[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/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 uint16List **host_memory_append_node(uint16List **node,
                                            unsigned long value)
{
     *node = g_malloc0(sizeof(**node));
     (*node)->value = value;
     return &(*node)->next;
}

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);

    node = host_memory_append_node(node, value);

    if (value == MAX_NODES) {
        goto out;
    }

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

        node = host_memory_append_node(node, value);
    } while (true);

out:
    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)
{
    Error *local_err = NULL;
    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, &local_err);
        if (local_err) {
            error_propagate(errp, local_err);
            return;
        }
        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;
}

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

void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
{
    backend->is_mapped = mapped;
}

bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
{
    return backend->is_mapped;
}

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) {
            goto out;
        }

        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,
                            &local_err);
            if (local_err) {
                goto out;
            }
        }
    }
out:
    error_propagate(errp, local_err);
}

static bool
host_memory_backend_can_be_deleted(UserCreatable *uc, Error **errp)
{
    if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
        return false;
    } else {
        return true;
    }
}

static char *get_id(Object *o, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(o);

    return g_strdup(backend->id);
}

static void set_id(Object *o, const char *str, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(o);

    if (backend->id) {
        error_setg(errp, "cannot change property value");
        return;
    }
    backend->id = g_strdup(str);
}

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;

    object_class_property_add_bool(oc, "merge",
        host_memory_backend_get_merge,
        host_memory_backend_set_merge, &error_abort);
    object_class_property_add_bool(oc, "dump",
        host_memory_backend_get_dump,
        host_memory_backend_set_dump, &error_abort);
    object_class_property_add_bool(oc, "prealloc",
        host_memory_backend_get_prealloc,
        host_memory_backend_set_prealloc, &error_abort);
    object_class_property_add(oc, "size", "int",
        host_memory_backend_get_size,
        host_memory_backend_set_size,
        NULL, NULL, &error_abort);
    object_class_property_add(oc, "host-nodes", "int",
        host_memory_backend_get_host_nodes,
        host_memory_backend_set_host_nodes,
        NULL, NULL, &error_abort);
    object_class_property_add_enum(oc, "policy", "HostMemPolicy",
        HostMemPolicy_lookup,
        host_memory_backend_get_policy,
        host_memory_backend_set_policy, &error_abort);
    object_class_property_add_str(oc, "id", get_id, set_id, &error_abort);
}

static void host_memory_backend_finalize(Object *o)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(o);
    g_free(backend->id);
}

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,
    .instance_finalize = host_memory_backend_finalize,
    .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"
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
1454d33f XG	67	static uint16List host_memory_append_node(uint16List node,
	68	unsigned long value)
	69	{
	70	node = g_malloc0(sizeof(*node));
	71	(*node)->value = value;
	72	return &(*node)->next;
	73	}
	74
4cf1b76b	75	static void
d7bce999 EB	76	host_memory_backend_get_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	77	void opaque, Error *errp)
4cf1b76b HT	78	{
	79	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	80	uint16List *host_nodes = NULL;
	81	uint16List **node = &host_nodes;
	82	unsigned long value;
	83
	84	value = find_first_bit(backend->host_nodes, MAX_NODES);
1454d33f XG	85
	86	node = host_memory_append_node(node, value);
	87
4cf1b76b	88	if (value == MAX_NODES) {
1454d33f	89	goto out;
4cf1b76b HT	90	}
4cf1b76b HT	91
4cf1b76b HT	92	do {
	93	value = find_next_bit(backend->host_nodes, MAX_NODES, value + 1);
	94	if (value == MAX_NODES) {
	95	break;
	96	}
	97
1454d33f	98	node = host_memory_append_node(node, value);
4cf1b76b HT	99	} while (true);
4cf1b76b HT	100
1454d33f	101	out:
51e72bc1	102	visit_type_uint16List(v, name, &host_nodes, errp);
4cf1b76b HT	103	}
	104
	105	static void
d7bce999 EB	106	host_memory_backend_set_host_nodes(Object obj, Visitor v, const char *name,
d7bce999 EB	107	void opaque, Error *errp)
4cf1b76b HT	108	{
	109	#ifdef CONFIG_NUMA
	110	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	111	uint16List *l = NULL;
	112
51e72bc1	113	visit_type_uint16List(v, name, &l, errp);
4cf1b76b HT	114
	115	while (l) {
	116	bitmap_set(backend->host_nodes, l->value, 1);
	117	l = l->next;
	118	}
	119	#else
	120	error_setg(errp, "NUMA node binding are not supported by this QEMU");
	121	#endif
	122	}
	123
a3590dac DB	124	static int
a3590dac DB	125	host_memory_backend_get_policy(Object obj, Error *errp G_GNUC_UNUSED)
4cf1b76b HT	126	{
4cf1b76b HT	127	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
a3590dac	128	return backend->policy;
4cf1b76b HT	129	}
	130
	131	static void
a3590dac	132	host_memory_backend_set_policy(Object obj, int policy, Error *errp)
4cf1b76b HT	133	{
4cf1b76b HT	134	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
4cf1b76b HT	135	backend->policy = policy;
	136
	137	#ifndef CONFIG_NUMA
	138	if (policy != HOST_MEM_POLICY_DEFAULT) {
	139	error_setg(errp, "NUMA policies are not supported by this QEMU");
	140	}
	141	#endif
	142	}
	143
605d0a94 PB	144	static bool host_memory_backend_get_merge(Object obj, Error *errp)
	145	{
	146	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	147
	148	return backend->merge;
	149	}
	150
	151	static void host_memory_backend_set_merge(Object obj, bool value, Error *errp)
	152	{
	153	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	154
	155	if (!memory_region_size(&backend->mr)) {
	156	backend->merge = value;
	157	return;
	158	}
	159
	160	if (value != backend->merge) {
	161	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	162	uint64_t sz = memory_region_size(&backend->mr);
	163
	164	qemu_madvise(ptr, sz,
	165	value ? QEMU_MADV_MERGEABLE : QEMU_MADV_UNMERGEABLE);
	166	backend->merge = value;
	167	}
	168	}
	169
	170	static bool host_memory_backend_get_dump(Object obj, Error *errp)
	171	{
	172	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	173
	174	return backend->dump;
	175	}
	176
	177	static void host_memory_backend_set_dump(Object obj, bool value, Error *errp)
	178	{
	179	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	180
	181	if (!memory_region_size(&backend->mr)) {
	182	backend->dump = value;
	183	return;
	184	}
	185
	186	if (value != backend->dump) {
	187	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	188	uint64_t sz = memory_region_size(&backend->mr);
	189
	190	qemu_madvise(ptr, sz,
	191	value ? QEMU_MADV_DODUMP : QEMU_MADV_DONTDUMP);
	192	backend->dump = value;
	193	}
	194	}
	195
a35ba7be PB	196	static bool host_memory_backend_get_prealloc(Object obj, Error *errp)
	197	{
	198	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	199
	200	return backend->prealloc \|\| backend->force_prealloc;
	201	}
	202
	203	static void host_memory_backend_set_prealloc(Object *obj, bool value,
	204	Error **errp)
	205	{
056b68af	206	Error *local_err = NULL;
a35ba7be PB	207	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
	208
	209	if (backend->force_prealloc) {
	210	if (value) {
	211	error_setg(errp,
	212	"remove -mem-prealloc to use the prealloc property");
	213	return;
	214	}
	215	}
	216
	217	if (!memory_region_size(&backend->mr)) {
	218	backend->prealloc = value;
	219	return;
	220	}
	221
	222	if (value && !backend->prealloc) {
	223	int fd = memory_region_get_fd(&backend->mr);
	224	void *ptr = memory_region_get_ram_ptr(&backend->mr);
	225	uint64_t sz = memory_region_size(&backend->mr);
	226
056b68af IM	227	os_mem_prealloc(fd, ptr, sz, &local_err);
	228	if (local_err) {
	229	error_propagate(errp, local_err);
	230	return;
	231	}
a35ba7be PB	232	backend->prealloc = true;
	233	}
	234	}
	235
58f4662c	236	static void host_memory_backend_init(Object *obj)
1f070489	237	{
605d0a94	238	HostMemoryBackend *backend = MEMORY_BACKEND(obj);
6b269967	239	MachineState *machine = MACHINE(qdev_get_machine());
605d0a94	240
6b269967 EH	241	backend->merge = machine_mem_merge(machine);
6b269967 EH	242	backend->dump = machine_dump_guest_core(machine);
a35ba7be	243	backend->prealloc = mem_prealloc;
1f070489 IM	244	}
1f070489 IM	245
1f070489 IM	246	MemoryRegion *
	247	host_memory_backend_get_memory(HostMemoryBackend backend, Error *errp)
	248	{
	249	return memory_region_size(&backend->mr) ? &backend->mr : NULL;
	250	}
	251
2aece63c XG	252	void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped)
	253	{
	254	backend->is_mapped = mapped;
	255	}
	256
	257	bool host_memory_backend_is_mapped(HostMemoryBackend *backend)
	258	{
	259	return backend->is_mapped;
	260	}
	261
bd9262d9 HT	262	static void
	263	host_memory_backend_memory_complete(UserCreatable uc, Error *errp)
	264	{
	265	HostMemoryBackend *backend = MEMORY_BACKEND(uc);
	266	HostMemoryBackendClass *bc = MEMORY_BACKEND_GET_CLASS(uc);
605d0a94 PB	267	Error *local_err = NULL;
	268	void *ptr;
	269	uint64_t sz;
bd9262d9 HT	270
bd9262d9 HT	271	if (bc->alloc) {
605d0a94 PB	272	bc->alloc(backend, &local_err);
605d0a94 PB	273	if (local_err) {
056b68af	274	goto out;
605d0a94 PB	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	329	if (backend->prealloc) {
056b68af IM	330	os_mem_prealloc(memory_region_get_fd(&backend->mr), ptr, sz,
	331	&local_err);
	332	if (local_err) {
	333	goto out;
	334	}
a35ba7be	335	}
bd9262d9	336	}
056b68af IM	337	out:
056b68af IM	338	error_propagate(errp, local_err);
bd9262d9 HT	339	}
bd9262d9 HT	340
36bce5ca LM	341	static bool
	342	host_memory_backend_can_be_deleted(UserCreatable uc, Error *errp)
	343	{
2aece63c	344	if (host_memory_backend_is_mapped(MEMORY_BACKEND(uc))) {
36bce5ca LM	345	return false;
	346	} else {
	347	return true;
	348	}
	349	}
	350
e1ff3c67 IM	351	static char get_id(Object o, Error **errp)
	352	{
	353	HostMemoryBackend *backend = MEMORY_BACKEND(o);
	354
	355	return g_strdup(backend->id);
	356	}
	357
	358	static void set_id(Object o, const char str, Error **errp)
	359	{
	360	HostMemoryBackend *backend = MEMORY_BACKEND(o);
	361
	362	if (backend->id) {
	363	error_setg(errp, "cannot change property value");
	364	return;
	365	}
	366	backend->id = g_strdup(str);
	367	}
	368
bd9262d9 HT	369	static void
	370	host_memory_backend_class_init(ObjectClass oc, void data)
	371	{
	372	UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
	373
	374	ucc->complete = host_memory_backend_memory_complete;
36bce5ca	375	ucc->can_be_deleted = host_memory_backend_can_be_deleted;
e62834ca EH	376
	377	object_class_property_add_bool(oc, "merge",
	378	host_memory_backend_get_merge,
	379	host_memory_backend_set_merge, &error_abort);
	380	object_class_property_add_bool(oc, "dump",
	381	host_memory_backend_get_dump,
	382	host_memory_backend_set_dump, &error_abort);
	383	object_class_property_add_bool(oc, "prealloc",
	384	host_memory_backend_get_prealloc,
	385	host_memory_backend_set_prealloc, &error_abort);
	386	object_class_property_add(oc, "size", "int",
	387	host_memory_backend_get_size,
	388	host_memory_backend_set_size,
	389	NULL, NULL, &error_abort);
	390	object_class_property_add(oc, "host-nodes", "int",
	391	host_memory_backend_get_host_nodes,
	392	host_memory_backend_set_host_nodes,
	393	NULL, NULL, &error_abort);
	394	object_class_property_add_enum(oc, "policy", "HostMemPolicy",
	395	HostMemPolicy_lookup,
	396	host_memory_backend_get_policy,
	397	host_memory_backend_set_policy, &error_abort);
e1ff3c67 IM	398	object_class_property_add_str(oc, "id", get_id, set_id, &error_abort);
	399	}
	400
	401	static void host_memory_backend_finalize(Object *o)
	402	{
	403	HostMemoryBackend *backend = MEMORY_BACKEND(o);
	404	g_free(backend->id);
bd9262d9 HT	405	}
bd9262d9 HT	406
58f4662c	407	static const TypeInfo host_memory_backend_info = {
1f070489 IM	408	.name = TYPE_MEMORY_BACKEND,
	409	.parent = TYPE_OBJECT,
	410	.abstract = true,
	411	.class_size = sizeof(HostMemoryBackendClass),
bd9262d9	412	.class_init = host_memory_backend_class_init,
1f070489	413	.instance_size = sizeof(HostMemoryBackend),
58f4662c	414	.instance_init = host_memory_backend_init,
e1ff3c67	415	.instance_finalize = host_memory_backend_finalize,
1f070489 IM	416	.interfaces = (InterfaceInfo[]) {
	417	{ TYPE_USER_CREATABLE },
	418	{ }
	419	}
	420	};
	421
	422	static void register_types(void)
	423	{
58f4662c	424	type_register_static(&host_memory_backend_info);
1f070489 IM	425	}
	426
	427	type_init(register_types);