tools/testing/selftests/kvm/dirty_log_perf_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * KVM dirty page logging performance test
   4  *
   5  * Based on dirty_log_test.c
   6  *
   7  * Copyright (C) 2018, Red Hat, Inc.
   8  * Copyright (C) 2020, Google, Inc.
   9  */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <time.h>
  14 #include <pthread.h>
  15 #include <linux/bitmap.h>
  16
  17 #include "kvm_util.h"
  18 #include "test_util.h"
  19 #include "perf_test_util.h"
  20 #include "guest_modes.h"
  21
  22 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
  23 #define TEST_HOST_LOOP_N                2UL
  24
  25 static int nr_vcpus = 1;
  26 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
  27
  28 /* Host variables */
  29 static u64 dirty_log_manual_caps;
  30 static bool host_quit;
  31 static int iteration;
  32 static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
  33
  34 static void *vcpu_worker(void *data)
  35 {
  36         int ret;
  37         struct kvm_vm *vm = perf_test_args.vm;
  38         uint64_t pages_count = 0;
  39         struct kvm_run *run;
  40         struct timespec start;
  41         struct timespec ts_diff;
  42         struct timespec total = (struct timespec){0};
  43         struct timespec avg;
  44         struct perf_test_vcpu_args *vcpu_args = (struct perf_test_vcpu_args *)data;
  45         int vcpu_id = vcpu_args->vcpu_id;
  46
  47         run = vcpu_state(vm, vcpu_id);
  48
  49         while (!READ_ONCE(host_quit)) {
  50                 int current_iteration = READ_ONCE(iteration);
  51
  52                 clock_gettime(CLOCK_MONOTONIC, &start);
  53                 ret = _vcpu_run(vm, vcpu_id);
  54                 ts_diff = timespec_elapsed(start);
  55
  56                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  57                 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
  58                             "Invalid guest sync status: exit_reason=%s\n",
  59                             exit_reason_str(run->exit_reason));
  60
  61                 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
  62                 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
  63                 pr_debug("vCPU %d updated last completed iteration to %d\n",
  64                          vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
  65
  66                 if (current_iteration) {
  67                         pages_count += vcpu_args->pages;
  68                         total = timespec_add(total, ts_diff);
  69                         pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
  70                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  71                                 ts_diff.tv_nsec);
  72                 } else {
  73                         pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
  74                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  75                                 ts_diff.tv_nsec);
  76                 }
  77
  78                 while (current_iteration == READ_ONCE(iteration) &&
  79                        !READ_ONCE(host_quit)) {}
  80         }
  81
  82         avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
  83         pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
  84                 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
  85                 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
  86
  87         return NULL;
  88 }
  89
  90 struct test_params {
  91         unsigned long iterations;
  92         uint64_t phys_offset;
  93         int wr_fract;
  94         bool partition_vcpu_memory_access;
  95         enum vm_mem_backing_src_type backing_src;
  96         int slots;
  97 };
  98
  99 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
 100 {
 101         int i;
 102
 103         for (i = 0; i < slots; i++) {
 104                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 105                 int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
 106
 107                 vm_mem_region_set_flags(vm, slot, flags);
 108         }
 109 }
 110
 111 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
 112 {
 113         toggle_dirty_logging(vm, slots, true);
 114 }
 115
 116 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
 117 {
 118         toggle_dirty_logging(vm, slots, false);
 119 }
 120
 121 static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots)
 122 {
 123         int i;
 124
 125         for (i = 0; i < slots; i++) {
 126                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 127
 128                 kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
 129         }
 130 }
 131
 132 static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
 133                             int slots, uint64_t pages_per_slot)
 134 {
 135         int i;
 136
 137         for (i = 0; i < slots; i++) {
 138                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 139
 140                 kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
 141         }
 142 }
 143
 144 static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot)
 145 {
 146         unsigned long **bitmaps;
 147         int i;
 148
 149         bitmaps = malloc(slots * sizeof(bitmaps[0]));
 150         TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array.");
 151
 152         for (i = 0; i < slots; i++) {
 153                 bitmaps[i] = bitmap_zalloc(pages_per_slot);
 154                 TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap.");
 155         }
 156
 157         return bitmaps;
 158 }
 159
 160 static void free_bitmaps(unsigned long *bitmaps[], int slots)
 161 {
 162         int i;
 163
 164         for (i = 0; i < slots; i++)
 165                 free(bitmaps[i]);
 166
 167         free(bitmaps);
 168 }
 169
 170 static void run_test(enum vm_guest_mode mode, void *arg)
 171 {
 172         struct test_params *p = arg;
 173         pthread_t *vcpu_threads;
 174         struct kvm_vm *vm;
 175         unsigned long **bitmaps;
 176         uint64_t guest_num_pages;
 177         uint64_t host_num_pages;
 178         uint64_t pages_per_slot;
 179         int vcpu_id;
 180         struct timespec start;
 181         struct timespec ts_diff;
 182         struct timespec get_dirty_log_total = (struct timespec){0};
 183         struct timespec vcpu_dirty_total = (struct timespec){0};
 184         struct timespec avg;
 185         struct kvm_enable_cap cap = {};
 186         struct timespec clear_dirty_log_total = (struct timespec){0};
 187
 188         vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 189                                  p->slots, p->backing_src);
 190
 191         perf_test_args.wr_fract = p->wr_fract;
 192
 193         guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
 194         guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 195         host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 196         pages_per_slot = host_num_pages / p->slots;
 197
 198         bitmaps = alloc_bitmaps(p->slots, pages_per_slot);
 199
 200         if (dirty_log_manual_caps) {
 201                 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 202                 cap.args[0] = dirty_log_manual_caps;
 203                 vm_enable_cap(vm, &cap);
 204         }
 205
 206         vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
 207         TEST_ASSERT(vcpu_threads, "Memory allocation failed");
 208
 209         perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
 210                               p->partition_vcpu_memory_access);
 211
 212         sync_global_to_guest(vm, perf_test_args);
 213
 214         /* Start the iterations */
 215         iteration = 0;
 216         host_quit = false;
 217
 218         clock_gettime(CLOCK_MONOTONIC, &start);
 219         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 220                 vcpu_last_completed_iteration[vcpu_id] = -1;
 221
 222                 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 223                                &perf_test_args.vcpu_args[vcpu_id]);
 224         }
 225
 226         /* Allow the vCPUs to populate memory */
 227         pr_debug("Starting iteration %d - Populating\n", iteration);
 228         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 229                 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
 230                        iteration)
 231                         ;
 232         }
 233
 234         ts_diff = timespec_elapsed(start);
 235         pr_info("Populate memory time: %ld.%.9lds\n",
 236                 ts_diff.tv_sec, ts_diff.tv_nsec);
 237
 238         /* Enable dirty logging */
 239         clock_gettime(CLOCK_MONOTONIC, &start);
 240         enable_dirty_logging(vm, p->slots);
 241         ts_diff = timespec_elapsed(start);
 242         pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 243                 ts_diff.tv_sec, ts_diff.tv_nsec);
 244
 245         while (iteration < p->iterations) {
 246                 /*
 247                  * Incrementing the iteration number will start the vCPUs
 248                  * dirtying memory again.
 249                  */
 250                 clock_gettime(CLOCK_MONOTONIC, &start);
 251                 iteration++;
 252
 253                 pr_debug("Starting iteration %d\n", iteration);
 254                 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 255                         while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
 256                                != iteration)
 257                                 ;
 258                 }
 259
 260                 ts_diff = timespec_elapsed(start);
 261                 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
 262                 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n",
 263                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 264
 265                 clock_gettime(CLOCK_MONOTONIC, &start);
 266                 get_dirty_log(vm, bitmaps, p->slots);
 267                 ts_diff = timespec_elapsed(start);
 268                 get_dirty_log_total = timespec_add(get_dirty_log_total,
 269                                                    ts_diff);
 270                 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
 271                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 272
 273                 if (dirty_log_manual_caps) {
 274                         clock_gettime(CLOCK_MONOTONIC, &start);
 275                         clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot);
 276                         ts_diff = timespec_elapsed(start);
 277                         clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 278                                                              ts_diff);
 279                         pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
 280                                 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 281                 }
 282         }
 283
 284         /* Disable dirty logging */
 285         clock_gettime(CLOCK_MONOTONIC, &start);
 286         disable_dirty_logging(vm, p->slots);
 287         ts_diff = timespec_elapsed(start);
 288         pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 289                 ts_diff.tv_sec, ts_diff.tv_nsec);
 290
 291         /* Tell the vcpu thread to quit */
 292         host_quit = true;
 293         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 294                 pthread_join(vcpu_threads[vcpu_id], NULL);
 295
 296         avg = timespec_div(get_dirty_log_total, p->iterations);
 297         pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 298                 p->iterations, get_dirty_log_total.tv_sec,
 299                 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 300
 301         if (dirty_log_manual_caps) {
 302                 avg = timespec_div(clear_dirty_log_total, p->iterations);
 303                 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 304                         p->iterations, clear_dirty_log_total.tv_sec,
 305                         clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 306         }
 307
 308         free_bitmaps(bitmaps, p->slots);
 309         free(vcpu_threads);
 310         perf_test_destroy_vm(vm);
 311 }
 312
 313 static void help(char *name)
 314 {
 315         puts("");
 316         printf("usage: %s [-h] [-i iterations] [-p offset] "
 317                "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
 318                "[-x memslots]\n", name);
 319         puts("");
 320         printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 321                TEST_HOST_LOOP_N);
 322         printf(" -p: specify guest physical test memory offset\n"
 323                "     Warning: a low offset can conflict with the loaded test code.\n");
 324         guest_modes_help();
 325         printf(" -b: specify the size of the memory region which should be\n"
 326                "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 327                "     (default: 1G)\n");
 328         printf(" -f: specify the fraction of pages which should be written to\n"
 329                "     as opposed to simply read, in the form\n"
 330                "     1/<fraction of pages to write>.\n"
 331                "     (default: 1 i.e. all pages are written to.)\n");
 332         printf(" -v: specify the number of vCPUs to run.\n");
 333         printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 334                "     them into a separate region of memory for each vCPU.\n");
 335         backing_src_help("-s");
 336         printf(" -x: Split the memory region into this number of memslots.\n"
 337                "     (default: 1)\n");
 338         puts("");
 339         exit(0);
 340 }
 341
 342 int main(int argc, char *argv[])
 343 {
 344         int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 345         struct test_params p = {
 346                 .iterations = TEST_HOST_LOOP_N,
 347                 .wr_fract = 1,
 348                 .partition_vcpu_memory_access = true,
 349                 .backing_src = DEFAULT_VM_MEM_SRC,
 350                 .slots = 1,
 351         };
 352         int opt;
 353
 354         dirty_log_manual_caps =
 355                 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 356         dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 357                                   KVM_DIRTY_LOG_INITIALLY_SET);
 358
 359         guest_modes_append_default();
 360
 361         while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:x:")) != -1) {
 362                 switch (opt) {
 363                 case 'i':
 364                         p.iterations = atoi(optarg);
 365                         break;
 366                 case 'p':
 367                         p.phys_offset = strtoull(optarg, NULL, 0);
 368                         break;
 369                 case 'm':
 370                         guest_modes_cmdline(optarg);
 371                         break;
 372                 case 'b':
 373                         guest_percpu_mem_size = parse_size(optarg);
 374                         break;
 375                 case 'f':
 376                         p.wr_fract = atoi(optarg);
 377                         TEST_ASSERT(p.wr_fract >= 1,
 378                                     "Write fraction cannot be less than one");
 379                         break;
 380                 case 'v':
 381                         nr_vcpus = atoi(optarg);
 382                         TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 383                                     "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 384                         break;
 385                 case 'o':
 386                         p.partition_vcpu_memory_access = false;
 387                         break;
 388                 case 's':
 389                         p.backing_src = parse_backing_src_type(optarg);
 390                         break;
 391                 case 'x':
 392                         p.slots = atoi(optarg);
 393                         break;
 394                 case 'h':
 395                 default:
 396                         help(argv[0]);
 397                         break;
 398                 }
 399         }
 400
 401         TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations");
 402
 403         pr_info("Test iterations: %"PRIu64"\n", p.iterations);
 404
 405         for_each_guest_mode(run_test, &p);
 406
 407         return 0;
 408 }