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 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <sys/syscall.h>
  12 #include <unistd.h>
  13 #include <asm/unistd.h>
  14 #include <time.h>
  15 #include <poll.h>
  16 #include <pthread.h>
  17 #include <linux/bitmap.h>
  18 #include <linux/bitops.h>
  19 #include <linux/userfaultfd.h>
  20
  21 #include "memstress.h"
  22 #include "processor.h"
  23 #include "test_util.h"
  24 #include "guest_modes.h"
  25
  26 #define DUMMY_MEMSLOT_INDEX 7
  27
  28 #define DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS 10
  29
  30
  31 static int nr_vcpus = 1;
  32 static uint64_t guest_percpu_mem_size = DEFAULT_PER_VCPU_MEM_SIZE;
  33
  34 static void vcpu_worker(struct memstress_vcpu_args *vcpu_args)
  35 {
  36         struct kvm_vcpu *vcpu = vcpu_args->vcpu;
  37         struct kvm_run *run;
  38         int ret;
  39
  40         run = vcpu->run;
  41
  42         /* Let the guest access its memory until a stop signal is received */
  43         while (!READ_ONCE(memstress_args.stop_vcpus)) {
  44                 ret = _vcpu_run(vcpu);
  45                 TEST_ASSERT(ret == 0, "vcpu_run failed: %d", ret);
  46
  47                 if (get_ucall(vcpu, NULL) == UCALL_SYNC)
  48                         continue;
  49
  50                 TEST_ASSERT(false,
  51                             "Invalid guest sync status: exit_reason=%s\n",
  52                             exit_reason_str(run->exit_reason));
  53         }
  54 }
  55
  56 static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay,
  57                                uint64_t nr_modifications)
  58 {
  59         uint64_t pages = max_t(int, vm->page_size, getpagesize()) / vm->page_size;
  60         uint64_t gpa;
  61         int i;
  62
  63         /*
  64          * Add the dummy memslot just below the memstress memslot, which is
  65          * at the top of the guest physical address space.
  66          */
  67         gpa = memstress_args.gpa - pages * vm->page_size;
  68
  69         for (i = 0; i < nr_modifications; i++) {
  70                 usleep(delay);
  71                 vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa,
  72                                             DUMMY_MEMSLOT_INDEX, pages, 0);
  73
  74                 vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX);
  75         }
  76 }
  77
  78 struct test_params {
  79         useconds_t delay;
  80         uint64_t nr_iterations;
  81         bool partition_vcpu_memory_access;
  82         bool disable_slot_zap_quirk;
  83 };
  84
  85 static void run_test(enum vm_guest_mode mode, void *arg)
  86 {
  87         struct test_params *p = arg;
  88         struct kvm_vm *vm;
  89
  90         vm = memstress_create_vm(mode, nr_vcpus, guest_percpu_mem_size, 1,
  91                                  VM_MEM_SRC_ANONYMOUS,
  92                                  p->partition_vcpu_memory_access);
  93 #ifdef __x86_64__
  94         if (p->disable_slot_zap_quirk)
  95                 vm_enable_cap(vm, KVM_CAP_DISABLE_QUIRKS2, KVM_X86_QUIRK_SLOT_ZAP_ALL);
  96
  97         pr_info("Memslot zap quirk %s\n", p->disable_slot_zap_quirk ?
  98                 "disabled" : "enabled");
  99 #endif
 100
 101         pr_info("Finished creating vCPUs\n");
 102
 103         memstress_start_vcpu_threads(nr_vcpus, vcpu_worker);
 104
 105         pr_info("Started all vCPUs\n");
 106
 107         add_remove_memslot(vm, p->delay, p->nr_iterations);
 108
 109         memstress_join_vcpu_threads(nr_vcpus);
 110         pr_info("All vCPU threads joined\n");
 111
 112         memstress_destroy_vm(vm);
 113 }
 114
 115 static void help(char *name)
 116 {
 117         puts("");
 118         printf("usage: %s [-h] [-m mode] [-d delay_usec] [-q]\n"
 119                "          [-b memory] [-v vcpus] [-o] [-i iterations]\n", name);
 120         guest_modes_help();
 121         printf(" -d: add a delay between each iteration of adding and\n"
 122                "     deleting a memslot in usec.\n");
 123         printf(" -q: Disable memslot zap quirk.\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:qb: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 #ifdef __x86_64__
 173                 case 'q':
 174                         p.disable_slot_zap_quirk = true;
 175
 176                         TEST_REQUIRE(kvm_check_cap(KVM_CAP_DISABLE_QUIRKS2) &
 177                                      KVM_X86_QUIRK_SLOT_ZAP_ALL);
 178                         break;
 179 #endif
 180                 case 'h':
 181                 default:
 182                         help(argv[0]);
 183                         break;
 184                 }
 185         }
 186
 187         for_each_guest_mode(run_test, &p);
 188
 189         return 0;
 190 }