Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' 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 "qom/object_interfaces.h"
16 #include "qemu/memfd.h"
17 #include "qemu/module.h"
18 #include "qapi/error.h"
19 #include "qom/object.h"
20
21 #define TYPE_MEMORY_BACKEND_MEMFD "memory-backend-memfd"
22
23 OBJECT_DECLARE_SIMPLE_TYPE(HostMemoryBackendMemfd, MEMORY_BACKEND_MEMFD)
24
25
26 struct HostMemoryBackendMemfd {
27 HostMemoryBackend parent_obj;
28
29 bool hugetlb;
30 uint64_t hugetlbsize;
31 bool seal;
32 };
33
34 static void
35 memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
36 {
37 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(backend);
38 uint32_t ram_flags;
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 ram_flags = backend->share ? RAM_SHARED : 0;
57 ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
58 memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), name,
59 backend->size, ram_flags, fd, 0, 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 uint64_t value;
81
82 if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) {
83 error_setg(errp, "cannot change property value");
84 return;
85 }
86
87 if (!visit_type_size(v, name, &value, errp)) {
88 return;
89 }
90 if (!value) {
91 error_setg(errp, "Property '%s.%s' doesn't take value '%" PRIu64 "'",
92 object_get_typename(obj), name, value);
93 return;
94 }
95 m->hugetlbsize = value;
96 }
97
98 static void
99 memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name,
100 void *opaque, Error **errp)
101 {
102 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
103 uint64_t value = m->hugetlbsize;
104
105 visit_type_size(v, name, &value, errp);
106 }
107
108 static bool
109 memfd_backend_get_seal(Object *o, Error **errp)
110 {
111 return MEMORY_BACKEND_MEMFD(o)->seal;
112 }
113
114 static void
115 memfd_backend_set_seal(Object *o, bool value, Error **errp)
116 {
117 MEMORY_BACKEND_MEMFD(o)->seal = value;
118 }
119
120 static void
121 memfd_backend_instance_init(Object *obj)
122 {
123 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
124
125 /* default to sealed file */
126 m->seal = true;
127 MEMORY_BACKEND(m)->share = true;
128 }
129
130 static void
131 memfd_backend_class_init(ObjectClass *oc, void *data)
132 {
133 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
134
135 bc->alloc = memfd_backend_memory_alloc;
136
137 if (qemu_memfd_check(MFD_HUGETLB)) {
138 object_class_property_add_bool(oc, "hugetlb",
139 memfd_backend_get_hugetlb,
140 memfd_backend_set_hugetlb);
141 object_class_property_set_description(oc, "hugetlb",
142 "Use huge pages");
143 object_class_property_add(oc, "hugetlbsize", "int",
144 memfd_backend_get_hugetlbsize,
145 memfd_backend_set_hugetlbsize,
146 NULL, NULL);
147 object_class_property_set_description(oc, "hugetlbsize",
148 "Huge pages size (ex: 2M, 1G)");
149 }
150 object_class_property_add_bool(oc, "seal",
151 memfd_backend_get_seal,
152 memfd_backend_set_seal);
153 object_class_property_set_description(oc, "seal",
154 "Seal growing & shrinking");
155 }
156
157 static const TypeInfo memfd_backend_info = {
158 .name = TYPE_MEMORY_BACKEND_MEMFD,
159 .parent = TYPE_MEMORY_BACKEND,
160 .instance_init = memfd_backend_instance_init,
161 .class_init = memfd_backend_class_init,
162 .instance_size = sizeof(HostMemoryBackendMemfd),
163 };
164
165 static void register_types(void)
166 {
167 if (qemu_memfd_check(MFD_ALLOW_SEALING)) {
168 type_register_static(&memfd_backend_info);
169 }
170 }
171
172 type_init(register_types);