[mirror_qemu.git] / backends / hostmem.c

/*
 * QEMU Host Memory Backend
 *
 * Copyright (C) 2013-2014 Red Hat Inc
 *
 * Authors:
 *   Igor Mammedov <imammedo@redhat.com>
 *
 * 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/error.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 <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	*/
9c058332	12	#include "qemu/osdep.h"
1f070489	13	#include "sysemu/hostmem.h"
6b269967	14	#include "hw/boards.h"
da34e65c	15	#include "qapi/error.h"
1f070489	16	#include "qapi/visitor.h"
4cf1b76b HT	17	#include "qapi-types.h"
4cf1b76b HT	18	#include "qapi-visit.h"
1f070489 IM	19	#include "qemu/config-file.h"
	20	#include "qom/object_interfaces.h"
	21
4cf1b76b HT	22	#ifdef CONFIG_NUMA
	23	#include <numaif.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);
	28	#endif
	29
1f070489	30	static void
d7bce999 EB	31	host_memory_backend_get_size(Object obj, Visitor v, const char *name,
d7bce999 EB	32	void opaque, Error *errp)
1f070489 IM	33	{
	34	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	35	uint64_t value = backend->size;
	36
51e72bc1	37	visit_type_size(v, name, &value, errp);
1f070489 IM	38	}
	39
	40	static void
d7bce999 EB	41	host_memory_backend_set_size(Object obj, Visitor v, const char *name,
d7bce999 EB	42	void opaque, Error *errp)
1f070489 IM	43	{
	44	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	45	Error *local_err = NULL;
	46	uint64_t value;
	47
	48	if (memory_region_size(&backend->mr)) {
	49	error_setg(&local_err, "cannot change property value");
	50	goto out;
	51	}
	52
51e72bc1	53	visit_type_size(v, name, &value, &local_err);
1f070489 IM	54	if (local_err) {
	55	goto out;
	56	}
	57	if (!value) {
	58	error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
	59	PRIu64 "'", object_get_typename(obj), name, value);
	60	goto out;
	61	}
	62	backend->size = value;
	63	out:
	64	error_propagate(errp, local_err);
	65	}
	66
4cf1b76b	67	static void
d7bce999 EB	68	host_memory_backend_get_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	69	void opaque, Error *errp)
4cf1b76b HT	70	{
	71	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	72	uint16List *host_nodes = NULL;
	73	uint16List **node = &host_nodes;
	74	unsigned long value;
	75
	76	value = find_first_bit(backend->host_nodes, MAX_NODES);
	77	if (value == MAX_NODES) {
	78	return;
	79	}
	80
	81	node = g_malloc0(sizeof(*node));
	82	(*node)->value = value;
	83	node = &(*node)->next;
	84
	85	do {
	86	value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
	87	if (value == MAX_NODES) {
	88	break;
	89	}
	90
	91	node = g_malloc0(sizeof(*node));
	92	(*node)->value = value;
	93	node = &(*node)->next;
	94	} while (true);
	95
51e72bc1	96	visit_type_uint16List(v, name, &host_nodes, errp);
4cf1b76b HT	97	}
	98
	99	static void
d7bce999 EB	100	host_memory_backend_set_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	101	void opaque, Error *errp)
4cf1b76b HT	102	{
	103	#ifdef CONFIG_NUMA
	104	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	105	uint16List *l = NULL;
	106
51e72bc1	107	visit_type_uint16List(v, name, &l, errp);
4cf1b76b HT	108
	109	while (l) {
	110	bitmap_set(backend->host_nodes, l->value, 1);
	111	l = l->next;
	112	}
	113	#else
	114	error_setg(errp, "NUMA node binding are not supported by this QEMU");
	115	#endif
	116	}
	117
a3590dac DB	118	static int
a3590dac DB	119	host_memory_backend_get_policy(Object obj, Error *errp G_GNUC_UNUSED)
4cf1b76b HT	120	{
4cf1b76b HT	121	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
a3590dac	122	return backend->policy;
4cf1b76b HT	123	}
	124
	125	static void
a3590dac	126	host_memory_backend_set_policy(Object obj, int policy, Error *errp)
4cf1b76b HT	127	{
4cf1b76b HT	128	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
4cf1b76b HT	129	backend->policy = policy;
	130
	131	#ifndef CONFIG_NUMA
	132	if (policy != HOST_MEM_POLICY_DEFAULT) {
	133	error_setg(errp, "NUMA policies are not supported by this QEMU");
	134	}
	135	#endif
	136	}
	137
605d0a94 PB	138	static bool host_memory_backend_get_merge(Object obj, Error *errp)
	139	{
	140	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	141
	142	return backend->merge;
	143	}
	144
	145	static void host_memory_backend_set_merge(Object obj, bool value, Error *errp)
	146	{
	147	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	148
	149	if (!memory_region_size(&backend->mr)) {
	150	backend->merge = value;
	151	return;
	152	}
	153
	154	if (value != backend->merge) {
	155	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	156	uint64_t sz = memory_region_size(&backend->mr);
	157
	158	qemu_madvise(ptr, sz,
	159	value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
	160	backend->merge = value;
	161	}
	162	}
	163
	164	static bool host_memory_backend_get_dump(Object obj, Error *errp)
	165	{
	166	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	167
	168	return backend->dump;
	169	}
	170
	171	static void host_memory_backend_set_dump(Object obj, bool value, Error *errp)
	172	{
	173	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	174
	175	if (!memory_region_size(&backend->mr)) {
	176	backend->dump = value;
	177	return;
	178	}
	179
	180	if (value != backend->dump) {
	181	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	182	uint64_t sz = memory_region_size(&backend->mr);
	183
	184	qemu_madvise(ptr, sz,
	185	value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
	186	backend->dump = value;
	187	}
	188	}
	189
a35ba7be PB	190	static bool host_memory_backend_get_prealloc(Object obj, Error *errp)
	191	{
	192	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	193
	194	return backend->prealloc \|\| backend->force_prealloc;
	195	}
	196
	197	static void host_memory_backend_set_prealloc(Object *obj, bool value,
	198	Error **errp)
	199	{
	200	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	201
	202	if (backend->force_prealloc) {
	203	if (value) {
	204	error_setg(errp,
	205	"remove -mem-prealloc to use the prealloc property");
	206	return;
	207	}
	208	}
	209
	210	if (!memory_region_size(&backend->mr)) {
	211	backend->prealloc = value;
	212	return;
	213	}
	214
	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);
	219
	220	os_mem_prealloc(fd, ptr, sz);
	221	backend->prealloc = true;
	222	}
	223	}
	224
58f4662c	225	static void host_memory_backend_init(Object *obj)
1f070489	226	{
605d0a94	227	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
6b269967	228	MachineState *machine = MACHINE(qdev_get_machine());
605d0a94	229
6b269967 EH	230	backend->merge = machine_mem_merge(machine);
6b269967 EH	231	backend->dump = machine_dump_guest_core(machine);
a35ba7be	232	backend->prealloc = mem_prealloc;
605d0a94 PB	233
	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);
a35ba7be PB	240	object_property_add_bool(obj, "prealloc",
	241	host_memory_backend_get_prealloc,
	242	host_memory_backend_set_prealloc, NULL);
1f070489	243	object_property_add(obj, "size", "int",
58f4662c HT	244	host_memory_backend_get_size,
58f4662c HT	245	host_memory_backend_set_size, NULL, NULL, NULL);
4cf1b76b HT	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);
a3590dac DB	249	object_property_add_enum(obj, "policy", "HostMemPolicy",
	250	HostMemPolicy_lookup,
	251	host_memory_backend_get_policy,
	252	host_memory_backend_set_policy, NULL);
1f070489 IM	253	}
1f070489 IM	254
1f070489 IM	255	MemoryRegion *
	256	host_memory_backend_get_memory(HostMemoryBackend backend, Error *errp)
	257	{
	258	return memory_region_size(&backend->mr) ? &backend->mr : NULL;
	259	}
	260
bd9262d9 HT	261	static void
	262	host_memory_backend_memory_complete(UserCreatable uc, Error *errp)
	263	{
	264	HostMemoryBackend *backend = MEMORY_BACKEND(uc);
	265	HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
605d0a94 PB	266	Error *local_err = NULL;
	267	void *ptr;
	268	uint64_t sz;
bd9262d9 HT	269
bd9262d9 HT	270	if (bc->alloc) {
605d0a94 PB	271	bc->alloc(backend, &local_err);
	272	if (local_err) {
	273	error_propagate(errp, local_err);
	274	return;
	275	}
	276
	277	ptr = memory_region_get_ram_ptr(&backend->mr);
	278	sz = memory_region_size(&backend->mr);
	279
	280	if (backend->merge) {
	281	qemu_madvise(ptr, sz, QEMU_MADV_MERGEABLE);
	282	}
	283	if (!backend->dump) {
	284	qemu_madvise(ptr, sz, QEMU_MADV_DONTDUMP);
	285	}
4cf1b76b HT	286	#ifdef CONFIG_NUMA
	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. */
288d3322	293	unsigned flags = MPOL_MF_STRICT \| MPOL_MF_MOVE;
4cf1b76b HT	294
	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"
	300	" than default");
	301	return;
	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]);
	305	return;
	306	}
	307
	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.
	312	*/
	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)) {
a3567ba1 PF	318	if (backend->policy != MPOL_DEFAULT \|\| errno != ENOSYS) {
	319	error_setg_errno(errp, errno,
	320	"cannot bind memory to host NUMA nodes");
	321	return;
	322	}
4cf1b76b HT	323	}
	324	#endif
	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.
	328	*/
a35ba7be PB	329	if (backend->prealloc) {
	330	os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz);
	331	}
bd9262d9 HT	332	}
	333	}
	334
36bce5ca LM	335	static bool
	336	host_memory_backend_can_be_deleted(UserCreatable uc, Error *errp)
	337	{
	338	MemoryRegion *mr;
	339
	340	mr = host_memory_backend_get_memory(MEMORY_BACKEND(uc), errp);
	341	if (memory_region_is_mapped(mr)) {
	342	return false;
	343	} else {
	344	return true;
	345	}
	346	}
	347
bd9262d9 HT	348	static void
	349	host_memory_backend_class_init(ObjectClass oc, void data)
	350	{
	351	UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
	352
	353	ucc->complete = host_memory_backend_memory_complete;
36bce5ca	354	ucc->can_be_deleted = host_memory_backend_can_be_deleted;
bd9262d9 HT	355	}
bd9262d9 HT	356
58f4662c	357	static const TypeInfo host_memory_backend_info = {
1f070489 IM	358	.name = TYPE_MEMORY_BACKEND,
	359	.parent = TYPE_OBJECT,
	360	.abstract = true,
	361	.class_size = sizeof(HostMemoryBackendClass),
bd9262d9	362	.class_init = host_memory_backend_class_init,
1f070489	363	.instance_size = sizeof(HostMemoryBackend),
58f4662c	364	.instance_init = host_memory_backend_init,
1f070489 IM	365	.interfaces = (InterfaceInfo[]) {
	366	{ TYPE_USER_CREATABLE },
	367	{ }
	368	}
	369	};
	370
	371	static void register_types(void)
	372	{
58f4662c	373	type_register_static(&host_memory_backend_info);
1f070489 IM	374	}
	375
	376	type_init(register_types);