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 */ 76static uint64_t host_page_size; 77static uint64_t guest_page_size; 78static uint64_t guest_num_pages; 79static uint64_t random_array[TEST_PAGES_PER_LOOP]; 80static 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 */ 87static 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 */ 93static 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 */ 99static 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 */ 130static bool host_quit; 131 132/* Points to the test VM memory region on which we track dirty logs */ 133static void *host_test_mem; 134static uint64_t host_num_pages; 135 136/* For statistics only */ 137static uint64_t host_dirty_count; 138static uint64_t host_clear_count; 139static uint64_t host_track_next_count; 140 141/* Whether dirty ring reset is requested, or finished */ 142static sem_t sem_vcpu_stop; 143static 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 */ 151static 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 */ 157static 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 */ 172static uint64_t dirty_ring_last_page; 173 174enum 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 */ 191static enum log_mode_t host_log_mode_option = LOG_MODE_ALL; 192/* Logging mode for current run */ 193static enum log_mode_t host_log_mode; 194static pthread_t vcpu_thread; 195static uint32_t test_dirty_ring_count = TEST_DIRTY_RING_COUNT; 196 197static 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 */ 206static 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 215static bool clear_log_supported(void) 216{ 217 return kvm_has_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2); 218} 219 220static 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 231static 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 238static 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 */ 247static 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 257static 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", 266 exit_reason_str(run->exit_reason)); 267 268 vcpu_handle_sync_stop(); 269} 270 271static 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 277static 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 305static 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 310static 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 315static 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 341static 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 348static void dirty_ring_continue_vcpu(void) 349{ 350 pr_info("Notifying vcpu to continue\n"); 351 sem_post(&sem_vcpu_cont); 352} 353 354static 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 /* 380 * Cleared pages should be the same as collected, as KVM is supposed to 381 * clear only the entries that have been harvested. 382 */ 383 TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch " 384 "with collected (%u)", cleared, count); 385 386 if (!continued_vcpu) { 387 TEST_ASSERT(dirty_ring_vcpu_ring_full, 388 "Didn't continue vcpu even without ring full"); 389 dirty_ring_continue_vcpu(); 390 } 391 392 pr_info("Iteration %ld collected %u pages\n", iteration, count); 393} 394 395static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) 396{ 397 struct kvm_run *run = vcpu->run; 398 399 /* A ucall-sync or ring-full event is allowed */ 400 if (get_ucall(vcpu, NULL) == UCALL_SYNC) { 401 /* We should allow this to continue */ 402 ; 403 } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL || 404 (ret == -1 && err == EINTR)) { 405 /* Update the flag first before pause */ 406 WRITE_ONCE(dirty_ring_vcpu_ring_full, 407 run->exit_reason == KVM_EXIT_DIRTY_RING_FULL); 408 sem_post(&sem_vcpu_stop); 409 pr_info("vcpu stops because %s...\n", 410 dirty_ring_vcpu_ring_full ? 411 "dirty ring is full" : "vcpu is kicked out"); 412 sem_wait_until(&sem_vcpu_cont); 413 pr_info("vcpu continues now.\n"); 414 } else { 415 TEST_ASSERT(false, "Invalid guest sync status: " 416 "exit_reason=%s", 417 exit_reason_str(run->exit_reason)); 418 } 419} 420 421struct log_mode { 422 const char *name; 423 /* Return true if this mode is supported, otherwise false */ 424 bool (*supported)(void); 425 /* Hook when the vm creation is done (before vcpu creation) */ 426 void (*create_vm_done)(struct kvm_vm *vm); 427 /* Hook to collect the dirty pages into the bitmap provided */ 428 void (*collect_dirty_pages) (struct kvm_vcpu *vcpu, int slot, 429 void *bitmap, uint32_t num_pages, 430 uint32_t *ring_buf_idx); 431 /* Hook to call when after each vcpu run */ 432 void (*after_vcpu_run)(struct kvm_vcpu *vcpu, int ret, int err); 433} log_modes[LOG_MODE_NUM] = { 434 { 435 .name = "dirty-log", 436 .collect_dirty_pages = dirty_log_collect_dirty_pages, 437 .after_vcpu_run = default_after_vcpu_run, 438 }, 439 { 440 .name = "clear-log", 441 .supported = clear_log_supported, 442 .create_vm_done = clear_log_create_vm_done, 443 .collect_dirty_pages = clear_log_collect_dirty_pages, 444 .after_vcpu_run = default_after_vcpu_run, 445 }, 446 { 447 .name = "dirty-ring", 448 .supported = dirty_ring_supported, 449 .create_vm_done = dirty_ring_create_vm_done, 450 .collect_dirty_pages = dirty_ring_collect_dirty_pages, 451 .after_vcpu_run = dirty_ring_after_vcpu_run, 452 }, 453}; 454 455/* 456 * We use this bitmap to track some pages that should have its dirty 457 * bit set in the _next_ iteration. For example, if we detected the 458 * page value changed to current iteration but at the same time the 459 * page bit is cleared in the latest bitmap, then the system must 460 * report that write in the next get dirty log call. 461 */ 462static unsigned long *host_bmap_track; 463 464static void log_modes_dump(void) 465{ 466 int i; 467 468 printf("all"); 469 for (i = 0; i < LOG_MODE_NUM; i++) 470 printf(", %s", log_modes[i].name); 471 printf("\n"); 472} 473 474static bool log_mode_supported(void) 475{ 476 struct log_mode *mode = &log_modes[host_log_mode]; 477 478 if (mode->supported) 479 return mode->supported(); 480 481 return true; 482} 483 484static void log_mode_create_vm_done(struct kvm_vm *vm) 485{ 486 struct log_mode *mode = &log_modes[host_log_mode]; 487 488 if (mode->create_vm_done) 489 mode->create_vm_done(vm); 490} 491 492static void log_mode_collect_dirty_pages(struct kvm_vcpu *vcpu, int slot, 493 void *bitmap, uint32_t num_pages, 494 uint32_t *ring_buf_idx) 495{ 496 struct log_mode *mode = &log_modes[host_log_mode]; 497 498 TEST_ASSERT(mode->collect_dirty_pages != NULL, 499 "collect_dirty_pages() is required for any log mode!"); 500 mode->collect_dirty_pages(vcpu, slot, bitmap, num_pages, ring_buf_idx); 501} 502 503static void log_mode_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) 504{ 505 struct log_mode *mode = &log_modes[host_log_mode]; 506 507 if (mode->after_vcpu_run) 508 mode->after_vcpu_run(vcpu, ret, err); 509} 510 511static void generate_random_array(uint64_t *guest_array, uint64_t size) 512{ 513 uint64_t i; 514 515 for (i = 0; i < size; i++) 516 guest_array[i] = random(); 517} 518 519static void *vcpu_worker(void *data) 520{ 521 int ret; 522 struct kvm_vcpu *vcpu = data; 523 struct kvm_vm *vm = vcpu->vm; 524 uint64_t *guest_array; 525 uint64_t pages_count = 0; 526 struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset) 527 + sizeof(sigset_t)); 528 sigset_t *sigset = (sigset_t *) &sigmask->sigset; 529 530 /* 531 * SIG_IPI is unblocked atomically while in KVM_RUN. It causes the 532 * ioctl to return with -EINTR, but it is still pending and we need 533 * to accept it with the sigwait. 534 */ 535 sigmask->len = 8; 536 pthread_sigmask(0, NULL, sigset); 537 sigdelset(sigset, SIG_IPI); 538 vcpu_ioctl(vcpu, KVM_SET_SIGNAL_MASK, sigmask); 539 540 sigemptyset(sigset); 541 sigaddset(sigset, SIG_IPI); 542 543 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 544 545 while (!READ_ONCE(host_quit)) { 546 /* Clear any existing kick signals */ 547 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 548 pages_count += TEST_PAGES_PER_LOOP; 549 /* Let the guest dirty the random pages */ 550 ret = __vcpu_run(vcpu); 551 if (ret == -1 && errno == EINTR) { 552 int sig = -1; 553 sigwait(sigset, &sig); 554 assert(sig == SIG_IPI); 555 } 556 log_mode_after_vcpu_run(vcpu, ret, errno); 557 } 558 559 pr_info("Dirtied %"PRIu64" pages\n", pages_count); 560 561 return NULL; 562} 563 564static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap) 565{ 566 uint64_t step = vm_num_host_pages(mode, 1); 567 uint64_t page; 568 uint64_t *value_ptr; 569 uint64_t min_iter = 0; 570 571 for (page = 0; page < host_num_pages; page += step) { 572 value_ptr = host_test_mem + page * host_page_size; 573 574 /* If this is a special page that we were tracking... */ 575 if (__test_and_clear_bit_le(page, host_bmap_track)) { 576 host_track_next_count++; 577 TEST_ASSERT(test_bit_le(page, bmap), 578 "Page %"PRIu64" should have its dirty bit " 579 "set in this iteration but it is missing", 580 page); 581 } 582 583 if (__test_and_clear_bit_le(page, bmap)) { 584 bool matched; 585 586 host_dirty_count++; 587 588 /* 589 * If the bit is set, the value written onto 590 * the corresponding page should be either the 591 * previous iteration number or the current one. 592 */ 593 matched = (*value_ptr == iteration || 594 *value_ptr == iteration - 1); 595 596 if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) { 597 if (*value_ptr == iteration - 2 && min_iter <= iteration - 2) { 598 /* 599 * Short answer: this case is special 600 * only for dirty ring test where the 601 * page is the last page before a kvm 602 * dirty ring full in iteration N-2. 603 * 604 * Long answer: Assuming ring size R, 605 * one possible condition is: 606 * 607 * main thr vcpu thr 608 * -------- -------- 609 * iter=1 610 * write 1 to page 0~(R-1) 611 * full, vmexit 612 * collect 0~(R-1) 613 * kick vcpu 614 * write 1 to (R-1)~(2R-2) 615 * full, vmexit 616 * iter=2 617 * collect (R-1)~(2R-2) 618 * kick vcpu 619 * write 1 to (2R-2) 620 * (NOTE!!! "1" cached in cpu reg) 621 * write 2 to (2R-1)~(3R-3) 622 * full, vmexit 623 * iter=3 624 * collect (2R-2)~(3R-3) 625 * (here if we read value on page 626 * "2R-2" is 1, while iter=3!!!) 627 * 628 * This however can only happen once per iteration. 629 */ 630 min_iter = iteration - 1; 631 continue; 632 } else if (page == dirty_ring_last_page) { 633 /* 634 * Please refer to comments in 635 * dirty_ring_last_page. 636 */ 637 continue; 638 } 639 } 640 641 TEST_ASSERT(matched, 642 "Set page %"PRIu64" value %"PRIu64 643 " incorrect (iteration=%"PRIu64")", 644 page, *value_ptr, iteration); 645 } else { 646 host_clear_count++; 647 /* 648 * If cleared, the value written can be any 649 * value smaller or equals to the iteration 650 * number. Note that the value can be exactly 651 * (iteration-1) if that write can happen 652 * like this: 653 * 654 * (1) increase loop count to "iteration-1" 655 * (2) write to page P happens (with value 656 * "iteration-1") 657 * (3) get dirty log for "iteration-1"; we'll 658 * see that page P bit is set (dirtied), 659 * and not set the bit in host_bmap_track 660 * (4) increase loop count to "iteration" 661 * (which is current iteration) 662 * (5) get dirty log for current iteration, 663 * we'll see that page P is cleared, with 664 * value "iteration-1". 665 */ 666 TEST_ASSERT(*value_ptr <= iteration, 667 "Clear page %"PRIu64" value %"PRIu64 668 " incorrect (iteration=%"PRIu64")", 669 page, *value_ptr, iteration); 670 if (*value_ptr == iteration) { 671 /* 672 * This page is _just_ modified; it 673 * should report its dirtyness in the 674 * next run 675 */ 676 __set_bit_le(page, host_bmap_track); 677 } 678 } 679 } 680} 681 682static struct kvm_vm *create_vm(enum vm_guest_mode mode, struct kvm_vcpu **vcpu, 683 uint64_t extra_mem_pages, void *guest_code) 684{ 685 struct kvm_vm *vm; 686 687 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 688 689 vm = __vm_create(VM_SHAPE(mode), 1, extra_mem_pages); 690 691 log_mode_create_vm_done(vm); 692 *vcpu = vm_vcpu_add(vm, 0, guest_code); 693 return vm; 694} 695 696struct test_params { 697 unsigned long iterations; 698 unsigned long interval; 699 uint64_t phys_offset; 700}; 701 702static void run_test(enum vm_guest_mode mode, void *arg) 703{ 704 struct test_params *p = arg; 705 struct kvm_vcpu *vcpu; 706 struct kvm_vm *vm; 707 unsigned long *bmap; 708 uint32_t ring_buf_idx = 0; 709 int sem_val; 710 711 if (!log_mode_supported()) { 712 print_skip("Log mode '%s' not supported", 713 log_modes[host_log_mode].name); 714 return; 715 } 716 717 /* 718 * We reserve page table for 2 times of extra dirty mem which 719 * will definitely cover the original (1G+) test range. Here 720 * we do the calculation with 4K page size which is the 721 * smallest so the page number will be enough for all archs 722 * (e.g., 64K page size guest will need even less memory for 723 * page tables). 724 */ 725 vm = create_vm(mode, &vcpu, 726 2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K), guest_code); 727 728 guest_page_size = vm->page_size; 729 /* 730 * A little more than 1G of guest page sized pages. Cover the 731 * case where the size is not aligned to 64 pages. 732 */ 733 guest_num_pages = (1ul << (DIRTY_MEM_BITS - vm->page_shift)) + 3; 734 guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages); 735 736 host_page_size = getpagesize(); 737 host_num_pages = vm_num_host_pages(mode, guest_num_pages); 738 739 if (!p->phys_offset) { 740 guest_test_phys_mem = (vm->max_gfn - guest_num_pages) * 741 guest_page_size; 742 guest_test_phys_mem = align_down(guest_test_phys_mem, host_page_size); 743 } else { 744 guest_test_phys_mem = p->phys_offset; 745 } 746 747#ifdef __s390x__ 748 /* Align to 1M (segment size) */ 749 guest_test_phys_mem = align_down(guest_test_phys_mem, 1 << 20); 750#endif 751 752 pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem); 753 754 bmap = bitmap_zalloc(host_num_pages); 755 host_bmap_track = bitmap_zalloc(host_num_pages); 756 757 /* Add an extra memory slot for testing dirty logging */ 758 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 759 guest_test_phys_mem, 760 TEST_MEM_SLOT_INDEX, 761 guest_num_pages, 762 KVM_MEM_LOG_DIRTY_PAGES); 763 764 /* Do mapping for the dirty track memory slot */ 765 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages); 766 767 /* Cache the HVA pointer of the region */ 768 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 769 770 /* Export the shared variables to the guest */ 771 sync_global_to_guest(vm, host_page_size); 772 sync_global_to_guest(vm, guest_page_size); 773 sync_global_to_guest(vm, guest_test_virt_mem); 774 sync_global_to_guest(vm, guest_num_pages); 775 776 /* Start the iterations */ 777 iteration = 1; 778 sync_global_to_guest(vm, iteration); 779 WRITE_ONCE(host_quit, false); 780 host_dirty_count = 0; 781 host_clear_count = 0; 782 host_track_next_count = 0; 783 WRITE_ONCE(dirty_ring_vcpu_ring_full, false); 784 785 /* 786 * Ensure the previous iteration didn't leave a dangling semaphore, i.e. 787 * that the main task and vCPU worker were synchronized and completed 788 * verification of all iterations. 789 */ 790 sem_getvalue(&sem_vcpu_stop, &sem_val); 791 TEST_ASSERT_EQ(sem_val, 0); 792 sem_getvalue(&sem_vcpu_cont, &sem_val); 793 TEST_ASSERT_EQ(sem_val, 0); 794 795 pthread_create(&vcpu_thread, NULL, vcpu_worker, vcpu); 796 797 while (iteration < p->iterations) { 798 /* Give the vcpu thread some time to dirty some pages */ 799 usleep(p->interval * 1000); 800 log_mode_collect_dirty_pages(vcpu, TEST_MEM_SLOT_INDEX, 801 bmap, host_num_pages, 802 &ring_buf_idx); 803 804 /* 805 * See vcpu_sync_stop_requested definition for details on why 806 * we need to stop vcpu when verify data. 807 */ 808 atomic_set(&vcpu_sync_stop_requested, true); 809 sem_wait_until(&sem_vcpu_stop); 810 /* 811 * NOTE: for dirty ring, it's possible that we didn't stop at 812 * GUEST_SYNC but instead we stopped because ring is full; 813 * that's okay too because ring full means we're only missing 814 * the flush of the last page, and since we handle the last 815 * page specially verification will succeed anyway. 816 */ 817 assert(host_log_mode == LOG_MODE_DIRTY_RING || 818 atomic_read(&vcpu_sync_stop_requested) == false); 819 vm_dirty_log_verify(mode, bmap); 820 821 /* 822 * Set host_quit before sem_vcpu_cont in the final iteration to 823 * ensure that the vCPU worker doesn't resume the guest. As 824 * above, the dirty ring test may stop and wait even when not 825 * explicitly request to do so, i.e. would hang waiting for a 826 * "continue" if it's allowed to resume the guest. 827 */ 828 if (++iteration == p->iterations) 829 WRITE_ONCE(host_quit, true); 830 831 sem_post(&sem_vcpu_cont); 832 sync_global_to_guest(vm, iteration); 833 } 834 835 pthread_join(vcpu_thread, NULL); 836 837 pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 838 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 839 host_track_next_count); 840 841 free(bmap); 842 free(host_bmap_track); 843 kvm_vm_free(vm); 844} 845 846static void help(char *name) 847{ 848 puts(""); 849 printf("usage: %s [-h] [-i iterations] [-I interval] " 850 "[-p offset] [-m mode]\n", name); 851 puts(""); 852 printf(" -c: hint to dirty ring size, in number of entries\n"); 853 printf(" (only useful for dirty-ring test; default: %"PRIu32")\n", 854 TEST_DIRTY_RING_COUNT); 855 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 856 TEST_HOST_LOOP_N); 857 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 858 TEST_HOST_LOOP_INTERVAL); 859 printf(" -p: specify guest physical test memory offset\n" 860 " Warning: a low offset can conflict with the loaded test code.\n"); 861 printf(" -M: specify the host logging mode " 862 "(default: run all log modes). Supported modes: \n\t"); 863 log_modes_dump(); 864 guest_modes_help(); 865 puts(""); 866 exit(0); 867} 868 869int main(int argc, char *argv[]) 870{ 871 struct test_params p = { 872 .iterations = TEST_HOST_LOOP_N, 873 .interval = TEST_HOST_LOOP_INTERVAL, 874 }; 875 int opt, i; 876 sigset_t sigset; 877 878 sem_init(&sem_vcpu_stop, 0, 0); 879 sem_init(&sem_vcpu_cont, 0, 0); 880 881 guest_modes_append_default(); 882 883 while ((opt = getopt(argc, argv, "c:hi:I:p:m:M:")) != -1) { 884 switch (opt) { 885 case 'c': 886 test_dirty_ring_count = strtol(optarg, NULL, 10); 887 break; 888 case 'i': 889 p.iterations = strtol(optarg, NULL, 10); 890 break; 891 case 'I': 892 p.interval = strtol(optarg, NULL, 10); 893 break; 894 case 'p': 895 p.phys_offset = strtoull(optarg, NULL, 0); 896 break; 897 case 'm': 898 guest_modes_cmdline(optarg); 899 break; 900 case 'M': 901 if (!strcmp(optarg, "all")) { 902 host_log_mode_option = LOG_MODE_ALL; 903 break; 904 } 905 for (i = 0; i < LOG_MODE_NUM; i++) { 906 if (!strcmp(optarg, log_modes[i].name)) { 907 pr_info("Setting log mode to: '%s'\n", 908 optarg); 909 host_log_mode_option = i; 910 break; 911 } 912 } 913 if (i == LOG_MODE_NUM) { 914 printf("Log mode '%s' invalid. Please choose " 915 "from: ", optarg); 916 log_modes_dump(); 917 exit(1); 918 } 919 break; 920 case 'h': 921 default: 922 help(argv[0]); 923 break; 924 } 925 } 926 927 TEST_ASSERT(p.iterations > 2, "Iterations must be greater than two"); 928 TEST_ASSERT(p.interval > 0, "Interval must be greater than zero"); 929 930 pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 931 p.iterations, p.interval); 932 933 srandom(time(0)); 934 935 /* Ensure that vCPU threads start with SIG_IPI blocked. */ 936 sigemptyset(&sigset); 937 sigaddset(&sigset, SIG_IPI); 938 pthread_sigmask(SIG_BLOCK, &sigset, NULL); 939 940 if (host_log_mode_option == LOG_MODE_ALL) { 941 /* Run each log mode */ 942 for (i = 0; i < LOG_MODE_NUM; i++) { 943 pr_info("Testing Log Mode '%s'\n", log_modes[i].name); 944 host_log_mode = i; 945 for_each_guest_mode(run_test, &p); 946 } 947 } else { 948 host_log_mode = host_log_mode_option; 949 for_each_guest_mode(run_test, &p); 950 } 951 952 return 0; 953} 954