Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20211016' into staging
[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 (!backend->reserve && value) {
220 error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible");
221 return;
222 }
223
224 if (!host_memory_backend_mr_inited(backend)) {
225 backend->prealloc = value;
226 return;
227 }
228
229 if (value && !backend->prealloc) {
230 int fd = memory_region_get_fd(&backend->mr);
231 void *ptr = memory_region_get_ram_ptr(&backend->mr);
232 uint64_t sz = memory_region_size(&backend->mr);
233
234 os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
235 if (local_err) {
236 error_propagate(errp, local_err);
237 return;
238 }
239 backend->prealloc = true;
240 }
241 }
242
243 static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
244 const char *name, void *opaque, Error **errp)
245 {
246 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
247 visit_type_uint32(v, name, &backend->prealloc_threads, errp);
248 }
249
250 static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
251 const char *name, void *opaque, Error **errp)
252 {
253 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
254 uint32_t value;
255
256 if (!visit_type_uint32(v, name, &value, errp)) {
257 return;
258 }
259 if (value <= 0) {
260 error_setg(errp, "property '%s' of %s doesn't take value '%d'", name,
261 object_get_typename(obj), value);
262 return;
263 }
264 backend->prealloc_threads = value;
265 }
266
267 static void host_memory_backend_init(Object *obj)
268 {
269 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
270 MachineState *machine = MACHINE(qdev_get_machine());
271
272 /* TODO: convert access to globals to compat properties */
273 backend->merge = machine_mem_merge(machine);
274 backend->dump = machine_dump_guest_core(machine);
275 backend->reserve = true;
276 backend->prealloc_threads = 1;
277 }
278
279 static void host_memory_backend_post_init(Object *obj)
280 {
281 object_apply_compat_props(obj);
282 }
283
284 bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
285 {
286 /*
287 * NOTE: We forbid zero-length memory backend, so here zero means
288 * "we haven't inited the backend memory region yet".
289 */
290 return memory_region_size(&backend->mr) != 0;
291 }
292
293 MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend)
294 {
295 return host_memory_backend_mr_inited(backend) ? &backend->mr : NULL;
296 }
297
298 void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
299 {
300 backend->is_mapped = mapped;
301 }
302
303 bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
304 {
305 return backend->is_mapped;
306 }
307
308 #ifdef __linux__
309 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
310 {
311 Object *obj = OBJECT(memdev);
312 char *path = object_property_get_str(obj, "mem-path", NULL);
313 size_t pagesize = qemu_mempath_getpagesize(path);
314
315 g_free(path);
316 return pagesize;
317 }
318 #else
319 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
320 {
321 return qemu_real_host_page_size;
322 }
323 #endif
324
325 static void
326 host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
327 {
328 HostMemoryBackend *backend = MEMORY_BACKEND(uc);
329 HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
330 Error *local_err = NULL;
331 void *ptr;
332 uint64_t sz;
333
334 if (bc->alloc) {
335 bc->alloc(backend, &local_err);
336 if (local_err) {
337 goto out;
338 }
339
340 ptr = memory_region_get_ram_ptr(&backend->mr);
341 sz = memory_region_size(&backend->mr);
342
343 if (backend->merge) {
344 qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
345 }
346 if (!backend->dump) {
347 qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
348 }
349 #ifdef CONFIG_NUMA
350 unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
351 /* lastbit == MAX_NODES means maxnode = 0 */
352 unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
353 /* ensure policy won't be ignored in case memory is preallocated
354 * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
355 * this doesn't catch hugepage case. */
356 unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
357
358 /* check for invalid host-nodes and policies and give more verbose
359 * error messages than mbind(). */
360 if (maxnode && backend->policy == MPOL_DEFAULT) {
361 error_setg(errp, "host-nodes must be empty for policy default,"
362 " or you should explicitly specify a policy other"
363 " than default");
364 return;
365 } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
366 error_setg(errp, "host-nodes must be set for policy %s",
367 HostMemPolicy_str(backend->policy));
368 return;
369 }
370
371 /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
372 * as argument to mbind() due to an old Linux bug (feature?) which
373 * cuts off the last specified node. This means backend->host_nodes
374 * must have MAX_NODES+1 bits available.
375 */
376 assert(sizeof(backend->host_nodes) >=
377 BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
378 assert(maxnode <= MAX_NODES);
379
380 if (maxnode &&
381 mbind(ptr, sz, backend->policy, backend->host_nodes, maxnode + 1,
382 flags)) {
383 if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
384 error_setg_errno(errp, errno,
385 "cannot bind memory to host NUMA nodes");
386 return;
387 }
388 }
389 #endif
390 /* Preallocate memory after the NUMA policy has been instantiated.
391 * This is necessary to guarantee memory is allocated with
392 * specified NUMA policy in place.
393 */
394 if (backend->prealloc) {
395 os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
396 backend->prealloc_threads, &local_err);
397 if (local_err) {
398 goto out;
399 }
400 }
401 }
402 out:
403 error_propagate(errp, local_err);
404 }
405
406 static bool
407 host_memory_backend_can_be_deleted(UserCreatable *uc)
408 {
409 if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
410 return false;
411 } else {
412 return true;
413 }
414 }
415
416 static bool host_memory_backend_get_share(Object *o, Error **errp)
417 {
418 HostMemoryBackend *backend = MEMORY_BACKEND(o);
419
420 return backend->share;
421 }
422
423 static void host_memory_backend_set_share(Object *o, bool value, Error **errp)
424 {
425 HostMemoryBackend *backend = MEMORY_BACKEND(o);
426
427 if (host_memory_backend_mr_inited(backend)) {
428 error_setg(errp, "cannot change property value");
429 return;
430 }
431 backend->share = value;
432 }
433
434 #ifdef CONFIG_LINUX
435 static bool host_memory_backend_get_reserve(Object *o, Error **errp)
436 {
437 HostMemoryBackend *backend = MEMORY_BACKEND(o);
438
439 return backend->reserve;
440 }
441
442 static void host_memory_backend_set_reserve(Object *o, bool value, Error **errp)
443 {
444 HostMemoryBackend *backend = MEMORY_BACKEND(o);
445
446 if (host_memory_backend_mr_inited(backend)) {
447 error_setg(errp, "cannot change property value");
448 return;
449 }
450 if (backend->prealloc && !value) {
451 error_setg(errp, "'prealloc=on' and 'reserve=off' are incompatible");
452 return;
453 }
454 backend->reserve = value;
455 }
456 #endif /* CONFIG_LINUX */
457
458 static bool
459 host_memory_backend_get_use_canonical_path(Object *obj, Error **errp)
460 {
461 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
462
463 return backend->use_canonical_path;
464 }
465
466 static void
467 host_memory_backend_set_use_canonical_path(Object *obj, bool value,
468 Error **errp)
469 {
470 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
471
472 backend->use_canonical_path = value;
473 }
474
475 static void
476 host_memory_backend_class_init(ObjectClass *oc, void *data)
477 {
478 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
479
480 ucc->complete = host_memory_backend_memory_complete;
481 ucc->can_be_deleted = host_memory_backend_can_be_deleted;
482
483 object_class_property_add_bool(oc, "merge",
484 host_memory_backend_get_merge,
485 host_memory_backend_set_merge);
486 object_class_property_set_description(oc, "merge",
487 "Mark memory as mergeable");
488 object_class_property_add_bool(oc, "dump",
489 host_memory_backend_get_dump,
490 host_memory_backend_set_dump);
491 object_class_property_set_description(oc, "dump",
492 "Set to 'off' to exclude from core dump");
493 object_class_property_add_bool(oc, "prealloc",
494 host_memory_backend_get_prealloc,
495 host_memory_backend_set_prealloc);
496 object_class_property_set_description(oc, "prealloc",
497 "Preallocate memory");
498 object_class_property_add(oc, "prealloc-threads", "int",
499 host_memory_backend_get_prealloc_threads,
500 host_memory_backend_set_prealloc_threads,
501 NULL, NULL);
502 object_class_property_set_description(oc, "prealloc-threads",
503 "Number of CPU threads to use for prealloc");
504 object_class_property_add(oc, "size", "int",
505 host_memory_backend_get_size,
506 host_memory_backend_set_size,
507 NULL, NULL);
508 object_class_property_set_description(oc, "size",
509 "Size of the memory region (ex: 500M)");
510 object_class_property_add(oc, "host-nodes", "int",
511 host_memory_backend_get_host_nodes,
512 host_memory_backend_set_host_nodes,
513 NULL, NULL);
514 object_class_property_set_description(oc, "host-nodes",
515 "Binds memory to the list of NUMA host nodes");
516 object_class_property_add_enum(oc, "policy", "HostMemPolicy",
517 &HostMemPolicy_lookup,
518 host_memory_backend_get_policy,
519 host_memory_backend_set_policy);
520 object_class_property_set_description(oc, "policy",
521 "Set the NUMA policy");
522 object_class_property_add_bool(oc, "share",
523 host_memory_backend_get_share, host_memory_backend_set_share);
524 object_class_property_set_description(oc, "share",
525 "Mark the memory as private to QEMU or shared");
526 #ifdef CONFIG_LINUX
527 object_class_property_add_bool(oc, "reserve",
528 host_memory_backend_get_reserve, host_memory_backend_set_reserve);
529 object_class_property_set_description(oc, "reserve",
530 "Reserve swap space (or huge pages) if applicable");
531 #endif /* CONFIG_LINUX */
532 /*
533 * Do not delete/rename option. This option must be considered stable
534 * (as if it didn't have the 'x-' prefix including deprecation period) as
535 * long as 4.0 and older machine types exists.
536 * Option will be used by upper layers to override (disable) canonical path
537 * for ramblock-id set by compat properties on old machine types ( <= 4.0),
538 * to keep migration working when backend is used for main RAM with
539 * -machine memory-backend= option (main RAM historically used prefix-less
540 * ramblock-id).
541 */
542 object_class_property_add_bool(oc, "x-use-canonical-path-for-ramblock-id",
543 host_memory_backend_get_use_canonical_path,
544 host_memory_backend_set_use_canonical_path);
545 }
546
547 static const TypeInfo host_memory_backend_info = {
548 .name = TYPE_MEMORY_BACKEND,
549 .parent = TYPE_OBJECT,
550 .abstract = true,
551 .class_size = sizeof(HostMemoryBackendClass),
552 .class_init = host_memory_backend_class_init,
553 .instance_size = sizeof(HostMemoryBackend),
554 .instance_init = host_memory_backend_init,
555 .instance_post_init = host_memory_backend_post_init,
556 .interfaces = (InterfaceInfo[]) {
557 { TYPE_USER_CREATABLE },
558 { }
559 }
560 };
561
562 static void register_types(void)
563 {
564 type_register_static(&host_memory_backend_info);
565 }
566
567 type_init(register_types);