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         vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
  48         run = vcpu_state(vm, vcpu_id);
  49
  50         while (!READ_ONCE(host_quit)) {
  51                 int current_iteration = READ_ONCE(iteration);
  52
  53                 clock_gettime(CLOCK_MONOTONIC, &start);
  54                 ret = _vcpu_run(vm, vcpu_id);
  55                 ts_diff = timespec_elapsed(start);
  56
  57                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  58                 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
  59                             "Invalid guest sync status: exit_reason=%s\n",
  60                             exit_reason_str(run->exit_reason));
  61
  62                 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
  63                 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
  64                 pr_debug("vCPU %d updated last completed iteration to %d\n",
  65                          vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
  66
  67                 if (current_iteration) {
  68                         pages_count += vcpu_args->pages;
  69                         total = timespec_add(total, ts_diff);
  70                         pr_debug("vCPU %d iteration %d dirty memory time: %ld.%.9lds\n",
  71                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  72                                 ts_diff.tv_nsec);
  73                 } else {
  74                         pr_debug("vCPU %d iteration %d populate memory time: %ld.%.9lds\n",
  75                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  76                                 ts_diff.tv_nsec);
  77                 }
  78
  79                 while (current_iteration == READ_ONCE(iteration) &&
  80                        !READ_ONCE(host_quit)) {}
  81         }
  82
  83         avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
  84         pr_debug("\nvCPU %d dirtied 0x%lx pages over %d iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
  85                 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
  86                 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
  87
  88         return NULL;
  89 }
  90
  91 struct test_params {
  92         unsigned long iterations;
  93         uint64_t phys_offset;
  94         int wr_fract;
  95         bool partition_vcpu_memory_access;
  96         enum vm_mem_backing_src_type backing_src;
  97 };
  98
  99 static void run_test(enum vm_guest_mode mode, void *arg)
 100 {
 101         struct test_params *p = arg;
 102         pthread_t *vcpu_threads;
 103         struct kvm_vm *vm;
 104         unsigned long *bmap;
 105         uint64_t guest_num_pages;
 106         uint64_t host_num_pages;
 107         int vcpu_id;
 108         struct timespec start;
 109         struct timespec ts_diff;
 110         struct timespec get_dirty_log_total = (struct timespec){0};
 111         struct timespec vcpu_dirty_total = (struct timespec){0};
 112         struct timespec avg;
 113         struct kvm_enable_cap cap = {};
 114         struct timespec clear_dirty_log_total = (struct timespec){0};
 115
 116         vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 117                                  p->backing_src);
 118
 119         perf_test_args.wr_fract = p->wr_fract;
 120
 121         guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
 122         guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 123         host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 124         bmap = bitmap_alloc(host_num_pages);
 125
 126         if (dirty_log_manual_caps) {
 127                 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 128                 cap.args[0] = dirty_log_manual_caps;
 129                 vm_enable_cap(vm, &cap);
 130         }
 131
 132         vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
 133         TEST_ASSERT(vcpu_threads, "Memory allocation failed");
 134
 135         perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
 136                               p->partition_vcpu_memory_access);
 137
 138         sync_global_to_guest(vm, perf_test_args);
 139
 140         /* Start the iterations */
 141         iteration = 0;
 142         host_quit = false;
 143
 144         clock_gettime(CLOCK_MONOTONIC, &start);
 145         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 146                 vcpu_last_completed_iteration[vcpu_id] = -1;
 147
 148                 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 149                                &perf_test_args.vcpu_args[vcpu_id]);
 150         }
 151
 152         /* Allow the vCPUs to populate memory */
 153         pr_debug("Starting iteration %d - Populating\n", iteration);
 154         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 155                 while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) !=
 156                        iteration)
 157                         ;
 158         }
 159
 160         ts_diff = timespec_elapsed(start);
 161         pr_info("Populate memory time: %ld.%.9lds\n",
 162                 ts_diff.tv_sec, ts_diff.tv_nsec);
 163
 164         /* Enable dirty logging */
 165         clock_gettime(CLOCK_MONOTONIC, &start);
 166         vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX,
 167                                 KVM_MEM_LOG_DIRTY_PAGES);
 168         ts_diff = timespec_elapsed(start);
 169         pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 170                 ts_diff.tv_sec, ts_diff.tv_nsec);
 171
 172         while (iteration < p->iterations) {
 173                 /*
 174                  * Incrementing the iteration number will start the vCPUs
 175                  * dirtying memory again.
 176                  */
 177                 clock_gettime(CLOCK_MONOTONIC, &start);
 178                 iteration++;
 179
 180                 pr_debug("Starting iteration %d\n", iteration);
 181                 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 182                         while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id])
 183                                != iteration)
 184                                 ;
 185                 }
 186
 187                 ts_diff = timespec_elapsed(start);
 188                 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
 189                 pr_info("Iteration %d dirty memory time: %ld.%.9lds\n",
 190                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 191
 192                 clock_gettime(CLOCK_MONOTONIC, &start);
 193                 kvm_vm_get_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap);
 194
 195                 ts_diff = timespec_elapsed(start);
 196                 get_dirty_log_total = timespec_add(get_dirty_log_total,
 197                                                    ts_diff);
 198                 pr_info("Iteration %d get dirty log time: %ld.%.9lds\n",
 199                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 200
 201                 if (dirty_log_manual_caps) {
 202                         clock_gettime(CLOCK_MONOTONIC, &start);
 203                         kvm_vm_clear_dirty_log(vm, PERF_TEST_MEM_SLOT_INDEX, bmap, 0,
 204                                                host_num_pages);
 205
 206                         ts_diff = timespec_elapsed(start);
 207                         clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 208                                                              ts_diff);
 209                         pr_info("Iteration %d clear dirty log time: %ld.%.9lds\n",
 210                                 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 211                 }
 212         }
 213
 214         /* Disable dirty logging */
 215         clock_gettime(CLOCK_MONOTONIC, &start);
 216         vm_mem_region_set_flags(vm, PERF_TEST_MEM_SLOT_INDEX, 0);
 217         ts_diff = timespec_elapsed(start);
 218         pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 219                 ts_diff.tv_sec, ts_diff.tv_nsec);
 220
 221         /* Tell the vcpu thread to quit */
 222         host_quit = true;
 223         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 224                 pthread_join(vcpu_threads[vcpu_id], NULL);
 225
 226         avg = timespec_div(get_dirty_log_total, p->iterations);
 227         pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 228                 p->iterations, get_dirty_log_total.tv_sec,
 229                 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 230
 231         if (dirty_log_manual_caps) {
 232                 avg = timespec_div(clear_dirty_log_total, p->iterations);
 233                 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 234                         p->iterations, clear_dirty_log_total.tv_sec,
 235                         clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 236         }
 237
 238         free(bmap);
 239         free(vcpu_threads);
 240         perf_test_destroy_vm(vm);
 241 }
 242
 243 static void help(char *name)
 244 {
 245         puts("");
 246         printf("usage: %s [-h] [-i iterations] [-p offset] "
 247                "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]\n", name);
 248         puts("");
 249         printf(" -i: specify iteration counts (default: %"PRIu64")\n",
 250                TEST_HOST_LOOP_N);
 251         printf(" -p: specify guest physical test memory offset\n"
 252                "     Warning: a low offset can conflict with the loaded test code.\n");
 253         guest_modes_help();
 254         printf(" -b: specify the size of the memory region which should be\n"
 255                "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 256                "     (default: 1G)\n");
 257         printf(" -f: specify the fraction of pages which should be written to\n"
 258                "     as opposed to simply read, in the form\n"
 259                "     1/<fraction of pages to write>.\n"
 260                "     (default: 1 i.e. all pages are written to.)\n");
 261         printf(" -v: specify the number of vCPUs to run.\n");
 262         printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 263                "     them into a separate region of memory for each vCPU.\n");
 264         printf(" -s: specify the type of memory that should be used to\n"
 265                "     back the guest data region.\n\n");
 266         backing_src_help();
 267         puts("");
 268         exit(0);
 269 }
 270
 271 int main(int argc, char *argv[])
 272 {
 273         int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 274         struct test_params p = {
 275                 .iterations = TEST_HOST_LOOP_N,
 276                 .wr_fract = 1,
 277                 .partition_vcpu_memory_access = true,
 278                 .backing_src = VM_MEM_SRC_ANONYMOUS,
 279         };
 280         int opt;
 281
 282         dirty_log_manual_caps =
 283                 kvm_check_cap(KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2);
 284         dirty_log_manual_caps &= (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE |
 285                                   KVM_DIRTY_LOG_INITIALLY_SET);
 286
 287         guest_modes_append_default();
 288
 289         while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:os:")) != -1) {
 290                 switch (opt) {
 291                 case 'i':
 292                         p.iterations = atoi(optarg);
 293                         break;
 294                 case 'p':
 295                         p.phys_offset = strtoull(optarg, NULL, 0);
 296                         break;
 297                 case 'm':
 298                         guest_modes_cmdline(optarg);
 299                         break;
 300                 case 'b':
 301                         guest_percpu_mem_size = parse_size(optarg);
 302                         break;
 303                 case 'f':
 304                         p.wr_fract = atoi(optarg);
 305                         TEST_ASSERT(p.wr_fract >= 1,
 306                                     "Write fraction cannot be less than one");
 307                         break;
 308                 case 'v':
 309                         nr_vcpus = atoi(optarg);
 310                         TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 311                                     "Invalid number of vcpus, must be between 1 and %d", max_vcpus);
 312                         break;
 313                 case 'o':
 314                         p.partition_vcpu_memory_access = false;
 315                         break;
 316                 case 's':
 317                         p.backing_src = parse_backing_src_type(optarg);
 318                         break;
 319                 case 'h':
 320                 default:
 321                         help(argv[0]);
 322                         break;
 323                 }
 324         }
 325
 326         TEST_ASSERT(p.iterations >= 2, "The test should have at least two iterations");
 327
 328         pr_info("Test iterations: %"PRIu64"\n", p.iterations);
 329
 330         for_each_guest_mode(run_test, &p);
 331
 332         return 0;
 333 }