xref: /openbmc/qemu/hw/core/machine-smp.c (revision e50a24ea)
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
122      * not be set to a value greater than 1.
123      */
124     if (!mc->smp_props.modules_supported &&
125         config->has_modules && config->modules > 1) {
126         error_setg(errp,
127                    "modules > 1 not supported by this machine's CPU topology");
128         return;
129     }
130     modules = modules > 0 ? modules : 1;
131 
132     if (!mc->smp_props.clusters_supported &&
133         config->has_clusters && config->clusters > 1) {
134         error_setg(errp,
135                    "clusters > 1 not supported by this machine's CPU topology");
136         return;
137     }
138     clusters = clusters > 0 ? clusters : 1;
139 
140     if (!mc->smp_props.dies_supported &&
141         config->has_dies && config->dies > 1) {
142         error_setg(errp,
143                    "dies > 1 not supported by this machine's CPU topology");
144         return;
145     }
146     dies = dies > 0 ? dies : 1;
147 
148     if (!mc->smp_props.books_supported &&
149         config->has_books && config->books > 1) {
150         error_setg(errp,
151                    "books > 1 not supported by this machine's CPU topology");
152         return;
153     }
154     books = books > 0 ? books : 1;
155 
156     if (!mc->smp_props.drawers_supported &&
157         config->has_drawers && config->drawers > 1) {
158         error_setg(errp,
159                    "drawers > 1 not supported by this machine's CPU topology");
160         return;
161     }
162     drawers = drawers > 0 ? drawers : 1;
163 
164     /* compute missing values based on the provided ones */
165     if (cpus == 0 && maxcpus == 0) {
166         sockets = sockets > 0 ? sockets : 1;
167         cores = cores > 0 ? cores : 1;
168         threads = threads > 0 ? threads : 1;
169     } else {
170         maxcpus = maxcpus > 0 ? maxcpus : cpus;
171 
172         if (mc->smp_props.prefer_sockets) {
173             /* prefer sockets over cores before 6.2 */
174             if (sockets == 0) {
175                 cores = cores > 0 ? cores : 1;
176                 threads = threads > 0 ? threads : 1;
177                 sockets = maxcpus /
178                           (drawers * books * dies * clusters *
179                            modules * cores * threads);
180             } else if (cores == 0) {
181                 threads = threads > 0 ? threads : 1;
182                 cores = maxcpus /
183                         (drawers * books * sockets * dies *
184                          clusters * modules * threads);
185             }
186         } else {
187             /* prefer cores over sockets since 6.2 */
188             if (cores == 0) {
189                 sockets = sockets > 0 ? sockets : 1;
190                 threads = threads > 0 ? threads : 1;
191                 cores = maxcpus /
192                         (drawers * books * sockets * dies *
193                          clusters * modules * threads);
194             } else if (sockets == 0) {
195                 threads = threads > 0 ? threads : 1;
196                 sockets = maxcpus /
197                           (drawers * books * dies * clusters *
198                            modules * cores * threads);
199             }
200         }
201 
202         /* try to calculate omitted threads at last */
203         if (threads == 0) {
204             threads = maxcpus /
205                       (drawers * books * sockets * dies *
206                        clusters * modules * cores);
207         }
208     }
209 
210     total_cpus = drawers * books * sockets * dies *
211                  clusters * modules * cores * threads;
212     maxcpus = maxcpus > 0 ? maxcpus : total_cpus;
213     cpus = cpus > 0 ? cpus : maxcpus;
214 
215     ms->smp.cpus = cpus;
216     ms->smp.drawers = drawers;
217     ms->smp.books = books;
218     ms->smp.sockets = sockets;
219     ms->smp.dies = dies;
220     ms->smp.clusters = clusters;
221     ms->smp.modules = modules;
222     ms->smp.cores = cores;
223     ms->smp.threads = threads;
224     ms->smp.max_cpus = maxcpus;
225 
226     mc->smp_props.has_clusters = config->has_clusters;
227 
228     /* sanity-check of the computed topology */
229     if (total_cpus != maxcpus) {
230         g_autofree char *topo_msg = cpu_hierarchy_to_string(ms);
231         error_setg(errp, "Invalid CPU topology: "
232                    "product of the hierarchy must match maxcpus: "
233                    "%s != maxcpus (%u)",
234                    topo_msg, maxcpus);
235         return;
236     }
237 
238     if (maxcpus < cpus) {
239         g_autofree char *topo_msg = cpu_hierarchy_to_string(ms);
240         error_setg(errp, "Invalid CPU topology: "
241                    "maxcpus must be equal to or greater than smp: "
242                    "%s == maxcpus (%u) < smp_cpus (%u)",
243                    topo_msg, maxcpus, cpus);
244         return;
245     }
246 
247     if (ms->smp.cpus < mc->min_cpus) {
248         error_setg(errp, "Invalid SMP CPUs %d. The min CPUs "
249                    "supported by machine '%s' is %d",
250                    ms->smp.cpus,
251                    mc->name, mc->min_cpus);
252         return;
253     }
254 
255     if (ms->smp.max_cpus > mc->max_cpus) {
256         error_setg(errp, "Invalid SMP CPUs %d. The max CPUs "
257                    "supported by machine '%s' is %d",
258                    ms->smp.max_cpus,
259                    mc->name, mc->max_cpus);
260         return;
261     }
262 }
263 
264 static bool machine_check_topo_support(MachineState *ms,
265                                        CpuTopologyLevel topo,
266                                        Error **errp)
267 {
268     MachineClass *mc = MACHINE_GET_CLASS(ms);
269 
270     if ((topo == CPU_TOPOLOGY_LEVEL_MODULE && !mc->smp_props.modules_supported) ||
271         (topo == CPU_TOPOLOGY_LEVEL_CLUSTER && !mc->smp_props.clusters_supported) ||
272         (topo == CPU_TOPOLOGY_LEVEL_DIE && !mc->smp_props.dies_supported) ||
273         (topo == CPU_TOPOLOGY_LEVEL_BOOK && !mc->smp_props.books_supported) ||
274         (topo == CPU_TOPOLOGY_LEVEL_DRAWER && !mc->smp_props.drawers_supported)) {
275         error_setg(errp,
276                    "Invalid topology level: %s. "
277                    "The topology level is not supported by this machine",
278                    CpuTopologyLevel_str(topo));
279         return false;
280     }
281 
282     return true;
283 }
284 
285 bool machine_parse_smp_cache(MachineState *ms,
286                              const SmpCachePropertiesList *caches,
287                              Error **errp)
288 {
289     MachineClass *mc = MACHINE_GET_CLASS(ms);
290     const SmpCachePropertiesList *node;
291     DECLARE_BITMAP(caches_bitmap, CACHE_LEVEL_AND_TYPE__MAX);
292 
293     bitmap_zero(caches_bitmap, CACHE_LEVEL_AND_TYPE__MAX);
294     for (node = caches; node; node = node->next) {
295         /* Prohibit users from repeating settings. */
296         if (test_bit(node->value->cache, caches_bitmap)) {
297             error_setg(errp,
298                        "Invalid cache properties: %s. "
299                        "The cache properties are duplicated",
300                        CacheLevelAndType_str(node->value->cache));
301             return false;
302         }
303 
304         machine_set_cache_topo_level(ms, node->value->cache,
305                                      node->value->topology);
306         set_bit(node->value->cache, caches_bitmap);
307     }
308 
309     for (int i = 0; i < CACHE_LEVEL_AND_TYPE__MAX; i++) {
310         const SmpCacheProperties *props = &ms->smp_cache.props[i];
311 
312         /*
313          * Reject non "default" topology level if the cache isn't
314          * supported by the machine.
315          */
316         if (props->topology != CPU_TOPOLOGY_LEVEL_DEFAULT &&
317             !mc->smp_props.cache_supported[props->cache]) {
318             error_setg(errp,
319                        "%s cache topology not supported by this machine",
320                        CacheLevelAndType_str(props->cache));
321             return false;
322         }
323 
324         if (!machine_check_topo_support(ms, props->topology, errp)) {
325             return false;
326         }
327     }
328     return true;
329 }
330 
331 unsigned int machine_topo_get_cores_per_socket(const MachineState *ms)
332 {
333     return ms->smp.cores * ms->smp.modules * ms->smp.clusters * ms->smp.dies;
334 }
335 
336 unsigned int machine_topo_get_threads_per_socket(const MachineState *ms)
337 {
338     return ms->smp.threads * machine_topo_get_cores_per_socket(ms);
339 }
340 
341 CpuTopologyLevel machine_get_cache_topo_level(const MachineState *ms,
342                                               CacheLevelAndType cache)
343 {
344     return ms->smp_cache.props[cache].topology;
345 }
346 
347 void machine_set_cache_topo_level(MachineState *ms, CacheLevelAndType cache,
348                                   CpuTopologyLevel level)
349 {
350     ms->smp_cache.props[cache].topology = level;
351 }
352 
353 /*
354  * When both cache1 and cache2 are configured with specific topology levels
355  * (not default level), is cache1's topology level higher than cache2?
356  */
357 static bool smp_cache_topo_cmp(const SmpCache *smp_cache,
358                                CacheLevelAndType cache1,
359                                CacheLevelAndType cache2)
360 {
361     /*
362      * Before comparing, the "default" topology level should be replaced
363      * with the specific level.
364      */
365     assert(smp_cache->props[cache1].topology != CPU_TOPOLOGY_LEVEL_DEFAULT);
366 
367     return smp_cache->props[cache1].topology > smp_cache->props[cache2].topology;
368 }
369 
370 /*
371  * Currently, we have no way to expose the arch-specific default cache model
372  * because the cache model is sometimes related to the CPU model (e.g., i386).
373  *
374  * We can only check the correctness of the cache topology after the arch loads
375  * the user-configured cache model from MachineState and consumes the special
376  * "default" level by replacing it with the specific level.
377  */
378 bool machine_check_smp_cache(const MachineState *ms, Error **errp)
379 {
380     if (smp_cache_topo_cmp(&ms->smp_cache, CACHE_LEVEL_AND_TYPE_L1D,
381                            CACHE_LEVEL_AND_TYPE_L2) ||
382         smp_cache_topo_cmp(&ms->smp_cache, CACHE_LEVEL_AND_TYPE_L1I,
383                            CACHE_LEVEL_AND_TYPE_L2)) {
384         error_setg(errp,
385                    "Invalid smp cache topology. "
386                    "L2 cache topology level shouldn't be lower than L1 cache");
387         return false;
388     }
389 
390     if (smp_cache_topo_cmp(&ms->smp_cache, CACHE_LEVEL_AND_TYPE_L2,
391                            CACHE_LEVEL_AND_TYPE_L3)) {
392         error_setg(errp,
393                    "Invalid smp cache topology. "
394                    "L3 cache topology level shouldn't be lower than L2 cache");
395         return false;
396     }
397 
398     return true;
399 }
400