Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu.git] / backends / hostmem-memfd.c
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
13 #include "qemu/osdep.h"
14 #include "sysemu/hostmem.h"
15 #include "sysemu/sysemu.h"
16 #include "qom/object_interfaces.h"
17 #include "qemu/memfd.h"
18 #include "qemu/module.h"
19 #include "qapi/error.h"
20 #include "qom/object.h"
21
22 #define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd"
23
24 OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendMemfd, MEMORY_BACKEND_MEMFD)
25
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 fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
48 m->hugetlb, m->hugetlbsize, m->seal ?
49 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0,
50 errp);
51 if (fd == -1) {
52 return;
53 }
54
55 name = host_memory_backend_get_name(backend);
56 memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
57 name, backend->size,
58 backend->share, fd, errp);
59 g_free(name);
60 }
61
62 static bool
63 memfd_backend_get_hugetlb(Object *o, Error **errp)
64 {
65 return MEMORY_BACKEND_MEMFD(o)->hugetlb;
66 }
67
68 static void
69 memfd_backend_set_hugetlb(Object *o, bool value, Error **errp)
70 {
71 MEMORY_BACKEND_MEMFD(o)->hugetlb = value;
72 }
73
74 static void
75 memfd_backend_set_hugetlbsize(Object *obj, Visitor *v, const char *name,
76 void *opaque, Error **errp)
77 {
78 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
79 uint64_t value;
80
81 if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) {
82 error_setg(errp, "cannot change property value");
83 return;
84 }
85
86 if (!visit_type_size(v, name, &value, errp)) {
87 return;
88 }
89 if (!value) {
90 error_setg(errp, "Property '%s.%s' doesn't take value '%" PRIu64 "'",
91 object_get_typename(obj), name, value);
92 return;
93 }
94 m->hugetlbsize = value;
95 }
96
97 static void
98 memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name,
99 void *opaque, Error **errp)
100 {
101 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
102 uint64_t value = m->hugetlbsize;
103
104 visit_type_size(v, name, &value, errp);
105 }
106
107 static bool
108 memfd_backend_get_seal(Object *o, Error **errp)
109 {
110 return MEMORY_BACKEND_MEMFD(o)->seal;
111 }
112
113 static void
114 memfd_backend_set_seal(Object *o, bool value, Error **errp)
115 {
116 MEMORY_BACKEND_MEMFD(o)->seal = value;
117 }
118
119 static void
120 memfd_backend_instance_init(Object *obj)
121 {
122 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
123
124 /* default to sealed file */
125 m->seal = true;
126 MEMORY_BACKEND(m)->share = true;
127 }
128
129 static void
130 memfd_backend_class_init(ObjectClass *oc, void *data)
131 {
132 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
133
134 bc->alloc = memfd_backend_memory_alloc;
135
136 if (qemu_memfd_check(MFD_HUGETLB)) {
137 object_class_property_add_bool(oc, "hugetlb",
138 memfd_backend_get_hugetlb,
139 memfd_backend_set_hugetlb);
140 object_class_property_set_description(oc, "hugetlb",
141 "Use huge pages");
142 object_class_property_add(oc, "hugetlbsize", "int",
143 memfd_backend_get_hugetlbsize,
144 memfd_backend_set_hugetlbsize,
145 NULL, NULL);
146 object_class_property_set_description(oc, "hugetlbsize",
147 "Huge pages size (ex: 2M, 1G)");
148 }
149 object_class_property_add_bool(oc, "seal",
150 memfd_backend_get_seal,
151 memfd_backend_set_seal);
152 object_class_property_set_description(oc, "seal",
153 "Seal growing & shrinking");
154 }
155
156 static const TypeInfo memfd_backend_info = {
157 .name = TYPE_MEMORY_BACKEND_MEMFD,
158 .parent = TYPE_MEMORY_BACKEND,
159 .instance_init = memfd_backend_instance_init,
160 .class_init = memfd_backend_class_init,
161 .instance_size = sizeof(HostMemoryBackendMemfd),
162 };
163
164 static void register_types(void)
165 {
166 if (qemu_memfd_check(MFD_ALLOW_SEALING)) {
167 type_register_static(&memfd_backend_info);
168 }
169 }
170
171 type_init(register_types);