jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
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>
26QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
27QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
28QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
29QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
30#endif
31
32char *
33host_memory_backend_get_name(HostMemoryBackend *backend)
34{
35 if (!backend->use_canonical_path) {
36 return object_get_canonical_path_component(OBJECT(backend));
37 }
38
39 return object_get_canonical_path(OBJECT(backend));
40}
41
42static void
43host_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
52static void
53host_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
77static void
78host_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 **node = &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 *node = g_malloc0(sizeof(**node));
92 (*node)->value = value;
93 node = &(*node)->next;
94
95 do {
96 value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
97 if (value == MAX_NODES) {
98 break;
99 }
100
101 *node = g_malloc0(sizeof(**node));
102 (*node)->value = value;
103 node = &(*node)->next;
104 } while (true);
105
106ret:
107 visit_type_uint16List(v, name, &host_nodes, errp);
108}
109
110static void
111host_memory_backend_set_host_nodes(Object *obj, Visitor *v, const char *name,
112 void *opaque, Error **errp)
113{
114#ifdef CONFIG_NUMA
115 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
116 uint16List *l, *host_nodes = NULL;
117
118 visit_type_uint16List(v, name, &host_nodes, errp);
119
120 for (l = host_nodes; l; l = l->next) {
121 if (l->value >= MAX_NODES) {
122 error_setg(errp, "Invalid host-nodes value: %d", l->value);
123 goto out;
124 }
125 }
126
127 for (l = host_nodes; l; l = l->next) {
128 bitmap_set(backend->host_nodes, l->value, 1);
129 }
130
131out:
132 qapi_free_uint16List(host_nodes);
133#else
134 error_setg(errp, "NUMA node binding are not supported by this QEMU");
135#endif
136}
137
138static int
139host_memory_backend_get_policy(Object *obj, Error **errp G_GNUC_UNUSED)
140{
141 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
142 return backend->policy;
143}
144
145static void
146host_memory_backend_set_policy(Object *obj, int policy, Error **errp)
147{
148 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
149 backend->policy = policy;
150
151#ifndef CONFIG_NUMA
152 if (policy != HOST_MEM_POLICY_DEFAULT) {
153 error_setg(errp, "NUMA policies are not supported by this QEMU");
154 }
155#endif
156}
157
158static bool host_memory_backend_get_merge(Object *obj, Error **errp)
159{
160 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
161
162 return backend->merge;
163}
164
165static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
166{
167 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
168
169 if (!host_memory_backend_mr_inited(backend)) {
170 backend->merge = value;
171 return;
172 }
173
174 if (value != backend->merge) {
175 void *ptr = memory_region_get_ram_ptr(&backend->mr);
176 uint64_t sz = memory_region_size(&backend->mr);
177
178 qemu_madvise(ptr, sz,
179 value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
180 backend->merge = value;
181 }
182}
183
184static bool host_memory_backend_get_dump(Object *obj, Error **errp)
185{
186 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
187
188 return backend->dump;
189}
190
191static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
192{
193 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
194
195 if (!host_memory_backend_mr_inited(backend)) {
196 backend->dump = value;
197 return;
198 }
199
200 if (value != backend->dump) {
201 void *ptr = memory_region_get_ram_ptr(&backend->mr);
202 uint64_t sz = memory_region_size(&backend->mr);
203
204 qemu_madvise(ptr, sz,
205 value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
206 backend->dump = value;
207 }
208}
209
210static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
211{
212 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
213
214 return backend->prealloc;
215}
216
217static void host_memory_backend_set_prealloc(Object *obj, bool value,
218 Error **errp)
219{
220 Error *local_err = NULL;
221 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
222
223 if (!host_memory_backend_mr_inited(backend)) {
224 backend->prealloc = value;
225 return;
226 }
227
228 if (value && !backend->prealloc) {
229 int fd = memory_region_get_fd(&backend->mr);
230 void *ptr = memory_region_get_ram_ptr(&backend->mr);
231 uint64_t sz = memory_region_size(&backend->mr);
232
233 os_mem_prealloc(fd, ptr, sz, backend->prealloc_threads, &local_err);
234 if (local_err) {
235 error_propagate(errp, local_err);
236 return;
237 }
238 backend->prealloc = true;
239 }
240}
241
242static void host_memory_backend_get_prealloc_threads(Object *obj, Visitor *v,
243 const char *name, void *opaque, Error **errp)
244{
245 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
246 visit_type_uint32(v, name, &backend->prealloc_threads, errp);
247}
248
249static void host_memory_backend_set_prealloc_threads(Object *obj, Visitor *v,
250 const char *name, void *opaque, Error **errp)
251{
252 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
253 uint32_t value;
254
255 if (!visit_type_uint32(v, name, &value, errp)) {
256 return;
257 }
258 if (value <= 0) {
259 error_setg(errp, "property '%s' of %s doesn't take value '%d'", name,
260 object_get_typename(obj), value);
261 return;
262 }
263 backend->prealloc_threads = value;
264}
265
266static void host_memory_backend_init(Object *obj)
267{
268 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
269 MachineState *machine = MACHINE(qdev_get_machine());
270
271 /* TODO: convert access to globals to compat properties */
272 backend->merge = machine_mem_merge(machine);
273 backend->dump = machine_dump_guest_core(machine);
274 backend->prealloc_threads = 1;
275}
276
277static void host_memory_backend_post_init(Object *obj)
278{
279 object_apply_compat_props(obj);
280}
281
282bool host_memory_backend_mr_inited(HostMemoryBackend *backend)
283{
284 /*
285 * NOTE: We forbid zero-length memory backend, so here zero means
286 * "we haven't inited the backend memory region yet".
287 */
288 return memory_region_size(&backend->mr) != 0;
289}
290
291MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend)
292{
293 return host_memory_backend_mr_inited(backend) ? &backend->mr : NULL;
294}
295
296void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
297{
298 backend->is_mapped = mapped;
299}
300
301bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
302{
303 return backend->is_mapped;
304}
305
306#ifdef __linux__
307size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
308{
309 Object *obj = OBJECT(memdev);
310 char *path = object_property_get_str(obj, "mem-path", NULL);
311 size_t pagesize = qemu_mempath_getpagesize(path);
312
313 g_free(path);
314 return pagesize;
315}
316#else
317size_t host_memory_backend_pagesize(HostMemoryBackend *memdev)
318{
319 return qemu_real_host_page_size;
320}
321#endif
322
323static void
324host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
325{
326 HostMemoryBackend *backend = MEMORY_BACKEND(uc);
327 HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
328 Error *local_err = NULL;
329 void *ptr;
330 uint64_t sz;
331
332 if (bc->alloc) {
333 bc->alloc(backend, &local_err);
334 if (local_err) {
335 goto out;
336 }
337
338 ptr = memory_region_get_ram_ptr(&backend->mr);
339 sz = memory_region_size(&backend->mr);
340
341 if (backend->merge) {
342 qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
343 }
344 if (!backend->dump) {
345 qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
346 }
347#ifdef CONFIG_NUMA
348 unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
349 /* lastbit == MAX_NODES means maxnode = 0 */
350 unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
351 /* ensure policy won't be ignored in case memory is preallocated
352 * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
353 * this doesn't catch hugepage case. */
354 unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
355
356 /* check for invalid host-nodes and policies and give more verbose
357 * error messages than mbind(). */
358 if (maxnode && backend->policy == MPOL_DEFAULT) {
359 error_setg(errp, "host-nodes must be empty for policy default,"
360 " or you should explicitly specify a policy other"
361 " than default");
362 return;
363 } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
364 error_setg(errp, "host-nodes must be set for policy %s",
365 HostMemPolicy_str(backend->policy));
366 return;
367 }
368
369 /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
370 * as argument to mbind() due to an old Linux bug (feature?) which
371 * cuts off the last specified node. This means backend->host_nodes
372 * must have MAX_NODES+1 bits available.
373 */
374 assert(sizeof(backend->host_nodes) >=
375 BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
376 assert(maxnode <= MAX_NODES);
377
378 if (maxnode &&
379 mbind(ptr, sz, backend->policy, backend->host_nodes, maxnode + 1,
380 flags)) {
381 if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
382 error_setg_errno(errp, errno,
383 "cannot bind memory to host NUMA nodes");
384 return;
385 }
386 }
387#endif
388 /* Preallocate memory after the NUMA policy has been instantiated.
389 * This is necessary to guarantee memory is allocated with
390 * specified NUMA policy in place.
391 */
392 if (backend->prealloc) {
393 os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
394 backend->prealloc_threads, &local_err);
395 if (local_err) {
396 goto out;
397 }
398 }
399 }
400out:
401 error_propagate(errp, local_err);
402}
403
404static bool
405host_memory_backend_can_be_deleted(UserCreatable *uc)
406{
407 if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
408 return false;
409 } else {
410 return true;
411 }
412}
413
414static bool host_memory_backend_get_share(Object *o, Error **errp)
415{
416 HostMemoryBackend *backend = MEMORY_BACKEND(o);
417
418 return backend->share;
419}
420
421static void host_memory_backend_set_share(Object *o, bool value, Error **errp)
422{
423 HostMemoryBackend *backend = MEMORY_BACKEND(o);
424
425 if (host_memory_backend_mr_inited(backend)) {
426 error_setg(errp, "cannot change property value");
427 return;
428 }
429 backend->share = value;
430}
431
432static bool
433host_memory_backend_get_use_canonical_path(Object *obj, Error **errp)
434{
435 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
436
437 return backend->use_canonical_path;
438}
439
440static void
441host_memory_backend_set_use_canonical_path(Object *obj, bool value,
442 Error **errp)
443{
444 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
445
446 backend->use_canonical_path = value;
447}
448
449static void
450host_memory_backend_class_init(ObjectClass *oc, void *data)
451{
452 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
453
454 ucc->complete = host_memory_backend_memory_complete;
455 ucc->can_be_deleted = host_memory_backend_can_be_deleted;
456
457 object_class_property_add_bool(oc, "merge",
458 host_memory_backend_get_merge,
459 host_memory_backend_set_merge);
460 object_class_property_set_description(oc, "merge",
461 "Mark memory as mergeable");
462 object_class_property_add_bool(oc, "dump",
463 host_memory_backend_get_dump,
464 host_memory_backend_set_dump);
465 object_class_property_set_description(oc, "dump",
466 "Set to 'off' to exclude from core dump");
467 object_class_property_add_bool(oc, "prealloc",
468 host_memory_backend_get_prealloc,
469 host_memory_backend_set_prealloc);
470 object_class_property_set_description(oc, "prealloc",
471 "Preallocate memory");
472 object_class_property_add(oc, "prealloc-threads", "int",
473 host_memory_backend_get_prealloc_threads,
474 host_memory_backend_set_prealloc_threads,
475 NULL, NULL);
476 object_class_property_set_description(oc, "prealloc-threads",
477 "Number of CPU threads to use for prealloc");
478 object_class_property_add(oc, "size", "int",
479 host_memory_backend_get_size,
480 host_memory_backend_set_size,
481 NULL, NULL);
482 object_class_property_set_description(oc, "size",
483 "Size of the memory region (ex: 500M)");
484 object_class_property_add(oc, "host-nodes", "int",
485 host_memory_backend_get_host_nodes,
486 host_memory_backend_set_host_nodes,
487 NULL, NULL);
488 object_class_property_set_description(oc, "host-nodes",
489 "Binds memory to the list of NUMA host nodes");
490 object_class_property_add_enum(oc, "policy", "HostMemPolicy",
491 &HostMemPolicy_lookup,
492 host_memory_backend_get_policy,
493 host_memory_backend_set_policy);
494 object_class_property_set_description(oc, "policy",
495 "Set the NUMA policy");
496 object_class_property_add_bool(oc, "share",
497 host_memory_backend_get_share, host_memory_backend_set_share);
498 object_class_property_set_description(oc, "share",
499 "Mark the memory as private to QEMU or shared");
500 object_class_property_add_bool(oc, "x-use-canonical-path-for-ramblock-id",
501 host_memory_backend_get_use_canonical_path,
502 host_memory_backend_set_use_canonical_path);
503}
504
505static const TypeInfo host_memory_backend_info = {
506 .name = TYPE_MEMORY_BACKEND,
507 .parent = TYPE_OBJECT,
508 .abstract = true,
509 .class_size = sizeof(HostMemoryBackendClass),
510 .class_init = host_memory_backend_class_init,
511 .instance_size = sizeof(HostMemoryBackend),
512 .instance_init = host_memory_backend_init,
513 .instance_post_init = host_memory_backend_post_init,
514 .interfaces = (InterfaceInfo[]) {
515 { TYPE_USER_CREATABLE },
516 { }
517 }
518};
519
520static void register_types(void)
521{
522 type_register_static(&host_memory_backend_info);
523}
524
525type_init(register_types);