tools/testing/selftests/kvm/memslot_modification_stress_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * KVM memslot modification stress test
   4  * Adapted from demand_paging_test.c
   5  *
   6  * Copyright (C) 2018, Red Hat, Inc.
   7  * Copyright (C) 2020, Google, Inc.
   8  */
   9
  10 #define _GNU_SOURCE /* for program_invocation_name */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <sys/syscall.h>
  15 #include <unistd.h>
  16 #include <asm/unistd.h>
  17 #include <time.h>
  18 #include <poll.h>
  19 #include <pthread.h>
  20 #include <linux/bitmap.h>
  21 #include <linux/bitops.h>
  22 #include <linux/userfaultfd.h>
  23
  24 #include "perf_test_util.h"
  25 #include "processor.h"
  26 #include "test_util.h"
  27 #include "guest_modes.h"
  28
  29 #define DUMMY_MEMSLOT_INDEX 7
  30
  31 #define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
  32
  33
  34 static int nr_vcpus = 1;
  35 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
  36
  37 static bool run_vcpus = true;
  38
  39 static void *vcpu_worker(void *data)
  40 {
  41         int ret;
  42         struct perf_test_vcpu_args *vcpu_args =
  43                 (struct perf_test_vcpu_args *)data;
  44         int vcpu_id = vcpu_args->vcpu_id;
  45         struct kvm_vm *vm = perf_test_args.vm;
  46         struct kvm_run *run;
  47
  48         vcpu_args_set(vm, vcpu_id, 1, vcpu_id);
  49         run = vcpu_state(vm, vcpu_id);
  50
  51         /* Let the guest access its memory until a stop signal is received */
  52         while (READ_ONCE(run_vcpus)) {
  53                 ret = _vcpu_run(vm, vcpu_id);
  54                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  55
  56                 if (get_ucall(vm, vcpu_id, NULL) == UCALL_SYNC)
  57                         continue;
  58
  59                 TEST_ASSERT(false,
  60                             "Invalid guest sync status: exit_reason=%s\n",
  61                             exit_reason_str(run->exit_reason));
  62         }
  63
  64         return NULL;
  65 }
  66
  67 struct memslot_antagonist_args {
  68         struct kvm_vm *vm;
  69         useconds_t delay;
  70         uint64_t nr_modifications;
  71 };
  72
  73 static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
  74                                uint64_t nr_modifications)
  75 {
  76         const uint64_t pages = 1;
  77         uint64_t gpa;
  78         int i;
  79
  80         /*
  81          * Add the dummy memslot just below the perf_test_util memslot, which is
  82          * at the top of the guest physical address space.
  83          */
  84         gpa = guest_test_phys_mem - pages * vm_get_page_size(vm);
  85
  86         for (i = 0; i < nr_modifications; i++) {
  87                 usleep(delay);
  88                 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
  89                                             DUMMY_MEMSLOT_INDEX, pages, 0);
  90
  91                 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
  92         }
  93 }
  94
  95 struct test_params {
  96         useconds_t memslot_modification_delay;
  97         uint64_t nr_memslot_modifications;
  98         bool partition_vcpu_memory_access;
  99 };
 100
 101 static void run_test(enum vm_guest_mode mode, void *arg)
 102 {
 103         struct test_params *p = arg;
 104         pthread_t *vcpu_threads;
 105         struct kvm_vm *vm;
 106         int vcpu_id;
 107
 108         vm = perf_test_create_vm(mode, nr_vcpus, guest_percpu_mem_size,
 109                                  VM_MEM_SRC_ANONYMOUS);
 110
 111         perf_test_args.wr_fract = 1;
 112
 113         vcpu_threads = malloc(nr_vcpus * sizeof(*vcpu_threads));
 114         TEST_ASSERT(vcpu_threads, "Memory allocation failed");
 115
 116         perf_test_setup_vcpus(vm, nr_vcpus, guest_percpu_mem_size,
 117                               p->partition_vcpu_memory_access);
 118
 119         /* Export the shared variables to the guest */
 120         sync_global_to_guest(vm, perf_test_args);
 121
 122         pr_info("Finished creating vCPUs\n");
 123
 124         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 125                 pthread_create(&vcpu_threads[vcpu_id], NULL, vcpu_worker,
 126                                &perf_test_args.vcpu_args[vcpu_id]);
 127
 128         pr_info("Started all vCPUs\n");
 129
 130         add_remove_memslot(vm, p->memslot_modification_delay,
 131                            p->nr_memslot_modifications);
 132
 133         run_vcpus = false;
 134
 135         /* Wait for the vcpu threads to quit */
 136         for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++)
 137                 pthread_join(vcpu_threads[vcpu_id], NULL);
 138
 139         pr_info("All vCPU threads joined\n");
 140
 141         ucall_uninit(vm);
 142         kvm_vm_free(vm);
 143
 144         free(vcpu_threads);
 145 }
 146
 147 static void help(char *name)
 148 {
 149         puts("");
 150         printf("usage: %s [-h] [-m mode] [-d delay_usec]\n"
 151                "          [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
 152         guest_modes_help();
 153         printf(" -d: add a delay between each iteration of adding and\n"
 154                "     deleting a memslot in usec.\n");
 155         printf(" -b: specify the size of the memory region which should be\n"
 156                "     accessed by each vCPU. e.g. 10M or 3G.\n"
 157                "     Default: 1G\n");
 158         printf(" -v: specify the number of vCPUs to run.\n");
 159         printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 160                "     them into a separate region of memory for each vCPU.\n");
 161         printf(" -i: specify the number of iterations of adding and removing\n"
 162                "     a memslot.\n"
 163                "     Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
 164         puts("");
 165         exit(0);
 166 }
 167
 168 int main(int argc, char *argv[])
 169 {
 170         int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 171         int opt;
 172         struct test_params p = {
 173                 .memslot_modification_delay = 0,
 174                 .nr_memslot_modifications =
 175                         DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
 176                 .partition_vcpu_memory_access = true
 177         };
 178
 179         guest_modes_append_default();
 180
 181         while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) {
 182                 switch (opt) {
 183                 case 'm':
 184                         guest_modes_cmdline(optarg);
 185                         break;
 186                 case 'd':
 187                         p.memslot_modification_delay = strtoul(optarg, NULL, 0);
 188                         TEST_ASSERT(p.memslot_modification_delay >= 0,
 189                                     "A negative delay is not supported.");
 190                         break;
 191                 case 'b':
 192                         guest_percpu_mem_size = parse_size(optarg);
 193                         break;
 194                 case 'v':
 195                         nr_vcpus = atoi(optarg);
 196                         TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus,
 197                                     "Invalid number of vcpus, must be between 1 and %d",
 198                                     max_vcpus);
 199                         break;
 200                 case 'o':
 201                         p.partition_vcpu_memory_access = false;
 202                         break;
 203                 case 'i':
 204                         p.nr_memslot_modifications = atoi(optarg);
 205                         break;
 206                 case 'h':
 207                 default:
 208                         help(argv[0]);
 209                         break;
 210                 }
 211         }
 212
 213         for_each_guest_mode(run_test, &p);
 214
 215         return 0;
 216 }