(enum vm_guest_mode mode, unsigned long iterations, 268 unsigned long interval, uint64_t phys_offset) 269 { 270 pthread_t vcpu_thread; 271 struct kvm_vm *vm; 272 unsigned long *bmap; 273 274 /* 275 * We reserve page table for 2 times of extra dirty mem which 276 * will definitely cover the original (1G+) test range. Here 277 * we do the calculation with 4K page size which is the 278 * smallest so the page number will be enough for all archs 279 * (e.g., 64K page size guest will need even less memory for 280 * page tables). 281 */ 282 vm = create_vm(mode, VCPU_ID, 283 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), 284 guest_code); 285 286 guest_page_size = vm_get_page_size(vm); 287 /* 288 * A little more than 1G of guest page sized pages. Cover the 289 * case where the size is not aligned to 64 pages. 290 */ 291 guest_num_pages = (1ul << (DIRTY_MEM_BITS - 292 vm_get_page_shift(vm))) + 16; 293 #ifdef __s390x__ 294 /* Round up to multiple of 1M (segment size) */ 295 guest_num_pages = (guest_num_pages + 0xff) & ~0xffUL; 296 #endif 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 = (vm_get_max_gfn(vm) - 303 guest_num_pages) * guest_page_size; 304 guest_test_phys_mem &= ~(host_page_size - 1); 305 } else { 306 guest_test_phys_mem = phys_offset; 307 } 308 309 #ifdef __s390x__ 310 /* Align to 1M (segment size) */ 311 guest_test_phys_mem &= ~((1 << 20) - 1); 312 #endif 313 314 DEBUG("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 315 316 bmap = bitmap_alloc(host_num_pages); 317 host_bmap_track = bitmap_alloc(host_num_pages); 318 319 #ifdef USE_CLEAR_DIRTY_LOG 320 struct kvm_enable_cap cap = {}; 321 322 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2; 323 cap.args[0] = 1; 324 vm_enable_cap(vm, &cap); 325 #endif 326 327 /* Add an extra memory slot for testing dirty logging */ 328 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 329 guest_test_phys_mem, 330 TEST_MEM_SLOT_INDEX, 331 guest_num_pages, 332 KVM_MEM_LOG_DIRTY_PAGES); 333 334 /* Do mapping for the dirty track memory slot */ 335 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, 336 guest_num_pages * guest_page_size, 0); 337 338 /* Cache the HVA pointer of the region */ 339 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 340 341 #ifdef __x86_64__ 342 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); 343 #endif 344 #ifdef __aarch64__ 345 ucall_init(vm, NULL); 346 #endif 347 348 /* Export the shared variables to the guest */ 349 sync_global_to_guest(vm, host_page_size); 350 sync_global_to_guest(vm, guest_page_size); 351 sync_global_to_guest(vm, guest_test_virt_mem); 352 sync_global_to_guest(vm, guest_num_pages); 353 354 /* Start the iterations */ 355 iteration = 1; 356 sync_global_to_guest(vm, iteration); 357 host_quit = false; 358 host_dirty_count = 0; 359 host_clear_count = 0; 360 host_track_next_count = 0; 361 362 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); 363 364 while (iteration < iterations) { 365 /* Give the vcpu thread some time to dirty some pages */ 366 usleep(interval * 1000); 367 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); 368 #ifdef USE_CLEAR_DIRTY_LOG 369 kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0, 370 host_num_pages); 371 #endif 372 vm_dirty_log_verify(bmap); 373 iteration++; 374 sync_global_to_guest(vm, iteration); 375 } 376 377 /* Tell the vcpu thread to quit */ 378 host_quit = true; 379 pthread_join(vcpu_thread, NULL); 380 381 DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 382 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 383 host_track_next_count); 384 385 free(bmap); 386 free(host_bmap_track); 387 ucall_uninit(vm); 388 kvm_vm_free(vm); 389 } 390 391 struct vm_guest_mode_params { 392 bool supported; 393 bool enabled; 394 }; 395 struct vm_guest_mode_params vm_guest_mode_params[NUM_VM_MODES]; 396 397 #define vm_guest_mode_params_init(mode, supported, enabled) \ 398 ({ \ 399 vm_guest_mode_params[mode] = (struct vm_guest_mode_params){ supported, enabled }; \ 400 }) 401 402 static void help(char *name) 403 { 404 int i; 405 406 puts(""); 407 printf("usage: %s [-h] [-i iterations] [-I interval] " 408 "[-p offset] [-m mode]\n", name); 409 puts(""); 410 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 411 TEST_HOST_LOOP_N); 412 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 413 TEST_HOST_LOOP_INTERVAL); 414 printf(" -p: specify guest physical test memory offset\n" 415 " Warning: a low offset can conflict with the loaded test code.\n"); 416 printf(" -m: specify the guest mode ID to test " 417 "(default: test all supported modes)\n" 418 " This option may be used multiple times.\n" 419 " Guest mode IDs:\n"); 420 for (i = 0; i < NUM_VM_MODES; ++i) { 421 printf(" %d: %s%s\n", i, vm_guest_mode_string(i), 422 vm_guest_mode_params[i].supported ? " (supported)" : ""); 423 } 424 puts(""); 425 exit(0); 426 } 427 428 int main(int argc, char *argv[]) 429 { 430 unsigned long iterations = TEST_HOST_LOOP_N; 431 unsigned long interval = TEST_HOST_LOOP_INTERVAL; 432 bool mode_selected = false; 433 uint64_t phys_offset = 0; 434 unsigned int mode; 435 int opt, i; 436 #ifdef __aarch64__ 437 unsigned int host_ipa_limit; 438 #endif 439 440 #ifdef USE_CLEAR_DIRTY_LOG 441 if (!kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2)) { 442 fprintf(stderr, "KVM_CLEAR_DIRTY_LOG not available, skipping tests\n"); 443 exit(KSFT_SKIP); 444 } 445 #endif 446 447 #ifdef __x86_64__ 448 vm_guest_mode_params_init(VM_MODE_PXXV48_4K, true, true); 449 #endif 450 #ifdef __aarch64__ 451 vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); 452 vm_guest_mode_params_init(VM_MODE_P40V48_64K, true, true); 453 454 host_ipa_limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE); 455 if (host_ipa_limit >= 52) 456 vm_guest_mode_params_init(VM_MODE_P52V48_64K, true, true); 457 if (host_ipa_limit >= 48) { 458 vm_guest_mode_params_init(VM_MODE_P48V48_4K, true, true); 459 vm_guest_mode_params_init(VM_MODE_P48V48_64K, true, true); 460 } 461 #endif 462 #ifdef __s390x__ 463 vm_guest_mode_params_init(VM_MODE_P40V48_4K, true, true); 464 #endif 465 466 while ((opt = getopt(argc, argv, "hi:I:p:m:")) != -1) { 467 switch (opt) { 468 case 'i': 469 iterations = strtol(optarg, NULL, 10); 470 break; 471 case 'I': 472 interval = strtol(optarg, NULL, 10); 473 break; 474 case 'p': 475 phys_offset = strtoull(optarg, NULL, 0); 476 break; 477 case 'm': 478 if (!mode_selected) { 479 for (i = 0; i < NUM_VM_MODES; ++i) 480 vm_guest_mode_params[i].enabled = false; 481 mode_selected = true; 482 } 483 mode = strtoul(optarg, NULL, 10); 484 TEST_ASSERT(mode < NUM_VM_MODES, 485 "Guest mode ID %d too big", mode); 486 vm_guest_mode_params[mode].enabled = true; 487 break; 488 case 'h': 489 default: 490 help(argv[0]); 491 break; 492 } 493 } 494 495 TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); 496 TEST_ASSERT(interval > 0, "Interval must be greater than zero"); 497 498 DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 499 iterations, interval); 500 501 srandom(time(0)); 502 503 for (i = 0; i < NUM_VM_MODES; ++i) { 504 if (!vm_guest_mode_params[i].enabled) 505 continue; 506 TEST_ASSERT(vm_guest_mode_params[i].supported, 507 "Guest mode ID %d (%s) not supported.", 508 i, vm_guest_mode_string(i)); 509 run_test(i, iterations, interval, phys_offset); 510 } 511 512 return 0; 513 } 514