Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-virtiofs-20210413...
[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 "sysemu/sysemu.h"
16 #include "hw/boards.h"
17 #include "qapi/error.h"
18 #include "qapi/qapi-builtin-visit.h"
19 #include "qapi/visitor.h"
20 #include "qemu/config-file.h"
21 #include "qom/object_interfaces.h"
22 #include "qemu/mmap-alloc.h"
23
24 #ifdef CONFIG_NUMA
25 #include <numaif.h>
26 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
27 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
28 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
29 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
30 #endif
31
32 char *
33 host_memory_backend_get_name(HostMemoryBackend *backend)
34 {
35 if (!backend->use_canonical_path) {
36 return g_strdup(object_get_canonical_path_component(OBJECT(backend)));
37 }
38
39 return object_get_canonical_path(OBJECT(backend));
40 }
41
42 static void
43 host_memory_backend_get_size(Object *obj, Visitor *v, const char *name,
44 void *opaque, Error **errp)
45 {
46 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
47 uint64_t value = backend->size;
48
49 visit_type_size(v, name, &value, errp);
50 }
51
52 static void
53 host_memory_backend_set_size(Object *obj, Visitor *v, const char *name,
54 void *opaque, Error **errp)
55 {
56 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
57 uint64_t value;
58
59 if (host_memory_backend_mr_inited(backend)) {
60 error_setg(errp, "cannot change property %s of %s ", name,
61 object_get_typename(obj));
62 return;
63 }
64
65 if (!visit_type_size(v, name, &value, errp)) {
66 return;
67 }
68 if (!value) {
69 error_setg(errp,
70 "property '%s' of %s doesn't take value '%" PRIu64 "'",
71 name, object_get_typename(obj), value);
72 return;
73 }
74 backend->size = value;
75 }
76
77 static void
78 host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
79 void *opaque, Error **errp)
80 {
81 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
82 uint16List *host_nodes = NULL;
83 uint16List **tail = &host_nodes;
84 unsigned long value;
85
86 value = find_first_bit(backend->host_nodes, MAX_NODES);
87 if (value == MAX_NODES) {
88 goto ret;
89 }
90
91 QAPI_LIST_APPEND(tail, value);
92
93 do {
94 value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
95 if (value == MAX_NODES) {
96 break;
97 }
98
99 QAPI_LIST_APPEND(tail, value);
100 } while (true);
101
102 ret:
103 visit_type_uint16List(v, name, &host_nodes, errp);
104 qapi_free_uint16List(host_nodes);
105 }
106
107 static void
108 host_memory_backend_set_host_nodes(Object *obj, Visitor *v, const char *name,
109 void *opaque, Error **errp)
110 {
111 #ifdef CONFIG_NUMA
112 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
113 uint16List *l, *host_nodes = NULL;
114
115 visit_type_uint16List(v, name, &host_nodes, errp);
116
117 for (l = host_nodes; l; l = l->next) {
118 if (l->value >= MAX_NODES) {
119 error_setg(errp, "Invalid host-nodes value: %d", l->value);
120 goto out;
121 }
122 }
123
124 for (l = host_nodes; l; l = l->next) {
125 bitmap_set(backend->host_nodes, l->value, 1);
126 }
127
128 out:
129 qapi_free_uint16List(host_nodes);
130 #else
131 error_setg(errp, "NUMA node binding are not supported by this QEMU");
132 #endif
133 }
134
135 static int
136 host_memory_backend_get_policy(Object *obj, Error **errp G_GNUC_UNUSED)
137 {
138 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
139 return backend->policy;
140 }
141
142 static void
143 host_memory_backend_set_policy(Object *obj, int policy, Error **errp)
144 {
145 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
146 backend->policy = policy;
147
148 #ifndef CONFIG_NUMA
149 if (policy != HOST_MEM_POLICY_DEFAULT) {
150 error_setg(errp, "NUMA policies are not supported by this QEMU");
151 }
152 #endif
153 }
154
155 static bool host_memory_backend_get_merge(Object *obj, Error **errp)
156 {
157 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
158
159 return backend->merge;
160 }
161
162 static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
163 {
164 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
165
166 if (!host_memory_backend_mr_inited(backend)) {
167 backend->merge = value;
168 return;
169 }
170
171 if (value != backend->merge) {
172 void *ptr = memory_region_get_ram_ptr(&backend->mr);
173 uint64_t sz = memory_region_size(&backend->mr);
174
175 qemu_madvise(ptr, sz,
176 value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
177 backend->merge = value;
178 }
179 }
180
181 static bool host_memory_backend_get_dump(Object *obj, Error **errp)
182 {
183 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
184
185 return backend->dump;
186 }
187
188 static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
189 {
190 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
191
192 if (!host_memory_backend_mr_inited(backend)) {
193 backend->dump = value;
194 return;
195 }
196
197 if (value != backend->dump) {
198 void *ptr = memory_region_get_ram_ptr(&backend->mr);
199 uint64_t sz = memory_region_size(&backend->mr);
200
201 qemu_madvise(ptr, sz,
202 value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
203 backend->dump = value;
204 }
205 }
206
207 static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
208 {
209 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
210
211 return backend->prealloc;
212 }
213
214 static void host_memory_backend_set_prealloc(Object *obj, bool value,
215 Error **errp)
216 {
217 Error *local_err = NULL;
218 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
219
220 if (!host_memory_backend_mr_inited(backend)) {
221 backend->prealloc = value;
222 return;
223 }
224
225 if (value && !backend->prealloc) {
226 int fd = memory_region_get_fd(&backend->mr);
227 void *ptr = memory_region_get_ram_ptr(&backend->mr);
228 uint64_t sz = memory_region_size(&backend->mr);
229
230 os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
231 if (local_err) {
232 error_propagate(errp, local_err);
233 return;
234 }
235 backend->prealloc = true;
236 }
237 }
238
239 static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
240 const char *name, void *opaque, Error **errp)
241 {
242 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
243 visit_type_uint32(v, name, &backend->prealloc_threads, errp);
244 }
245
246 static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
247 const char *name, void *opaque, Error **errp)
248 {
249 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
250 uint32_t value;
251
252 if (!visit_type_uint32(v, name, &value, errp)) {
253 return;
254 }
255 if (value <= 0) {
256 error_setg(errp, "property '%s' of %s doesn't take value '%d'", name,
257 object_get_typename(obj), value);
258 return;
259 }
260 backend->prealloc_threads = value;
261 }
262
263 static void host_memory_backend_init(Object *obj)
264 {
265 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
266 MachineState *machine = MACHINE(qdev_get_machine());
267
268 /* TODO: convert access to globals to compat properties */
269 backend->merge = machine_mem_merge(machine);
270 backend->dump = machine_dump_guest_core(machine);
271 backend->prealloc_threads = 1;
272 }
273
274 static void host_memory_backend_post_init(Object *obj)
275 {
276 object_apply_compat_props(obj);
277 }
278
279 bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
280 {
281 /*
282 * NOTE: We forbid zero-length memory backend, so here zero means
283 * "we haven't inited the backend memory region yet".
284 */
285 return memory_region_size(&backend->mr) != 0;
286 }
287
288 MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend)
289 {
290 return host_memory_backend_mr_inited(backend) ? &backend->mr : NULL;
291 }
292
293 void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
294 {
295 backend->is_mapped = mapped;
296 }
297
298 bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
299 {
300 return backend->is_mapped;
301 }
302
303 #ifdef __linux__
304 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
305 {
306 Object *obj = OBJECT(memdev);
307 char *path = object_property_get_str(obj, "mem-path", NULL);
308 size_t pagesize = qemu_mempath_getpagesize(path);
309
310 g_free(path);
311 return pagesize;
312 }
313 #else
314 size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
315 {
316 return qemu_real_host_page_size;
317 }
318 #endif
319
320 static void
321 host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
322 {
323 HostMemoryBackend *backend = MEMORY_BACKEND(uc);
324 HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
325 Error *local_err = NULL;
326 void *ptr;
327 uint64_t sz;
328
329 if (bc->alloc) {
330 bc->alloc(backend, &local_err);
331 if (local_err) {
332 goto out;
333 }
334
335 ptr = memory_region_get_ram_ptr(&backend->mr);
336 sz = memory_region_size(&backend->mr);
337
338 if (backend->merge) {
339 qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
340 }
341 if (!backend->dump) {
342 qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
343 }
344 #ifdef CONFIG_NUMA
345 unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
346 /* lastbit == MAX_NODES means maxnode = 0 */
347 unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
348 /* ensure policy won't be ignored in case memory is preallocated
349 * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
350 * this doesn't catch hugepage case. */
351 unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
352
353 /* check for invalid host-nodes and policies and give more verbose
354 * error messages than mbind(). */
355 if (maxnode && backend->policy == MPOL_DEFAULT) {
356 error_setg(errp, "host-nodes must be empty for policy default,"
357 " or you should explicitly specify a policy other"
358 " than default");
359 return;
360 } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
361 error_setg(errp, "host-nodes must be set for policy %s",
362 HostMemPolicy_str(backend->policy));
363 return;
364 }
365
366 /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
367 * as argument to mbind() due to an old Linux bug (feature?) which
368 * cuts off the last specified node. This means backend->host_nodes
369 * must have MAX_NODES+1 bits available.
370 */
371 assert(sizeof(backend->host_nodes) >=
372 BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
373 assert(maxnode <= MAX_NODES);
374
375 if (maxnode &&
376 mbind(ptr, sz, backend->policy, backend->host_nodes, maxnode + 1,
377 flags)) {
378 if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
379 error_setg_errno(errp, errno,
380 "cannot bind memory to host NUMA nodes");
381 return;
382 }
383 }
384 #endif
385 /* Preallocate memory after the NUMA policy has been instantiated.
386 * This is necessary to guarantee memory is allocated with
387 * specified NUMA policy in place.
388 */
389 if (backend->prealloc) {
390 os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
391 backend->prealloc_threads, &local_err);
392 if (local_err) {
393 goto out;
394 }
395 }
396 }
397 out:
398 error_propagate(errp, local_err);
399 }
400
401 static bool
402 host_memory_backend_can_be_deleted(UserCreatable *uc)
403 {
404 if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
405 return false;
406 } else {
407 return true;
408 }
409 }
410
411 static bool host_memory_backend_get_share(Object *o, Error **errp)
412 {
413 HostMemoryBackend *backend = MEMORY_BACKEND(o);
414
415 return backend->share;
416 }
417
418 static void host_memory_backend_set_share(Object *o, bool value, Error **errp)
419 {
420 HostMemoryBackend *backend = MEMORY_BACKEND(o);
421
422 if (host_memory_backend_mr_inited(backend)) {
423 error_setg(errp, "cannot change property value");
424 return;
425 }
426 backend->share = value;
427 }
428
429 static bool
430 host_memory_backend_get_use_canonical_path(Object *obj, Error **errp)
431 {
432 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
433
434 return backend->use_canonical_path;
435 }
436
437 static void
438 host_memory_backend_set_use_canonical_path(Object *obj, bool value,
439 Error **errp)
440 {
441 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
442
443 backend->use_canonical_path = value;
444 }
445
446 static void
447 host_memory_backend_class_init(ObjectClass *oc, void *data)
448 {
449 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
450
451 ucc->complete = host_memory_backend_memory_complete;
452 ucc->can_be_deleted = host_memory_backend_can_be_deleted;
453
454 object_class_property_add_bool(oc, "merge",
455 host_memory_backend_get_merge,
456 host_memory_backend_set_merge);
457 object_class_property_set_description(oc, "merge",
458 "Mark memory as mergeable");
459 object_class_property_add_bool(oc, "dump",
460 host_memory_backend_get_dump,
461 host_memory_backend_set_dump);
462 object_class_property_set_description(oc, "dump",
463 "Set to 'off' to exclude from core dump");
464 object_class_property_add_bool(oc, "prealloc",
465 host_memory_backend_get_prealloc,
466 host_memory_backend_set_prealloc);
467 object_class_property_set_description(oc, "prealloc",
468 "Preallocate memory");
469 object_class_property_add(oc, "prealloc-threads", "int",
470 host_memory_backend_get_prealloc_threads,
471 host_memory_backend_set_prealloc_threads,
472 NULL, NULL);
473 object_class_property_set_description(oc, "prealloc-threads",
474 "Number of CPU threads to use for prealloc");
475 object_class_property_add(oc, "size", "int",
476 host_memory_backend_get_size,
477 host_memory_backend_set_size,
478 NULL, NULL);
479 object_class_property_set_description(oc, "size",
480 "Size of the memory region (ex: 500M)");
481 object_class_property_add(oc, "host-nodes", "int",
482 host_memory_backend_get_host_nodes,
483 host_memory_backend_set_host_nodes,
484 NULL, NULL);
485 object_class_property_set_description(oc, "host-nodes",
486 "Binds memory to the list of NUMA host nodes");
487 object_class_property_add_enum(oc, "policy", "HostMemPolicy",
488 &HostMemPolicy_lookup,
489 host_memory_backend_get_policy,
490 host_memory_backend_set_policy);
491 object_class_property_set_description(oc, "policy",
492 "Set the NUMA policy");
493 object_class_property_add_bool(oc, "share",
494 host_memory_backend_get_share, host_memory_backend_set_share);
495 object_class_property_set_description(oc, "share",
496 "Mark the memory as private to QEMU or shared");
497 /*
498 * Do not delete/rename option. This option must be considered stable
499 * (as if it didn't have the 'x-' prefix including deprecation period) as
500 * long as 4.0 and older machine types exists.
501 * Option will be used by upper layers to override (disable) canonical path
502 * for ramblock-id set by compat properties on old machine types ( <= 4.0),
503 * to keep migration working when backend is used for main RAM with
504 * -machine memory-backend= option (main RAM historically used prefix-less
505 * ramblock-id).
506 */
507 object_class_property_add_bool(oc, "x-use-canonical-path-for-ramblock-id",
508 host_memory_backend_get_use_canonical_path,
509 host_memory_backend_set_use_canonical_path);
510 }
511
512 static const TypeInfo host_memory_backend_info = {
513 .name = TYPE_MEMORY_BACKEND,
514 .parent = TYPE_OBJECT,
515 .abstract = true,
516 .class_size = sizeof(HostMemoryBackendClass),
517 .class_init = host_memory_backend_class_init,
518 .instance_size = sizeof(HostMemoryBackend),
519 .instance_init = host_memory_backend_init,
520 .instance_post_init = host_memory_backend_post_init,
521 .interfaces = (InterfaceInfo[]) {
522 { TYPE_USER_CREATABLE },
523 { }
524 }
525 };
526
527 static void register_types(void)
528 {
529 type_register_static(&host_memory_backend_info);
530 }
531
532 type_init(register_types);