1 /* 2 * QEMU Machine core (related to -smp parsing) 3 * 4 * Copyright (c) 2021 Huawei Technologies Co., Ltd 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, 9 * or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include "qemu/osdep.h" 21 #include "hw/boards.h" 22 #include "qapi/error.h" 23 #include "qemu/error-report.h" 24 25 26 /* 27 * Report information of a machine's supported CPU topology hierarchy. 28 * Topology members will be ordered from the largest to the smallest 29 * in the string. 30 */ 31 static char *cpu_hierarchy_to_string(MachineState *ms) 32 { 33 MachineClass *mc = MACHINE_GET_CLASS(ms); 34 GString *s = g_string_new(NULL); 35 36 if (mc->smp_props.drawers_supported) { 37 g_string_append_printf(s, "drawers (%u) * ", ms->smp.drawers); 38 } 39 40 if (mc->smp_props.books_supported) { 41 g_string_append_printf(s, "books (%u) * ", ms->smp.books); 42 } 43 44 g_string_append_printf(s, "sockets (%u)", ms->smp.sockets); 45 46 if (mc->smp_props.dies_supported) { 47 g_string_append_printf(s, " * dies (%u)", ms->smp.dies); 48 } 49 50 if (mc->smp_props.clusters_supported) { 51 g_string_append_printf(s, " * clusters (%u)", ms->smp.clusters); 52 } 53 54 if (mc->smp_props.modules_supported) { 55 g_string_append_printf(s, " * modules (%u)", ms->smp.modules); 56 } 57 58 g_string_append_printf(s, " * cores (%u)", ms->smp.cores); 59 g_string_append_printf(s, " * threads (%u)", ms->smp.threads); 60 61 return g_string_free(s, false); 62 } 63 64 /* 65 * machine_parse_smp_config: Generic function used to parse the given 66 * SMP configuration 67 * 68 * Any missing parameter in "cpus/maxcpus/sockets/cores/threads" will be 69 * automatically computed based on the provided ones. 70 * 71 * In the calculation of omitted sockets/cores/threads: we prefer sockets 72 * over cores over threads before 6.2, while preferring cores over sockets 73 * over threads since 6.2. 74 * 75 * In the calculation of cpus/maxcpus: When both maxcpus and cpus are omitted, 76 * maxcpus will be computed from the given parameters and cpus will be set 77 * equal to maxcpus. When only one of maxcpus and cpus is given then the 78 * omitted one will be set to its given counterpart's value. Both maxcpus and 79 * cpus may be specified, but maxcpus must be equal to or greater than cpus. 80 * 81 * For compatibility, apart from the parameters that will be computed, newly 82 * introduced topology members which are likely to be target specific should 83 * be directly set as 1 if they are omitted (e.g. dies for PC since 4.1). 84 */ 85 void machine_parse_smp_config(MachineState *ms, 86 const SMPConfiguration *config, Error **errp) 87 { 88 MachineClass *mc = MACHINE_GET_CLASS(ms); 89 unsigned cpus = config->has_cpus ? config->cpus : 0; 90 unsigned drawers = config->has_drawers ? config->drawers : 0; 91 unsigned books = config->has_books ? config->books : 0; 92 unsigned sockets = config->has_sockets ? config->sockets : 0; 93 unsigned dies = config->has_dies ? config->dies : 0; 94 unsigned clusters = config->has_clusters ? config->clusters : 0; 95 unsigned modules = config->has_modules ? config->modules : 0; 96 unsigned cores = config->has_cores ? config->cores : 0; 97 unsigned threads = config->has_threads ? config->threads : 0; 98 unsigned maxcpus = config->has_maxcpus ? config->maxcpus : 0; 99 unsigned total_cpus; 100 101 /* 102 * Specified CPU topology parameters must be greater than zero, 103 * explicit configuration like "cpus=0" is not allowed. 104 */ 105 if ((config->has_cpus && config->cpus == 0) || 106 (config->has_drawers && config->drawers == 0) || 107 (config->has_books && config->books == 0) || 108 (config->has_sockets && config->sockets == 0) || 109 (config->has_dies && config->dies == 0) || 110 (config->has_clusters && config->clusters == 0) || 111 (config->has_modules && config->modules == 0) || 112 (config->has_cores && config->cores == 0) || 113 (config->has_threads && config->threads == 0) || 114 (config->has_maxcpus && config->maxcpus == 0)) { 115 error_setg(errp, "Invalid CPU topology: " 116 "CPU topology parameters must be greater than zero"); 117 return; 118 } 119 120 /* 121 * If not supported by the machine, a topology parameter must be 122 * omitted. 123 */ 124 if (!mc->smp_props.modules_supported && config->has_modules) { 125 if (config->modules > 1) { 126 error_setg(errp, "modules not supported by this " 127 "machine's CPU topology"); 128 return; 129 } else { 130 /* Here modules only equals 1 since we've checked zero case. */ 131 warn_report("Deprecated CPU topology (considered invalid): " 132 "Unsupported modules parameter mustn't be " 133 "specified as 1"); 134 } 135 } 136 modules = modules > 0 ? modules : 1; 137 138 if (!mc->smp_props.clusters_supported && config->has_clusters) { 139 if (config->clusters > 1) { 140 error_setg(errp, "clusters not supported by this " 141 "machine's CPU topology"); 142 return; 143 } else { 144 /* Here clusters only equals 1 since we've checked zero case. */ 145 warn_report("Deprecated CPU topology (considered invalid): " 146 "Unsupported clusters parameter mustn't be " 147 "specified as 1"); 148 } 149 } 150 clusters = clusters > 0 ? clusters : 1; 151 152 if (!mc->smp_props.dies_supported && config->has_dies) { 153 if (config->dies > 1) { 154 error_setg(errp, "dies not supported by this " 155 "machine's CPU topology"); 156 return; 157 } else { 158 /* Here dies only equals 1 since we've checked zero case. */ 159 warn_report("Deprecated CPU topology (considered invalid): " 160 "Unsupported dies parameter mustn't be " 161 "specified as 1"); 162 } 163 } 164 dies = dies > 0 ? dies : 1; 165 166 if (!mc->smp_props.books_supported && config->has_books) { 167 if (config->books > 1) { 168 error_setg(errp, "books not supported by this " 169 "machine's CPU topology"); 170 return; 171 } else { 172 /* Here books only equals 1 since we've checked zero case. */ 173 warn_report("Deprecated CPU topology (considered invalid): " 174 "Unsupported books parameter mustn't be " 175 "specified as 1"); 176 } 177 } 178 books = books > 0 ? books : 1; 179 180 if (!mc->smp_props.drawers_supported && config->has_drawers) { 181 if (config->drawers > 1) { 182 error_setg(errp, "drawers not supported by this " 183 "machine's CPU topology"); 184 return; 185 } else { 186 /* Here drawers only equals 1 since we've checked zero case. */ 187 warn_report("Deprecated CPU topology (considered invalid): " 188 "Unsupported drawers parameter mustn't be " 189 "specified as 1"); 190 } 191 } 192 drawers = drawers > 0 ? drawers : 1; 193 194 /* compute missing values based on the provided ones */ 195 if (cpus == 0 && maxcpus == 0) { 196 sockets = sockets > 0 ? sockets : 1; 197 cores = cores > 0 ? cores : 1; 198 threads = threads > 0 ? threads : 1; 199 } else { 200 maxcpus = maxcpus > 0 ? maxcpus : cpus; 201 202 if (mc->smp_props.prefer_sockets) { 203 /* prefer sockets over cores before 6.2 */ 204 if (sockets == 0) { 205 cores = cores > 0 ? cores : 1; 206 threads = threads > 0 ? threads : 1; 207 sockets = maxcpus / 208 (drawers * books * dies * clusters * 209 modules * cores * threads); 210 } else if (cores == 0) { 211 threads = threads > 0 ? threads : 1; 212 cores = maxcpus / 213 (drawers * books * sockets * dies * 214 clusters * modules * threads); 215 } 216 } else { 217 /* prefer cores over sockets since 6.2 */ 218 if (cores == 0) { 219 sockets = sockets > 0 ? sockets : 1; 220 threads = threads > 0 ? threads : 1; 221 cores = maxcpus / 222 (drawers * books * sockets * dies * 223 clusters * modules * threads); 224 } else if (sockets == 0) { 225 threads = threads > 0 ? threads : 1; 226 sockets = maxcpus / 227 (drawers * books * dies * clusters * 228 modules * cores * threads); 229 } 230 } 231 232 /* try to calculate omitted threads at last */ 233 if (threads == 0) { 234 threads = maxcpus / 235 (drawers * books * sockets * dies * 236 clusters * modules * cores); 237 } 238 } 239 240 total_cpus = drawers * books * sockets * dies * 241 clusters * modules * cores * threads; 242 maxcpus = maxcpus > 0 ? maxcpus : total_cpus; 243 cpus = cpus > 0 ? cpus : maxcpus; 244 245 ms->smp.cpus = cpus; 246 ms->smp.drawers = drawers; 247 ms->smp.books = books; 248 ms->smp.sockets = sockets; 249 ms->smp.dies = dies; 250 ms->smp.clusters = clusters; 251 ms->smp.modules = modules; 252 ms->smp.cores = cores; 253 ms->smp.threads = threads; 254 ms->smp.max_cpus = maxcpus; 255 256 mc->smp_props.has_clusters = config->has_clusters; 257 258 /* sanity-check of the computed topology */ 259 if (total_cpus != maxcpus) { 260 g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); 261 error_setg(errp, "Invalid CPU topology: " 262 "product of the hierarchy must match maxcpus: " 263 "%s != maxcpus (%u)", 264 topo_msg, maxcpus); 265 return; 266 } 267 268 if (maxcpus < cpus) { 269 g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); 270 error_setg(errp, "Invalid CPU topology: " 271 "maxcpus must be equal to or greater than smp: " 272 "%s == maxcpus (%u) < smp_cpus (%u)", 273 topo_msg, maxcpus, cpus); 274 return; 275 } 276 277 if (ms->smp.cpus < mc->min_cpus) { 278 error_setg(errp, "Invalid SMP CPUs %d. The min CPUs " 279 "supported by machine '%s' is %d", 280 ms->smp.cpus, 281 mc->name, mc->min_cpus); 282 return; 283 } 284 285 if (ms->smp.max_cpus > mc->max_cpus) { 286 error_setg(errp, "Invalid SMP CPUs %d. The max CPUs " 287 "supported by machine '%s' is %d", 288 ms->smp.max_cpus, 289 mc->name, mc->max_cpus); 290 return; 291 } 292 } 293 294 unsigned int machine_topo_get_cores_per_socket(const MachineState *ms) 295 { 296 return ms->smp.cores * ms->smp.modules * ms->smp.clusters * ms->smp.dies; 297 } 298 299 unsigned int machine_topo_get_threads_per_socket(const MachineState *ms) 300 { 301 return ms->smp.threads * machine_topo_get_cores_per_socket(ms); 302 } 303