1// SPDX-License-Identifier: GPL-2.0 2/* 3 * KVM page table test 4 * 5 * Copyright (C) 2021, Huawei, Inc. 6 * 7 * Make sure that THP has been enabled or enough HUGETLB pages with specific 8 * page size have been pre-allocated on your system, if you are planning to 9 * use hugepages to back the guest memory for testing. 10 */ 11 12#define _GNU_SOURCE /* for program_invocation_name */ 13 14#include <stdio.h> 15#include <stdlib.h> 16#include <time.h> 17#include <pthread.h> 18#include <semaphore.h> 19 20#include "test_util.h" 21#include "kvm_util.h" 22#include "processor.h" 23#include "guest_modes.h" 24 25#define TEST_MEM_SLOT_INDEX 1 26 27/* Default size(1GB) of the memory for testing */ 28#define DEFAULT_TEST_MEM_SIZE (1 << 30) 29 30/* Default guest test virtual memory offset */ 31#define DEFAULT_GUEST_TEST_MEM 0xc0000000 32 33/* Different guest memory accessing stages */ 34enum test_stage { 35 KVM_BEFORE_MAPPINGS, 36 KVM_CREATE_MAPPINGS, 37 KVM_UPDATE_MAPPINGS, 38 KVM_ADJUST_MAPPINGS, 39 NUM_TEST_STAGES, 40}; 41 42static const char * const test_stage_string[] = { 43 "KVM_BEFORE_MAPPINGS", 44 "KVM_CREATE_MAPPINGS", 45 "KVM_UPDATE_MAPPINGS", 46 "KVM_ADJUST_MAPPINGS", 47}; 48 49struct test_args { 50 struct kvm_vm *vm; 51 uint64_t guest_test_virt_mem; 52 uint64_t host_page_size; 53 uint64_t host_num_pages; 54 uint64_t large_page_size; 55 uint64_t large_num_pages; 56 uint64_t host_pages_per_lpage; 57 enum vm_mem_backing_src_type src_type; 58 struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; 59}; 60 61/* 62 * Guest variables. Use addr_gva2hva() if these variables need 63 * to be changed in host. 64 */ 65static enum test_stage guest_test_stage; 66 67/* Host variables */ 68static uint32_t nr_vcpus = 1; 69static struct test_args test_args; 70static enum test_stage *current_stage; 71static bool host_quit; 72 73/* Whether the test stage is updated, or completed */ 74static sem_t test_stage_updated; 75static sem_t test_stage_completed; 76 77/* 78 * Guest physical memory offset of the testing memory slot. 79 * This will be set to the topmost valid physical address minus 80 * the test memory size. 81 */ 82static uint64_t guest_test_phys_mem; 83 84/* 85 * Guest virtual memory offset of the testing memory slot. 86 * Must not conflict with identity mapped test code. 87 */ 88static uint64_t guest_test_virt_mem = DEFAULT_GUEST_TEST_MEM; 89 90static void guest_code(bool do_write) 91{ 92 struct test_args *p = &test_args; 93 enum test_stage *current_stage = &guest_test_stage; 94 uint64_t addr; 95 int i, j; 96 97 while (true) { 98 addr = p->guest_test_virt_mem; 99 100 switch (READ_ONCE(*current_stage)) { 101 /* 102 * All vCPU threads will be started in this stage, 103 * where guest code of each vCPU will do nothing. 104 */ 105 case KVM_BEFORE_MAPPINGS: 106 break; 107 108 /* 109 * Before dirty logging, vCPUs concurrently access the first 110 * 8 bytes of each page (host page/large page) within the same 111 * memory region with different accessing types (read/write). 112 * Then KVM will create normal page mappings or huge block 113 * mappings for them. 114 */ 115 case KVM_CREATE_MAPPINGS: 116 for (i = 0; i < p->large_num_pages; i++) { 117 if (do_write) 118 *(uint64_t *)addr = 0x0123456789ABCDEF; 119 else 120 READ_ONCE(*(uint64_t *)addr); 121 122 addr += p->large_page_size; 123 } 124 break; 125 126 /* 127 * During dirty logging, KVM will only update attributes of the 128 * normal page mappings from RO to RW if memory backing src type 129 * is anonymous. In other cases, KVM will split the huge block 130 * mappings into normal page mappings if memory backing src type 131 * is THP or HUGETLB. 132 */ 133 case KVM_UPDATE_MAPPINGS: 134 if (p->src_type == VM_MEM_SRC_ANONYMOUS) { 135 for (i = 0; i < p->host_num_pages; i++) { 136 *(uint64_t *)addr = 0x0123456789ABCDEF; 137 addr += p->host_page_size; 138 } 139 break; 140 } 141 142 for (i = 0; i < p->large_num_pages; i++) { 143 /* 144 * Write to the first host page in each large 145 * page region, and triger break of large pages. 146 */ 147 *(uint64_t *)addr = 0x0123456789ABCDEF; 148 149 /* 150 * Access the middle host pages in each large 151 * page region. Since dirty logging is enabled, 152 * this will create new mappings at the smallest 153 * granularity. 154 */ 155 addr += p->large_page_size / 2; 156 for (j = 0; j < p->host_pages_per_lpage / 2; j++) { 157 READ_ONCE(*(uint64_t *)addr); 158 addr += p->host_page_size; 159 } 160 } 161 break; 162 163 /* 164 * After dirty logging is stopped, vCPUs concurrently read 165 * from every single host page. Then KVM will coalesce the 166 * split page mappings back to block mappings. And a TLB 167 * conflict abort could occur here if TLB entries of the 168 * page mappings are not fully invalidated. 169 */ 170 case KVM_ADJUST_MAPPINGS: 171 for (i = 0; i < p->host_num_pages; i++) { 172 READ_ONCE(*(uint64_t *)addr); 173 addr += p->host_page_size; 174 } 175 break; 176 177 default: 178 GUEST_ASSERT(0); 179 } 180 181 GUEST_SYNC(1); 182 } 183} 184 185static void *vcpu_worker(void *data) 186{ 187 struct kvm_vcpu *vcpu = data; 188 bool do_write = !(vcpu->id % 2); 189 struct timespec start; 190 struct timespec ts_diff; 191 enum test_stage stage; 192 int ret; 193 194 vcpu_args_set(vcpu, 1, do_write); 195 196 while (!READ_ONCE(host_quit)) { 197 ret = sem_wait(&test_stage_updated); 198 TEST_ASSERT(ret == 0, "Error in sem_wait"); 199 200 if (READ_ONCE(host_quit)) 201 return NULL; 202 203 clock_gettime(CLOCK_MONOTONIC, &start); 204 ret = _vcpu_run(vcpu); 205 ts_diff = timespec_elapsed(start); 206 207 TEST_ASSERT(ret == 0, "vcpu_run failed: %d", ret); 208 TEST_ASSERT(get_ucall(vcpu, NULL) == UCALL_SYNC, 209 "Invalid guest sync status: exit_reason=%s", 210 exit_reason_str(vcpu->run->exit_reason)); 211 212 pr_debug("Got sync event from vCPU %d\n", vcpu->id); 213 stage = READ_ONCE(*current_stage); 214 215 /* 216 * Here we can know the execution time of every 217 * single vcpu running in different test stages. 218 */ 219 pr_debug("vCPU %d has completed stage %s\n" 220 "execution time is: %ld.%.9lds\n\n", 221 vcpu->id, test_stage_string[stage], 222 ts_diff.tv_sec, ts_diff.tv_nsec); 223 224 ret = sem_post(&test_stage_completed); 225 TEST_ASSERT(ret == 0, "Error in sem_post"); 226 } 227 228 return NULL; 229} 230 231struct test_params { 232 uint64_t phys_offset; 233 uint64_t test_mem_size; 234 enum vm_mem_backing_src_type src_type; 235}; 236 237static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg) 238{ 239 int ret; 240 struct test_params *p = arg; 241 enum vm_mem_backing_src_type src_type = p->src_type; 242 uint64_t large_page_size = get_backing_src_pagesz(src_type); 243 uint64_t guest_page_size = vm_guest_mode_params[mode].page_size; 244 uint64_t host_page_size = getpagesize(); 245 uint64_t test_mem_size = p->test_mem_size; 246 uint64_t guest_num_pages; 247 uint64_t alignment; 248 void *host_test_mem; 249 struct kvm_vm *vm; 250 251 /* Align up the test memory size */ 252 alignment = max(large_page_size, guest_page_size); 253 test_mem_size = (test_mem_size + alignment - 1) & ~(alignment - 1); 254 255 /* Create a VM with enough guest pages */ 256 guest_num_pages = test_mem_size / guest_page_size; 257 vm = __vm_create_with_vcpus(VM_SHAPE(mode), nr_vcpus, guest_num_pages, 258 guest_code, test_args.vcpus); 259 260 /* Align down GPA of the testing memslot */ 261 if (!p->phys_offset) 262 guest_test_phys_mem = (vm->max_gfn - guest_num_pages) * 263 guest_page_size; 264 else 265 guest_test_phys_mem = p->phys_offset; 266#ifdef __s390x__ 267 alignment = max(0x100000UL, alignment); 268#endif 269 guest_test_phys_mem = align_down(guest_test_phys_mem, alignment); 270 271 /* Set up the shared data structure test_args */ 272 test_args.vm = vm; 273 test_args.guest_test_virt_mem = guest_test_virt_mem; 274 test_args.host_page_size = host_page_size; 275 test_args.host_num_pages = test_mem_size / host_page_size; 276 test_args.large_page_size = large_page_size; 277 test_args.large_num_pages = test_mem_size / large_page_size; 278 test_args.host_pages_per_lpage = large_page_size / host_page_size; 279 test_args.src_type = src_type; 280 281 /* Add an extra memory slot with specified backing src type */ 282 vm_userspace_mem_region_add(vm, src_type, guest_test_phys_mem, 283 TEST_MEM_SLOT_INDEX, guest_num_pages, 0); 284 285 /* Do mapping(GVA->GPA) for the testing memory slot */ 286 virt_map(vm, guest_test_virt_mem, guest_test_phys_mem, guest_num_pages); 287 288 /* Cache the HVA pointer of the region */ 289 host_test_mem = addr_gpa2hva(vm, (vm_paddr_t)guest_test_phys_mem); 290 291 /* Export shared structure test_args to guest */ 292 sync_global_to_guest(vm, test_args); 293 294 ret = sem_init(&test_stage_updated, 0, 0); 295 TEST_ASSERT(ret == 0, "Error in sem_init"); 296 297 ret = sem_init(&test_stage_completed, 0, 0); 298 TEST_ASSERT(ret == 0, "Error in sem_init"); 299 300 current_stage = addr_gva2hva(vm, (vm_vaddr_t)(&guest_test_stage)); 301 *current_stage = NUM_TEST_STAGES; 302 303 pr_info("Testing guest mode: %s\n", vm_guest_mode_string(mode)); 304 pr_info("Testing memory backing src type: %s\n", 305 vm_mem_backing_src_alias(src_type)->name); 306 pr_info("Testing memory backing src granularity: 0x%lx\n", 307 large_page_size); 308 pr_info("Testing memory size(aligned): 0x%lx\n", test_mem_size); 309 pr_info("Guest physical test memory offset: 0x%lx\n", 310 guest_test_phys_mem); 311 pr_info("Host virtual test memory offset: 0x%lx\n", 312 (uint64_t)host_test_mem); 313 pr_info("Number of testing vCPUs: %d\n", nr_vcpus); 314 315 return vm; 316} 317 318static void vcpus_complete_new_stage(enum test_stage stage) 319{ 320 int ret; 321 int vcpus; 322 323 /* Wake up all the vcpus to run new test stage */ 324 for (vcpus = 0; vcpus < nr_vcpus; vcpus++) { 325 ret = sem_post(&test_stage_updated); 326 TEST_ASSERT(ret == 0, "Error in sem_post"); 327 } 328 pr_debug("All vcpus have been notified to continue\n"); 329 330 /* Wait for all the vcpus to complete new test stage */ 331 for (vcpus = 0; vcpus < nr_vcpus; vcpus++) { 332 ret = sem_wait(&test_stage_completed); 333 TEST_ASSERT(ret == 0, "Error in sem_wait"); 334 335 pr_debug("%d vcpus have completed stage %s\n", 336 vcpus + 1, test_stage_string[stage]); 337 } 338 339 pr_debug("All vcpus have completed stage %s\n", 340 test_stage_string[stage]); 341} 342 343static void run_test(enum vm_guest_mode mode, void *arg) 344{ 345 pthread_t *vcpu_threads; 346 struct kvm_vm *vm; 347 struct timespec start; 348 struct timespec ts_diff; 349 int ret, i; 350 351 /* Create VM with vCPUs and make some pre-initialization */ 352 vm = pre_init_before_test(mode, arg); 353 354 vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads)); 355 TEST_ASSERT(vcpu_threads, "Memory allocation failed"); 356 357 host_quit = false; 358 *current_stage = KVM_BEFORE_MAPPINGS; 359 360 for (i = 0; i < nr_vcpus; i++) 361 pthread_create(&vcpu_threads[i], NULL, vcpu_worker, 362 test_args.vcpus[i]); 363 364 vcpus_complete_new_stage(*current_stage); 365 pr_info("Started all vCPUs successfully\n"); 366 367 /* Test the stage of KVM creating mappings */ 368 *current_stage = KVM_CREATE_MAPPINGS; 369 370 clock_gettime(CLOCK_MONOTONIC, &start); 371 vcpus_complete_new_stage(*current_stage); 372 ts_diff = timespec_elapsed(start); 373 374 pr_info("KVM_CREATE_MAPPINGS: total execution time: %ld.%.9lds\n\n", 375 ts_diff.tv_sec, ts_diff.tv_nsec); 376 377 /* Test the stage of KVM updating mappings */ 378 vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 379 KVM_MEM_LOG_DIRTY_PAGES); 380 381 *current_stage = KVM_UPDATE_MAPPINGS; 382 383 clock_gettime(CLOCK_MONOTONIC, &start); 384 vcpus_complete_new_stage(*current_stage); 385 ts_diff = timespec_elapsed(start); 386 387 pr_info("KVM_UPDATE_MAPPINGS: total execution time: %ld.%.9lds\n\n", 388 ts_diff.tv_sec, ts_diff.tv_nsec); 389 390 /* Test the stage of KVM adjusting mappings */ 391 vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0); 392 393 *current_stage = KVM_ADJUST_MAPPINGS; 394 395 clock_gettime(CLOCK_MONOTONIC, &start); 396 vcpus_complete_new_stage(*current_stage); 397 ts_diff = timespec_elapsed(start); 398 399 pr_info("KVM_ADJUST_MAPPINGS: total execution time: %ld.%.9lds\n\n", 400 ts_diff.tv_sec, ts_diff.tv_nsec); 401 402 /* Tell the vcpu thread to quit */ 403 host_quit = true; 404 for (i = 0; i < nr_vcpus; i++) { 405 ret = sem_post(&test_stage_updated); 406 TEST_ASSERT(ret == 0, "Error in sem_post"); 407 } 408 409 for (i = 0; i < nr_vcpus; i++) 410 pthread_join(vcpu_threads[i], NULL); 411 412 ret = sem_destroy(&test_stage_updated); 413 TEST_ASSERT(ret == 0, "Error in sem_destroy"); 414 415 ret = sem_destroy(&test_stage_completed); 416 TEST_ASSERT(ret == 0, "Error in sem_destroy"); 417 418 free(vcpu_threads); 419 kvm_vm_free(vm); 420} 421 422static void help(char *name) 423{ 424 puts(""); 425 printf("usage: %s [-h] [-p offset] [-m mode] " 426 "[-b mem-size] [-v vcpus] [-s mem-type]\n", name); 427 puts(""); 428 printf(" -p: specify guest physical test memory offset\n" 429 " Warning: a low offset can conflict with the loaded test code.\n"); 430 guest_modes_help(); 431 printf(" -b: specify size of the memory region for testing. e.g. 10M or 3G.\n" 432 " (default: 1G)\n"); 433 printf(" -v: specify the number of vCPUs to run\n" 434 " (default: 1)\n"); 435 backing_src_help("-s"); 436 puts(""); 437} 438 439int main(int argc, char *argv[]) 440{ 441 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 442 struct test_params p = { 443 .test_mem_size = DEFAULT_TEST_MEM_SIZE, 444 .src_type = DEFAULT_VM_MEM_SRC, 445 }; 446 int opt; 447 448 guest_modes_append_default(); 449 450 while ((opt = getopt(argc, argv, "hp:m:b:v:s:")) != -1) { 451 switch (opt) { 452 case 'p': 453 p.phys_offset = strtoull(optarg, NULL, 0); 454 break; 455 case 'm': 456 guest_modes_cmdline(optarg); 457 break; 458 case 'b': 459 p.test_mem_size = parse_size(optarg); 460 break; 461 case 'v': 462 nr_vcpus = atoi_positive("Number of vCPUs", optarg); 463 TEST_ASSERT(nr_vcpus <= max_vcpus, 464 "Invalid number of vcpus, must be between 1 and %d", max_vcpus); 465 break; 466 case 's': 467 p.src_type = parse_backing_src_type(optarg); 468 break; 469 case 'h': 470 default: 471 help(argv[0]); 472 exit(0); 473 } 474 } 475 476 for_each_guest_mode(run_test, &p); 477 478 return 0; 479} 480