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 "memstress.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 void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
  38 {
  39         struct kvm_vcpu *vcpu = vcpu_args->vcpu;
  40         struct kvm_run *run;
  41         int ret;
  42
  43         run = vcpu->run;
  44
  45         /* Let the guest access its memory until a stop signal is received */
  46         while (!READ_ONCE(memstress_args.stop_vcpus)) {
  47                 ret = _vcpu_run(vcpu);
  48                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d\n", ret);
  49
  50                 if (get_ucall(vcpu, NULL) == UCALL_SYNC)
  51                         continue;
  52
  53                 TEST_ASSERT(false,
  54                             "Invalid guest sync status: exit_reason=%s\n",
  55                             exit_reason_str(run->exit_reason));
  56         }
  57 }
  58
  59 struct memslot_antagonist_args {
  60         struct kvm_vm *vm;
  61         useconds_t delay;
  62         uint64_t nr_modifications;
  63 };
  64
  65 static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
  66                                uint64_t nr_modifications)
  67 {
  68         uint64_t pages = max_t(int, vm->page_size, getpagesize()) / vm->page_size;
  69         uint64_t gpa;
  70         int i;
  71
  72         /*
  73          * Add the dummy memslot just below the memstress memslot, which is
  74          * at the top of the guest physical address space.
  75          */
  76         gpa = memstress_args.gpa - pages * vm->page_size;
  77
  78         for (i = 0; i < nr_modifications; i++) {
  79                 usleep(delay);
  80                 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
  81                                             DUMMY_MEMSLOT_INDEX, pages, 0);
  82
  83                 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
  84         }
  85 }
  86
  87 struct test_params {
  88         useconds_t delay;
  89         uint64_t nr_iterations;
  90         bool partition_vcpu_memory_access;
  91 };
  92
  93 static void run_test(enum vm_guest_mode mode, void *arg)
  94 {
  95         struct test_params *p = arg;
  96         struct kvm_vm *vm;
  97
  98         vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
  99                                  VM_MEM_SRC_ANONYMOUS,
 100                                  p->partition_vcpu_memory_access);
 101
 102         pr_info("Finished creating vCPUs\n");
 103
 104         memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
 105
 106         pr_info("Started all vCPUs\n");
 107
 108         add_remove_memslot(vm, p->delay, p->nr_iterations);
 109
 110         memstress_join_vcpu_threads(nr_vcpus);
 111         pr_info("All vCPU threads joined\n");
 112
 113         memstress_destroy_vm(vm);
 114 }
 115
 116 static void help(char *name)
 117 {
 118         puts("");
 119         printf("usage: %s [-h] [-m mode] [-d delay_usec]\n"
 120                "          [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
 121         guest_modes_help();
 122         printf(" -d: add a delay between each iteration of adding and\n"
 123                "     deleting a memslot in usec.\n");
 124         printf(" -b: specify the size of the memory region which should be\n"
 125                "     accessed by each vCPU. e.g. 10M or 3G.\n"
 126                "     Default: 1G\n");
 127         printf(" -v: specify the number of vCPUs to run.\n");
 128         printf(" -o: Overlap guest memory accesses instead of partitioning\n"
 129                "     them into a separate region of memory for each vCPU.\n");
 130         printf(" -i: specify the number of iterations of adding and removing\n"
 131                "     a memslot.\n"
 132                "     Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS);
 133         puts("");
 134         exit(0);
 135 }
 136
 137 int main(int argc, char *argv[])
 138 {
 139         int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS);
 140         int opt;
 141         struct test_params p = {
 142                 .delay = 0,
 143                 .nr_iterations = DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS,
 144                 .partition_vcpu_memory_access = true
 145         };
 146
 147         guest_modes_append_default();
 148
 149         while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) {
 150                 switch (opt) {
 151                 case 'm':
 152                         guest_modes_cmdline(optarg);
 153                         break;
 154                 case 'd':
 155                         p.delay = atoi_non_negative("Delay", optarg);
 156                         break;
 157                 case 'b':
 158                         guest_percpu_mem_size = parse_size(optarg);
 159                         break;
 160                 case 'v':
 161                         nr_vcpus = atoi_positive("Number of vCPUs", optarg);
 162                         TEST_ASSERT(nr_vcpus <= max_vcpus,
 163                                     "Invalid number of vcpus, must be between 1 and %d",
 164                                     max_vcpus);
 165                         break;
 166                 case 'o':
 167                         p.partition_vcpu_memory_access = false;
 168                         break;
 169                 case 'i':
 170                         p.nr_iterations = atoi_positive("Number of iterations", optarg);
 171                         break;
 172                 case 'h':
 173                 default:
 174                         help(argv[0]);
 175                         break;
 176                 }
 177         }
 178
 179         for_each_guest_mode(run_test, &p);
 180
 181         return 0;
 182 }