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