Merge remote-tracking branch 'remotes/vivier/tags/trivial-branch-for-6.2-pull-request...
[qemu.git] / backends / hostmem.c
1 /*
2 * QEMU Host Memory Backend
3 *
4 * Copyright (C) 2013-2014 Red Hat Inc
5 *
6 * Authors:
7 * Igor Mammedov <imammedo@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 #include "qemu/osdep.h"
14 #include "sysemu/hostmem.h"
15 #include "hw/boards.h"
16 #include "qapi/error.h"
17 #include "qapi/qapi-builtin-visit.h"
18 #include "qapi/visitor.h"
19 #include "qemu/config-file.h"
20 #include "qom/object_interfaces.h"
21 #include "qemu/mmap-alloc.h"
22
23 #ifdef CONFIG_NUMA
24 #include <numaif.h>
25 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
26 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
27 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
28 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
29 #endif
30
31 char *
32 host_memory_backend_get_name(HostMemoryBackend *backend)
33 {
34 if (!backend->use_canonical_path) {
35 return g_strdup(object_get_canonical_path_component(OBJECT(backend)));
36 }
37
38 return object_get_canonical_path(OBJECT(backend));
39 }
40
41 static void
42 host_memory_backend_get_size(Object *obj, Visitor *v, const char *name,
43 void *opaque, Error **errp)
44 {
45 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
46 uint64_t value = backend->size;
47
48 visit_type_size(v, name, &value, errp);
49 }
50
51 static void
52 host_memory_backend_set_size(Object *obj, Visitor *v, const char *name,
53 void *opaque, Error **errp)
54 {
55 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
56 uint64_t value;
57
58 if (host_memory_backend_mr_inited(backend)) {
59 error_setg(errp, "cannot change property %s of %s ", name,
60 object_get_typename(obj));
61 return;
62 }
63
64 if (!visit_type_size(v, name, &value, errp)) {
65 return;
66 }
67 if (!value) {
68 error_setg(errp,
69 "property '%s' of %s doesn't take value '%" PRIu64 "'",
70 name, object_get_typename(obj), value);
71 return;
72 }
73 backend->size = value;
74 }
75
76 static void
77 host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
78 void *opaque, Error **errp)
79 {
80 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
81 uint16List *host_nodes = NULL;
82 uint16List **tail = &host_nodes;
83 unsigned long value;
84
85 value = find_first_bit(backend->host_nodes, MAX_NODES);
86 if (value == MAX_NODES) {
87 goto ret;
88 }
89
90 QAPI_LIST_APPEND(tail, value);
91
92 do {
93 value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
94 if (value == MAX_NODES) {
95 break;
96 }
97
98 QAPI_LIST_APPEND(tail, value);
99 } while (true);
100
101 ret:
102 visit_type_uint16List(v, name, &host_nodes, errp);
103 qapi_free_uint16List(host_nodes);
104 }
105
106 static void
107 host_memory_backend_set_host_nodes(Object *obj, Visitor *v, const char *name,
108 void *opaque, Error **errp)
109 {
110 #ifdef CONFIG_NUMA
111 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
112 uint16List *l, *host_nodes = NULL;
113
114 visit_type_uint16List(v, name, &host_nodes, errp);
115
116 for (l = host_nodes; l; l = l->next) {
117 if (l->value >= MAX_NODES) {
118 error_setg(errp, "Invalid host-nodes value: %d", l->value);
119 goto out;
120 }
121 }
122
123 for (l = host_nodes; l; l = l->next) {
124 bitmap_set(backend->host_nodes, l->value, 1);
125 }
126
127 out:
128 qapi_free_uint16List(host_nodes);
129 #else
130 error_setg(errp, "NUMA node binding are not supported by this QEMU");
131 #endif
132 }
133
134 static int
135 host_memory_backend_get_policy(Object *obj, Error **errp G_GNUC_UNUSED)
136 {
137 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
138 return backend->policy;
139 }
140
141 static void
142 host_memory_backend_set_policy(Object *obj, int policy, Error **errp)
143 {
144 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
145 backend->policy = policy;
146
147 #ifndef CONFIG_NUMA
148 if (policy != HOST_MEM_POLICY_DEFAULT) {
149 error_setg(errp, "NUMA policies are not supported by this QEMU");
150 }
151 #endif
152 }
153
154 static bool host_memory_backend_get_merge(Object *obj, Error **errp)
155 {
156 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
157
158 return backend->merge;
159 }
160
161 static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
162 {
163 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
164
165 if (!host_memory_backend_mr_inited(backend)) {
166 backend->merge = value;
167 return;
168 }
169
170 if (value != backend->merge) {
171 void *ptr = memory_region_get_ram_ptr(&backend->mr);
172 uint64_t sz = memory_region_size(&backend->mr);
173
174 qemu_madvise(ptr, sz,
175 value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
176 backend->merge = value;
177 }
178 }
179
180 static bool host_memory_backend_get_dump(Object *obj, Error **errp)
181 {
182 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
183
184 return backend->dump;
185 }
186
187 static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
188 {
189 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
190
191 if (!host_memory_backend_mr_inited(backend)) {
192 backend->dump = value;
193 return;
194 }
195
196 if (value != backend->dump) {
197 void *ptr = memory_region_get_ram_ptr(&backend->mr);
198 uint64_t sz = memory_region_size(&backend->mr);
199
200 qemu_madvise(ptr, sz,
201 value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
202 backend->dump = value;
203 }
204 }
205
206 static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
207 {
208 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
209
210 return backend->prealloc;
211 }
212
213 static void host_memory_backend_set_prealloc(Object *obj, bool value,
214 Error **errp)
215 {
216 Error *local_err = NULL;
217 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
218
219 if (!host_memory_backend_mr_inited(backend)) {
220 backend->prealloc = value;
221 return;
222 }
223
224 if (value && !backend->prealloc) {
225 int fd = memory_region_get_fd(&backend->mr);
226 void *ptr = memory_region_get_ram_ptr(&backend->mr);
227 uint64_t sz = memory_region_size(&backend->mr);
228
229 os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
230 if (local_err) {
231 error_propagate(errp, local_err);
232 return;
233 }
234 backend->prealloc = true;
235 }
236 }
237
238 static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
239 const char *name, void *opaque, Error **errp)
240 {
241 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
242 visit_type_uint32(v, name, &backend->prealloc_threads, errp);
243 }
244
245 static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
246 const char *name, void *opaque, Error **errp)
247 {
248 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
249 uint32_t value;
250
251 if (!visit_type_uint32(v, name, &value, errp)) {
252 return;
253 }
254 if (value <= 0) {
255 error_setg(errp, "property '%s' of %s doesn't take value '%d'", name,
256 object_get_typename(obj), value);
257 return;
258 }
259 backend->prealloc_threads = value;
260 }
261
262 static void host_memory_backend_init(Object *obj)
263 {
264 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
265 MachineState *machine = MACHINE(qdev_get_machine());
266
267 /* TODO: convert access to globals to compat properties */
268 backend->merge = machine_mem_merge(machine);
269 backend->dump = machine_dump_guest_core(machine);
270 backend->prealloc_threads = 1;
271 }
272
273 static void host_memory_backend_post_init(Object *obj)
274 {
275 object_apply_compat_props(obj);
276 }
277
278 bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
279 {
280 /*
281 * NOTE: We forbid zero-length memory backend, so here zero means
282 * "we haven't inited the backend memory region yet".
283 */
284 return memory_region_size(&backend->mr) != 0;
285 }
286
287 MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend)
288 {
289 return host_memory_backend_mr_inited(backend) ? &backend->mr : NULL;
290 }
291
292 void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
293 {
294 backend->is_mapped = mapped;
295 }
296
297 bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
298 {
299 return backend->is_mapped;
300 }
301
302 #ifdef __linux__
303 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
304 {
305 Object *obj = OBJECT(memdev);
306 char *path = object_property_get_str(obj, "mem-path", NULL);
307 size_t pagesize = qemu_mempath_getpagesize(path);
308
309 g_free(path);
310 return pagesize;
311 }
312 #else
313 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
314 {
315 return qemu_real_host_page_size;
316 }
317 #endif
318
319 static void
320 host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
321 {
322 HostMemoryBackend *backend = MEMORY_BACKEND(uc);
323 HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
324 Error *local_err = NULL;
325 void *ptr;
326 uint64_t sz;
327
328 if (bc->alloc) {
329 bc->alloc(backend, &local_err);
330 if (local_err) {
331 goto out;
332 }
333
334 ptr = memory_region_get_ram_ptr(&backend->mr);
335 sz = memory_region_size(&backend->mr);
336
337 if (backend->merge) {
338 qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
339 }
340 if (!backend->dump) {
341 qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
342 }
343 #ifdef CONFIG_NUMA
344 unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
345 /* lastbit == MAX_NODES means maxnode = 0 */
346 unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
347 /* ensure policy won't be ignored in case memory is preallocated
348 * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
349 * this doesn't catch hugepage case. */
350 unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
351
352 /* check for invalid host-nodes and policies and give more verbose
353 * error messages than mbind(). */
354 if (maxnode && backend->policy == MPOL_DEFAULT) {
355 error_setg(errp, "host-nodes must be empty for policy default,"
356 " or you should explicitly specify a policy other"
357 " than default");
358 return;
359 } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
360 error_setg(errp, "host-nodes must be set for policy %s",
361 HostMemPolicy_str(backend->policy));
362 return;
363 }
364
365 /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
366 * as argument to mbind() due to an old Linux bug (feature?) which
367 * cuts off the last specified node. This means backend->host_nodes
368 * must have MAX_NODES+1 bits available.
369 */
370 assert(sizeof(backend->host_nodes) >=
371 BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
372 assert(maxnode <= MAX_NODES);
373
374 if (maxnode &&
375 mbind(ptr, sz, backend->policy, backend->host_nodes, maxnode + 1,
376 flags)) {
377 if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
378 error_setg_errno(errp, errno,
379 "cannot bind memory to host NUMA nodes");
380 return;
381 }
382 }
383 #endif
384 /* Preallocate memory after the NUMA policy has been instantiated.
385 * This is necessary to guarantee memory is allocated with
386 * specified NUMA policy in place.
387 */
388 if (backend->prealloc) {
389 os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
390 backend->prealloc_threads, &local_err);
391 if (local_err) {
392 goto out;
393 }
394 }
395 }
396 out:
397 error_propagate(errp, local_err);
398 }
399
400 static bool
401 host_memory_backend_can_be_deleted(UserCreatable *uc)
402 {
403 if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
404 return false;
405 } else {
406 return true;
407 }
408 }
409
410 static bool host_memory_backend_get_share(Object *o, Error **errp)
411 {
412 HostMemoryBackend *backend = MEMORY_BACKEND(o);
413
414 return backend->share;
415 }
416
417 static void host_memory_backend_set_share(Object *o, bool value, Error **errp)
418 {
419 HostMemoryBackend *backend = MEMORY_BACKEND(o);
420
421 if (host_memory_backend_mr_inited(backend)) {
422 error_setg(errp, "cannot change property value");
423 return;
424 }
425 backend->share = value;
426 }
427
428 static bool
429 host_memory_backend_get_use_canonical_path(Object *obj, Error **errp)
430 {
431 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
432
433 return backend->use_canonical_path;
434 }
435
436 static void
437 host_memory_backend_set_use_canonical_path(Object *obj, bool value,
438 Error **errp)
439 {
440 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
441
442 backend->use_canonical_path = value;
443 }
444
445 static void
446 host_memory_backend_class_init(ObjectClass *oc, void *data)
447 {
448 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
449
450 ucc->complete = host_memory_backend_memory_complete;
451 ucc->can_be_deleted = host_memory_backend_can_be_deleted;
452
453 object_class_property_add_bool(oc, "merge",
454 host_memory_backend_get_merge,
455 host_memory_backend_set_merge);
456 object_class_property_set_description(oc, "merge",
457 "Mark memory as mergeable");
458 object_class_property_add_bool(oc, "dump",
459 host_memory_backend_get_dump,
460 host_memory_backend_set_dump);
461 object_class_property_set_description(oc, "dump",
462 "Set to 'off' to exclude from core dump");
463 object_class_property_add_bool(oc, "prealloc",
464 host_memory_backend_get_prealloc,
465 host_memory_backend_set_prealloc);
466 object_class_property_set_description(oc, "prealloc",
467 "Preallocate memory");
468 object_class_property_add(oc, "prealloc-threads", "int",
469 host_memory_backend_get_prealloc_threads,
470 host_memory_backend_set_prealloc_threads,
471 NULL, NULL);
472 object_class_property_set_description(oc, "prealloc-threads",
473 "Number of CPU threads to use for prealloc");
474 object_class_property_add(oc, "size", "int",
475 host_memory_backend_get_size,
476 host_memory_backend_set_size,
477 NULL, NULL);
478 object_class_property_set_description(oc, "size",
479 "Size of the memory region (ex: 500M)");
480 object_class_property_add(oc, "host-nodes", "int",
481 host_memory_backend_get_host_nodes,
482 host_memory_backend_set_host_nodes,
483 NULL, NULL);
484 object_class_property_set_description(oc, "host-nodes",
485 "Binds memory to the list of NUMA host nodes");
486 object_class_property_add_enum(oc, "policy", "HostMemPolicy",
487 &HostMemPolicy_lookup,
488 host_memory_backend_get_policy,
489 host_memory_backend_set_policy);
490 object_class_property_set_description(oc, "policy",
491 "Set the NUMA policy");
492 object_class_property_add_bool(oc, "share",
493 host_memory_backend_get_share, host_memory_backend_set_share);
494 object_class_property_set_description(oc, "share",
495 "Mark the memory as private to QEMU or shared");
496 /*
497 * Do not delete/rename option. This option must be considered stable
498 * (as if it didn't have the 'x-' prefix including deprecation period) as
499 * long as 4.0 and older machine types exists.
500 * Option will be used by upper layers to override (disable) canonical path
501 * for ramblock-id set by compat properties on old machine types ( <= 4.0),
502 * to keep migration working when backend is used for main RAM with
503 * -machine memory-backend= option (main RAM historically used prefix-less
504 * ramblock-id).
505 */
506 object_class_property_add_bool(oc, "x-use-canonical-path-for-ramblock-id",
507 host_memory_backend_get_use_canonical_path,
508 host_memory_backend_set_use_canonical_path);
509 }
510
511 static const TypeInfo host_memory_backend_info = {
512 .name = TYPE_MEMORY_BACKEND,
513 .parent = TYPE_OBJECT,
514 .abstract = true,
515 .class_size = sizeof(HostMemoryBackendClass),
516 .class_init = host_memory_backend_class_init,
517 .instance_size = sizeof(HostMemoryBackend),
518 .instance_init = host_memory_backend_init,
519 .instance_post_init = host_memory_backend_post_init,
520 .interfaces = (InterfaceInfo[]) {
521 { TYPE_USER_CREATABLE },
522 { }
523 }
524 };
525
526 static void register_types(void)
527 {
528 type_register_static(&host_memory_backend_info);
529 }
530
531 type_init(register_types);