| /* |
| * QEMU Machine core (related to -smp parsing) |
| * |
| * Copyright (c) 2021 Huawei Technologies Co., Ltd |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, |
| * or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "hw/boards.h" |
| #include "qapi/error.h" |
| |
| /* |
| * Report information of a machine's supported CPU topology hierarchy. |
| * Topology members will be ordered from the largest to the smallest |
| * in the string. |
| */ |
| static char *cpu_hierarchy_to_string(MachineState *ms) |
| { |
| MachineClass *mc = MACHINE_GET_CLASS(ms); |
| GString *s = g_string_new(NULL); |
| |
| g_string_append_printf(s, "sockets (%u)", ms->smp.sockets); |
| |
| if (mc->smp_props.dies_supported) { |
| g_string_append_printf(s, " * dies (%u)", ms->smp.dies); |
| } |
| |
| if (mc->smp_props.clusters_supported) { |
| g_string_append_printf(s, " * clusters (%u)", ms->smp.clusters); |
| } |
| |
| g_string_append_printf(s, " * cores (%u)", ms->smp.cores); |
| g_string_append_printf(s, " * threads (%u)", ms->smp.threads); |
| |
| return g_string_free(s, false); |
| } |
| |
| /* |
| * machine_parse_smp_config: Generic function used to parse the given |
| * SMP configuration |
| * |
| * Any missing parameter in "cpus/maxcpus/sockets/cores/threads" will be |
| * automatically computed based on the provided ones. |
| * |
| * In the calculation of omitted sockets/cores/threads: we prefer sockets |
| * over cores over threads before 6.2, while preferring cores over sockets |
| * over threads since 6.2. |
| * |
| * In the calculation of cpus/maxcpus: When both maxcpus and cpus are omitted, |
| * maxcpus will be computed from the given parameters and cpus will be set |
| * equal to maxcpus. When only one of maxcpus and cpus is given then the |
| * omitted one will be set to its given counterpart's value. Both maxcpus and |
| * cpus may be specified, but maxcpus must be equal to or greater than cpus. |
| * |
| * For compatibility, apart from the parameters that will be computed, newly |
| * introduced topology members which are likely to be target specific should |
| * be directly set as 1 if they are omitted (e.g. dies for PC since 4.1). |
| */ |
| void machine_parse_smp_config(MachineState *ms, |
| const SMPConfiguration *config, Error **errp) |
| { |
| MachineClass *mc = MACHINE_GET_CLASS(ms); |
| unsigned cpus = config->has_cpus ? config->cpus : 0; |
| unsigned sockets = config->has_sockets ? config->sockets : 0; |
| unsigned dies = config->has_dies ? config->dies : 0; |
| unsigned clusters = config->has_clusters ? config->clusters : 0; |
| unsigned cores = config->has_cores ? config->cores : 0; |
| unsigned threads = config->has_threads ? config->threads : 0; |
| unsigned maxcpus = config->has_maxcpus ? config->maxcpus : 0; |
| |
| /* |
| * Specified CPU topology parameters must be greater than zero, |
| * explicit configuration like "cpus=0" is not allowed. |
| */ |
| if ((config->has_cpus && config->cpus == 0) || |
| (config->has_sockets && config->sockets == 0) || |
| (config->has_dies && config->dies == 0) || |
| (config->has_clusters && config->clusters == 0) || |
| (config->has_cores && config->cores == 0) || |
| (config->has_threads && config->threads == 0) || |
| (config->has_maxcpus && config->maxcpus == 0)) { |
| warn_report("Deprecated CPU topology (considered invalid): " |
| "CPU topology parameters must be greater than zero"); |
| } |
| |
| /* |
| * If not supported by the machine, a topology parameter must be |
| * omitted or specified equal to 1. |
| */ |
| if (!mc->smp_props.dies_supported && dies > 1) { |
| error_setg(errp, "dies not supported by this machine's CPU topology"); |
| return; |
| } |
| if (!mc->smp_props.clusters_supported && clusters > 1) { |
| error_setg(errp, "clusters not supported by this machine's CPU topology"); |
| return; |
| } |
| |
| dies = dies > 0 ? dies : 1; |
| clusters = clusters > 0 ? clusters : 1; |
| |
| /* compute missing values based on the provided ones */ |
| if (cpus == 0 && maxcpus == 0) { |
| sockets = sockets > 0 ? sockets : 1; |
| cores = cores > 0 ? cores : 1; |
| threads = threads > 0 ? threads : 1; |
| } else { |
| maxcpus = maxcpus > 0 ? maxcpus : cpus; |
| |
| if (mc->smp_props.prefer_sockets) { |
| /* prefer sockets over cores before 6.2 */ |
| if (sockets == 0) { |
| cores = cores > 0 ? cores : 1; |
| threads = threads > 0 ? threads : 1; |
| sockets = maxcpus / (dies * clusters * cores * threads); |
| } else if (cores == 0) { |
| threads = threads > 0 ? threads : 1; |
| cores = maxcpus / (sockets * dies * clusters * threads); |
| } |
| } else { |
| /* prefer cores over sockets since 6.2 */ |
| if (cores == 0) { |
| sockets = sockets > 0 ? sockets : 1; |
| threads = threads > 0 ? threads : 1; |
| cores = maxcpus / (sockets * dies * clusters * threads); |
| } else if (sockets == 0) { |
| threads = threads > 0 ? threads : 1; |
| sockets = maxcpus / (dies * clusters * cores * threads); |
| } |
| } |
| |
| /* try to calculate omitted threads at last */ |
| if (threads == 0) { |
| threads = maxcpus / (sockets * dies * clusters * cores); |
| } |
| } |
| |
| maxcpus = maxcpus > 0 ? maxcpus : sockets * dies * clusters * cores * threads; |
| cpus = cpus > 0 ? cpus : maxcpus; |
| |
| ms->smp.cpus = cpus; |
| ms->smp.sockets = sockets; |
| ms->smp.dies = dies; |
| ms->smp.clusters = clusters; |
| ms->smp.cores = cores; |
| ms->smp.threads = threads; |
| ms->smp.max_cpus = maxcpus; |
| |
| mc->smp_props.has_clusters = config->has_clusters; |
| |
| /* sanity-check of the computed topology */ |
| if (sockets * dies * clusters * cores * threads != maxcpus) { |
| g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); |
| error_setg(errp, "Invalid CPU topology: " |
| "product of the hierarchy must match maxcpus: " |
| "%s != maxcpus (%u)", |
| topo_msg, maxcpus); |
| return; |
| } |
| |
| if (maxcpus < cpus) { |
| g_autofree char *topo_msg = cpu_hierarchy_to_string(ms); |
| error_setg(errp, "Invalid CPU topology: " |
| "maxcpus must be equal to or greater than smp: " |
| "%s == maxcpus (%u) < smp_cpus (%u)", |
| topo_msg, maxcpus, cpus); |
| return; |
| } |
| |
| if (ms->smp.cpus < mc->min_cpus) { |
| error_setg(errp, "Invalid SMP CPUs %d. The min CPUs " |
| "supported by machine '%s' is %d", |
| ms->smp.cpus, |
| mc->name, mc->min_cpus); |
| return; |
| } |
| |
| if (ms->smp.max_cpus > mc->max_cpus) { |
| error_setg(errp, "Invalid SMP CPUs %d. The max CPUs " |
| "supported by machine '%s' is %d", |
| ms->smp.max_cpus, |
| mc->name, mc->max_cpus); |
| return; |
| } |
| } |
