aboutsummaryrefslogtreecommitdiff
path: root/backends/hostmem-file.c
blob: e44c319915acac43183176ce993c515932948dd8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/*
 * QEMU Host Memory Backend for hugetlbfs
 *
 * Copyright (C) 2013-2014 Red Hat Inc
 *
 * Authors:
 *   Paolo Bonzini <pbonzini@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 "qapi/error.h"
#include "qemu-common.h"
#include "sysemu/hostmem.h"
#include "sysemu/sysemu.h"
#include "qom/object_interfaces.h"

/* hostmem-file.c */
/**
 * @TYPE_MEMORY_BACKEND_FILE:
 * name of backend that uses mmap on a file descriptor
 */
#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"

#define MEMORY_BACKEND_FILE(obj) \
    OBJECT_CHECK(HostMemoryBackendFile, (obj), TYPE_MEMORY_BACKEND_FILE)

typedef struct HostMemoryBackendFile HostMemoryBackendFile;

struct HostMemoryBackendFile {
    HostMemoryBackend parent_obj;

    bool share;
    bool discard_data;
    char *mem_path;
};

static void
file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
{
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(backend);

    if (!backend->size) {
        error_setg(errp, "can't create backend with size 0");
        return;
    }
    if (!fb->mem_path) {
        error_setg(errp, "mem-path property not set");
        return;
    }
#ifndef CONFIG_LINUX
    error_setg(errp, "-mem-path not supported on this host");
#else
    if (!host_memory_backend_mr_inited(backend)) {
        gchar *path;
        backend->force_prealloc = mem_prealloc;
        path = object_get_canonical_path(OBJECT(backend));
        memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
                                 path,
                                 backend->size, fb->share,
                                 fb->mem_path, errp);
        g_free(path);
    }
#endif
}

static char *get_mem_path(Object *o, Error **errp)
{
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);

    return g_strdup(fb->mem_path);
}

static void set_mem_path(Object *o, const char *str, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(o);
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);

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

static bool file_memory_backend_get_share(Object *o, Error **errp)
{
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);

    return fb->share;
}

static void file_memory_backend_set_share(Object *o, bool value, Error **errp)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(o);
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);

    if (host_memory_backend_mr_inited(backend)) {
        error_setg(errp, "cannot change property value");
        return;
    }
    fb->share = value;
}

static bool file_memory_backend_get_discard_data(Object *o, Error **errp)
{
    return MEMORY_BACKEND_FILE(o)->discard_data;
}

static void file_memory_backend_set_discard_data(Object *o, bool value,
                                               Error **errp)
{
    MEMORY_BACKEND_FILE(o)->discard_data = value;
}

static void file_backend_unparent(Object *obj)
{
    HostMemoryBackend *backend = MEMORY_BACKEND(obj);
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(obj);

    if (host_memory_backend_mr_inited(backend) && fb->discard_data) {
        void *ptr = memory_region_get_ram_ptr(&backend->mr);
        uint64_t sz = memory_region_size(&backend->mr);

        qemu_madvise(ptr, sz, QEMU_MADV_REMOVE);
    }
}

static void
file_backend_class_init(ObjectClass *oc, void *data)
{
    HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);

    bc->alloc = file_backend_memory_alloc;
    oc->unparent = file_backend_unparent;

    object_class_property_add_bool(oc, "share",
        file_memory_backend_get_share, file_memory_backend_set_share,
        &error_abort);
    object_class_property_add_bool(oc, "discard-data",
        file_memory_backend_get_discard_data, file_memory_backend_set_discard_data,
        &error_abort);
    object_class_property_add_str(oc, "mem-path",
        get_mem_path, set_mem_path,
        &error_abort);
}

static void file_backend_instance_finalize(Object *o)
{
    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);

    g_free(fb->mem_path);
}

static const TypeInfo file_backend_info = {
    .name = TYPE_MEMORY_BACKEND_FILE,
    .parent = TYPE_MEMORY_BACKEND,
    .class_init = file_backend_class_init,
    .instance_finalize = file_backend_instance_finalize,
    .instance_size = sizeof(HostMemoryBackendFile),
};

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

type_init(register_types);