1 /* 2 * QEMU KVM support -- x86 virtual RAPL msr 3 * 4 * Copyright 2024 Red Hat, Inc. 2024 5 * 6 * Author: 7 * Anthony Harivel <aharivel@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 * 12 */ 13 14 #include "qemu/osdep.h" 15 #include "qemu/error-report.h" 16 #include "vmsr_energy.h" 17 #include "io/channel.h" 18 #include "io/channel-socket.h" 19 #include "hw/boards.h" 20 #include "cpu.h" 21 #include "host-cpu.h" 22 23 char *vmsr_compute_default_paths(void) 24 { 25 g_autofree char *state = qemu_get_local_state_dir(); 26 27 return g_build_filename(state, "run", "qemu-vmsr-helper.sock", NULL); 28 } 29 30 int is_rapl_enabled(void) 31 { 32 const char *path = "/sys/class/powercap/intel-rapl/enabled"; 33 FILE *file = fopen(path, "r"); 34 int value = 0; 35 36 if (file != NULL) { 37 if (fscanf(file, "%d", &value) != 1) { 38 error_report("INTEL RAPL not enabled"); 39 } 40 fclose(file); 41 } else { 42 error_report("Error opening %s", path); 43 } 44 45 return value; 46 } 47 48 QIOChannelSocket *vmsr_open_socket(const char *path) 49 { 50 g_autofree char *socket_path = NULL; 51 52 socket_path = g_strdup(path); 53 54 SocketAddress saddr = { 55 .type = SOCKET_ADDRESS_TYPE_UNIX, 56 .u.q_unix.path = socket_path 57 }; 58 59 QIOChannelSocket *sioc = qio_channel_socket_new(); 60 61 qio_channel_set_name(QIO_CHANNEL(sioc), "vmsr-helper"); 62 if (qio_channel_socket_connect_sync(sioc, &saddr, NULL) < 0) { 63 /* Close socket. */ 64 qio_channel_close(QIO_CHANNEL(sioc), NULL); 65 object_unref(OBJECT(sioc)); 66 sioc = NULL; 67 goto out; 68 } 69 70 qio_channel_set_delay(QIO_CHANNEL(sioc), false); 71 out: 72 return sioc; 73 } 74 75 uint64_t vmsr_read_msr(uint32_t reg, uint32_t cpu_id, uint32_t tid, 76 QIOChannelSocket *sioc) 77 { 78 uint64_t data = 0; 79 int r = 0; 80 Error *local_err = NULL; 81 uint32_t buffer[3]; 82 /* 83 * Send the required arguments: 84 * 1. RAPL MSR register to read 85 * 2. On which CPU ID 86 * 3. From which vCPU (Thread ID) 87 */ 88 buffer[0] = reg; 89 buffer[1] = cpu_id; 90 buffer[2] = tid; 91 92 r = qio_channel_write_all(QIO_CHANNEL(sioc), 93 (char *)buffer, sizeof(buffer), 94 &local_err); 95 if (r < 0) { 96 goto out_close; 97 } 98 99 r = qio_channel_read(QIO_CHANNEL(sioc), 100 (char *)&data, sizeof(data), 101 &local_err); 102 if (r < 0) { 103 data = 0; 104 goto out_close; 105 } 106 107 out_close: 108 return data; 109 } 110 111 /* Retrieve the max number of physical package */ 112 unsigned int vmsr_get_max_physical_package(unsigned int max_cpus) 113 { 114 const char *dir = "/sys/devices/system/cpu/"; 115 const char *topo_path = "topology/physical_package_id"; 116 g_autofree int *uniquePackages = g_new0(int, max_cpus); 117 unsigned int packageCount = 0; 118 FILE *file = NULL; 119 120 for (int i = 0; i < max_cpus; i++) { 121 g_autofree char *filePath = NULL; 122 g_autofree char *cpuid = g_strdup_printf("cpu%d", i); 123 124 filePath = g_build_filename(dir, cpuid, topo_path, NULL); 125 126 file = fopen(filePath, "r"); 127 128 if (file == NULL) { 129 error_report("Error opening physical_package_id file"); 130 return 0; 131 } 132 133 char packageId[10]; 134 if (fgets(packageId, sizeof(packageId), file) == NULL) { 135 packageCount = 0; 136 } 137 138 fclose(file); 139 140 int currentPackageId = atoi(packageId); 141 142 bool isUnique = true; 143 for (int j = 0; j < packageCount; j++) { 144 if (uniquePackages[j] == currentPackageId) { 145 isUnique = false; 146 break; 147 } 148 } 149 150 if (isUnique) { 151 uniquePackages[packageCount] = currentPackageId; 152 packageCount++; 153 154 if (packageCount >= max_cpus) { 155 break; 156 } 157 } 158 } 159 160 return (packageCount == 0) ? 1 : packageCount; 161 } 162 163 /* Retrieve the max number of physical cpu on the host */ 164 unsigned int vmsr_get_maxcpus(void) 165 { 166 GDir *dir; 167 const gchar *entry_name; 168 unsigned int cpu_count = 0; 169 const char *path = "/sys/devices/system/cpu/"; 170 171 dir = g_dir_open(path, 0, NULL); 172 if (dir == NULL) { 173 error_report("Unable to open cpu directory"); 174 return -1; 175 } 176 177 while ((entry_name = g_dir_read_name(dir)) != NULL) { 178 if (g_ascii_strncasecmp(entry_name, "cpu", 3) == 0 && 179 isdigit(entry_name[3])) { 180 cpu_count++; 181 } 182 } 183 184 g_dir_close(dir); 185 186 return cpu_count; 187 } 188 189 /* Count the number of physical cpu on each packages */ 190 unsigned int vmsr_count_cpus_per_package(unsigned int *package_count, 191 unsigned int max_pkgs) 192 { 193 g_autofree char *file_contents = NULL; 194 g_autofree char *path = NULL; 195 g_autofree char *path_name = NULL; 196 gsize length; 197 198 /* Iterate over cpus and count cpus in each package */ 199 for (int cpu_id = 0; ; cpu_id++) { 200 path_name = g_strdup_printf("/sys/devices/system/cpu/cpu%d/" 201 "topology/physical_package_id", cpu_id); 202 203 path = g_build_filename(path_name, NULL); 204 205 if (!g_file_get_contents(path, &file_contents, &length, NULL)) { 206 break; /* No more cpus */ 207 } 208 209 /* Get the physical package ID for this CPU */ 210 int package_id = atoi(file_contents); 211 212 /* Check if the package ID is within the known number of packages */ 213 if (package_id >= 0 && package_id < max_pkgs) { 214 /* If yes, count the cpu for this package*/ 215 package_count[package_id]++; 216 } 217 } 218 219 return 0; 220 } 221 222 /* Get the physical package id from a given cpu id */ 223 int vmsr_get_physical_package_id(int cpu_id) 224 { 225 g_autofree char *file_contents = NULL; 226 g_autofree char *file_path = NULL; 227 int package_id = -1; 228 gsize length; 229 230 file_path = g_strdup_printf("/sys/devices/system/cpu/cpu%d" 231 "/topology/physical_package_id", cpu_id); 232 233 if (!g_file_get_contents(file_path, &file_contents, &length, NULL)) { 234 goto out; 235 } 236 237 package_id = atoi(file_contents); 238 239 out: 240 return package_id; 241 } 242 243 /* Read the scheduled time for a given thread of a give pid */ 244 void vmsr_read_thread_stat(pid_t pid, 245 unsigned int thread_id, 246 unsigned long long *utime, 247 unsigned long long *stime, 248 unsigned int *cpu_id) 249 { 250 g_autofree char *path = NULL; 251 g_autofree char *path_name = NULL; 252 253 path_name = g_strdup_printf("/proc/%u/task/%d/stat", pid, thread_id); 254 255 path = g_build_filename(path_name, NULL); 256 257 FILE *file = fopen(path, "r"); 258 if (file == NULL) { 259 error_report("Error opening %s", path_name); 260 return; 261 } 262 263 if (fscanf(file, "%*d (%*[^)]) %*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u" 264 " %llu %llu %*d %*d %*d %*d %*d %*d %*u %*u %*d %*u %*u" 265 " %*u %*u %*u %*u %*u %*u %*u %*u %*u %*d %*u %*u %u", 266 utime, stime, cpu_id) != 3) 267 { 268 fclose(file); 269 error_report("Error fscanf did not report the right amount of items"); 270 return; 271 } 272 273 fclose(file); 274 } 275 276 /* Read QEMU stat task folder to retrieve all QEMU threads ID */ 277 pid_t *vmsr_get_thread_ids(pid_t pid, unsigned int *num_threads) 278 { 279 g_autofree char *task_path = g_strdup_printf("%d/task", pid); 280 g_autofree char *path = g_build_filename("/proc", task_path, NULL); 281 282 DIR *dir = opendir(path); 283 if (dir == NULL) { 284 error_report("Error opening /proc/qemu/task"); 285 return NULL; 286 } 287 288 pid_t *thread_ids = NULL; 289 unsigned int thread_count = 0; 290 291 g_autofree struct dirent *ent = NULL; 292 while ((ent = readdir(dir)) != NULL) { 293 if (ent->d_name[0] == '.') { 294 continue; 295 } 296 pid_t tid = atoi(ent->d_name); 297 if (pid != tid) { 298 thread_ids = g_renew(pid_t, thread_ids, (thread_count + 1)); 299 thread_ids[thread_count] = tid; 300 thread_count++; 301 } 302 } 303 304 closedir(dir); 305 306 *num_threads = thread_count; 307 return thread_ids; 308 } 309 310 void vmsr_delta_ticks(vmsr_thread_stat *thd_stat, int i) 311 { 312 thd_stat[i].delta_ticks = (thd_stat[i].utime[1] + thd_stat[i].stime[1]) 313 - (thd_stat[i].utime[0] + thd_stat[i].stime[0]); 314 } 315 316 double vmsr_get_ratio(uint64_t e_delta, 317 unsigned long long delta_ticks, 318 unsigned int maxticks) 319 { 320 return (e_delta / 100.0) * ((100.0 / maxticks) * delta_ticks); 321 } 322 323 void vmsr_init_topo_info(X86CPUTopoInfo *topo_info, 324 const MachineState *ms) 325 { 326 topo_info->dies_per_pkg = ms->smp.dies; 327 topo_info->modules_per_die = ms->smp.modules; 328 topo_info->cores_per_module = ms->smp.cores; 329 topo_info->threads_per_core = ms->smp.threads; 330 } 331 332