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 g_string_append_printf(s, " * cores (%u)", ms->smp.cores); 55 g_string_append_printf(s, " * threads (%u)", ms->smp.threads); 56 57 return g_string_free(s, false); 58 } 59 60 /* 61 * machine_parse_smp_config: Generic function used to parse the given 62 * SMP configuration 63 * 64 * Any missing parameter in "cpus/maxcpus/sockets/cores/threads" will be 65 * automatically computed based on the provided ones. 66 * 67 * In the calculation of omitted sockets/cores/threads: we prefer sockets 68 * over cores over threads before 6.2, while preferring cores over sockets 69 * over threads since 6.2. 70 * 71 * In the calculation of cpus/maxcpus: When both maxcpus and cpus are omitted, 72 * maxcpus will be computed from the given parameters and cpus will be set 73 * equal to maxcpus. When only one of maxcpus and cpus is given then the 74 * omitted one will be set to its given counterpart's value. Both maxcpus and 75 * cpus may be specified, but maxcpus must be equal to or greater than cpus. 76 * 77 * For compatibility, apart from the parameters that will be computed, newly 78 * introduced topology members which are likely to be target specific should 79 * be directly set as 1 if they are omitted (e.g. dies for PC since 4.1). 80 */ 81 void machine_parse_smp_config(MachineState *ms, 82 const SMPConfiguration *config, Error **errp) 83 { 84 MachineClass *mc = MACHINE_GET_CLASS(ms); 85 unsigned cpus = config->has_cpus ? config->cpus : 0; 86 unsigned drawers = config->has_drawers ? config->drawers : 0; 87 unsigned books = config->has_books ? config->books : 0; 88 unsigned sockets = config->has_sockets ? config->sockets : 0; 89 unsigned dies = config->has_dies ? config->dies : 0; 90 unsigned clusters = config->has_clusters ? config->clusters : 0; 91 unsigned cores = config->has_cores ? config->cores : 0; 92 unsigned threads = config->has_threads ? config->threads : 0; 93 unsigned maxcpus = config->has_maxcpus ? config->maxcpus : 0; 94 95 /* 96 * Specified CPU topology parameters must be greater than zero, 97 * explicit configuration like "cpus=0" is not allowed. 98 */ 99 if ((config->has_cpus && config->cpus == 0) || 100 (config->has_drawers && config->drawers == 0) || 101 (config->has_books && config->books == 0) || 102 (config->has_sockets && config->sockets == 0) || 103 (config->has_dies && config->dies == 0) || 104 (config->has_clusters && config->clusters == 0) || 105 (config->has_cores && config->cores == 0) || 106 (config->has_threads && config->threads == 0) || 107 (config->has_maxcpus && config->maxcpus == 0)) { 108 warn_report("Deprecated CPU topology (considered invalid): " 109 "CPU topology parameters must be greater than zero"); 110 } 111 112 /* 113 * If not supported by the machine, a topology parameter must be 114 * omitted or specified equal to 1. 115 */ 116 if (!mc->smp_props.dies_supported && dies > 1) { 117 error_setg(errp, "dies not supported by this machine's CPU topology"); 118 return; 119 } 120 if (!mc->smp_props.clusters_supported && clusters > 1) { 121 error_setg(errp, "clusters not supported by this machine's CPU topology"); 122 return; 123 } 124 125 dies = dies > 0 ? dies : 1; 126 clusters = clusters > 0 ? clusters : 1; 127 128 if (!mc->smp_props.books_supported && books > 1) { 129 error_setg(errp, "books not supported by this machine's CPU topology"); 130 return; 131 } 132 books = books > 0 ? books : 1; 133 134 if (!mc->smp_props.drawers_supported && drawers > 1) { 135 error_setg(errp, 136 "drawers not supported by this machine's CPU topology"); 137 return; 138 } 139 drawers = drawers > 0 ? drawers : 1; 140 141 /* compute missing values based on the provided ones */ 142 if (cpus == 0 && maxcpus == 0) { 143 sockets = sockets > 0 ? sockets : 1; 144 cores = cores > 0 ? cores : 1; 145 threads = threads > 0 ? threads : 1; 146 } else { 147 maxcpus = maxcpus > 0 ? maxcpus : cpus; 148 149 if (mc->smp_props.prefer_sockets) { 150 /* prefer sockets over cores before 6.2 */ 151 if (sockets == 0) { 152 cores = cores > 0 ? cores : 1; 153 threads = threads > 0 ? threads : 1; 154 sockets = maxcpus / 155 (drawers * books * dies * clusters * cores * threads); 156 } else if (cores == 0) { 157 threads = threads > 0 ? threads : 1; 158 cores = maxcpus / 159 (drawers * books * sockets * dies * clusters * threads); 160 } 161 } else { 162 /* prefer cores over sockets since 6.2 */ 163 if (cores == 0) { 164 sockets = sockets > 0 ? sockets : 1; 165 threads = threads > 0 ? threads : 1; 166 cores = maxcpus / 167 (drawers * books * sockets * dies * clusters * threads); 168 } else if (sockets == 0) { 169 threads = threads > 0 ? threads : 1; 170 sockets = maxcpus / 171 (drawers * books * dies * clusters * cores * threads); 172 } 173 } 174 175 /* try to calculate omitted threads at last */ 176 if (threads == 0) { 177 threads = maxcpus / 178 (drawers * books * sockets * dies * clusters * cores); 179 } 180 } 181 182 maxcpus = maxcpus > 0 ? maxcpus : drawers * books * sockets * dies * 183 clusters * cores * threads; 184 cpus = cpus > 0 ? cpus : maxcpus; 185 186 ms->smp.cpus = cpus; 187 ms->smp.drawers = drawers; 188 ms->smp.books = books; 189 ms->smp.sockets = sockets; 190 ms->smp.dies = dies; 191 ms->smp.clusters = clusters; 192 ms->smp.cores = cores; 193 ms->smp.threads = threads; 194 ms->smp.max_cpus = maxcpus; 195 196 mc->smp_props.has_clusters = config->has_clusters; 197 198 /* sanity-check of the computed topology */ 199 if (drawers * books * sockets * dies * clusters * cores * threads != 200 maxcpus) { 201 g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); 202 error_setg(errp, "Invalid CPU topology: " 203 "product of the hierarchy must match maxcpus: " 204 "%s != maxcpus (%u)", 205 topo_msg, maxcpus); 206 return; 207 } 208 209 if (maxcpus < cpus) { 210 g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); 211 error_setg(errp, "Invalid CPU topology: " 212 "maxcpus must be equal to or greater than smp: " 213 "%s == maxcpus (%u) < smp_cpus (%u)", 214 topo_msg, maxcpus, cpus); 215 return; 216 } 217 218 if (ms->smp.cpus < mc->min_cpus) { 219 error_setg(errp, "Invalid SMP CPUs %d. The min CPUs " 220 "supported by machine '%s' is %d", 221 ms->smp.cpus, 222 mc->name, mc->min_cpus); 223 return; 224 } 225 226 if (ms->smp.max_cpus > mc->max_cpus) { 227 error_setg(errp, "Invalid SMP CPUs %d. The max CPUs " 228 "supported by machine '%s' is %d", 229 ms->smp.max_cpus, 230 mc->name, mc->max_cpus); 231 return; 232 } 233 } 234 235 unsigned int machine_topo_get_cores_per_socket(const MachineState *ms) 236 { 237 return ms->smp.cores * ms->smp.clusters * ms->smp.dies; 238 } 239 240 unsigned int machine_topo_get_threads_per_socket(const MachineState *ms) 241 { 242 return ms->smp.threads * machine_topo_get_cores_per_socket(ms); 243 } 244