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 void vcpu_worker(struct perf_test_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(perf_test_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 perf_test_util memslot, which is 74 * at the top of the guest physical address space. 75 */ 76 gpa = perf_test_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 memslot_modification_delay; 89 uint64_t nr_memslot_modifications; 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 = perf_test_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 perf_test_start_vcpu_threads(nr_vcpus, vcpu_worker); 105 106 pr_info("Started all vCPUs\n"); 107 108 add_remove_memslot(vm, p->memslot_modification_delay, 109 p->nr_memslot_modifications); 110 111 perf_test_join_vcpu_threads(nr_vcpus); 112 pr_info("All vCPU threads joined\n"); 113 114 perf_test_destroy_vm(vm); 115 } 116 117 static void help(char *name) 118 { 119 puts(""); 120 printf("usage: %s [-h] [-m mode] [-d delay_usec]\n" 121 " [-b memory] [-v vcpus] [-o] [-i iterations]\n", name); 122 guest_modes_help(); 123 printf(" -d: add a delay between each iteration of adding and\n" 124 " deleting a memslot in usec.\n"); 125 printf(" -b: specify the size of the memory region which should be\n" 126 " accessed by each vCPU. e.g. 10M or 3G.\n" 127 " Default: 1G\n"); 128 printf(" -v: specify the number of vCPUs to run.\n"); 129 printf(" -o: Overlap guest memory accesses instead of partitioning\n" 130 " them into a separate region of memory for each vCPU.\n"); 131 printf(" -i: specify the number of iterations of adding and removing\n" 132 " a memslot.\n" 133 " Default: %d\n", DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS); 134 puts(""); 135 exit(0); 136 } 137 138 int main(int argc, char *argv[]) 139 { 140 int max_vcpus = kvm_check_cap(KVM_CAP_MAX_VCPUS); 141 int opt; 142 struct test_params p = { 143 .memslot_modification_delay = 0, 144 .nr_memslot_modifications = 145 DEFAULT_MEMSLOT_MODIFICATION_ITERATIONS, 146 .partition_vcpu_memory_access = true 147 }; 148 149 guest_modes_append_default(); 150 151 while ((opt = getopt(argc, argv, "hm:d:b:v:oi:")) != -1) { 152 switch (opt) { 153 case 'm': 154 guest_modes_cmdline(optarg); 155 break; 156 case 'd': 157 p.memslot_modification_delay = strtoul(optarg, NULL, 0); 158 TEST_ASSERT(p.memslot_modification_delay >= 0, 159 "A negative delay is not supported."); 160 break; 161 case 'b': 162 guest_percpu_mem_size = parse_size(optarg); 163 break; 164 case 'v': 165 nr_vcpus = atoi(optarg); 166 TEST_ASSERT(nr_vcpus > 0 && nr_vcpus <= max_vcpus, 167 "Invalid number of vcpus, must be between 1 and %d", 168 max_vcpus); 169 break; 170 case 'o': 171 p.partition_vcpu_memory_access = false; 172 break; 173 case 'i': 174 p.nr_memslot_modifications = atoi(optarg); 175 break; 176 case 'h': 177 default: 178 help(argv[0]); 179 break; 180 } 181 } 182 183 for_each_guest_mode(run_test, &p); 184 185 return 0; 186 } 187