2 * QEMU Host Memory Backend
4 * Copyright (C) 2013-2014 Red Hat Inc
7 * Igor Mammedov <imammedo@redhat.com>
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.
12 #include "qemu/osdep.h"
13 #include "sysemu/hostmem.h"
14 #include "hw/boards.h"
15 #include "qapi/error.h"
16 #include "qapi/visitor.h"
17 #include "qapi-types.h"
18 #include "qapi-visit.h"
19 #include "qemu/config-file.h"
20 #include "qom/object_interfaces.h"
24 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
25 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
26 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
27 QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
31 host_memory_backend_get_size(Object *obj, Visitor *v, const char *name,
32 void *opaque, Error **errp)
34 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
35 uint64_t value = backend->size;
37 visit_type_size(v, name, &value, errp);
41 host_memory_backend_set_size(Object *obj, Visitor *v, const char *name,
42 void *opaque, Error **errp)
44 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
45 Error *local_err = NULL;
48 if (memory_region_size(&backend->mr)) {
49 error_setg(&local_err, "cannot change property value");
53 visit_type_size(v, name, &value, &local_err);
58 error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
59 PRIu64 "'", object_get_typename(obj), name, value);
62 backend->size = value;
64 error_propagate(errp, local_err);
68 host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
69 void *opaque, Error **errp)
71 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
72 uint16List *host_nodes = NULL;
73 uint16List **node = &host_nodes;
76 value = find_first_bit(backend->host_nodes, MAX_NODES);
77 if (value == MAX_NODES) {
81 *node = g_malloc0(sizeof(**node));
82 (*node)->value = value;
83 node = &(*node)->next;
86 value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
87 if (value == MAX_NODES) {
91 *node = g_malloc0(sizeof(**node));
92 (*node)->value = value;
93 node = &(*node)->next;
96 visit_type_uint16List(v, name, &host_nodes, errp);
100 host_memory_backend_set_host_nodes(Object *obj, Visitor *v, const char *name,
101 void *opaque, Error **errp)
104 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
105 uint16List *l = NULL;
107 visit_type_uint16List(v, name, &l, errp);
110 bitmap_set(backend->host_nodes, l->value, 1);
114 error_setg(errp, "NUMA node binding are not supported by this QEMU");
119 host_memory_backend_get_policy(Object *obj, Error **errp G_GNUC_UNUSED)
121 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
122 return backend->policy;
126 host_memory_backend_set_policy(Object *obj, int policy, Error **errp)
128 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
129 backend->policy = policy;
132 if (policy != HOST_MEM_POLICY_DEFAULT) {
133 error_setg(errp, "NUMA policies are not supported by this QEMU");
138 static bool host_memory_backend_get_merge(Object *obj, Error **errp)
140 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
142 return backend->merge;
145 static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
147 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
149 if (!memory_region_size(&backend->mr)) {
150 backend->merge = value;
154 if (value != backend->merge) {
155 void *ptr = memory_region_get_ram_ptr(&backend->mr);
156 uint64_t sz = memory_region_size(&backend->mr);
158 qemu_madvise(ptr, sz,
159 value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
160 backend->merge = value;
164 static bool host_memory_backend_get_dump(Object *obj, Error **errp)
166 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
168 return backend->dump;
171 static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
173 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
175 if (!memory_region_size(&backend->mr)) {
176 backend->dump = value;
180 if (value != backend->dump) {
181 void *ptr = memory_region_get_ram_ptr(&backend->mr);
182 uint64_t sz = memory_region_size(&backend->mr);
184 qemu_madvise(ptr, sz,
185 value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
186 backend->dump = value;
190 static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
192 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
194 return backend->prealloc || backend->force_prealloc;
197 static void host_memory_backend_set_prealloc(Object *obj, bool value,
200 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
202 if (backend->force_prealloc) {
205 "remove -mem-prealloc to use the prealloc property");
210 if (!memory_region_size(&backend->mr)) {
211 backend->prealloc = value;
215 if (value && !backend->prealloc) {
216 int fd = memory_region_get_fd(&backend->mr);
217 void *ptr = memory_region_get_ram_ptr(&backend->mr);
218 uint64_t sz = memory_region_size(&backend->mr);
220 os_mem_prealloc(fd, ptr, sz);
221 backend->prealloc = true;
225 static void host_memory_backend_init(Object *obj)
227 HostMemoryBackend *backend = MEMORY_BACKEND(obj);
228 MachineState *machine = MACHINE(qdev_get_machine());
230 backend->merge = machine_mem_merge(machine);
231 backend->dump = machine_dump_guest_core(machine);
232 backend->prealloc = mem_prealloc;
234 object_property_add_bool(obj, "merge",
235 host_memory_backend_get_merge,
236 host_memory_backend_set_merge, NULL);
237 object_property_add_bool(obj, "dump",
238 host_memory_backend_get_dump,
239 host_memory_backend_set_dump, NULL);
240 object_property_add_bool(obj, "prealloc",
241 host_memory_backend_get_prealloc,
242 host_memory_backend_set_prealloc, NULL);
243 object_property_add(obj, "size", "int",
244 host_memory_backend_get_size,
245 host_memory_backend_set_size, NULL, NULL, NULL);
246 object_property_add(obj, "host-nodes", "int",
247 host_memory_backend_get_host_nodes,
248 host_memory_backend_set_host_nodes, NULL, NULL, NULL);
249 object_property_add_enum(obj, "policy", "HostMemPolicy",
250 HostMemPolicy_lookup,
251 host_memory_backend_get_policy,
252 host_memory_backend_set_policy, NULL);
256 host_memory_backend_get_memory(HostMemoryBackend *backend, Error **errp)
258 return memory_region_size(&backend->mr) ? &backend->mr : NULL;
262 host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
264 HostMemoryBackend *backend = MEMORY_BACKEND(uc);
265 HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
266 Error *local_err = NULL;
271 bc->alloc(backend, &local_err);
273 error_propagate(errp, local_err);
277 ptr = memory_region_get_ram_ptr(&backend->mr);
278 sz = memory_region_size(&backend->mr);
280 if (backend->merge) {
281 qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
283 if (!backend->dump) {
284 qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
287 unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
288 /* lastbit == MAX_NODES means maxnode = 0 */
289 unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
290 /* ensure policy won't be ignored in case memory is preallocated
291 * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
292 * this doesn't catch hugepage case. */
293 unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;
295 /* check for invalid host-nodes and policies and give more verbose
296 * error messages than mbind(). */
297 if (maxnode && backend->policy == MPOL_DEFAULT) {
298 error_setg(errp, "host-nodes must be empty for policy default,"
299 " or you should explicitly specify a policy other"
302 } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
303 error_setg(errp, "host-nodes must be set for policy %s",
304 HostMemPolicy_lookup[backend->policy]);
308 /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
309 * as argument to mbind() due to an old Linux bug (feature?) which
310 * cuts off the last specified node. This means backend->host_nodes
311 * must have MAX_NODES+1 bits available.
313 assert(sizeof(backend->host_nodes) >=
314 BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
315 assert(maxnode <= MAX_NODES);
316 if (mbind(ptr, sz, backend->policy,
317 maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) {
318 if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
319 error_setg_errno(errp, errno,
320 "cannot bind memory to host NUMA nodes");
325 /* Preallocate memory after the NUMA policy has been instantiated.
326 * This is necessary to guarantee memory is allocated with
327 * specified NUMA policy in place.
329 if (backend->prealloc) {
330 os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
336 host_memory_backend_can_be_deleted(UserCreatable *uc, Error **errp)
340 mr = host_memory_backend_get_memory(MEMORY_BACKEND(uc), errp);
341 if (memory_region_is_mapped(mr)) {
349 host_memory_backend_class_init(ObjectClass *oc, void *data)
351 UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
353 ucc->complete = host_memory_backend_memory_complete;
354 ucc->can_be_deleted = host_memory_backend_can_be_deleted;
357 static const TypeInfo host_memory_backend_info = {
358 .name = TYPE_MEMORY_BACKEND,
359 .parent = TYPE_OBJECT,
361 .class_size = sizeof(HostMemoryBackendClass),
362 .class_init = host_memory_backend_class_init,
363 .instance_size = sizeof(HostMemoryBackend),
364 .instance_init = host_memory_backend_init,
365 .interfaces = (InterfaceInfo[]) {
366 { TYPE_USER_CREATABLE },
371 static void register_types(void)
373 type_register_static(&host_memory_backend_info);
376 type_init(register_types);