tools/testing/selftests/kvm/dirty_log_test.c

   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
  21 #include "kvm_util.h"
  22 #include "test_util.h"
  23 #include "guest_modes.h"
  24 #include "processor.h"
  25
  26 #define VCPU_ID                         1
  27
  28 /* The memory slot index to track dirty pages */
  29 #define TEST_MEM_SLOT_INDEX             1
  30
  31 /* Default guest test virtual memory offset */
  32 #define DEFAULT_GUEST_TEST_MEM          0xc0000000
  33
  34 /* How many pages to dirty for each guest loop */
  35 #define TEST_PAGES_PER_LOOP             1024
  36
  37 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */
  38 #define TEST_HOST_LOOP_N                32UL
  39
  40 /* Interval for each host loop (ms) */
  41 #define TEST_HOST_LOOP_INTERVAL         10UL
  42
  43 /* Dirty bitmaps are always little endian, so we need to swap on big endian */
  44 #if defined(__s390x__)
  45 # define BITOP_LE_SWIZZLE       ((BITS_PER_LONG-1) & ~0x7)
  46 # define test_bit_le(nr, addr) \
  47         test_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
  48 # define set_bit_le(nr, addr) \
  49         set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
  50 # define clear_bit_le(nr, addr) \
  51         clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
  52 # define test_and_set_bit_le(nr, addr) \
  53         test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
  54 # define test_and_clear_bit_le(nr, addr) \
  55         test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, addr)
  56 #else
  57 # define test_bit_le            test_bit
  58 # define set_bit_le             set_bit
  59 # define clear_bit_le           clear_bit
  60 # define test_and_set_bit_le    test_and_set_bit
  61 # define test_and_clear_bit_le  test_and_clear_bit
  62 #endif
  63
  64 #define TEST_DIRTY_RING_COUNT           65536
  65
  66 #define SIG_IPI SIGUSR1
  67
  68 /*
  69  * Guest/Host shared variables. Ensure addr_gva2hva() and/or
  70  * sync_global_to/from_guest() are used when accessing from
  71  * the host. READ/WRITE_ONCE() should also be used with anything
  72  * that may change.
  73  */
  74 static uint64_t host_page_size;
  75 static uint64_t guest_page_size;
  76 static uint64_t guest_num_pages;
  77 static uint64_t random_array[TEST_PAGES_PER_LOOP];
  78 static uint64_t iteration;
  79
  80 /*
  81  * Guest physical memory offset of the testing memory slot.
  82  * This will be set to the topmost valid physical address minus
  83  * the test memory size.
  84  */
  85 static uint64_t guest_test_phys_mem;
  86
  87 /*
  88  * Guest virtual memory offset of the testing memory slot.
  89  * Must not conflict with identity mapped test code.
  90  */
  91 static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM;
  92
  93 /*
  94  * Continuously write to the first 8 bytes of a random pages within
  95  * the testing memory region.
  96  */
  97 static void guest_code(void)
  98 {
  99         uint64_t addr;
 100         int i;
 101
 102         /*
 103          * On s390x, all pages of a 1M segment are initially marked as dirty
 104          * when a page of the segment is written to for the very first time.
 105          * To compensate this specialty in this test, we need to touch all
 106          * pages during the first iteration.
 107          */
 108         for (i = 0; i < guest_num_pages; i++) {
 109                 addr = guest_test_virt_mem + i * guest_page_size;
 110                 *(uint64_t *)addr = READ_ONCE(iteration);
 111         }
 112
 113         while (true) {
 114                 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) {
 115                         addr = guest_test_virt_mem;
 116                         addr += (READ_ONCE(random_array[i]) % guest_num_pages)
 117                                 * guest_page_size;
 118                         addr &= ~(host_page_size - 1);
 119                         *(uint64_t *)addr = READ_ONCE(iteration);
 120                 }
 121
 122                 /* Tell the host that we need more random numbers */
 123                 GUEST_SYNC(1);
 124         }
 125 }
 126
 127 /* Host variables */
 128 static bool host_quit;
 129
 130 /* Points to the test VM memory region on which we track dirty logs */
 131 static void *host_test_mem;
 132 static uint64_t host_num_pages;
 133
 134 /* For statistics only */
 135 static uint64_t host_dirty_count;
 136 static uint64_t host_clear_count;
 137 static uint64_t host_track_next_count;
 138
 139 /* Whether dirty ring reset is requested, or finished */
 140 static sem_t sem_vcpu_stop;
 141 static sem_t sem_vcpu_cont;
 142 /*
 143  * This is only set by main thread, and only cleared by vcpu thread.  It is
 144  * used to request vcpu thread to stop at the next GUEST_SYNC, since GUEST_SYNC
 145  * is the only place that we'll guarantee both "dirty bit" and "dirty data"
 146  * will match.  E.g., SIG_IPI won't guarantee that if the vcpu is interrupted
 147  * after setting dirty bit but before the data is written.
 148  */
 149 static atomic_t vcpu_sync_stop_requested;
 150 /*
 151  * This is updated by the vcpu thread to tell the host whether it's a
 152  * ring-full event.  It should only be read until a sem_wait() of
 153  * sem_vcpu_stop and before vcpu continues to run.
 154  */
 155 static bool dirty_ring_vcpu_ring_full;
 156 /*
 157  * This is only used for verifying the dirty pages.  Dirty ring has a very
 158  * tricky case when the ring just got full, kvm will do userspace exit due to
 159  * ring full.  When that happens, the very last PFN is set but actually the
 160  * data is not changed (the guest WRITE is not really applied yet), because
 161  * we found that the dirty ring is full, refused to continue the vcpu, and
 162  * recorded the dirty gfn with the old contents.
 163  *
 164  * For this specific case, it's safe to skip checking this pfn for this
 165  * bit, because it's a redundant bit, and when the write happens later the bit
 166  * will be set again.  We use this variable to always keep track of the latest
 167  * dirty gfn we've collected, so that if a mismatch of data found later in the
 168  * verifying process, we let it pass.
 169  */
 170 static uint64_t dirty_ring_last_page;
 171
 172 enum log_mode_t {
 173         /* Only use KVM_GET_DIRTY_LOG for logging */
 174         LOG_MODE_DIRTY_LOG = 0,
 175
 176         /* Use both KVM_[GET|CLEAR]_DIRTY_LOG for logging */
 177         LOG_MODE_CLEAR_LOG = 1,
 178
 179         /* Use dirty ring for logging */
 180         LOG_MODE_DIRTY_RING = 2,
 181
 182         LOG_MODE_NUM,
 183
 184         /* Run all supported modes */
 185         LOG_MODE_ALL = LOG_MODE_NUM,
 186 };
 187
 188 /* Mode of logging to test.  Default is to run all supported modes */
 189 static enum log_mode_t host_log_mode_option = LOG_MODE_ALL;
 190 /* Logging mode for current run */
 191 static enum log_mode_t host_log_mode;
 192 static pthread_t vcpu_thread;
 193 static uint32_t test_dirty_ring_count = TEST_DIRTY_RING_COUNT;
 194
 195 static void vcpu_kick(void)
 196 {
 197         pthread_kill(vcpu_thread, SIG_IPI);
 198 }
 199
 200 /*
 201  * In our test we do signal tricks, let's use a better version of
 202  * sem_wait to avoid signal interrupts
 203  */
 204 static void sem_wait_until(sem_t *sem)
 205 {
 206         int ret;
 207
 208         do
 209                 ret = sem_wait(sem);
 210         while (ret == -1 && errno == EINTR);
 211 }
 212
 213 static bool clear_log_supported(void)
 214 {
 215         return kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 216 }
 217
 218 static void clear_log_create_vm_done(struct kvm_vm *vm)
 219 {
 220         struct kvm_enable_cap cap = {};
 221         u64 manual_caps;
 222
 223         manual_caps = kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 224         TEST_ASSERT(manual_caps, "MANUAL_CAPS is zero!");
 225         manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 226                         KVM_DIRTY_LOG_INITIALLY_SET);
 227         cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 228         cap.args[0] = manual_caps;
 229         vm_enable_cap(vm, &cap);
 230 }
 231
 232 static void dirty_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
 233                                           void *bitmap, uint32_t num_pages)
 234 {
 235         kvm_vm_get_dirty_log(vm, slot, bitmap);
 236 }
 237
 238 static void clear_log_collect_dirty_pages(struct kvm_vm *vm, int slot,
 239                                           void *bitmap, uint32_t num_pages)
 240 {
 241         kvm_vm_get_dirty_log(vm, slot, bitmap);
 242         kvm_vm_clear_dirty_log(vm, slot, bitmap, 0, num_pages);
 243 }
 244
 245 /* Should only be called after a GUEST_SYNC */
 246 static void vcpu_handle_sync_stop(void)
 247 {
 248         if (atomic_read(&vcpu_sync_stop_requested)) {
 249                 /* It means main thread is sleeping waiting */
 250                 atomic_set(&vcpu_sync_stop_requested, false);
 251                 sem_post(&sem_vcpu_stop);
 252                 sem_wait_until(&sem_vcpu_cont);
 253         }
 254 }
 255
 256 static void default_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
 257 {
 258         struct kvm_run *run = vcpu_state(vm, VCPU_ID);
 259
 260         TEST_ASSERT(ret == 0 || (ret == -1 && err == EINTR),
 261                     "vcpu run failed: errno=%d", err);
 262
 263         TEST_ASSERT(get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC,
 264                     "Invalid guest sync status: exit_reason=%s\n",
 265                     exit_reason_str(run->exit_reason));
 266
 267         vcpu_handle_sync_stop();
 268 }
 269
 270 static bool dirty_ring_supported(void)
 271 {
 272         return kvm_check_cap(KVM_CAP_DIRTY_LOG_RING);
 273 }
 274
 275 static void dirty_ring_create_vm_done(struct kvm_vm *vm)
 276 {
 277         /*
 278          * Switch to dirty ring mode after VM creation but before any
 279          * of the vcpu creation.
 280          */
 281         vm_enable_dirty_ring(vm, test_dirty_ring_count *
 282                              sizeof(struct kvm_dirty_gfn));
 283 }
 284
 285 static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
 286 {
 287         return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
 288 }
 289
 290 static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
 291 {
 292         gfn->flags = KVM_DIRTY_GFN_F_RESET;
 293 }
 294
 295 static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
 296                                        int slot, void *bitmap,
 297                                        uint32_t num_pages, uint32_t *fetch_index)
 298 {
 299         struct kvm_dirty_gfn *cur;
 300         uint32_t count = 0;
 301
 302         while (true) {
 303                 cur = &dirty_gfns[*fetch_index % test_dirty_ring_count];
 304                 if (!dirty_gfn_is_dirtied(cur))
 305                         break;
 306                 TEST_ASSERT(cur->slot == slot, "Slot number didn't match: "
 307                             "%u != %u", cur->slot, slot);
 308                 TEST_ASSERT(cur->offset < num_pages, "Offset overflow: "
 309                             "0x%llx >= 0x%x", cur->offset, num_pages);
 310                 //pr_info("fetch 0x%x page %llu\n", *fetch_index, cur->offset);
 311                 set_bit_le(cur->offset, bitmap);
 312                 dirty_ring_last_page = cur->offset;
 313                 dirty_gfn_set_collected(cur);
 314                 (*fetch_index)++;
 315                 count++;
 316         }
 317
 318         return count;
 319 }
 320
 321 static void dirty_ring_wait_vcpu(void)
 322 {
 323         /* This makes sure that hardware PML cache flushed */
 324         vcpu_kick();
 325         sem_wait_until(&sem_vcpu_stop);
 326 }
 327
 328 static void dirty_ring_continue_vcpu(void)
 329 {
 330         pr_info("Notifying vcpu to continue\n");
 331         sem_post(&sem_vcpu_cont);
 332 }
 333
 334 static void dirty_ring_collect_dirty_pages(struct kvm_vm *vm, int slot,
 335                                            void *bitmap, uint32_t num_pages)
 336 {
 337         /* We only have one vcpu */
 338         static uint32_t fetch_index = 0;
 339         uint32_t count = 0, cleared;
 340         bool continued_vcpu = false;
 341
 342         dirty_ring_wait_vcpu();
 343
 344         if (!dirty_ring_vcpu_ring_full) {
 345                 /*
 346                  * This is not a ring-full event, it's safe to allow
 347                  * vcpu to continue
 348                  */
 349                 dirty_ring_continue_vcpu();
 350                 continued_vcpu = true;
 351         }
 352
 353         /* Only have one vcpu */
 354         count = dirty_ring_collect_one(vcpu_map_dirty_ring(vm, VCPU_ID),
 355                                        slot, bitmap, num_pages, &fetch_index);
 356
 357         cleared = kvm_vm_reset_dirty_ring(vm);
 358
 359         /* Cleared pages should be the same as collected */
 360         TEST_ASSERT(cleared == count, "Reset dirty pages (%u) mismatch "
 361                     "with collected (%u)", cleared, count);
 362
 363         if (!continued_vcpu) {
 364                 TEST_ASSERT(dirty_ring_vcpu_ring_full,
 365                             "Didn't continue vcpu even without ring full");
 366                 dirty_ring_continue_vcpu();
 367         }
 368
 369         pr_info("Iteration %ld collected %u pages\n", iteration, count);
 370 }
 371
 372 static void dirty_ring_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
 373 {
 374         struct kvm_run *run = vcpu_state(vm, VCPU_ID);
 375
 376         /* A ucall-sync or ring-full event is allowed */
 377         if (get_ucall(vm, VCPU_ID, NULL) == UCALL_SYNC) {
 378                 /* We should allow this to continue */
 379                 ;
 380         } else if (run->exit_reason == KVM_EXIT_DIRTY_RING_FULL ||
 381                    (ret == -1 && err == EINTR)) {
 382                 /* Update the flag first before pause */
 383                 WRITE_ONCE(dirty_ring_vcpu_ring_full,
 384                            run->exit_reason == KVM_EXIT_DIRTY_RING_FULL);
 385                 sem_post(&sem_vcpu_stop);
 386                 pr_info("vcpu stops because %s...\n",
 387                         dirty_ring_vcpu_ring_full ?
 388                         "dirty ring is full" : "vcpu is kicked out");
 389                 sem_wait_until(&sem_vcpu_cont);
 390                 pr_info("vcpu continues now.\n");
 391         } else {
 392                 TEST_ASSERT(false, "Invalid guest sync status: "
 393                             "exit_reason=%s\n",
 394                             exit_reason_str(run->exit_reason));
 395         }
 396 }
 397
 398 static void dirty_ring_before_vcpu_join(void)
 399 {
 400         /* Kick another round of vcpu just to make sure it will quit */
 401         sem_post(&sem_vcpu_cont);
 402 }
 403
 404 struct log_mode {
 405         const char *name;
 406         /* Return true if this mode is supported, otherwise false */
 407         bool (*supported)(void);
 408         /* Hook when the vm creation is done (before vcpu creation) */
 409         void (*create_vm_done)(struct kvm_vm *vm);
 410         /* Hook to collect the dirty pages into the bitmap provided */
 411         void (*collect_dirty_pages) (struct kvm_vm *vm, int slot,
 412                                      void *bitmap, uint32_t num_pages);
 413         /* Hook to call when after each vcpu run */
 414         void (*after_vcpu_run)(struct kvm_vm *vm, int ret, int err);
 415         void (*before_vcpu_join) (void);
 416 } log_modes[LOG_MODE_NUM] = {
 417         {
 418                 .name = "dirty-log",
 419                 .collect_dirty_pages = dirty_log_collect_dirty_pages,
 420                 .after_vcpu_run = default_after_vcpu_run,
 421         },
 422         {
 423                 .name = "clear-log",
 424                 .supported = clear_log_supported,
 425                 .create_vm_done = clear_log_create_vm_done,
 426                 .collect_dirty_pages = clear_log_collect_dirty_pages,
 427                 .after_vcpu_run = default_after_vcpu_run,
 428         },
 429         {
 430                 .name = "dirty-ring",
 431                 .supported = dirty_ring_supported,
 432                 .create_vm_done = dirty_ring_create_vm_done,
 433                 .collect_dirty_pages = dirty_ring_collect_dirty_pages,
 434                 .before_vcpu_join = dirty_ring_before_vcpu_join,
 435                 .after_vcpu_run = dirty_ring_after_vcpu_run,
 436         },
 437 };
 438
 439 /*
 440  * We use this bitmap to track some pages that should have its dirty
 441  * bit set in the _next_ iteration.  For example, if we detected the
 442  * page value changed to current iteration but at the same time the
 443  * page bit is cleared in the latest bitmap, then the system must
 444  * report that write in the next get dirty log call.
 445  */
 446 static unsigned long *host_bmap_track;
 447
 448 static void log_modes_dump(void)
 449 {
 450         int i;
 451
 452         printf("all");
 453         for (i = 0; i < LOG_MODE_NUM; i++)
 454                 printf(", %s", log_modes[i].name);
 455         printf("\n");
 456 }
 457
 458 static bool log_mode_supported(void)
 459 {
 460         struct log_mode *mode = &log_modes[host_log_mode];
 461
 462         if (mode->supported)
 463                 return mode->supported();
 464
 465         return true;
 466 }
 467
 468 static void log_mode_create_vm_done(struct kvm_vm *vm)
 469 {
 470         struct log_mode *mode = &log_modes[host_log_mode];
 471
 472         if (mode->create_vm_done)
 473                 mode->create_vm_done(vm);
 474 }
 475
 476 static void log_mode_collect_dirty_pages(struct kvm_vm *vm, int slot,
 477                                          void *bitmap, uint32_t num_pages)
 478 {
 479         struct log_mode *mode = &log_modes[host_log_mode];
 480
 481         TEST_ASSERT(mode->collect_dirty_pages != NULL,
 482                     "collect_dirty_pages() is required for any log mode!");
 483         mode->collect_dirty_pages(vm, slot, bitmap, num_pages);
 484 }
 485
 486 static void log_mode_after_vcpu_run(struct kvm_vm *vm, int ret, int err)
 487 {
 488         struct log_mode *mode = &log_modes[host_log_mode];
 489
 490         if (mode->after_vcpu_run)
 491                 mode->after_vcpu_run(vm, ret, err);
 492 }
 493
 494 static void log_mode_before_vcpu_join(void)
 495 {
 496         struct log_mode *mode = &log_modes[host_log_mode];
 497
 498         if (mode->before_vcpu_join)
 499                 mode->before_vcpu_join();
 500 }
 501
 502 static void generate_random_array(uint64_t *guest_array, uint64_t size)
 503 {
 504         uint64_t i;
 505
 506         for (i = 0; i < size; i++)
 507                 guest_array[i] = random();
 508 }
 509
 510 static void *vcpu_worker(void *data)
 511 {
 512         int ret, vcpu_fd;
 513         struct kvm_vm *vm = data;
 514         uint64_t *guest_array;
 515         uint64_t pages_count = 0;
 516         struct kvm_signal_mask *sigmask = alloca(offsetof(struct kvm_signal_mask, sigset)
 517                                                  + sizeof(sigset_t));
 518         sigset_t *sigset = (sigset_t *) &sigmask->sigset;
 519
 520         vcpu_fd = vcpu_get_fd(vm, VCPU_ID);
 521
 522         /*
 523          * SIG_IPI is unblocked atomically while in KVM_RUN.  It causes the
 524          * ioctl to return with -EINTR, but it is still pending and we need
 525          * to accept it with the sigwait.
 526          */
 527         sigmask->len = 8;
 528         pthread_sigmask(0, NULL, sigset);
 529         sigdelset(sigset, SIG_IPI);
 530         vcpu_ioctl(vm, VCPU_ID, KVM_SET_SIGNAL_MASK, sigmask);
 531
 532         sigemptyset(sigset);
 533         sigaddset(sigset, SIG_IPI);
 534
 535         guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array);
 536
 537         while (!READ_ONCE(host_quit)) {
 538                 /* Clear any existing kick signals */
 539                 generate_random_array(guest_array, TEST_PAGES_PER_LOOP);
 540                 pages_count += TEST_PAGES_PER_LOOP;
 541                 /* Let the guest dirty the random pages */
 542                 ret = ioctl(vcpu_fd, KVM_RUN, NULL);
 543                 if (ret == -1 && errno == EINTR) {
 544                         int sig = -1;
 545                         sigwait(sigset, &sig);
 546                         assert(sig == SIG_IPI);
 547                 }
 548                 log_mode_after_vcpu_run(vm, ret, errno);
 549         }
 550
 551         pr_info("Dirtied %"PRIu64" pages\n", pages_count);
 552
 553         return NULL;
 554 }
 555
 556 static void vm_dirty_log_verify(enum vm_guest_mode mode, unsigned long *bmap)
 557 {
 558         uint64_t step = vm_num_host_pages(mode, 1);
 559         uint64_t page;
 560         uint64_t *value_ptr;
 561         uint64_t min_iter = 0;
 562
 563         for (page = 0; page < host_num_pages; page += step) {
 564                 value_ptr = host_test_mem + page * host_page_size;
 565
 566                 /* If this is a special page that we were tracking... */
 567                 if (test_and_clear_bit_le(page, host_bmap_track)) {
 568                         host_track_next_count++;
 569                         TEST_ASSERT(test_bit_le(page, bmap),
 570                                     "Page %"PRIu64" should have its dirty bit "
 571                                     "set in this iteration but it is missing",
 572                                     page);
 573                 }
 574
 575                 if (test_and_clear_bit_le(page, bmap)) {
 576                         bool matched;
 577
 578                         host_dirty_count++;
 579
 580                         /*
 581                          * If the bit is set, the value written onto
 582                          * the corresponding page should be either the
 583                          * previous iteration number or the current one.
 584                          */
 585                         matched = (*value_ptr == iteration ||
 586                                    *value_ptr == iteration - 1);
 587
 588                         if (host_log_mode == LOG_MODE_DIRTY_RING && !matched) {
 589                                 if (*value_ptr == iteration - 2 && min_iter <= iteration - 2) {
 590                                         /*
 591                                          * Short answer: this case is special
 592                                          * only for dirty ring test where the
 593                                          * page is the last page before a kvm
 594                                          * dirty ring full in iteration N-2.
 595                                          *
 596                                          * Long answer: Assuming ring size R,
 597                                          * one possible condition is:
 598                                          *
 599                                          *      main thr       vcpu thr
 600                                          *      --------       --------
 601                                          *    iter=1
 602                                          *                   write 1 to page 0~(R-1)
 603                                          *                   full, vmexit
 604                                          *    collect 0~(R-1)
 605                                          *    kick vcpu
 606                                          *                   write 1 to (R-1)~(2R-2)
 607                                          *                   full, vmexit
 608                                          *    iter=2
 609                                          *    collect (R-1)~(2R-2)
 610                                          *    kick vcpu
 611                                          *                   write 1 to (2R-2)
 612                                          *                   (NOTE!!! "1" cached in cpu reg)
 613                                          *                   write 2 to (2R-1)~(3R-3)
 614                                          *                   full, vmexit
 615                                          *    iter=3
 616                                          *    collect (2R-2)~(3R-3)
 617                                          *    (here if we read value on page
 618                                          *     "2R-2" is 1, while iter=3!!!)
 619                                          *
 620                                          * This however can only happen once per iteration.
 621                                          */
 622                                         min_iter = iteration - 1;
 623                                         continue;
 624                                 } else if (page == dirty_ring_last_page) {
 625                                         /*
 626                                          * Please refer to comments in
 627                                          * dirty_ring_last_page.
 628                                          */
 629                                         continue;
 630                                 }
 631                         }
 632
 633                         TEST_ASSERT(matched,
 634                                     "Set page %"PRIu64" value %"PRIu64
 635                                     " incorrect (iteration=%"PRIu64")",
 636                                     page, *value_ptr, iteration);
 637                 } else {
 638                         host_clear_count++;
 639                         /*
 640                          * If cleared, the value written can be any
 641                          * value smaller or equals to the iteration
 642                          * number.  Note that the value can be exactly
 643                          * (iteration-1) if that write can happen
 644                          * like this:
 645                          *
 646                          * (1) increase loop count to "iteration-1"
 647                          * (2) write to page P happens (with value
 648                          *     "iteration-1")
 649                          * (3) get dirty log for "iteration-1"; we'll
 650                          *     see that page P bit is set (dirtied),
 651                          *     and not set the bit in host_bmap_track
 652                          * (4) increase loop count to "iteration"
 653                          *     (which is current iteration)
 654                          * (5) get dirty log for current iteration,
 655                          *     we'll see that page P is cleared, with
 656                          *     value "iteration-1".
 657                          */
 658                         TEST_ASSERT(*value_ptr <= iteration,
 659                                     "Clear page %"PRIu64" value %"PRIu64
 660                                     " incorrect (iteration=%"PRIu64")",
 661                                     page, *value_ptr, iteration);
 662                         if (*value_ptr == iteration) {
 663                                 /*
 664                                  * This page is _just_ modified; it
 665                                  * should report its dirtyness in the
 666                                  * next run
 667                                  */
 668                                 set_bit_le(page, host_bmap_track);
 669                         }
 670                 }
 671         }
 672 }
 673
 674 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid,
 675                                 uint64_t extra_mem_pages, void *guest_code)
 676 {
 677         struct kvm_vm *vm;
 678         uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
 679
 680         pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode));
 681
 682         vm = vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
 683         kvm_vm_elf_load(vm, program_invocation_name);
 684 #ifdef __x86_64__
 685         vm_create_irqchip(vm);
 686 #endif
 687         log_mode_create_vm_done(vm);
 688         vm_vcpu_add_default(vm, vcpuid, guest_code);
 689         return vm;
 690 }
 691
 692 #define DIRTY_MEM_BITS 30 /* 1G */
 693 #define PAGE_SHIFT_4K  12
 694
 695 struct test_params {
 696         unsigned long iterations;
 697         unsigned long interval;
 698         uint64_t phys_offset;
 699 };
 700
 701 static void run_test(enum vm_guest_mode mode, void *arg)
 702 {
 703         struct test_params *p = arg;
 704         struct kvm_vm *vm;
 705         unsigned long *bmap;
 706
 707         if (!log_mode_supported()) {
 708                 print_skip("Log mode '%s' not supported",
 709                            log_modes[host_log_mode].name);
 710                 return;
 711         }
 712
 713         /*
 714          * We reserve page table for 2 times of extra dirty mem which
 715          * will definitely cover the original (1G+) test range.  Here
 716          * we do the calculation with 4K page size which is the
 717          * smallest so the page number will be enough for all archs
 718          * (e.g., 64K page size guest will need even less memory for
 719          * page tables).
 720          */
 721         vm = create_vm(mode, VCPU_ID,
 722                        2ul << (DIRTY_MEM_BITS - PAGE_SHIFT_4K),
 723                        guest_code);
 724
 725         guest_page_size = vm_get_page_size(vm);
 726         /*
 727          * A little more than 1G of guest page sized pages.  Cover the
 728          * case where the size is not aligned to 64 pages.
 729          */
 730         guest_num_pages = (1ul << (DIRTY_MEM_BITS -
 731                                    vm_get_page_shift(vm))) + 3;
 732         guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 733
 734         host_page_size = getpagesize();
 735         host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 736
 737         if (!p->phys_offset) {
 738                 guest_test_phys_mem = (vm_get_max_gfn(vm) -
 739                                        guest_num_pages) * guest_page_size;
 740                 guest_test_phys_mem &= ~(host_page_size - 1);
 741         } else {
 742                 guest_test_phys_mem = p->phys_offset;
 743         }
 744
 745 #ifdef __s390x__
 746         /* Align to 1M (segment size) */
 747         guest_test_phys_mem &= ~((1 << 20) - 1);
 748 #endif
 749
 750         pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);
 751
 752         bmap = bitmap_zalloc(host_num_pages);
 753         host_bmap_track = bitmap_zalloc(host_num_pages);
 754
 755         /* Add an extra memory slot for testing dirty logging */
 756         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
 757                                     guest_test_phys_mem,
 758                                     TEST_MEM_SLOT_INDEX,
 759                                     guest_num_pages,
 760                                     KVM_MEM_LOG_DIRTY_PAGES);
 761
 762         /* Do mapping for the dirty track memory slot */
 763         virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages);
 764
 765         /* Cache the HVA pointer of the region */
 766         host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem);
 767
 768         ucall_init(vm, NULL);
 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         host_quit = false;
 780         host_dirty_count = 0;
 781         host_clear_count = 0;
 782         host_track_next_count = 0;
 783
 784         pthread_create(&vcpu_thread, NULL, vcpu_worker, vm);
 785
 786         while (iteration < p->iterations) {
 787                 /* Give the vcpu thread some time to dirty some pages */
 788                 usleep(p->interval * 1000);
 789                 log_mode_collect_dirty_pages(vm, TEST_MEM_SLOT_INDEX,
 790                                              bmap, host_num_pages);
 791
 792                 /*
 793                  * See vcpu_sync_stop_requested definition for details on why
 794                  * we need to stop vcpu when verify data.
 795                  */
 796                 atomic_set(&vcpu_sync_stop_requested, true);
 797                 sem_wait_until(&sem_vcpu_stop);
 798                 /*
 799                  * NOTE: for dirty ring, it's possible that we didn't stop at
 800                  * GUEST_SYNC but instead we stopped because ring is full;
 801                  * that's okay too because ring full means we're only missing
 802                  * the flush of the last page, and since we handle the last
 803                  * page specially verification will succeed anyway.
 804                  */
 805                 assert(host_log_mode == LOG_MODE_DIRTY_RING ||
 806                        atomic_read(&vcpu_sync_stop_requested) == false);
 807                 vm_dirty_log_verify(mode, bmap);
 808                 sem_post(&sem_vcpu_cont);
 809
 810                 iteration++;
 811                 sync_global_to_guest(vm, iteration);
 812         }
 813
 814         /* Tell the vcpu thread to quit */
 815         host_quit = true;
 816         log_mode_before_vcpu_join();
 817         pthread_join(vcpu_thread, NULL);
 818
 819         pr_info("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), "
 820                 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count,
 821                 host_track_next_count);
 822
 823         free(bmap);
 824         free(host_bmap_track);
 825         ucall_uninit(vm);
 826         kvm_vm_free(vm);
 827 }
 828
 829 static void help(char *name)
 830 {
 831         puts("");
 832         printf("usage: %s [-h] [-i iterations] [-I interval] "
 833                "[-p offset] [-m mode]\n", name);
 834         puts("");
 835         printf(" -c: specify dirty ring size, in number of entries\n");
 836         printf("     (only useful for dirty-ring test; default: %"PRIu32")\n",
 837                TEST_DIRTY_RING_COUNT);
 838         printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 839                TEST_HOST_LOOP_N);
 840         printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n",
 841                TEST_HOST_LOOP_INTERVAL);
 842         printf(" -p: specify guest physical test memory offset\n"
 843                "     Warning: a low offset can conflict with the loaded test code.\n");
 844         printf(" -M: specify the host logging mode "
 845                "(default: run all log modes).  Supported modes: \n\t");
 846         log_modes_dump();
 847         guest_modes_help();
 848         puts("");
 849         exit(0);
 850 }
 851
 852 int main(int argc, char *argv[])
 853 {
 854         struct test_params p = {
 855                 .iterations = TEST_HOST_LOOP_N,
 856                 .interval = TEST_HOST_LOOP_INTERVAL,
 857         };
 858         int opt, i;
 859         sigset_t sigset;
 860
 861         sem_init(&sem_vcpu_stop, 0, 0);
 862         sem_init(&sem_vcpu_cont, 0, 0);
 863
 864         guest_modes_append_default();
 865
 866         while ((opt = getopt(argc, argv, "c:hi:I:p:m:M:")) != -1) {
 867                 switch (opt) {
 868                 case 'c':
 869                         test_dirty_ring_count = strtol(optarg, NULL, 10);
 870                         break;
 871                 case 'i':
 872                         p.iterations = strtol(optarg, NULL, 10);
 873                         break;
 874                 case 'I':
 875                         p.interval = strtol(optarg, NULL, 10);
 876                         break;
 877                 case 'p':
 878                         p.phys_offset = strtoull(optarg, NULL, 0);
 879                         break;
 880                 case 'm':
 881                         guest_modes_cmdline(optarg);
 882                         break;
 883                 case 'M':
 884                         if (!strcmp(optarg, "all")) {
 885                                 host_log_mode_option = LOG_MODE_ALL;
 886                                 break;
 887                         }
 888                         for (i = 0; i < LOG_MODE_NUM; i++) {
 889                                 if (!strcmp(optarg, log_modes[i].name)) {
 890                                         pr_info("Setting log mode to: '%s'\n",
 891                                                 optarg);
 892                                         host_log_mode_option = i;
 893                                         break;
 894                                 }
 895                         }
 896                         if (i == LOG_MODE_NUM) {
 897                                 printf("Log mode '%s' invalid. Please choose "
 898                                        "from: ", optarg);
 899                                 log_modes_dump();
 900                                 exit(1);
 901                         }
 902                         break;
 903                 case 'h':
 904                 default:
 905                         help(argv[0]);
 906                         break;
 907                 }
 908         }
 909
 910         TEST_ASSERT(p.iterations > 2, "Iterations must be greater than two");
 911         TEST_ASSERT(p.interval > 0, "Interval must be greater than zero");
 912
 913         pr_info("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n",
 914                 p.iterations, p.interval);
 915
 916         srandom(time(0));
 917
 918         /* Ensure that vCPU threads start with SIG_IPI blocked.  */
 919         sigemptyset(&sigset);
 920         sigaddset(&sigset, SIG_IPI);
 921         pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 922
 923         if (host_log_mode_option == LOG_MODE_ALL) {
 924                 /* Run each log mode */
 925                 for (i = 0; i < LOG_MODE_NUM; i++) {
 926                         pr_info("Testing Log Mode '%s'\n", log_modes[i].name);
 927                         host_log_mode = i;
 928                         for_each_guest_mode(run_test, &p);
 929                 }
 930         } else {
 931                 host_log_mode = host_log_mode_option;
 932                 for_each_guest_mode(run_test, &p);
 933         }
 934
 935         return 0;
 936 }