linux-user, s390x: remove syscall definitions for !TARGET_S390X
[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
21 #define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd"
22
23 #define MEMORY_BACKEND_MEMFD(obj) \
24 OBJECT_CHECK(HostMemoryBackendMemfd, (obj), TYPE_MEMORY_BACKEND_MEMFD)
25
26 typedef struct HostMemoryBackendMemfd HostMemoryBackendMemfd;
27
28 struct HostMemoryBackendMemfd {
29 HostMemoryBackend parent_obj;
30
31 bool hugetlb;
32 uint64_t hugetlbsize;
33 bool seal;
34 };
35
36 static void
37 memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
38 {
39 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(backend);
40 char *name;
41 int fd;
42
43 if (!backend->size) {
44 error_setg(errp, "can't create backend with size 0");
45 return;
46 }
47
48 fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
49 m->hugetlb, m->hugetlbsize, m->seal ?
50 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0,
51 errp);
52 if (fd == -1) {
53 return;
54 }
55
56 name = host_memory_backend_get_name(backend);
57 memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
58 name, backend->size,
59 backend->share, fd, errp);
60 g_free(name);
61 }
62
63 static bool
64 memfd_backend_get_hugetlb(Object *o, Error **errp)
65 {
66 return MEMORY_BACKEND_MEMFD(o)->hugetlb;
67 }
68
69 static void
70 memfd_backend_set_hugetlb(Object *o, bool value, Error **errp)
71 {
72 MEMORY_BACKEND_MEMFD(o)->hugetlb = value;
73 }
74
75 static void
76 memfd_backend_set_hugetlbsize(Object *obj, Visitor *v, const char *name,
77 void *opaque, Error **errp)
78 {
79 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
80 Error *local_err = NULL;
81 uint64_t value;
82
83 if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) {
84 error_setg(&local_err, "cannot change property value");
85 goto out;
86 }
87
88 visit_type_size(v, name, &value, &local_err);
89 if (local_err) {
90 goto out;
91 }
92 if (!value) {
93 error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
94 PRIu64 "'", object_get_typename(obj), name, value);
95 goto out;
96 }
97 m->hugetlbsize = value;
98 out:
99 error_propagate(errp, local_err);
100 }
101
102 static void
103 memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name,
104 void *opaque, Error **errp)
105 {
106 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
107 uint64_t value = m->hugetlbsize;
108
109 visit_type_size(v, name, &value, errp);
110 }
111
112 static bool
113 memfd_backend_get_seal(Object *o, Error **errp)
114 {
115 return MEMORY_BACKEND_MEMFD(o)->seal;
116 }
117
118 static void
119 memfd_backend_set_seal(Object *o, bool value, Error **errp)
120 {
121 MEMORY_BACKEND_MEMFD(o)->seal = value;
122 }
123
124 static void
125 memfd_backend_instance_init(Object *obj)
126 {
127 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
128
129 /* default to sealed file */
130 m->seal = true;
131 MEMORY_BACKEND(m)->share = true;
132 }
133
134 static void
135 memfd_backend_class_init(ObjectClass *oc, void *data)
136 {
137 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
138
139 bc->alloc = memfd_backend_memory_alloc;
140
141 if (qemu_memfd_check(MFD_HUGETLB)) {
142 object_class_property_add_bool(oc, "hugetlb",
143 memfd_backend_get_hugetlb,
144 memfd_backend_set_hugetlb,
145 &error_abort);
146 object_class_property_set_description(oc, "hugetlb",
147 "Use huge pages",
148 &error_abort);
149 object_class_property_add(oc, "hugetlbsize", "int",
150 memfd_backend_get_hugetlbsize,
151 memfd_backend_set_hugetlbsize,
152 NULL, NULL, &error_abort);
153 object_class_property_set_description(oc, "hugetlbsize",
154 "Huge pages size (ex: 2M, 1G)",
155 &error_abort);
156 }
157 object_class_property_add_bool(oc, "seal",
158 memfd_backend_get_seal,
159 memfd_backend_set_seal,
160 &error_abort);
161 object_class_property_set_description(oc, "seal",
162 "Seal growing & shrinking",
163 &error_abort);
164 }
165
166 static const TypeInfo memfd_backend_info = {
167 .name = TYPE_MEMORY_BACKEND_MEMFD,
168 .parent = TYPE_MEMORY_BACKEND,
169 .instance_init = memfd_backend_instance_init,
170 .class_init = memfd_backend_class_init,
171 .instance_size = sizeof(HostMemoryBackendMemfd),
172 };
173
174 static void register_types(void)
175 {
176 if (qemu_memfd_check(MFD_ALLOW_SEALING)) {
177 type_register_static(&memfd_backend_info);
178 }
179 }
180
181 type_init(register_types);