1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * kvm_binary_stats_test 4 * 5 * Copyright (C) 2021, Google LLC. 6 * 7 * Test the fd-based interface for KVM statistics. 8 */ 9 10 #define _GNU_SOURCE /* for program_invocation_short_name */ 11 #include <fcntl.h> 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <errno.h> 16 17 #include "test_util.h" 18 19 #include "kvm_util.h" 20 #include "asm/kvm.h" 21 #include "linux/kvm.h" 22 #include "kselftest.h" 23 24 static void stats_test(int stats_fd) 25 { 26 ssize_t ret; 27 int i; 28 size_t size_desc; 29 size_t size_data = 0; 30 struct kvm_stats_header header; 31 char *id; 32 struct kvm_stats_desc *stats_desc; 33 u64 *stats_data; 34 struct kvm_stats_desc *pdesc; 35 u32 type, unit, base; 36 37 /* Read kvm stats header */ 38 read_stats_header(stats_fd, &header); 39 40 size_desc = get_stats_descriptor_size(&header); 41 42 /* Read kvm stats id string */ 43 id = malloc(header.name_size); 44 TEST_ASSERT(id, "Allocate memory for id string"); 45 46 ret = pread(stats_fd, id, header.name_size, sizeof(header)); 47 TEST_ASSERT(ret == header.name_size, 48 "Expected header size '%u', read '%lu' bytes", 49 header.name_size, ret); 50 51 /* Check id string, that should start with "kvm" */ 52 TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header.name_size, 53 "Invalid KVM stats type, id: %s", id); 54 55 /* Sanity check for other fields in header */ 56 if (header.num_desc == 0) { 57 ksft_print_msg("No KVM stats defined!\n"); 58 return; 59 } 60 /* 61 * The descriptor and data offsets must be valid, they must not overlap 62 * the header, and the descriptor and data blocks must not overlap each 63 * other. Note, the data block is rechecked after its size is known. 64 */ 65 TEST_ASSERT(header.desc_offset && header.desc_offset >= sizeof(header) && 66 header.data_offset && header.data_offset >= sizeof(header), 67 "Invalid offset fields in header"); 68 69 TEST_ASSERT(header.desc_offset > header.data_offset || 70 (header.desc_offset + size_desc * header.num_desc <= header.data_offset), 71 "Descriptor block is overlapped with data block"); 72 73 /* Read kvm stats descriptors */ 74 stats_desc = read_stats_descriptors(stats_fd, &header); 75 76 /* Sanity check for fields in descriptors */ 77 for (i = 0; i < header.num_desc; ++i) { 78 pdesc = get_stats_descriptor(stats_desc, i, &header); 79 type = pdesc->flags & KVM_STATS_TYPE_MASK; 80 unit = pdesc->flags & KVM_STATS_UNIT_MASK; 81 base = pdesc->flags & KVM_STATS_BASE_MASK; 82 83 /* Check name string */ 84 TEST_ASSERT(strlen(pdesc->name) < header.name_size, 85 "KVM stats name (index: %d) too long", i); 86 87 /* Check type,unit,base boundaries */ 88 TEST_ASSERT(type <= KVM_STATS_TYPE_MAX, 89 "Unknown KVM stats (%s) type: %u", pdesc->name, type); 90 TEST_ASSERT(unit <= KVM_STATS_UNIT_MAX, 91 "Unknown KVM stats (%s) unit: %u", pdesc->name, unit); 92 TEST_ASSERT(base <= KVM_STATS_BASE_MAX, 93 "Unknown KVM stats (%s) base: %u", pdesc->name, base); 94 95 /* 96 * Check exponent for stats unit 97 * Exponent for counter should be greater than or equal to 0 98 * Exponent for unit bytes should be greater than or equal to 0 99 * Exponent for unit seconds should be less than or equal to 0 100 * Exponent for unit clock cycles should be greater than or 101 * equal to 0 102 * Exponent for unit boolean should be 0 103 */ 104 switch (pdesc->flags & KVM_STATS_UNIT_MASK) { 105 case KVM_STATS_UNIT_NONE: 106 case KVM_STATS_UNIT_BYTES: 107 case KVM_STATS_UNIT_CYCLES: 108 TEST_ASSERT(pdesc->exponent >= 0, 109 "Unsupported KVM stats (%s) exponent: %i", 110 pdesc->name, pdesc->exponent); 111 break; 112 case KVM_STATS_UNIT_SECONDS: 113 TEST_ASSERT(pdesc->exponent <= 0, 114 "Unsupported KVM stats (%s) exponent: %i", 115 pdesc->name, pdesc->exponent); 116 break; 117 case KVM_STATS_UNIT_BOOLEAN: 118 TEST_ASSERT(pdesc->exponent == 0, 119 "Unsupported KVM stats (%s) exponent: %d", 120 pdesc->name, pdesc->exponent); 121 break; 122 } 123 124 /* Check size field, which should not be zero */ 125 TEST_ASSERT(pdesc->size, 126 "KVM descriptor(%s) with size of 0", pdesc->name); 127 /* Check bucket_size field */ 128 switch (pdesc->flags & KVM_STATS_TYPE_MASK) { 129 case KVM_STATS_TYPE_LINEAR_HIST: 130 TEST_ASSERT(pdesc->bucket_size, 131 "Bucket size of Linear Histogram stats (%s) is zero", 132 pdesc->name); 133 break; 134 default: 135 TEST_ASSERT(!pdesc->bucket_size, 136 "Bucket size of stats (%s) is not zero", 137 pdesc->name); 138 } 139 size_data = max(size_data, pdesc->offset + pdesc->size * sizeof(*stats_data)); 140 } 141 142 /* 143 * Now that the size of the data block is known, verify the data block 144 * doesn't overlap the descriptor block. 145 */ 146 TEST_ASSERT(header.data_offset >= header.desc_offset || 147 header.data_offset + size_data <= header.desc_offset, 148 "Data block is overlapped with Descriptor block"); 149 150 /* Check validity of all stats data size */ 151 TEST_ASSERT(size_data >= header.num_desc * sizeof(*stats_data), 152 "Data size is not correct"); 153 154 /* Allocate memory for stats data */ 155 stats_data = malloc(size_data); 156 TEST_ASSERT(stats_data, "Allocate memory for stats data"); 157 /* Read kvm stats data as a bulk */ 158 ret = pread(stats_fd, stats_data, size_data, header.data_offset); 159 TEST_ASSERT(ret == size_data, "Read KVM stats data"); 160 /* Read kvm stats data one by one */ 161 for (i = 0; i < header.num_desc; ++i) { 162 pdesc = get_stats_descriptor(stats_desc, i, &header); 163 read_stat_data(stats_fd, &header, pdesc, stats_data, 164 pdesc->size); 165 } 166 167 free(stats_data); 168 free(stats_desc); 169 free(id); 170 171 close(stats_fd); 172 TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed"); 173 } 174 175 #define DEFAULT_NUM_VM 4 176 #define DEFAULT_NUM_VCPU 4 177 178 /* 179 * Usage: kvm_bin_form_stats [#vm] [#vcpu] 180 * The first parameter #vm set the number of VMs being created. 181 * The second parameter #vcpu set the number of VCPUs being created. 182 * By default, DEFAULT_NUM_VM VM and DEFAULT_NUM_VCPU VCPU for the VM would be 183 * created for testing. 184 */ 185 186 int main(int argc, char *argv[]) 187 { 188 int vm_stats_fds, *vcpu_stats_fds; 189 int i, j; 190 struct kvm_vcpu **vcpus; 191 struct kvm_vm **vms; 192 int max_vm = DEFAULT_NUM_VM; 193 int max_vcpu = DEFAULT_NUM_VCPU; 194 195 /* Get the number of VMs and VCPUs that would be created for testing. */ 196 if (argc > 1) { 197 max_vm = strtol(argv[1], NULL, 0); 198 if (max_vm <= 0) 199 max_vm = DEFAULT_NUM_VM; 200 } 201 if (argc > 2) { 202 max_vcpu = strtol(argv[2], NULL, 0); 203 if (max_vcpu <= 0) 204 max_vcpu = DEFAULT_NUM_VCPU; 205 } 206 207 ksft_print_header(); 208 209 /* Check the extension for binary stats */ 210 TEST_REQUIRE(kvm_has_cap(KVM_CAP_BINARY_STATS_FD)); 211 212 ksft_set_plan(max_vm); 213 214 /* Create VMs and VCPUs */ 215 vms = malloc(sizeof(vms[0]) * max_vm); 216 TEST_ASSERT(vms, "Allocate memory for storing VM pointers"); 217 218 vcpus = malloc(sizeof(struct kvm_vcpu *) * max_vm * max_vcpu); 219 TEST_ASSERT(vcpus, "Allocate memory for storing vCPU pointers"); 220 221 /* 222 * Not per-VM as the array is populated, used, and invalidated within a 223 * single for-loop iteration. 224 */ 225 vcpu_stats_fds = calloc(max_vm, sizeof(*vcpu_stats_fds)); 226 TEST_ASSERT(vcpu_stats_fds, "Allocate memory for VM stats fds"); 227 228 for (i = 0; i < max_vm; ++i) { 229 vms[i] = vm_create_barebones(); 230 for (j = 0; j < max_vcpu; ++j) 231 vcpus[i * max_vcpu + j] = __vm_vcpu_add(vms[i], j); 232 } 233 234 /* 235 * Check stats read for every VM and vCPU, with a variety of flavors. 236 * Note, stats_test() closes the passed in stats fd. 237 */ 238 for (i = 0; i < max_vm; ++i) { 239 /* 240 * Verify that creating multiple userspace references to a 241 * single stats file works and doesn't cause explosions. 242 */ 243 vm_stats_fds = vm_get_stats_fd(vms[i]); 244 stats_test(dup(vm_stats_fds)); 245 246 /* Verify userspace can instantiate multiple stats files. */ 247 stats_test(vm_get_stats_fd(vms[i])); 248 249 for (j = 0; j < max_vcpu; ++j) { 250 vcpu_stats_fds[j] = vcpu_get_stats_fd(vcpus[i * max_vcpu + j]); 251 stats_test(dup(vcpu_stats_fds[j])); 252 stats_test(vcpu_get_stats_fd(vcpus[i * max_vcpu + j])); 253 } 254 255 /* 256 * Close the VM fd and redo the stats tests. KVM should gift a 257 * reference (to the VM) to each stats fd, i.e. stats should 258 * still be accessible even after userspace has put its last 259 * _direct_ reference to the VM. 260 */ 261 kvm_vm_free(vms[i]); 262 263 stats_test(vm_stats_fds); 264 for (j = 0; j < max_vcpu; ++j) 265 stats_test(vcpu_stats_fds[j]); 266 267 ksft_test_result_pass("vm%i\n", i); 268 } 269 270 free(vms); 271 free(vcpus); 272 free(vcpu_stats_fds); 273 274 ksft_finished(); /* Print results and exit() accordingly */ 275 } 276