[qemu.git] / backends / hostmem.c

/*
 * QEMU Host Memory Backend
 *
 * Copyright (C) 2013-2014 Red Hat Inc
 *
 * Authors:
 *   Igor Mammedov <[email protected]>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include "qemu/osdep.h"
#include "sysemu/hostmem.h"
#include "hw/boards.h"
#include "qapi/visitor.h"
#include "qapi-types.h"
#include "qapi-visit.h"
#include "qemu/config-file.h"
#include "qom/object_interfaces.h"

#ifdef CONFIG_NUMA
#include <numaif.h>
QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
#endif

static void
host_memory_backend_get_size(Object *obj, Visitor *v, const char *name,
                             void *opaque, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    uint64_t value = backend->size;

    visit_type_size(v, name, &value, errp);
}

static void
host_memory_backend_set_size(Object *obj, Visitor *v, const char *name,
                             void *opaque, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    Error *local_err = NULL;
    uint64_t value;

    if (memory_region_size(&backend->mr)) {
        error_setg(&local_err, "cannot change property value");
        goto out;
    }

    visit_type_size(v, name, &value, &local_err);
    if (local_err) {
        goto out;
    }
    if (!value) {
        error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
                   PRIu64 "'", object_get_typename(obj), name, value);
        goto out;
    }
    backend->size = value;
out:
    error_propagate(errp, local_err);
}

static void
host_memory_backend_get_host_nodes(Object *obj, Visitor *v, const char *name,
                                   void *opaque, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    uint16List *host_nodes = NULL;
    uint16List **node = &host_nodes;
    unsigned long value;

    value = find_first_bit(backend->host_nodes, MAX_NODES);
    if (value == MAX_NODES) {
        return;
    }

    *node = g_malloc0(sizeof(**node));
    (*node)->value = value;
    node = &(*node)->next;

    do {
        value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
        if (value == MAX_NODES) {
            break;
        }

        *node = g_malloc0(sizeof(**node));
        (*node)->value = value;
        node = &(*node)->next;
    } while (true);

    visit_type_uint16List(v, name, &host_nodes, errp);
}

static void
host_memory_backend_set_host_nodes(Object *obj, Visitor *v, const char *name,
                                   void *opaque, Error **errp)
{
#ifdef CONFIG_NUMA
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    uint16List *l = NULL;

    visit_type_uint16List(v, name, &l, errp);

    while (l) {
        bitmap_set(backend->host_nodes, l->value, 1);
        l = l->next;
    }
#else
    error_setg(errp, "NUMA node binding are not supported by this QEMU");
#endif
}

static int
host_memory_backend_get_policy(Object *obj, Error **errp G_GNUC_UNUSED)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    return backend->policy;
}

static void
host_memory_backend_set_policy(Object *obj, int policy, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    backend->policy = policy;

#ifndef CONFIG_NUMA
    if (policy != HOST_MEM_POLICY_DEFAULT) {
        error_setg(errp, "NUMA policies are not supported by this QEMU");
    }
#endif
}

static bool host_memory_backend_get_merge(Object *obj, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    return backend->merge;
}

static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    if (!memory_region_size(&backend->mr)) {
        backend->merge = value;
        return;
    }

    if (value != backend->merge) {
        void *ptr = memory_region_get_ram_ptr(&backend->mr);
        uint64_t sz = memory_region_size(&backend->mr);

        qemu_madvise(ptr, sz,
                     value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
        backend->merge = value;
    }
}

static bool host_memory_backend_get_dump(Object *obj, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    return backend->dump;
}

static void host_memory_backend_set_dump(Object *obj, bool value, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    if (!memory_region_size(&backend->mr)) {
        backend->dump = value;
        return;
    }

    if (value != backend->dump) {
        void *ptr = memory_region_get_ram_ptr(&backend->mr);
        uint64_t sz = memory_region_size(&backend->mr);

        qemu_madvise(ptr, sz,
                     value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
        backend->dump = value;
    }
}

static bool host_memory_backend_get_prealloc(Object *obj, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    return backend->prealloc || backend->force_prealloc;
}

static void host_memory_backend_set_prealloc(Object *obj, bool value,
                                             Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);

    if (backend->force_prealloc) {
        if (value) {
            error_setg(errp,
                       "remove -mem-prealloc to use the prealloc property");
            return;
        }
    }

    if (!memory_region_size(&backend->mr)) {
        backend->prealloc = value;
        return;
    }

    if (value && !backend->prealloc) {
        int fd = memory_region_get_fd(&backend->mr);
        void *ptr = memory_region_get_ram_ptr(&backend->mr);
        uint64_t sz = memory_region_size(&backend->mr);

        os_mem_prealloc(fd, ptr, sz);
        backend->prealloc = true;
    }
}

static void host_memory_backend_init(Object *obj)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    MachineState *machine = MACHINE(qdev_get_machine());

    backend->merge = machine_mem_merge(machine);
    backend->dump = machine_dump_guest_core(machine);
    backend->prealloc = mem_prealloc;

    object_property_add_bool(obj, "merge",
                        host_memory_backend_get_merge,
                        host_memory_backend_set_merge, NULL);
    object_property_add_bool(obj, "dump",
                        host_memory_backend_get_dump,
                        host_memory_backend_set_dump, NULL);
    object_property_add_bool(obj, "prealloc",
                        host_memory_backend_get_prealloc,
                        host_memory_backend_set_prealloc, NULL);
    object_property_add(obj, "size", "int",
                        host_memory_backend_get_size,
                        host_memory_backend_set_size, NULL, NULL, NULL);
    object_property_add(obj, "host-nodes", "int",
                        host_memory_backend_get_host_nodes,
                        host_memory_backend_set_host_nodes, NULL, NULL, NULL);
    object_property_add_enum(obj, "policy", "HostMemPolicy",
                             HostMemPolicy_lookup,
                             host_memory_backend_get_policy,
                             host_memory_backend_set_policy, NULL);
}

MemoryRegion *
host_memory_backend_get_memory(HostMemoryBackend *backend, Error **errp)
{
    return memory_region_size(&backend->mr) ? &backend->mr : NULL;
}

static void
host_memory_backend_memory_complete(UserCreatable *uc, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(uc);
    HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
    Error *local_err = NULL;
    void *ptr;
    uint64_t sz;

    if (bc->alloc) {
        bc->alloc(backend, &local_err);
        if (local_err) {
            error_propagate(errp, local_err);
            return;
        }

        ptr = memory_region_get_ram_ptr(&backend->mr);
        sz = memory_region_size(&backend->mr);

        if (backend->merge) {
            qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
        }
        if (!backend->dump) {
            qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
        }
#ifdef CONFIG_NUMA
        unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
        /* lastbit == MAX_NODES means maxnode = 0 */
        unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
        /* ensure policy won't be ignored in case memory is preallocated
         * before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
         * this doesn't catch hugepage case. */
        unsigned flags = MPOL_MF_STRICT | MPOL_MF_MOVE;

        /* check for invalid host-nodes and policies and give more verbose
         * error messages than mbind(). */
        if (maxnode && backend->policy == MPOL_DEFAULT) {
            error_setg(errp, "host-nodes must be empty for policy default,"
                       " or you should explicitly specify a policy other"
                       " than default");
            return;
        } else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
            error_setg(errp, "host-nodes must be set for policy %s",
                       HostMemPolicy_lookup[backend->policy]);
            return;
        }

        /* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
         * as argument to mbind() due to an old Linux bug (feature?) which
         * cuts off the last specified node. This means backend->host_nodes
         * must have MAX_NODES+1 bits available.
         */
        assert(sizeof(backend->host_nodes) >=
               BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
        assert(maxnode <= MAX_NODES);
        if (mbind(ptr, sz, backend->policy,
                  maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) {
            if (backend->policy != MPOL_DEFAULT || errno != ENOSYS) {
                error_setg_errno(errp, errno,
                                 "cannot bind memory to host NUMA nodes");
                return;
            }
        }
#endif
        /* Preallocate memory after the NUMA policy has been instantiated.
         * This is necessary to guarantee memory is allocated with
         * specified NUMA policy in place.
         */
        if (backend->prealloc) {
            os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
        }
    }
}

static bool
host_memory_backend_can_be_deleted(UserCreatable *uc, Error **errp)
{
    MemoryRegion *mr;

    mr = host_memory_backend_get_memory(MEMORY_BACKEND(uc), errp);
    if (memory_region_is_mapped(mr)) {
        return false;
    } else {
        return true;
    }
}

static void
host_memory_backend_class_init(ObjectClass *oc, void *data)
{
    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);

    ucc->complete = host_memory_backend_memory_complete;
    ucc->can_be_deleted = host_memory_backend_can_be_deleted;
}

static const TypeInfo host_memory_backend_info = {
    .name = TYPE_MEMORY_BACKEND,
    .parent = TYPE_OBJECT,
    .abstract = true,
    .class_size = sizeof(HostMemoryBackendClass),
    .class_init = host_memory_backend_class_init,
    .instance_size = sizeof(HostMemoryBackend),
    .instance_init = host_memory_backend_init,
    .interfaces = (InterfaceInfo[]) {
        { TYPE_USER_CREATABLE },
        { }
    }
};

static void register_types(void)
{
    type_register_static(&host_memory_backend_info);
}

type_init(register_types);
Commit	Line	Data
1f070489 IM	1	/*
	2	* QEMU Host Memory Backend
	3	*
	4	* Copyright (C) 2013-2014 Red Hat Inc
	5	*
	6	* Authors:
	7	* Igor Mammedov <[email protected]>
	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	*/
9c058332	12	#include "qemu/osdep.h"
1f070489	13	#include "sysemu/hostmem.h"
6b269967	14	#include "hw/boards.h"
1f070489	15	#include "qapi/visitor.h"
4cf1b76b HT	16	#include "qapi-types.h"
4cf1b76b HT	17	#include "qapi-visit.h"
1f070489 IM	18	#include "qemu/config-file.h"
	19	#include "qom/object_interfaces.h"
	20
4cf1b76b HT	21	#ifdef CONFIG_NUMA
	22	#include <numaif.h>
	23	QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_DEFAULT != MPOL_DEFAULT);
	24	QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_PREFERRED != MPOL_PREFERRED);
	25	QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_BIND != MPOL_BIND);
	26	QEMU_BUILD_BUG_ON(HOST_MEM_POLICY_INTERLEAVE != MPOL_INTERLEAVE);
	27	#endif
	28
1f070489	29	static void
d7bce999 EB	30	host_memory_backend_get_size(Object obj, Visitor v, const char *name,
d7bce999 EB	31	void opaque, Error *errp)
1f070489 IM	32	{
	33	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	34	uint64_t value = backend->size;
	35
51e72bc1	36	visit_type_size(v, name, &value, errp);
1f070489 IM	37	}
	38
	39	static void
d7bce999 EB	40	host_memory_backend_set_size(Object obj, Visitor v, const char *name,
d7bce999 EB	41	void opaque, Error *errp)
1f070489 IM	42	{
	43	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	44	Error *local_err = NULL;
	45	uint64_t value;
	46
	47	if (memory_region_size(&backend->mr)) {
	48	error_setg(&local_err, "cannot change property value");
	49	goto out;
	50	}
	51
51e72bc1	52	visit_type_size(v, name, &value, &local_err);
1f070489 IM	53	if (local_err) {
	54	goto out;
	55	}
	56	if (!value) {
	57	error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
	58	PRIu64 "'", object_get_typename(obj), name, value);
	59	goto out;
	60	}
	61	backend->size = value;
	62	out:
	63	error_propagate(errp, local_err);
	64	}
	65
4cf1b76b	66	static void
d7bce999 EB	67	host_memory_backend_get_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	68	void opaque, Error *errp)
4cf1b76b HT	69	{
	70	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	71	uint16List *host_nodes = NULL;
	72	uint16List **node = &host_nodes;
	73	unsigned long value;
	74
	75	value = find_first_bit(backend->host_nodes, MAX_NODES);
	76	if (value == MAX_NODES) {
	77	return;
	78	}
	79
	80	node = g_malloc0(sizeof(*node));
	81	(*node)->value = value;
	82	node = &(*node)->next;
	83
	84	do {
	85	value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
	86	if (value == MAX_NODES) {
	87	break;
	88	}
	89
	90	node = g_malloc0(sizeof(*node));
	91	(*node)->value = value;
	92	node = &(*node)->next;
	93	} while (true);
	94
51e72bc1	95	visit_type_uint16List(v, name, &host_nodes, errp);
4cf1b76b HT	96	}
	97
	98	static void
d7bce999 EB	99	host_memory_backend_set_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	100	void opaque, Error *errp)
4cf1b76b HT	101	{
	102	#ifdef CONFIG_NUMA
	103	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	104	uint16List *l = NULL;
	105
51e72bc1	106	visit_type_uint16List(v, name, &l, errp);
4cf1b76b HT	107
	108	while (l) {
	109	bitmap_set(backend->host_nodes, l->value, 1);
	110	l = l->next;
	111	}
	112	#else
	113	error_setg(errp, "NUMA node binding are not supported by this QEMU");
	114	#endif
	115	}
	116
a3590dac DB	117	static int
a3590dac DB	118	host_memory_backend_get_policy(Object obj, Error *errp G_GNUC_UNUSED)
4cf1b76b HT	119	{
4cf1b76b HT	120	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
a3590dac	121	return backend->policy;
4cf1b76b HT	122	}
	123
	124	static void
a3590dac	125	host_memory_backend_set_policy(Object obj, int policy, Error *errp)
4cf1b76b HT	126	{
4cf1b76b HT	127	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
4cf1b76b HT	128	backend->policy = policy;
	129
	130	#ifndef CONFIG_NUMA
	131	if (policy != HOST_MEM_POLICY_DEFAULT) {
	132	error_setg(errp, "NUMA policies are not supported by this QEMU");
	133	}
	134	#endif
	135	}
	136
605d0a94 PB	137	static bool host_memory_backend_get_merge(Object obj, Error *errp)
	138	{
	139	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	140
	141	return backend->merge;
	142	}
	143
	144	static void host_memory_backend_set_merge(Object obj, bool value, Error *errp)
	145	{
	146	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	147
	148	if (!memory_region_size(&backend->mr)) {
	149	backend->merge = value;
	150	return;
	151	}
	152
	153	if (value != backend->merge) {
	154	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	155	uint64_t sz = memory_region_size(&backend->mr);
	156
	157	qemu_madvise(ptr, sz,
	158	value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
	159	backend->merge = value;
	160	}
	161	}
	162
	163	static bool host_memory_backend_get_dump(Object obj, Error *errp)
	164	{
	165	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	166
	167	return backend->dump;
	168	}
	169
	170	static void host_memory_backend_set_dump(Object obj, bool value, Error *errp)
	171	{
	172	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	173
	174	if (!memory_region_size(&backend->mr)) {
	175	backend->dump = value;
	176	return;
	177	}
	178
	179	if (value != backend->dump) {
	180	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	181	uint64_t sz = memory_region_size(&backend->mr);
	182
	183	qemu_madvise(ptr, sz,
	184	value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
	185	backend->dump = value;
	186	}
	187	}
	188
a35ba7be PB	189	static bool host_memory_backend_get_prealloc(Object obj, Error *errp)
	190	{
	191	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	192
	193	return backend->prealloc \|\| backend->force_prealloc;
	194	}
	195
	196	static void host_memory_backend_set_prealloc(Object *obj, bool value,
	197	Error **errp)
	198	{
	199	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	200
	201	if (backend->force_prealloc) {
	202	if (value) {
	203	error_setg(errp,
	204	"remove -mem-prealloc to use the prealloc property");
	205	return;
	206	}
	207	}
	208
	209	if (!memory_region_size(&backend->mr)) {
	210	backend->prealloc = value;
	211	return;
	212	}
	213
	214	if (value && !backend->prealloc) {
	215	int fd = memory_region_get_fd(&backend->mr);
	216	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	217	uint64_t sz = memory_region_size(&backend->mr);
	218
	219	os_mem_prealloc(fd, ptr, sz);
	220	backend->prealloc = true;
	221	}
	222	}
	223
58f4662c	224	static void host_memory_backend_init(Object *obj)
1f070489	225	{
605d0a94	226	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
6b269967	227	MachineState *machine = MACHINE(qdev_get_machine());
605d0a94	228
6b269967 EH	229	backend->merge = machine_mem_merge(machine);
6b269967 EH	230	backend->dump = machine_dump_guest_core(machine);
a35ba7be	231	backend->prealloc = mem_prealloc;
605d0a94 PB	232
	233	object_property_add_bool(obj, "merge",
	234	host_memory_backend_get_merge,
	235	host_memory_backend_set_merge, NULL);
	236	object_property_add_bool(obj, "dump",
	237	host_memory_backend_get_dump,
	238	host_memory_backend_set_dump, NULL);
a35ba7be PB	239	object_property_add_bool(obj, "prealloc",
	240	host_memory_backend_get_prealloc,
	241	host_memory_backend_set_prealloc, NULL);
1f070489	242	object_property_add(obj, "size", "int",
58f4662c HT	243	host_memory_backend_get_size,
58f4662c HT	244	host_memory_backend_set_size, NULL, NULL, NULL);
4cf1b76b HT	245	object_property_add(obj, "host-nodes", "int",
	246	host_memory_backend_get_host_nodes,
	247	host_memory_backend_set_host_nodes, NULL, NULL, NULL);
a3590dac DB	248	object_property_add_enum(obj, "policy", "HostMemPolicy",
	249	HostMemPolicy_lookup,
	250	host_memory_backend_get_policy,
	251	host_memory_backend_set_policy, NULL);
1f070489 IM	252	}
1f070489 IM	253
1f070489 IM	254	MemoryRegion *
	255	host_memory_backend_get_memory(HostMemoryBackend backend, Error *errp)
	256	{
	257	return memory_region_size(&backend->mr) ? &backend->mr : NULL;
	258	}
	259
bd9262d9 HT	260	static void
	261	host_memory_backend_memory_complete(UserCreatable uc, Error *errp)
	262	{
	263	HostMemoryBackend *backend = MEMORY_BACKEND(uc);
	264	HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
605d0a94 PB	265	Error *local_err = NULL;
	266	void *ptr;
	267	uint64_t sz;
bd9262d9 HT	268
bd9262d9 HT	269	if (bc->alloc) {
605d0a94 PB	270	bc->alloc(backend, &local_err);
	271	if (local_err) {
	272	error_propagate(errp, local_err);
	273	return;
	274	}
	275
	276	ptr = memory_region_get_ram_ptr(&backend->mr);
	277	sz = memory_region_size(&backend->mr);
	278
	279	if (backend->merge) {
	280	qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
	281	}
	282	if (!backend->dump) {
	283	qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
	284	}
4cf1b76b HT	285	#ifdef CONFIG_NUMA
	286	unsigned long lastbit = find_last_bit(backend->host_nodes, MAX_NODES);
	287	/* lastbit == MAX_NODES means maxnode = 0 */
	288	unsigned long maxnode = (lastbit + 1) % (MAX_NODES + 1);
	289	/* ensure policy won't be ignored in case memory is preallocated
	290	* before mbind(). note: MPOL_MF_STRICT is ignored on hugepages so
	291	* this doesn't catch hugepage case. */
288d3322	292	unsigned flags = MPOL_MF_STRICT \| MPOL_MF_MOVE;
4cf1b76b HT	293
	294	/* check for invalid host-nodes and policies and give more verbose
	295	* error messages than mbind(). */
	296	if (maxnode && backend->policy == MPOL_DEFAULT) {
	297	error_setg(errp, "host-nodes must be empty for policy default,"
	298	" or you should explicitly specify a policy other"
	299	" than default");
	300	return;
	301	} else if (maxnode == 0 && backend->policy != MPOL_DEFAULT) {
	302	error_setg(errp, "host-nodes must be set for policy %s",
	303	HostMemPolicy_lookup[backend->policy]);
	304	return;
	305	}
	306
	307	/* We can have up to MAX_NODES nodes, but we need to pass maxnode+1
	308	* as argument to mbind() due to an old Linux bug (feature?) which
	309	* cuts off the last specified node. This means backend->host_nodes
	310	* must have MAX_NODES+1 bits available.
	311	*/
	312	assert(sizeof(backend->host_nodes) >=
	313	BITS_TO_LONGS(MAX_NODES + 1) * sizeof(unsigned long));
	314	assert(maxnode <= MAX_NODES);
	315	if (mbind(ptr, sz, backend->policy,
	316	maxnode ? backend->host_nodes : NULL, maxnode + 1, flags)) {
a3567ba1 PF	317	if (backend->policy != MPOL_DEFAULT \|\| errno != ENOSYS) {
	318	error_setg_errno(errp, errno,
	319	"cannot bind memory to host NUMA nodes");
	320	return;
	321	}
4cf1b76b HT	322	}
	323	#endif
	324	/* Preallocate memory after the NUMA policy has been instantiated.
	325	* This is necessary to guarantee memory is allocated with
	326	* specified NUMA policy in place.
	327	*/
a35ba7be PB	328	if (backend->prealloc) {
	329	os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
	330	}
bd9262d9 HT	331	}
	332	}
	333
36bce5ca LM	334	static bool
	335	host_memory_backend_can_be_deleted(UserCreatable uc, Error *errp)
	336	{
	337	MemoryRegion *mr;
	338
	339	mr = host_memory_backend_get_memory(MEMORY_BACKEND(uc), errp);
	340	if (memory_region_is_mapped(mr)) {
	341	return false;
	342	} else {
	343	return true;
	344	}
	345	}
	346
bd9262d9 HT	347	static void
	348	host_memory_backend_class_init(ObjectClass oc, void data)
	349	{
	350	UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
	351
	352	ucc->complete = host_memory_backend_memory_complete;
36bce5ca	353	ucc->can_be_deleted = host_memory_backend_can_be_deleted;
bd9262d9 HT	354	}
bd9262d9 HT	355
58f4662c	356	static const TypeInfo host_memory_backend_info = {
1f070489 IM	357	.name = TYPE_MEMORY_BACKEND,
	358	.parent = TYPE_OBJECT,
	359	.abstract = true,
	360	.class_size = sizeof(HostMemoryBackendClass),
bd9262d9	361	.class_init = host_memory_backend_class_init,
1f070489	362	.instance_size = sizeof(HostMemoryBackend),
58f4662c	363	.instance_init = host_memory_backend_init,
1f070489 IM	364	.interfaces = (InterfaceInfo[]) {
	365	{ TYPE_USER_CREATABLE },
	366	{ }
	367	}
	368	};
	369
	370	static void register_types(void)
	371	{
58f4662c	372	type_register_static(&host_memory_backend_info);
1f070489 IM	373	}
	374
	375	type_init(register_types);