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dbb9e0f4 MAL |
1 | /* |
2 | * QEMU host memfd memory backend | |
3 | * | |
4 | * Copyright (C) 2018 Red Hat Inc | |
5 | * | |
6 | * Authors: | |
7 | * Marc-André Lureau <marcandre.lureau@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 | */ | |
12 | #include "qemu/osdep.h" | |
13 | #include "qemu-common.h" | |
14 | #include "sysemu/hostmem.h" | |
15 | #include "sysemu/sysemu.h" | |
16 | #include "qom/object_interfaces.h" | |
17 | #include "qemu/memfd.h" | |
18 | #include "qapi/error.h" | |
19 | ||
20 | #define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd" | |
21 | ||
22 | #define MEMORY_BACKEND_MEMFD(obj) \ | |
23 | OBJECT_CHECK(HostMemoryBackendMemfd, (obj), TYPE_MEMORY_BACKEND_MEMFD) | |
24 | ||
25 | typedef struct HostMemoryBackendMemfd HostMemoryBackendMemfd; | |
26 | ||
27 | struct HostMemoryBackendMemfd { | |
28 | HostMemoryBackend parent_obj; | |
29 | ||
30 | bool hugetlb; | |
31 | uint64_t hugetlbsize; | |
32 | bool seal; | |
33 | }; | |
34 | ||
35 | static void | |
36 | memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) | |
37 | { | |
38 | HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(backend); | |
39 | char *name; | |
40 | int fd; | |
41 | ||
42 | if (!backend->size) { | |
43 | error_setg(errp, "can't create backend with size 0"); | |
44 | return; | |
45 | } | |
46 | ||
47 | if (host_memory_backend_mr_inited(backend)) { | |
48 | return; | |
49 | } | |
50 | ||
51 | backend->force_prealloc = mem_prealloc; | |
52 | fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size, | |
53 | m->hugetlb, m->hugetlbsize, m->seal ? | |
54 | F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0, | |
55 | errp); | |
56 | if (fd == -1) { | |
57 | return; | |
58 | } | |
59 | ||
60 | name = object_get_canonical_path(OBJECT(backend)); | |
61 | memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), | |
36ea3979 MAL |
62 | name, backend->size, |
63 | backend->share, fd, errp); | |
dbb9e0f4 MAL |
64 | g_free(name); |
65 | } | |
66 | ||
67 | static bool | |
68 | memfd_backend_get_hugetlb(Object *o, Error **errp) | |
69 | { | |
70 | return MEMORY_BACKEND_MEMFD(o)->hugetlb; | |
71 | } | |
72 | ||
73 | static void | |
74 | memfd_backend_set_hugetlb(Object *o, bool value, Error **errp) | |
75 | { | |
76 | MEMORY_BACKEND_MEMFD(o)->hugetlb = value; | |
77 | } | |
78 | ||
79 | static void | |
80 | memfd_backend_set_hugetlbsize(Object *obj, Visitor *v, const char *name, | |
81 | void *opaque, Error **errp) | |
82 | { | |
83 | HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); | |
84 | Error *local_err = NULL; | |
85 | uint64_t value; | |
86 | ||
87 | if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) { | |
88 | error_setg(&local_err, "cannot change property value"); | |
89 | goto out; | |
90 | } | |
91 | ||
92 | visit_type_size(v, name, &value, &local_err); | |
93 | if (local_err) { | |
94 | goto out; | |
95 | } | |
96 | if (!value) { | |
97 | error_setg(&local_err, "Property '%s.%s' doesn't take value '%" | |
98 | PRIu64 "'", object_get_typename(obj), name, value); | |
99 | goto out; | |
100 | } | |
101 | m->hugetlbsize = value; | |
102 | out: | |
103 | error_propagate(errp, local_err); | |
104 | } | |
105 | ||
106 | static void | |
107 | memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name, | |
108 | void *opaque, Error **errp) | |
109 | { | |
110 | HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); | |
111 | uint64_t value = m->hugetlbsize; | |
112 | ||
113 | visit_type_size(v, name, &value, errp); | |
114 | } | |
115 | ||
116 | static bool | |
117 | memfd_backend_get_seal(Object *o, Error **errp) | |
118 | { | |
119 | return MEMORY_BACKEND_MEMFD(o)->seal; | |
120 | } | |
121 | ||
122 | static void | |
123 | memfd_backend_set_seal(Object *o, bool value, Error **errp) | |
124 | { | |
125 | MEMORY_BACKEND_MEMFD(o)->seal = value; | |
126 | } | |
127 | ||
128 | static void | |
129 | memfd_backend_instance_init(Object *obj) | |
130 | { | |
131 | HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj); | |
132 | ||
133 | /* default to sealed file */ | |
134 | m->seal = true; | |
36ea3979 | 135 | MEMORY_BACKEND(m)->share = true; |
dbb9e0f4 MAL |
136 | } |
137 | ||
138 | static void | |
139 | memfd_backend_class_init(ObjectClass *oc, void *data) | |
140 | { | |
141 | HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc); | |
142 | ||
143 | bc->alloc = memfd_backend_memory_alloc; | |
144 | ||
38296400 MAL |
145 | if (qemu_memfd_check(MFD_HUGETLB)) { |
146 | object_class_property_add_bool(oc, "hugetlb", | |
147 | memfd_backend_get_hugetlb, | |
148 | memfd_backend_set_hugetlb, | |
149 | &error_abort); | |
033bfc5e MAL |
150 | object_class_property_set_description(oc, "hugetlb", |
151 | "Use huge pages", | |
152 | &error_abort); | |
38296400 MAL |
153 | object_class_property_add(oc, "hugetlbsize", "int", |
154 | memfd_backend_get_hugetlbsize, | |
155 | memfd_backend_set_hugetlbsize, | |
156 | NULL, NULL, &error_abort); | |
033bfc5e MAL |
157 | object_class_property_set_description(oc, "hugetlbsize", |
158 | "Huge pages size (ex: 2M, 1G)", | |
159 | &error_abort); | |
38296400 MAL |
160 | } |
161 | if (qemu_memfd_check(MFD_ALLOW_SEALING)) { | |
162 | object_class_property_add_bool(oc, "seal", | |
163 | memfd_backend_get_seal, | |
164 | memfd_backend_set_seal, | |
165 | &error_abort); | |
033bfc5e MAL |
166 | object_class_property_set_description(oc, "seal", |
167 | "Seal growing & shrinking", | |
168 | &error_abort); | |
38296400 | 169 | } |
dbb9e0f4 MAL |
170 | } |
171 | ||
172 | static const TypeInfo memfd_backend_info = { | |
173 | .name = TYPE_MEMORY_BACKEND_MEMFD, | |
174 | .parent = TYPE_MEMORY_BACKEND, | |
175 | .instance_init = memfd_backend_instance_init, | |
176 | .class_init = memfd_backend_class_init, | |
177 | .instance_size = sizeof(HostMemoryBackendMemfd), | |
178 | }; | |
179 | ||
180 | static void register_types(void) | |
181 | { | |
38296400 MAL |
182 | if (qemu_memfd_check(0)) { |
183 | type_register_static(&memfd_backend_info); | |
184 | } | |
dbb9e0f4 MAL |
185 | } |
186 | ||
187 | type_init(register_types); |