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 <pthread.h> 13 #include <semaphore.h> 14 #include <sys/types.h> 15 #include <signal.h> 16 #include <errno.h> 17 #include <linux/bitmap.h> 18 #include <linux/bitops.h> 19 #include <linux/atomic.h> 20 #include <asm/barrier.h> 21 22 #include "kvm_util.h" 23 #include "test_util.h" 24 #include "guest_modes.h" 25 #include "processor.h" 26 27 #define DIRTY_MEM_BITS 30 /* 1G */ 28 #define PAGE_SHIFT_4K 12 29 30 /* The memory slot index to track dirty pages */ 31 #define TEST_MEM_SLOT_INDEX 1 32 33 /* Default guest test virtual memory offset */ 34 #define DEFAULT_GUEST_TEST_MEM 0xc0000000 35 36 /* How many pages to dirty for each guest loop */ 37 #define TEST_PAGES_PER_LOOP 1024 38 39 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */ 40 #define TEST_HOST_LOOP_N 32UL 41 42 /* Interval for each host loop (ms) */ 43 #define TEST_HOST_LOOP_INTERVAL 10UL 44 45 /* Dirty bitmaps are always little endian, so we need to swap on big endian */ 46 #if defined(__s390x__) 47 # define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7) 48 # define test_bit_le(nr, addr) \ 49 test_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 50 # define __set_bit_le(nr, addr) \ 51 __set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 52 # define __clear_bit_le(nr, addr) \ 53 __clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 54 # define __test_and_set_bit_le(nr, addr) \ 55 __test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 56 # define __test_and_clear_bit_le(nr, addr) \ 57 __test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr) 58 #else 59 # define test_bit_le test_bit 60 # define __set_bit_le __set_bit 61 # define __clear_bit_le __clear_bit 62 # define __test_and_set_bit_le __test_and_set_bit 63 # define __test_and_clear_bit_le __test_and_clear_bit 64 #endif 65 66 #define TEST_DIRTY_RING_COUNT 65536 67 68 #define SIG_IPI SIGUSR1 69 70 /* 71 * Guest/Host shared variables. Ensure addr_gva2hva() and/or 72 * sync_global_to/from_guest() are used when accessing from 73 * the host. READ/WRITE_ONCE() should also be used with anything 74 * that may change. 75 */ 76 static uint64_t host_page_size; 77 static uint64_t guest_page_size; 78 static uint64_t guest_num_pages; 79 static uint64_t random_array[TEST_PAGES_PER_LOOP]; 80 static uint64_t iteration; 81 82 /* 83 * Guest physical memory offset of the testing memory slot. 84 * This will be set to the topmost valid physical address minus 85 * the test memory size. 86 */ 87 static uint64_t guest_test_phys_mem; 88 89 /* 90 * Guest virtual memory offset of the testing memory slot. 91 * Must not conflict with identity mapped test code. 92 */ 93 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; 94 95 /* 96 * Continuously write to the first 8 bytes of a random pages within 97 * the testing memory region. 98 */ 99 static void guest_code(void) 100 { 101 uint64_t addr; 102 int i; 103 104 /* 105 * On s390x, all pages of a 1M segment are initially marked as dirty 106 * when a page of the segment is written to for the very first time. 107 * To compensate this specialty in this test, we need to touch all 108 * pages during the first iteration. 109 */ 110 for (i = 0; i < guest_num_pages; i++) { 111 addr = guest_test_virt_mem + i * guest_page_size; 112 *(uint64_t *)addr = READ_ONCE(iteration); 113 } 114 115 while (true) { 116 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { 117 addr = guest_test_virt_mem; 118 addr += (READ_ONCE(random_array[i]) % guest_num_pages) 119 * guest_page_size; 120 addr = align_down(addr, host_page_size); 121 *(uint64_t *)addr = READ_ONCE(iteration); 122 } 123 124 /* Tell the host that we need more random numbers */ 125 GUEST_SYNC(1); 126 } 127 } 128 129 /* Host variables */ 130 static bool host_quit; 131 132 /* Points to the test VM memory region on which we track dirty logs */ 133 static void *host_test_mem; 134 static uint64_t host_num_pages; 135 136 /* For statistics only */ 137 static uint64_t host_dirty_count; 138 static uint64_t host_clear_count; 139 static uint64_t host_track_next_count; 140 141 /* Whether dirty ring reset is requested, or finished */ 142 static sem_t sem_vcpu_stop; 143 static sem_t sem_vcpu_cont; 144 /* 145 * This is only set by main thread, and only cleared by vcpu thread. It is 146 * used to request vcpu thread to stop at the next GUEST_SYNC, since GUEST_SYNC 147 * is the only place that we'll guarantee both "dirty bit" and "dirty data" 148 * will match. E.g., SIG_IPI won't guarantee that if the vcpu is interrupted 149 * after setting dirty bit but before the data is written. 150 */ 151 static atomic_t vcpu_sync_stop_requested; 152 /* 153 * This is updated by the vcpu thread to tell the host whether it's a 154 * ring-full event. It should only be read until a sem_wait() of 155 * sem_vcpu_stop and before vcpu continues to run. 156 */ 157 static bool dirty_ring_vcpu_ring_full; 158 /* 159 * This is only used for verifying the dirty pages. Dirty ring has a very 160 * tricky case when the ring just got full, kvm will do userspace exit due to 161 * ring full. When that happens, the very last PFN is set but actually the 162 * data is not changed (the guest WRITE is not really applied yet), because 163 * we found that the dirty ring is full, refused to continue the vcpu, and 164 * recorded the dirty gfn with the old contents. 165 * 166 * For this specific case, it's safe to skip checking this pfn for this 167 * bit, because it's a redundant bit, and when the write happens later the bit 168 * will be set again. We use this variable to always keep track of the latest 169 * dirty gfn we've collected, so that if a mismatch of data found later in the 170 * verifying process, we let it pass. 171 */ 172 static uint64_t dirty_ring_last_page; 173 174 enum log_mode_t { 175 /* Only use KVM_GET_DIRTY_LOG for logging */ 176 LOG_MODE_DIRTY_LOG = 0, 177 178 /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */ 179 LOG_MODE_CLEAR_LOG = 1, 180 181 /* Use dirty ring for logging */ 182 LOG_MODE_DIRTY_RING = 2, 183 184 LOG_MODE_NUM, 185 186 /* Run all supported modes */ 187 LOG_MODE_ALL = LOG_MODE_NUM, 188 }; 189 190 /* Mode of logging to test. Default is to run all supported modes */ 191 static enum log_mode_t host_log_mode_option = LOG_MODE_ALL; 192 /* Logging mode for current run */ 193 static enum log_mode_t host_log_mode; 194 static pthread_t vcpu_thread; 195 static uint32_t test_dirty_ring_count = TEST_DIRTY_RING_COUNT; 196 197 static void vcpu_kick(void) 198 { 199 pthread_kill(vcpu_thread, SIG_IPI); 200 } 201 202 /* 203 * In our test we do signal tricks, let's use a better version of 204 * sem_wait to avoid signal interrupts 205 */ 206 static void sem_wait_until(sem_t *sem) 207 { 208 int ret; 209 210 do 211 ret = sem_wait(sem); 212 while (ret == -1 && errno == EINTR); 213 } 214 215 static bool clear_log_supported(void) 216 { 217 return kvm_has_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 218 } 219 220 static void clear_log_create_vm_done(struct kvm_vm *vm) 221 { 222 u64 manual_caps; 223 224 manual_caps = kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 225 TEST_ASSERT(manual_caps, "MANUAL_CAPS is zero!"); 226 manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | 227 KVM_DIRTY_LOG_INITIALLY_SET); 228 vm_enable_cap(vm, KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2, manual_caps); 229 } 230 231 static void dirty_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot, 232 void *bitmap, uint32_t num_pages, 233 uint32_t *unused) 234 { 235 kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap); 236 } 237 238 static void clear_log_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot, 239 void *bitmap, uint32_t num_pages, 240 uint32_t *unused) 241 { 242 kvm_vm_get_dirty_log(vcpu->vm, slot, bitmap); 243 kvm_vm_clear_dirty_log(vcpu->vm, slot, bitmap, 0, num_pages); 244 } 245 246 /* Should only be called after a GUEST_SYNC */ 247 static void vcpu_handle_sync_stop(void) 248 { 249 if (atomic_read(&vcpu_sync_stop_requested)) { 250 /* It means main thread is sleeping waiting */ 251 atomic_set(&vcpu_sync_stop_requested, false); 252 sem_post(&sem_vcpu_stop); 253 sem_wait_until(&sem_vcpu_cont); 254 } 255 } 256 257 static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) 258 { 259 struct kvm_run *run = vcpu->run; 260 261 TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR), 262 "vcpu run failed: errno=%d", err); 263 264 TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC, 265 "Invalid guest sync status: exit_reason=%s\n", 266 exit_reason_str(run->exit_reason)); 267 268 vcpu_handle_sync_stop(); 269 } 270 271 static bool dirty_ring_supported(void) 272 { 273 return (kvm_has_cap(KVM_CAP_DIRTY_LOG_RING) || 274 kvm_has_cap(KVM_CAP_DIRTY_LOG_RING_ACQ_REL)); 275 } 276 277 static void dirty_ring_create_vm_done(struct kvm_vm *vm) 278 { 279 uint64_t pages; 280 uint32_t limit; 281 282 /* 283 * We rely on vcpu exit due to full dirty ring state. Adjust 284 * the ring buffer size to ensure we're able to reach the 285 * full dirty ring state. 286 */ 287 pages = (1ul << (DIRTY_MEM_BITS - vm->page_shift)) + 3; 288 pages = vm_adjust_num_guest_pages(vm->mode, pages); 289 if (vm->page_size < getpagesize()) 290 pages = vm_num_host_pages(vm->mode, pages); 291 292 limit = 1 << (31 - __builtin_clz(pages)); 293 test_dirty_ring_count = 1 << (31 - __builtin_clz(test_dirty_ring_count)); 294 test_dirty_ring_count = min(limit, test_dirty_ring_count); 295 pr_info("dirty ring count: 0x%x\n", test_dirty_ring_count); 296 297 /* 298 * Switch to dirty ring mode after VM creation but before any 299 * of the vcpu creation. 300 */ 301 vm_enable_dirty_ring(vm, test_dirty_ring_count * 302 sizeof(struct kvm_dirty_gfn)); 303 } 304 305 static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn) 306 { 307 return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY; 308 } 309 310 static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn) 311 { 312 smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET); 313 } 314 315 static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns, 316 int slot, void *bitmap, 317 uint32_t num_pages, uint32_t *fetch_index) 318 { 319 struct kvm_dirty_gfn *cur; 320 uint32_t count = 0; 321 322 while (true) { 323 cur = &dirty_gfns[*fetch_index % test_dirty_ring_count]; 324 if (!dirty_gfn_is_dirtied(cur)) 325 break; 326 TEST_ASSERT(cur->slot == slot, "Slot number didn't match: " 327 "%u != %u", cur->slot, slot); 328 TEST_ASSERT(cur->offset < num_pages, "Offset overflow: " 329 "0x%llx >= 0x%x", cur->offset, num_pages); 330 //pr_info("fetch 0x%x page %llu\n", *fetch_index, cur->offset); 331 __set_bit_le(cur->offset, bitmap); 332 dirty_ring_last_page = cur->offset; 333 dirty_gfn_set_collected(cur); 334 (*fetch_index)++; 335 count++; 336 } 337 338 return count; 339 } 340 341 static void dirty_ring_wait_vcpu(void) 342 { 343 /* This makes sure that hardware PML cache flushed */ 344 vcpu_kick(); 345 sem_wait_until(&sem_vcpu_stop); 346 } 347 348 static void dirty_ring_continue_vcpu(void) 349 { 350 pr_info("Notifying vcpu to continue\n"); 351 sem_post(&sem_vcpu_cont); 352 } 353 354 static void dirty_ring_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot, 355 void *bitmap, uint32_t num_pages, 356 uint32_t *ring_buf_idx) 357 { 358 uint32_t count = 0, cleared; 359 bool continued_vcpu = false; 360 361 dirty_ring_wait_vcpu(); 362 363 if (!dirty_ring_vcpu_ring_full) { 364 /* 365 * This is not a ring-full event, it's safe to allow 366 * vcpu to continue 367 */ 368 dirty_ring_continue_vcpu(); 369 continued_vcpu = true; 370 } 371 372 /* Only have one vcpu */ 373 count = dirty_ring_collect_one(vcpu_map_dirty_ring(vcpu), 374 slot, bitmap, num_pages, 375 ring_buf_idx); 376 377 cleared = kvm_vm_reset_dirty_ring(vcpu->vm); 378 379 /* Cleared pages should be the same as collected */ 380 TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch " 381 "with collected (%u)", cleared, count); 382 383 if (!continued_vcpu) { 384 TEST_ASSERT(dirty_ring_vcpu_ring_full, 385 "Didn't continue vcpu even without ring full"); 386 dirty_ring_continue_vcpu(); 387 } 388 389 pr_info("Iteration %ld collected %u pages\n", iteration, count); 390 } 391 392 static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) 393 { 394 struct kvm_run *run = vcpu->run; 395 396 /* A ucall-sync or ring-full event is allowed */ 397 if (get_ucall(vcpu, NULL) == UCALL_SYNC) { 398 /* We should allow this to continue */ 399 ; 400 } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL || 401 (ret == -1 && err == EINTR)) { 402 /* Update the flag first before pause */ 403 WRITE_ONCE(dirty_ring_vcpu_ring_full, 404 run->exit_reason == KVM_EXIT_DIRTY_RING_FULL); 405 sem_post(&sem_vcpu_stop); 406 pr_info("vcpu stops because %s...\n", 407 dirty_ring_vcpu_ring_full ? 408 "dirty ring is full" : "vcpu is kicked out"); 409 sem_wait_until(&sem_vcpu_cont); 410 pr_info("vcpu continues now.\n"); 411 } else { 412 TEST_ASSERT(false, "Invalid guest sync status: " 413 "exit_reason=%s\n", 414 exit_reason_str(run->exit_reason)); 415 } 416 } 417 418 static void dirty_ring_before_vcpu_join(void) 419 { 420 /* Kick another round of vcpu just to make sure it will quit */ 421 sem_post(&sem_vcpu_cont); 422 } 423 424 struct log_mode { 425 const char *name; 426 /* Return true if this mode is supported, otherwise false */ 427 bool (*supported)(void); 428 /* Hook when the vm creation is done (before vcpu creation) */ 429 void (*create_vm_done)(struct kvm_vm *vm); 430 /* Hook to collect the dirty pages into the bitmap provided */ 431 void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot, 432 void *bitmap, uint32_t num_pages, 433 uint32_t *ring_buf_idx); 434 /* Hook to call when after each vcpu run */ 435 void (*after_vcpu_run)(struct kvm_vcpu *vcpu, int ret, int err); 436 void (*before_vcpu_join) (void); 437 } log_modes[LOG_MODE_NUM] = { 438 { 439 .name = "dirty-log", 440 .collect_dirty_pages = dirty_log_collect_dirty_pages, 441 .after_vcpu_run = default_after_vcpu_run, 442 }, 443 { 444 .name = "clear-log", 445 .supported = clear_log_supported, 446 .create_vm_done = clear_log_create_vm_done, 447 .collect_dirty_pages = clear_log_collect_dirty_pages, 448 .after_vcpu_run = default_after_vcpu_run, 449 }, 450 { 451 .name = "dirty-ring", 452 .supported = dirty_ring_supported, 453 .create_vm_done = dirty_ring_create_vm_done, 454 .collect_dirty_pages = dirty_ring_collect_dirty_pages, 455 .before_vcpu_join = dirty_ring_before_vcpu_join, 456 .after_vcpu_run = dirty_ring_after_vcpu_run, 457 }, 458 }; 459 460 /* 461 * We use this bitmap to track some pages that should have its dirty 462 * bit set in the _next_ iteration. For example, if we detected the 463 * page value changed to current iteration but at the same time the 464 * page bit is cleared in the latest bitmap, then the system must 465 * report that write in the next get dirty log call. 466 */ 467 static unsigned long *host_bmap_track; 468 469 static void log_modes_dump(void) 470 { 471 int i; 472 473 printf("all"); 474 for (i = 0; i < LOG_MODE_NUM; i++) 475 printf(", %s", log_modes[i].name); 476 printf("\n"); 477 } 478 479 static bool log_mode_supported(void) 480 { 481 struct log_mode *mode = &log_modes[host_log_mode]; 482 483 if (mode->supported) 484 return mode->supported(); 485 486 return true; 487 } 488 489 static void log_mode_create_vm_done(struct kvm_vm *vm) 490 { 491 struct log_mode *mode = &log_modes[host_log_mode]; 492 493 if (mode->create_vm_done) 494 mode->create_vm_done(vm); 495 } 496 497 static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot, 498 void *bitmap, uint32_t num_pages, 499 uint32_t *ring_buf_idx) 500 { 501 struct log_mode *mode = &log_modes[host_log_mode]; 502 503 TEST_ASSERT(mode->collect_dirty_pages != NULL, 504 "collect_dirty_pages() is required for any log mode!"); 505 mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx); 506 } 507 508 static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) 509 { 510 struct log_mode *mode = &log_modes[host_log_mode]; 511 512 if (mode->after_vcpu_run) 513 mode->after_vcpu_run(vcpu, ret, err); 514 } 515 516 static void log_mode_before_vcpu_join(void) 517 { 518 struct log_mode *mode = &log_modes[host_log_mode]; 519 520 if (mode->before_vcpu_join) 521 mode->before_vcpu_join(); 522 } 523 524 static void generate_random_array(uint64_t *guest_array, uint64_t size) 525 { 526 uint64_t i; 527 528 for (i = 0; i < size; i++) 529 guest_array[i] = random(); 530 } 531 532 static void *vcpu_worker(void *data) 533 { 534 int ret; 535 struct kvm_vcpu *vcpu = data; 536 struct kvm_vm *vm = vcpu->vm; 537 uint64_t *guest_array; 538 uint64_t pages_count = 0; 539 struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset) 540 + sizeof(sigset_t)); 541 sigset_t *sigset = (sigset_t *) &sigmask->sigset; 542 543 /* 544 * SIG_IPI is unblocked atomically while in KVM_RUN. It causes the 545 * ioctl to return with -EINTR, but it is still pending and we need 546 * to accept it with the sigwait. 547 */ 548 sigmask->len = 8; 549 pthread_sigmask(0, NULL, sigset); 550 sigdelset(sigset, SIG_IPI); 551 vcpu_ioctl(vcpu, KVM_SET_SIGNAL_MASK, sigmask); 552 553 sigemptyset(sigset); 554 sigaddset(sigset, SIG_IPI); 555 556 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 557 558 while (!READ_ONCE(host_quit)) { 559 /* Clear any existing kick signals */ 560 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 561 pages_count += TEST_PAGES_PER_LOOP; 562 /* Let the guest dirty the random pages */ 563 ret = __vcpu_run(vcpu); 564 if (ret == -1 && errno == EINTR) { 565 int sig = -1; 566 sigwait(sigset, &sig); 567 assert(sig == SIG_IPI); 568 } 569 log_mode_after_vcpu_run(vcpu, ret, errno); 570 } 571 572 pr_info("Dirtied %"PRIu64" pages\n", pages_count); 573 574 return NULL; 575 } 576 577 static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap) 578 { 579 uint64_t step = vm_num_host_pages(mode, 1); 580 uint64_t page; 581 uint64_t *value_ptr; 582 uint64_t min_iter = 0; 583 584 for (page = 0; page < host_num_pages; page += step) { 585 value_ptr = host_test_mem + page * host_page_size; 586 587 /* If this is a special page that we were tracking... */ 588 if (__test_and_clear_bit_le(page, host_bmap_track)) { 589 host_track_next_count++; 590 TEST_ASSERT(test_bit_le(page, bmap), 591 "Page %"PRIu64" should have its dirty bit " 592 "set in this iteration but it is missing", 593 page); 594 } 595 596 if (__test_and_clear_bit_le(page, bmap)) { 597 bool matched; 598 599 host_dirty_count++; 600 601 /* 602 * If the bit is set, the value written onto 603 * the corresponding page should be either the 604 * previous iteration number or the current one. 605 */ 606 matched = (*value_ptr == iteration || 607 *value_ptr == iteration - 1); 608 609 if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) { 610 if (*value_ptr == iteration - 2 && min_iter <= iteration - 2) { 611 /* 612 * Short answer: this case is special 613 * only for dirty ring test where the 614 * page is the last page before a kvm 615 * dirty ring full in iteration N-2. 616 * 617 * Long answer: Assuming ring size R, 618 * one possible condition is: 619 * 620 * main thr vcpu thr 621 * -------- -------- 622 * iter=1 623 * write 1 to page 0~(R-1) 624 * full, vmexit 625 * collect 0~(R-1) 626 * kick vcpu 627 * write 1 to (R-1)~(2R-2) 628 * full, vmexit 629 * iter=2 630 * collect (R-1)~(2R-2) 631 * kick vcpu 632 * write 1 to (2R-2) 633 * (NOTE!!! "1" cached in cpu reg) 634 * write 2 to (2R-1)~(3R-3) 635 * full, vmexit 636 * iter=3 637 * collect (2R-2)~(3R-3) 638 * (here if we read value on page 639 * "2R-2" is 1, while iter=3!!!) 640 * 641 * This however can only happen once per iteration. 642 */ 643 min_iter = iteration - 1; 644 continue; 645 } else if (page == dirty_ring_last_page) { 646 /* 647 * Please refer to comments in 648 * dirty_ring_last_page. 649 */ 650 continue; 651 } 652 } 653 654 TEST_ASSERT(matched, 655 "Set page %"PRIu64" value %"PRIu64 656 " incorrect (iteration=%"PRIu64")", 657 page, *value_ptr, iteration); 658 } else { 659 host_clear_count++; 660 /* 661 * If cleared, the value written can be any 662 * value smaller or equals to the iteration 663 * number. Note that the value can be exactly 664 * (iteration-1) if that write can happen 665 * like this: 666 * 667 * (1) increase loop count to "iteration-1" 668 * (2) write to page P happens (with value 669 * "iteration-1") 670 * (3) get dirty log for "iteration-1"; we'll 671 * see that page P bit is set (dirtied), 672 * and not set the bit in host_bmap_track 673 * (4) increase loop count to "iteration" 674 * (which is current iteration) 675 * (5) get dirty log for current iteration, 676 * we'll see that page P is cleared, with 677 * value "iteration-1". 678 */ 679 TEST_ASSERT(*value_ptr <= iteration, 680 "Clear page %"PRIu64" value %"PRIu64 681 " incorrect (iteration=%"PRIu64")", 682 page, *value_ptr, iteration); 683 if (*value_ptr == iteration) { 684 /* 685 * This page is _just_ modified; it 686 * should report its dirtyness in the 687 * next run 688 */ 689 __set_bit_le(page, host_bmap_track); 690 } 691 } 692 } 693 } 694 695 static struct kvm_vm *create_vm(enum vm_guest_mode mode, struct kvm_vcpu **vcpu, 696 uint64_t extra_mem_pages, void *guest_code) 697 { 698 struct kvm_vm *vm; 699 700 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 701 702 vm = __vm_create(VM_SHAPE(mode), 1, extra_mem_pages); 703 704 log_mode_create_vm_done(vm); 705 *vcpu = vm_vcpu_add(vm, 0, guest_code); 706 return vm; 707 } 708 709 struct test_params { 710 unsigned long iterations; 711 unsigned long interval; 712 uint64_t phys_offset; 713 }; 714 715 static void run_test(enum vm_guest_mode mode, void *arg) 716 { 717 struct test_params *p = arg; 718 struct kvm_vcpu *vcpu; 719 struct kvm_vm *vm; 720 unsigned long *bmap; 721 uint32_t ring_buf_idx = 0; 722 723 if (!log_mode_supported()) { 724 print_skip("Log mode '%s' not supported", 725 log_modes[host_log_mode].name); 726 return; 727 } 728 729 /* 730 * We reserve page table for 2 times of extra dirty mem which 731 * will definitely cover the original (1G+) test range. Here 732 * we do the calculation with 4K page size which is the 733 * smallest so the page number will be enough for all archs 734 * (e.g., 64K page size guest will need even less memory for 735 * page tables). 736 */ 737 vm = create_vm(mode, &vcpu, 738 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), guest_code); 739 740 guest_page_size = vm->page_size; 741 /* 742 * A little more than 1G of guest page sized pages. Cover the 743 * case where the size is not aligned to 64 pages. 744 */ 745 guest_num_pages = (1ul << (DIRTY_MEM_BITS - vm->page_shift)) + 3; 746 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 747 748 host_page_size = getpagesize(); 749 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 750 751 if (!p->phys_offset) { 752 guest_test_phys_mem = (vm->max_gfn - guest_num_pages) * 753 guest_page_size; 754 guest_test_phys_mem = align_down(guest_test_phys_mem, host_page_size); 755 } else { 756 guest_test_phys_mem = p->phys_offset; 757 } 758 759 #ifdef __s390x__ 760 /* Align to 1M (segment size) */ 761 guest_test_phys_mem = align_down(guest_test_phys_mem, 1 << 20); 762 #endif 763 764 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 765 766 bmap = bitmap_zalloc(host_num_pages); 767 host_bmap_track = bitmap_zalloc(host_num_pages); 768 769 /* Add an extra memory slot for testing dirty logging */ 770 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 771 guest_test_phys_mem, 772 TEST_MEM_SLOT_INDEX, 773 guest_num_pages, 774 KVM_MEM_LOG_DIRTY_PAGES); 775 776 /* Do mapping for the dirty track memory slot */ 777 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages); 778 779 /* Cache the HVA pointer of the region */ 780 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 781 782 /* Export the shared variables to the guest */ 783 sync_global_to_guest(vm, host_page_size); 784 sync_global_to_guest(vm, guest_page_size); 785 sync_global_to_guest(vm, guest_test_virt_mem); 786 sync_global_to_guest(vm, guest_num_pages); 787 788 /* Start the iterations */ 789 iteration = 1; 790 sync_global_to_guest(vm, iteration); 791 host_quit = false; 792 host_dirty_count = 0; 793 host_clear_count = 0; 794 host_track_next_count = 0; 795 WRITE_ONCE(dirty_ring_vcpu_ring_full, false); 796 797 pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu); 798 799 while (iteration < p->iterations) { 800 /* Give the vcpu thread some time to dirty some pages */ 801 usleep(p->interval * 1000); 802 log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX, 803 bmap, host_num_pages, 804 &ring_buf_idx); 805 806 /* 807 * See vcpu_sync_stop_requested definition for details on why 808 * we need to stop vcpu when verify data. 809 */ 810 atomic_set(&vcpu_sync_stop_requested, true); 811 sem_wait_until(&sem_vcpu_stop); 812 /* 813 * NOTE: for dirty ring, it's possible that we didn't stop at 814 * GUEST_SYNC but instead we stopped because ring is full; 815 * that's okay too because ring full means we're only missing 816 * the flush of the last page, and since we handle the last 817 * page specially verification will succeed anyway. 818 */ 819 assert(host_log_mode == LOG_MODE_DIRTY_RING || 820 atomic_read(&vcpu_sync_stop_requested) == false); 821 vm_dirty_log_verify(mode, bmap); 822 sem_post(&sem_vcpu_cont); 823 824 iteration++; 825 sync_global_to_guest(vm, iteration); 826 } 827 828 /* Tell the vcpu thread to quit */ 829 host_quit = true; 830 log_mode_before_vcpu_join(); 831 pthread_join(vcpu_thread, NULL); 832 833 pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 834 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 835 host_track_next_count); 836 837 free(bmap); 838 free(host_bmap_track); 839 kvm_vm_free(vm); 840 } 841 842 static void help(char *name) 843 { 844 puts(""); 845 printf("usage: %s [-h] [-i iterations] [-I interval] " 846 "[-p offset] [-m mode]\n", name); 847 puts(""); 848 printf(" -c: hint to dirty ring size, in number of entries\n"); 849 printf(" (only useful for dirty-ring test; default: %"PRIu32")\n", 850 TEST_DIRTY_RING_COUNT); 851 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 852 TEST_HOST_LOOP_N); 853 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 854 TEST_HOST_LOOP_INTERVAL); 855 printf(" -p: specify guest physical test memory offset\n" 856 " Warning: a low offset can conflict with the loaded test code.\n"); 857 printf(" -M: specify the host logging mode " 858 "(default: run all log modes). Supported modes: \n\t"); 859 log_modes_dump(); 860 guest_modes_help(); 861 puts(""); 862 exit(0); 863 } 864 865 int main(int argc, char *argv[]) 866 { 867 struct test_params p = { 868 .iterations = TEST_HOST_LOOP_N, 869 .interval = TEST_HOST_LOOP_INTERVAL, 870 }; 871 int opt, i; 872 sigset_t sigset; 873 874 sem_init(&sem_vcpu_stop, 0, 0); 875 sem_init(&sem_vcpu_cont, 0, 0); 876 877 guest_modes_append_default(); 878 879 while ((opt = getopt(argc, argv, "c:hi:I:p:m:M:")) != -1) { 880 switch (opt) { 881 case 'c': 882 test_dirty_ring_count = strtol(optarg, NULL, 10); 883 break; 884 case 'i': 885 p.iterations = strtol(optarg, NULL, 10); 886 break; 887 case 'I': 888 p.interval = strtol(optarg, NULL, 10); 889 break; 890 case 'p': 891 p.phys_offset = strtoull(optarg, NULL, 0); 892 break; 893 case 'm': 894 guest_modes_cmdline(optarg); 895 break; 896 case 'M': 897 if (!strcmp(optarg, "all")) { 898 host_log_mode_option = LOG_MODE_ALL; 899 break; 900 } 901 for (i = 0; i < LOG_MODE_NUM; i++) { 902 if (!strcmp(optarg, log_modes[i].name)) { 903 pr_info("Setting log mode to: '%s'\n", 904 optarg); 905 host_log_mode_option = i; 906 break; 907 } 908 } 909 if (i == LOG_MODE_NUM) { 910 printf("Log mode '%s' invalid. Please choose " 911 "from: ", optarg); 912 log_modes_dump(); 913 exit(1); 914 } 915 break; 916 case 'h': 917 default: 918 help(argv[0]); 919 break; 920 } 921 } 922 923 TEST_ASSERT(p.iterations > 2, "Iterations must be greater than two"); 924 TEST_ASSERT(p.interval > 0, "Interval must be greater than zero"); 925 926 pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 927 p.iterations, p.interval); 928 929 srandom(time(0)); 930 931 /* Ensure that vCPU threads start with SIG_IPI blocked. */ 932 sigemptyset(&sigset); 933 sigaddset(&sigset, SIG_IPI); 934 pthread_sigmask(SIG_BLOCK, &sigset, NULL); 935 936 if (host_log_mode_option == LOG_MODE_ALL) { 937 /* Run each log mode */ 938 for (i = 0; i < LOG_MODE_NUM; i++) { 939 pr_info("Testing Log Mode '%s'\n", log_modes[i].name); 940 host_log_mode = i; 941 for_each_guest_mode(run_test, &p); 942 } 943 } else { 944 host_log_mode = host_log_mode_option; 945 for_each_guest_mode(run_test, &p); 946 } 947 948 return 0; 949 } 950