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 #define _GNU_SOURCE /* for program_invocation_name */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <time.h>
  17 #include <pthread.h>
  18 #include <linux/bitmap.h>
  19 #include <linux/bitops.h>
  20
  21 #include "kvm_util.h"
  22 #include "perf_test_util.h"
  23 #include "processor.h"
  24 #include "test_util.h"
  25
  26 /* How many host loops to run by default (one KVM_GET_DIRTY_LOG for each loop)*/
  27 #define TEST_HOST_LOOP_N                2UL
  28
  29 /* Host variables */
  30 static u64 dirty_log_manual_caps;
  31 static bool host_quit;
  32 static uint64_t iteration;
  33 static uint64_t vcpu_last_completed_iteration[MAX_VCPUS];
  34
  35 static void *vcpu_worker(void *data)
  36 {
  37         int ret;
  38         struct kvm_vm *vm = perf_test_args.vm;
  39         uint64_t pages_count = 0;
  40         struct kvm_run *run;
  41         struct timespec start;
  42         struct timespec ts_diff;
  43         struct timespec total = (struct timespec){0};
  44         struct timespec avg;
  45         struct vcpu_args *vcpu_args = (struct vcpu_args *)data;
  46         int vcpu_id = vcpu_args->vcpu_id;
  47
  48         vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
  49         run = vcpu_state(vm, vcpu_id);
  50
  51         while (!READ_ONCE(host_quit)) {
  52                 uint64_t current_iteration = READ_ONCE(iteration);
  53
  54                 clock_gettime(CLOCK_MONOTONIC, &start);
  55                 ret = _vcpu_run(vm, vcpu_id);
  56                 ts_diff = timespec_diff_now(start);
  57
  58                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  59                 TEST_ASSERT(get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC,
  60                             "Invalid guest sync status: exit_reason=%s\n",
  61                             exit_reason_str(run->exit_reason));
  62
  63                 pr_debug("Got sync event from vCPU %d\n", vcpu_id);
  64                 vcpu_last_completed_iteration[vcpu_id] = current_iteration;
  65                 pr_debug("vCPU %d updated last completed iteration to %lu\n",
  66                          vcpu_id, vcpu_last_completed_iteration[vcpu_id]);
  67
  68                 if (current_iteration) {
  69                         pages_count += vcpu_args->pages;
  70                         total = timespec_add(total, ts_diff);
  71                         pr_debug("vCPU %d iteration %lu dirty memory time: %ld.%.9lds\n",
  72                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  73                                 ts_diff.tv_nsec);
  74                 } else {
  75                         pr_debug("vCPU %d iteration %lu populate memory time: %ld.%.9lds\n",
  76                                 vcpu_id, current_iteration, ts_diff.tv_sec,
  77                                 ts_diff.tv_nsec);
  78                 }
  79
  80                 while (current_iteration == READ_ONCE(iteration) &&
  81                        !READ_ONCE(host_quit)) {}
  82         }
  83
  84         avg = timespec_div(total, vcpu_last_completed_iteration[vcpu_id]);
  85         pr_debug("\nvCPU %d dirtied 0x%lx pages over %lu iterations in %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
  86                 vcpu_id, pages_count, vcpu_last_completed_iteration[vcpu_id],
  87                 total.tv_sec, total.tv_nsec, avg.tv_sec, avg.tv_nsec);
  88
  89         return NULL;
  90 }
  91
  92 static void run_test(enum vm_guest_mode mode, unsigned long iterations,
  93                      uint64_t phys_offset, int wr_fract)
  94 {
  95         pthread_t *vcpu_threads;
  96         struct kvm_vm *vm;
  97         unsigned long *bmap;
  98         uint64_t guest_num_pages;
  99         uint64_t host_num_pages;
 100         int vcpu_id;
 101         struct timespec start;
 102         struct timespec ts_diff;
 103         struct timespec get_dirty_log_total = (struct timespec){0};
 104         struct timespec vcpu_dirty_total = (struct timespec){0};
 105         struct timespec avg;
 106         struct kvm_enable_cap cap = {};
 107         struct timespec clear_dirty_log_total = (struct timespec){0};
 108
 109         vm = create_vm(mode, nr_vcpus, guest_percpu_mem_size);
 110
 111         perf_test_args.wr_fract = wr_fract;
 112
 113         guest_num_pages = (nr_vcpus * guest_percpu_mem_size) >> vm_get_page_shift(vm);
 114         guest_num_pages = vm_adjust_num_guest_pages(mode, guest_num_pages);
 115         host_num_pages = vm_num_host_pages(mode, guest_num_pages);
 116         bmap = bitmap_alloc(host_num_pages);
 117
 118         if (dirty_log_manual_caps) {
 119                 cap.cap = KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2;
 120                 cap.args[0] = dirty_log_manual_caps;
 121                 vm_enable_cap(vm, &cap);
 122         }
 123
 124         vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
 125         TEST_ASSERT(vcpu_threads, "Memory allocation failed");
 126
 127         add_vcpus(vm, nr_vcpus, guest_percpu_mem_size);
 128
 129         sync_global_to_guest(vm, perf_test_args);
 130
 131         /* Start the iterations */
 132         iteration = 0;
 133         host_quit = false;
 134
 135         clock_gettime(CLOCK_MONOTONIC, &start);
 136         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 137                 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 138                                &perf_test_args.vcpu_args[vcpu_id]);
 139         }
 140
 141         /* Allow the vCPU to populate memory */
 142         pr_debug("Starting iteration %lu - Populating\n", iteration);
 143         while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
 144                 pr_debug("Waiting for vcpu_last_completed_iteration == %lu\n",
 145                         iteration);
 146
 147         ts_diff = timespec_diff_now(start);
 148         pr_info("Populate memory time: %ld.%.9lds\n",
 149                 ts_diff.tv_sec, ts_diff.tv_nsec);
 150
 151         /* Enable dirty logging */
 152         clock_gettime(CLOCK_MONOTONIC, &start);
 153         vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX,
 154                                 KVM_MEM_LOG_DIRTY_PAGES);
 155         ts_diff = timespec_diff_now(start);
 156         pr_info("Enabling dirty logging time: %ld.%.9lds\n\n",
 157                 ts_diff.tv_sec, ts_diff.tv_nsec);
 158
 159         while (iteration < iterations) {
 160                 /*
 161                  * Incrementing the iteration number will start the vCPUs
 162                  * dirtying memory again.
 163                  */
 164                 clock_gettime(CLOCK_MONOTONIC, &start);
 165                 iteration++;
 166
 167                 pr_debug("Starting iteration %lu\n", iteration);
 168                 for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 169                         while (READ_ONCE(vcpu_last_completed_iteration[vcpu_id]) != iteration)
 170                                 pr_debug("Waiting for vCPU %d vcpu_last_completed_iteration == %lu\n",
 171                                          vcpu_id, iteration);
 172                 }
 173
 174                 ts_diff = timespec_diff_now(start);
 175                 vcpu_dirty_total = timespec_add(vcpu_dirty_total, ts_diff);
 176                 pr_info("Iteration %lu dirty memory time: %ld.%.9lds\n",
 177                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 178
 179                 clock_gettime(CLOCK_MONOTONIC, &start);
 180                 kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap);
 181
 182                 ts_diff = timespec_diff_now(start);
 183                 get_dirty_log_total = timespec_add(get_dirty_log_total,
 184                                                    ts_diff);
 185                 pr_info("Iteration %lu get dirty log time: %ld.%.9lds\n",
 186                         iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 187
 188                 if (dirty_log_manual_caps) {
 189                         clock_gettime(CLOCK_MONOTONIC, &start);
 190                         kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0,
 191                                                host_num_pages);
 192
 193                         ts_diff = timespec_diff_now(start);
 194                         clear_dirty_log_total = timespec_add(clear_dirty_log_total,
 195                                                              ts_diff);
 196                         pr_info("Iteration %lu clear dirty log time: %ld.%.9lds\n",
 197                                 iteration, ts_diff.tv_sec, ts_diff.tv_nsec);
 198                 }
 199         }
 200
 201         /* Tell the vcpu thread to quit */
 202         host_quit = true;
 203         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 204                 pthread_join(vcpu_threads[vcpu_id], NULL);
 205
 206         /* Disable dirty logging */
 207         clock_gettime(CLOCK_MONOTONIC, &start);
 208         vm_mem_region_set_flags(vm, TEST_MEM_SLOT_INDEX, 0);
 209         ts_diff = timespec_diff_now(start);
 210         pr_info("Disabling dirty logging time: %ld.%.9lds\n",
 211                 ts_diff.tv_sec, ts_diff.tv_nsec);
 212
 213         avg = timespec_div(get_dirty_log_total, iterations);
 214         pr_info("Get dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 215                 iterations, get_dirty_log_total.tv_sec,
 216                 get_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 217
 218         if (dirty_log_manual_caps) {
 219                 avg = timespec_div(clear_dirty_log_total, iterations);
 220                 pr_info("Clear dirty log over %lu iterations took %ld.%.9lds. (Avg %ld.%.9lds/iteration)\n",
 221                         iterations, clear_dirty_log_total.tv_sec,
 222                         clear_dirty_log_total.tv_nsec, avg.tv_sec, avg.tv_nsec);
 223         }
 224
 225         free(bmap);
 226         free(vcpu_threads);
 227         ucall_uninit(vm);
 228         kvm_vm_free(vm);
 229 }
 230
 231 struct guest_mode {
 232         bool supported;
 233         bool enabled;
 234 };
 235 static struct guest_mode guest_modes[NUM_VM_MODES];
 236
 237 #define guest_mode_init(mode, supported, enabled) ({ \
 238         guest_modes[mode] = (struct guest_mode){ supported, enabled }; \
 239 })
 240
 241 static void help(char *name)
 242 {
 243         int i;
 244
 245         puts("");
 246         printf("usage: %s [-h] [-i iterations] [-p offset] "
 247                "[-m mode] [-b vcpu bytes] [-v vcpus]\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         printf(" -m: specify the guest mode ID to test "
 254                "(default: test all supported modes)\n"
 255                "     This option may be used multiple times.\n"
 256                "     Guest mode IDs:\n");
 257         for (i = 0; i < NUM_VM_MODES; ++i) {
 258                 printf("         %d:    %s%s\n", i, vm_guest_mode_string(i),
 259                        guest_modes[i].supported ? " (supported)" : "");
 260         }
 261         printf(" -b: specify the size of the memory region which should be\n"
 262                "     dirtied by each vCPU. e.g. 10M or 3G.\n"
 263                "     (default: 1G)\n");
 264         printf(" -f: specify the fraction of pages which should be written to\n"
 265                "     as opposed to simply read, in the form\n"
 266                "     1/<fraction of pages to write>.\n"
 267                "     (default: 1 i.e. all pages are written to.)\n");
 268         printf(" -v: specify the number of vCPUs to run.\n");
 269         puts("");
 270         exit(0);
 271 }
 272
 273 int main(int argc, char *argv[])
 274 {
 275         unsigned long iterations = TEST_HOST_LOOP_N;
 276         bool mode_selected = false;
 277         uint64_t phys_offset = 0;
 278         unsigned int mode;
 279         int opt, i;
 280         int wr_fract = 1;
 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 #ifdef __x86_64__
 288         guest_mode_init(VM_MODE_PXXV48_4K, true, true);
 289 #endif
 290 #ifdef __aarch64__
 291         guest_mode_init(VM_MODE_P40V48_4K, true, true);
 292         guest_mode_init(VM_MODE_P40V48_64K, true, true);
 293
 294         {
 295                 unsigned int limit = kvm_check_cap(KVM_CAP_ARM_VM_IPA_SIZE);
 296
 297                 if (limit >= 52)
 298                         guest_mode_init(VM_MODE_P52V48_64K, true, true);
 299                 if (limit >= 48) {
 300                         guest_mode_init(VM_MODE_P48V48_4K, true, true);
 301                         guest_mode_init(VM_MODE_P48V48_64K, true, true);
 302                 }
 303         }
 304 #endif
 305 #ifdef __s390x__
 306         guest_mode_init(VM_MODE_P40V48_4K, true, true);
 307 #endif
 308
 309         while ((opt = getopt(argc, argv, "hi:p:m:b:f:v:")) != -1) {
 310                 switch (opt) {
 311                 case 'i':
 312                         iterations = strtol(optarg, NULL, 10);
 313                         break;
 314                 case 'p':
 315                         phys_offset = strtoull(optarg, NULL, 0);
 316                         break;
 317                 case 'm':
 318                         if (!mode_selected) {
 319                                 for (i = 0; i < NUM_VM_MODES; ++i)
 320                                         guest_modes[i].enabled = false;
 321                                 mode_selected = true;
 322                         }
 323                         mode = strtoul(optarg, NULL, 10);
 324                         TEST_ASSERT(mode < NUM_VM_MODES,
 325                                     "Guest mode ID %d too big", mode);
 326                         guest_modes[mode].enabled = true;
 327                         break;
 328                 case 'b':
 329                         guest_percpu_mem_size = parse_size(optarg);
 330                         break;
 331                 case 'f':
 332                         wr_fract = atoi(optarg);
 333                         TEST_ASSERT(wr_fract >= 1,
 334                                     "Write fraction cannot be less than one");
 335                         break;
 336                 case 'v':
 337                         nr_vcpus = atoi(optarg);
 338                         TEST_ASSERT(nr_vcpus > 0,
 339                                     "Must have a positive number of vCPUs");
 340                         TEST_ASSERT(nr_vcpus <= MAX_VCPUS,
 341                                     "This test does not currently support\n"
 342                                     "more than %d vCPUs.", MAX_VCPUS);
 343                         break;
 344                 case 'h':
 345                 default:
 346                         help(argv[0]);
 347                         break;
 348                 }
 349         }
 350
 351         TEST_ASSERT(iterations >= 2, "The test should have at least two iterations");
 352
 353         pr_info("Test iterations: %"PRIu64"\n", iterations);
 354
 355         for (i = 0; i < NUM_VM_MODES; ++i) {
 356                 if (!guest_modes[i].enabled)
 357                         continue;
 358                 TEST_ASSERT(guest_modes[i].supported,
 359                             "Guest mode ID %d (%s) not supported.",
 360                             i, vm_guest_mode_string(i));
 361                 run_test(i, iterations, phys_offset, wr_fract);
 362         }
 363
 364         return 0;
 365 }