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 #ifdef __aarch64__
  22 #include "aarch64/vgic.h"
  23
  24 #define GICD_BASE_GPA                   0x8000000ULL
  25 #define GICR_BASE_GPA                   0x80A0000ULL
  26 #endif
  27
  28 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
  29 #define TEST_HOST_LOOP_N                2UL
  30
  31 static int nr_vcpus = 1;
  32 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
  33
  34 /* Host variables */
  35 static u64 dirty_log_manual_caps;
  36 static bool host_quit;
  37 static int iteration;
  38 static int vcpu_last_completed_iteration[KVM_MAX_VCPUS];
  39
  40 static void vcpu_worker(struct perf_test_vcpu_args *vcpu_args)
  41 {
  42         int ret;
  43         struct kvm_vm *vm = perf_test_args.vm;
  44         uint64_t pages_count = 0;
  45         struct kvm_run *run;
  46         struct timespec start;
  47         struct timespec ts_diff;
  48         struct timespec total = (struct timespec){0};
  49         struct timespec avg;
  50         int vcpu_id = vcpu_args->vcpu_id;
  51
  52         run = vcpu_state(vm, vcpu_id);
  53
  54         while (!READ_ONCE(host_quit)) {
  55                 int current_iteration = READ_ONCE(iteration);
  56
  57                 clock_gettime(CLOCK_MONOTONIC, &start);
  58                 ret = _vcpu_run(vm, vcpu_id);
  59                 ts_diff = timespec_elapsed(start);
  60
  61                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  62                 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
  63                             "Invalid guest sync status: exit_reason=%s\n",
  64                             exit_reason_str(run->exit_reason));
  65
  66                 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
  67                 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
  68                 pr_debug("vCPU %d updated last completed iteration to %d\n",
  69                          vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
  70
  71                 if (current_iteration) {
  72                         pages_count += vcpu_args->pages;
  73                         total = timespec_add(total, ts_diff);
  74                         pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
  75                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  76                                 ts_diff.tv_nsec);
  77                 } else {
  78                         pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
  79                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  80                                 ts_diff.tv_nsec);
  81                 }
  82
  83                 while (current_iteration == READ_ONCE(iteration) &&
  84                        !READ_ONCE(host_quit)) {}
  85         }
  86
  87         avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
  88         pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
  89                 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
  90                 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
  91 }
  92
  93 struct test_params {
  94         unsigned long iterations;
  95         uint64_t phys_offset;
  96         int wr_fract;
  97         bool partition_vcpu_memory_access;
  98         enum vm_mem_backing_src_type backing_src;
  99         int slots;
 100 };
 101
 102 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)
 103 {
 104         int i;
 105
 106         for (i = 0; i < slots; i++) {
 107                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 108                 int flags = enable ? KVM_MEM_LOG_DIRTY_PAGES : 0;
 109
 110                 vm_mem_region_set_flags(vm, slot, flags);
 111         }
 112 }
 113
 114 static inline void enable_dirty_logging(struct kvm_vm *vm, int slots)
 115 {
 116         toggle_dirty_logging(vm, slots, true);
 117 }
 118
 119 static inline void disable_dirty_logging(struct kvm_vm *vm, int slots)
 120 {
 121         toggle_dirty_logging(vm, slots, false);
 122 }
 123
 124 static void get_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[], int slots)
 125 {
 126         int i;
 127
 128         for (i = 0; i < slots; i++) {
 129                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 130
 131                 kvm_vm_get_dirty_log(vm, slot, bitmaps[i]);
 132         }
 133 }
 134
 135 static void clear_dirty_log(struct kvm_vm *vm, unsigned long *bitmaps[],
 136                             int slots, uint64_t pages_per_slot)
 137 {
 138         int i;
 139
 140         for (i = 0; i < slots; i++) {
 141                 int slot = PERF_TEST_MEM_SLOT_INDEX + i;
 142
 143                 kvm_vm_clear_dirty_log(vm, slot, bitmaps[i], 0, pages_per_slot);
 144         }
 145 }
 146
 147 static unsigned long **alloc_bitmaps(int slots, uint64_t pages_per_slot)
 148 {
 149         unsigned long **bitmaps;
 150         int i;
 151
 152         bitmaps = malloc(slots * sizeof(bitmaps[0]));
 153         TEST_ASSERT(bitmaps, "Failed to allocate bitmaps array.");
 154
 155         for (i = 0; i < slots; i++) {
 156                 bitmaps[i] = bitmap_zalloc(pages_per_slot);
 157                 TEST_ASSERT(bitmaps[i], "Failed to allocate slot bitmap.");
 158         }
 159
 160         return bitmaps;
 161 }
 162
 163 static void free_bitmaps(unsigned long *bitmaps[], int slots)
 164 {
 165         int i;
 166
 167         for (i = 0; i < slots; i++)
 168                 free(bitmaps[i]);
 169
 170         free(bitmaps);
 171 }
 172
 173 static void run_test(enum vm_guest_mode mode, void *arg)
 174 {
 175         struct test_params *p = arg;
 176         struct kvm_vm *vm;
 177         unsigned long **bitmaps;
 178         uint64_t guest_num_pages;
 179         uint64_t host_num_pages;
 180         uint64_t pages_per_slot;
 181         int vcpu_id;
 182         struct timespec start;
 183         struct timespec ts_diff;
 184         struct timespec get_dirty_log_total = (struct timespec){0};
 185         struct timespec vcpu_dirty_total = (struct timespec){0};
 186         struct timespec avg;
 187         struct kvm_enable_cap cap = {};
 188         struct timespec clear_dirty_log_total = (struct timespec){0};
 189
 190         vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 191                                  p->slots, p->backing_src,
 192                                  p->partition_vcpu_memory_access);
 193
 194         perf_test_set_wr_fract(vm, p->wr_fract);
 195
 196         guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
 197         guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 198         host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 199         pages_per_slot = host_num_pages / p->slots;
 200
 201         bitmaps = alloc_bitmaps(p->slots, pages_per_slot);
 202
 203         if (dirty_log_manual_caps) {
 204                 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 205                 cap.args[0] = dirty_log_manual_caps;
 206                 vm_enable_cap(vm, &cap);
 207         }
 208
 209 #ifdef __aarch64__
 210         vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
 211 #endif
 212
 213         /* Start the iterations */
 214         iteration = 0;
 215         host_quit = false;
 216
 217         clock_gettime(CLOCK_MONOTONIC, &start);
 218         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 219                 vcpu_last_completed_iteration[vcpu_id] = -1;
 220
 221         perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker);
 222
 223         /* Allow the vCPUs to populate memory */
 224         pr_debug("Starting iteration %d - Populating\n", iteration);
 225         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 226                 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
 227                        iteration)
 228                         ;
 229         }
 230
 231         ts_diff = timespec_elapsed(start);
 232         pr_info("Populate memory time: %ld.%.9lds\n",
 233                 ts_diff.tv_sec, ts_diff.tv_nsec);
 234
 235         /* Enable dirty logging */
 236         clock_gettime(CLOCK_MONOTONIC, &start);
 237         enable_dirty_logging(vm, p->slots);
 238         ts_diff = timespec_elapsed(start);
 239         pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 240                 ts_diff.tv_sec, ts_diff.tv_nsec);
 241
 242         while (iteration < p->iterations) {
 243                 /*
 244                  * Incrementing the iteration number will start the vCPUs
 245                  * dirtying memory again.
 246                  */
 247                 clock_gettime(CLOCK_MONOTONIC, &start);
 248                 iteration++;
 249
 250                 pr_debug("Starting iteration %d\n", iteration);
 251                 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 252                         while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
 253                                != iteration)
 254                                 ;
 255                 }
 256
 257                 ts_diff = timespec_elapsed(start);
 258                 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
 259                 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n",
 260                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 261
 262                 clock_gettime(CLOCK_MONOTONIC, &start);
 263                 get_dirty_log(vm, bitmaps, p->slots);
 264                 ts_diff = timespec_elapsed(start);
 265                 get_dirty_log_total = timespec_add(get_dirty_log_total,
 266                                                    ts_diff);
 267                 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
 268                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 269
 270                 if (dirty_log_manual_caps) {
 271                         clock_gettime(CLOCK_MONOTONIC, &start);
 272                         clear_dirty_log(vm, bitmaps, p->slots, pages_per_slot);
 273                         ts_diff = timespec_elapsed(start);
 274                         clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 275                                                              ts_diff);
 276                         pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
 277                                 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 278                 }
 279         }
 280
 281         /* Disable dirty logging */
 282         clock_gettime(CLOCK_MONOTONIC, &start);
 283         disable_dirty_logging(vm, p->slots);
 284         ts_diff = timespec_elapsed(start);
 285         pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 286                 ts_diff.tv_sec, ts_diff.tv_nsec);
 287
 288         /* Tell the vcpu thread to quit */
 289         host_quit = true;
 290         perf_test_join_vcpu_threads(nr_vcpus);
 291
 292         avg = timespec_div(get_dirty_log_total, p->iterations);
 293         pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 294                 p->iterations, get_dirty_log_total.tv_sec,
 295                 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 296
 297         if (dirty_log_manual_caps) {
 298                 avg = timespec_div(clear_dirty_log_total, p->iterations);
 299                 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 300                         p->iterations, clear_dirty_log_total.tv_sec,
 301                         clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 302         }
 303
 304         free_bitmaps(bitmaps, p->slots);
 305         perf_test_destroy_vm(vm);
 306 }
 307
 308 static void help(char *name)
 309 {
 310         puts("");
 311         printf("usage: %s [-h] [-i iterations] [-p offset] [-g]"
 312                "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]"
 313                "[-x memslots]\n", name);
 314         puts("");
 315         printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 316                TEST_HOST_LOOP_N);
 317         printf(" -g: Do not enable KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2. This\n"
 318                "     makes KVM_GET_DIRTY_LOG clear the dirty log (i.e.\n"
 319                "     KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is not enabled)\n"
 320                "     and writes will be tracked as soon as dirty logging is\n"
 321                "     enabled on the memslot (i.e. KVM_DIRTY_LOG_INITIALLY_SET\n"
 322                "     is not enabled).\n");
 323         printf(" -p: specify guest physical test memory offset\n"
 324                "     Warning: a low offset can conflict with the loaded test code.\n");
 325         guest_modes_help();
 326         printf(" -b: specify the size of the memory region which should be\n"
 327                "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 328                "     (default: 1G)\n");
 329         printf(" -f: specify the fraction of pages which should be written to\n"
 330                "     as opposed to simply read, in the form\n"
 331                "     1/<fraction of pages to write>.\n"
 332                "     (default: 1 i.e. all pages are written to.)\n");
 333         printf(" -v: specify the number of vCPUs to run.\n");
 334         printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 335                "     them into a separate region of memory for each vCPU.\n");
 336         backing_src_help("-s");
 337         printf(" -x: Split the memory region into this number of memslots.\n"
 338                "     (default: 1)\n");
 339         puts("");
 340         exit(0);
 341 }
 342
 343 int main(int argc, char *argv[])
 344 {
 345         int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 346         struct test_params p = {
 347                 .iterations = TEST_HOST_LOOP_N,
 348                 .wr_fract = 1,
 349                 .partition_vcpu_memory_access = true,
 350                 .backing_src = DEFAULT_VM_MEM_SRC,
 351                 .slots = 1,
 352         };
 353         int opt;
 354
 355         dirty_log_manual_caps =
 356                 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 357         dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 358                                   KVM_DIRTY_LOG_INITIALLY_SET);
 359
 360         guest_modes_append_default();
 361
 362         while ((opt = getopt(argc, argv, "ghi:p:m:b:f:v:os:x:")) != -1) {
 363                 switch (opt) {
 364                 case 'g':
 365                         dirty_log_manual_caps = 0;
 366                         break;
 367                 case 'i':
 368                         p.iterations = atoi(optarg);
 369                         break;
 370                 case 'p':
 371                         p.phys_offset = strtoull(optarg, NULL, 0);
 372                         break;
 373                 case 'm':
 374                         guest_modes_cmdline(optarg);
 375                         break;
 376                 case 'b':
 377                         guest_percpu_mem_size = parse_size(optarg);
 378                         break;
 379                 case 'f':
 380                         p.wr_fract = atoi(optarg);
 381                         TEST_ASSERT(p.wr_fract >= 1,
 382                                     "Write fraction cannot be less than one");
 383                         break;
 384                 case 'v':
 385                         nr_vcpus = atoi(optarg);
 386                         TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 387                                     "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 388                         break;
 389                 case 'o':
 390                         p.partition_vcpu_memory_access = false;
 391                         break;
 392                 case 's':
 393                         p.backing_src = parse_backing_src_type(optarg);
 394                         break;
 395                 case 'x':
 396                         p.slots = atoi(optarg);
 397                         break;
 398                 case 'h':
 399                 default:
 400                         help(argv[0]);
 401                         break;
 402                 }
 403         }
 404
 405         TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations");
 406
 407         pr_info("Test iterations: %"PRIu64"\n", p.iterations);
 408
 409         for_each_guest_mode(run_test, &p);
 410
 411         return 0;
 412 }