1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * KVM dirty page logging test 4 * 5 * Copyright (C) 2018, Red Hat, Inc. 6 */ 7 8 #define _GNU_SOURCE /* for program_invocation_name */ 9 10 #include <stdio.h> 11 #include <stdlib.h> 12 #include <unistd.h> 13 #include <time.h> 14 #include <pthread.h> 15 #include <linux/bitmap.h> 16 #include <linux/bitops.h> 17 18 #include "test_util.h" 19 #include "kvm_util.h" 20 #include "processor.h" 21 22 #define DEBUG printf 23 24 #define VCPU_ID 1 25 26 /* The memory slot index to track dirty pages */ 27 #define TEST_MEM_SLOT_INDEX 1 28 29 /* Default guest test memory offset, 1G */ 30 #define DEFAULT_GUEST_TEST_MEM 0x40000000 31 32 /* How many pages to dirty for each guest loop */ 33 #define TEST_PAGES_PER_LOOP 1024 34 35 /* How many host loops to run (one KVM_GET_DIRTY_LOG for each loop) */ 36 #define TEST_HOST_LOOP_N 32UL 37 38 /* Interval for each host loop (ms) */ 39 #define TEST_HOST_LOOP_INTERVAL 10UL 40 41 /* 42 * Guest/Host shared variables. Ensure addr_gva2hva() and/or 43 * sync_global_to/from_guest() are used when accessing from 44 * the host. READ/WRITE_ONCE() should also be used with anything 45 * that may change. 46 */ 47 static uint64_t host_page_size; 48 static uint64_t guest_page_size; 49 static uint64_t guest_num_pages; 50 static uint64_t random_array[TEST_PAGES_PER_LOOP]; 51 static uint64_t iteration; 52 53 /* 54 * GPA offset of the testing memory slot. Must be bigger than 55 * DEFAULT_GUEST_PHY_PAGES. 56 */ 57 static uint64_t guest_test_mem = DEFAULT_GUEST_TEST_MEM; 58 59 /* 60 * Continuously write to the first 8 bytes of a random pages within 61 * the testing memory region. 62 */ 63 static void guest_code(void) 64 { 65 int i; 66 67 while (true) { 68 for (i = 0; i < TEST_PAGES_PER_LOOP; i++) { 69 uint64_t addr = guest_test_mem; 70 addr += (READ_ONCE(random_array[i]) % guest_num_pages) 71 * guest_page_size; 72 addr &= ~(host_page_size - 1); 73 *(uint64_t *)addr = READ_ONCE(iteration); 74 } 75 76 /* Tell the host that we need more random numbers */ 77 GUEST_SYNC(1); 78 } 79 } 80 81 /* Host variables */ 82 static bool host_quit; 83 84 /* Points to the test VM memory region on which we track dirty logs */ 85 static void *host_test_mem; 86 static uint64_t host_num_pages; 87 88 /* For statistics only */ 89 static uint64_t host_dirty_count; 90 static uint64_t host_clear_count; 91 static uint64_t host_track_next_count; 92 93 /* 94 * We use this bitmap to track some pages that should have its dirty 95 * bit set in the _next_ iteration. For example, if we detected the 96 * page value changed to current iteration but at the same time the 97 * page bit is cleared in the latest bitmap, then the system must 98 * report that write in the next get dirty log call. 99 */ 100 static unsigned long *host_bmap_track; 101 102 static void generate_random_array(uint64_t *guest_array, uint64_t size) 103 { 104 uint64_t i; 105 106 for (i = 0; i < size; i++) 107 guest_array[i] = random(); 108 } 109 110 static void *vcpu_worker(void *data) 111 { 112 int ret; 113 struct kvm_vm *vm = data; 114 uint64_t *guest_array; 115 uint64_t pages_count = 0; 116 struct kvm_run *run; 117 struct ucall uc; 118 119 run = vcpu_state(vm, VCPU_ID); 120 121 guest_array = addr_gva2hva(vm, (vm_vaddr_t)random_array); 122 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 123 124 while (!READ_ONCE(host_quit)) { 125 /* Let the guest dirty the random pages */ 126 ret = _vcpu_run(vm, VCPU_ID); 127 if (get_ucall(vm, VCPU_ID, &uc) == UCALL_SYNC) { 128 pages_count += TEST_PAGES_PER_LOOP; 129 generate_random_array(guest_array, TEST_PAGES_PER_LOOP); 130 } else { 131 TEST_ASSERT(false, 132 "Invalid guest sync status: " 133 "exit_reason=%s\n", 134 exit_reason_str(run->exit_reason)); 135 } 136 } 137 138 DEBUG("Dirtied %"PRIu64" pages\n", pages_count); 139 140 return NULL; 141 } 142 143 static void vm_dirty_log_verify(unsigned long *bmap) 144 { 145 uint64_t page; 146 uint64_t *value_ptr; 147 uint64_t step = host_page_size >= guest_page_size ? 1 : 148 guest_page_size / host_page_size; 149 150 for (page = 0; page < host_num_pages; page += step) { 151 value_ptr = host_test_mem + page * host_page_size; 152 153 /* If this is a special page that we were tracking... */ 154 if (test_and_clear_bit(page, host_bmap_track)) { 155 host_track_next_count++; 156 TEST_ASSERT(test_bit(page, bmap), 157 "Page %"PRIu64" should have its dirty bit " 158 "set in this iteration but it is missing", 159 page); 160 } 161 162 if (test_bit(page, bmap)) { 163 host_dirty_count++; 164 /* 165 * If the bit is set, the value written onto 166 * the corresponding page should be either the 167 * previous iteration number or the current one. 168 */ 169 TEST_ASSERT(*value_ptr == iteration || 170 *value_ptr == iteration - 1, 171 "Set page %"PRIu64" value %"PRIu64 172 " incorrect (iteration=%"PRIu64")", 173 page, *value_ptr, iteration); 174 } else { 175 host_clear_count++; 176 /* 177 * If cleared, the value written can be any 178 * value smaller or equals to the iteration 179 * number. Note that the value can be exactly 180 * (iteration-1) if that write can happen 181 * like this: 182 * 183 * (1) increase loop count to "iteration-1" 184 * (2) write to page P happens (with value 185 * "iteration-1") 186 * (3) get dirty log for "iteration-1"; we'll 187 * see that page P bit is set (dirtied), 188 * and not set the bit in host_bmap_track 189 * (4) increase loop count to "iteration" 190 * (which is current iteration) 191 * (5) get dirty log for current iteration, 192 * we'll see that page P is cleared, with 193 * value "iteration-1". 194 */ 195 TEST_ASSERT(*value_ptr <= iteration, 196 "Clear page %"PRIu64" value %"PRIu64 197 " incorrect (iteration=%"PRIu64")", 198 page, *value_ptr, iteration); 199 if (*value_ptr == iteration) { 200 /* 201 * This page is _just_ modified; it 202 * should report its dirtyness in the 203 * next run 204 */ 205 set_bit(page, host_bmap_track); 206 } 207 } 208 } 209 } 210 211 static struct kvm_vm *create_vm(enum vm_guest_mode mode, uint32_t vcpuid, 212 uint64_t extra_mem_pages, void *guest_code) 213 { 214 struct kvm_vm *vm; 215 uint64_t extra_pg_pages = extra_mem_pages / 512 * 2; 216 217 vm = vm_create(mode, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR); 218 kvm_vm_elf_load(vm, program_invocation_name, 0, 0); 219 #ifdef __x86_64__ 220 vm_create_irqchip(vm); 221 #endif 222 vm_vcpu_add_default(vm, vcpuid, guest_code); 223 return vm; 224 } 225 226 static void run_test(enum vm_guest_mode mode, unsigned long iterations, 227 unsigned long interval, bool top_offset) 228 { 229 unsigned int guest_pa_bits, guest_page_shift; 230 pthread_t vcpu_thread; 231 struct kvm_vm *vm; 232 uint64_t max_gfn; 233 unsigned long *bmap; 234 235 switch (mode) { 236 case VM_MODE_P52V48_4K: 237 guest_pa_bits = 52; 238 guest_page_shift = 12; 239 break; 240 case VM_MODE_P52V48_64K: 241 guest_pa_bits = 52; 242 guest_page_shift = 16; 243 break; 244 case VM_MODE_P40V48_4K: 245 guest_pa_bits = 40; 246 guest_page_shift = 12; 247 break; 248 case VM_MODE_P40V48_64K: 249 guest_pa_bits = 40; 250 guest_page_shift = 16; 251 break; 252 default: 253 TEST_ASSERT(false, "Unknown guest mode, mode: 0x%x", mode); 254 } 255 256 DEBUG("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 257 258 max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1; 259 guest_page_size = (1ul << guest_page_shift); 260 /* 1G of guest page sized pages */ 261 guest_num_pages = (1ul << (30 - guest_page_shift)); 262 host_page_size = getpagesize(); 263 host_num_pages = (guest_num_pages * guest_page_size) / host_page_size + 264 !!((guest_num_pages * guest_page_size) % host_page_size); 265 266 if (top_offset) { 267 guest_test_mem = (max_gfn - guest_num_pages) * guest_page_size; 268 guest_test_mem &= ~(host_page_size - 1); 269 } 270 271 DEBUG("guest test mem offset: 0x%lx\n", guest_test_mem); 272 273 bmap = bitmap_alloc(host_num_pages); 274 host_bmap_track = bitmap_alloc(host_num_pages); 275 276 vm = create_vm(mode, VCPU_ID, guest_num_pages, guest_code); 277 278 /* Add an extra memory slot for testing dirty logging */ 279 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 280 guest_test_mem, 281 TEST_MEM_SLOT_INDEX, 282 guest_num_pages, 283 KVM_MEM_LOG_DIRTY_PAGES); 284 285 /* Do 1:1 mapping for the dirty track memory slot */ 286 virt_map(vm, guest_test_mem, guest_test_mem, 287 guest_num_pages * guest_page_size, 0); 288 289 /* Cache the HVA pointer of the region */ 290 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_mem); 291 292 #ifdef __x86_64__ 293 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid()); 294 #endif 295 #ifdef __aarch64__ 296 ucall_init(vm, UCALL_MMIO, NULL); 297 #endif 298 299 /* Export the shared variables to the guest */ 300 sync_global_to_guest(vm, host_page_size); 301 sync_global_to_guest(vm, guest_page_size); 302 sync_global_to_guest(vm, guest_test_mem); 303 sync_global_to_guest(vm, guest_num_pages); 304 305 /* Start the iterations */ 306 iteration = 1; 307 sync_global_to_guest(vm, iteration); 308 host_quit = false; 309 host_dirty_count = 0; 310 host_clear_count = 0; 311 host_track_next_count = 0; 312 313 pthread_create(&vcpu_thread, NULL, vcpu_worker, vm); 314 315 while (iteration < iterations) { 316 /* Give the vcpu thread some time to dirty some pages */ 317 usleep(interval * 1000); 318 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); 319 vm_dirty_log_verify(bmap); 320 iteration++; 321 sync_global_to_guest(vm, iteration); 322 } 323 324 /* Tell the vcpu thread to quit */ 325 host_quit = true; 326 pthread_join(vcpu_thread, NULL); 327 328 DEBUG("Total bits checked: dirty (%"PRIu64"), clear (%"PRIu64"), " 329 "track_next (%"PRIu64")\n", host_dirty_count, host_clear_count, 330 host_track_next_count); 331 332 free(bmap); 333 free(host_bmap_track); 334 ucall_uninit(vm); 335 kvm_vm_free(vm); 336 } 337 338 static struct vm_guest_modes { 339 enum vm_guest_mode mode; 340 bool supported; 341 bool enabled; 342 } vm_guest_modes[NUM_VM_MODES] = { 343 #if defined(__x86_64__) 344 { VM_MODE_P52V48_4K, 1, 1, }, 345 { VM_MODE_P52V48_64K, 0, 0, }, 346 { VM_MODE_P40V48_4K, 0, 0, }, 347 { VM_MODE_P40V48_64K, 0, 0, }, 348 #elif defined(__aarch64__) 349 { VM_MODE_P52V48_4K, 0, 0, }, 350 { VM_MODE_P52V48_64K, 0, 0, }, 351 { VM_MODE_P40V48_4K, 1, 1, }, 352 { VM_MODE_P40V48_64K, 1, 1, }, 353 #endif 354 }; 355 356 static void help(char *name) 357 { 358 int i; 359 360 puts(""); 361 printf("usage: %s [-h] [-i iterations] [-I interval] " 362 "[-o offset] [-t] [-m mode]\n", name); 363 puts(""); 364 printf(" -i: specify iteration counts (default: %"PRIu64")\n", 365 TEST_HOST_LOOP_N); 366 printf(" -I: specify interval in ms (default: %"PRIu64" ms)\n", 367 TEST_HOST_LOOP_INTERVAL); 368 printf(" -o: guest test memory offset (default: 0x%lx)\n", 369 DEFAULT_GUEST_TEST_MEM); 370 printf(" -t: map guest test memory at the top of the allowed " 371 "physical address range\n"); 372 printf(" -m: specify the guest mode ID to test " 373 "(default: test all supported modes)\n" 374 " This option may be used multiple times.\n" 375 " Guest mode IDs:\n"); 376 for (i = 0; i < NUM_VM_MODES; ++i) { 377 printf(" %d: %s%s\n", 378 vm_guest_modes[i].mode, 379 vm_guest_mode_string(vm_guest_modes[i].mode), 380 vm_guest_modes[i].supported ? " (supported)" : ""); 381 } 382 puts(""); 383 exit(0); 384 } 385 386 int main(int argc, char *argv[]) 387 { 388 unsigned long iterations = TEST_HOST_LOOP_N; 389 unsigned long interval = TEST_HOST_LOOP_INTERVAL; 390 bool mode_selected = false; 391 bool top_offset = false; 392 unsigned int mode; 393 int opt, i; 394 395 while ((opt = getopt(argc, argv, "hi:I:o:tm:")) != -1) { 396 switch (opt) { 397 case 'i': 398 iterations = strtol(optarg, NULL, 10); 399 break; 400 case 'I': 401 interval = strtol(optarg, NULL, 10); 402 break; 403 case 'o': 404 guest_test_mem = strtoull(optarg, NULL, 0); 405 break; 406 case 't': 407 top_offset = true; 408 break; 409 case 'm': 410 if (!mode_selected) { 411 for (i = 0; i < NUM_VM_MODES; ++i) 412 vm_guest_modes[i].enabled = 0; 413 mode_selected = true; 414 } 415 mode = strtoul(optarg, NULL, 10); 416 TEST_ASSERT(mode < NUM_VM_MODES, 417 "Guest mode ID %d too big", mode); 418 vm_guest_modes[mode].enabled = 1; 419 break; 420 case 'h': 421 default: 422 help(argv[0]); 423 break; 424 } 425 } 426 427 TEST_ASSERT(iterations > 2, "Iterations must be greater than two"); 428 TEST_ASSERT(interval > 0, "Interval must be greater than zero"); 429 TEST_ASSERT(!top_offset || guest_test_mem == DEFAULT_GUEST_TEST_MEM, 430 "Cannot use both -o [offset] and -t at the same time"); 431 432 DEBUG("Test iterations: %"PRIu64", interval: %"PRIu64" (ms)\n", 433 iterations, interval); 434 435 srandom(time(0)); 436 437 for (i = 0; i < NUM_VM_MODES; ++i) { 438 if (!vm_guest_modes[i].enabled) 439 continue; 440 TEST_ASSERT(vm_guest_modes[i].supported, 441 "Guest mode ID %d (%s) not supported.", 442 vm_guest_modes[i].mode, 443 vm_guest_mode_string(vm_guest_modes[i].mode)); 444 run_test(vm_guest_modes[i].mode, iterations, interval, top_offset); 445 } 446 447 return 0; 448 } 449
