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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
26typedef struct HostMemoryBackendMemfd HostMemoryBackendMemfd;
27
28struct HostMemoryBackendMemfd {
29 HostMemoryBackend parent_obj;
30
31 bool hugetlb;
32 uint64_t hugetlbsize;
33 bool seal;
34};
35
36static void
37memfd_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 backend->force_prealloc = mem_prealloc;
49 fd = qemu_memfd_create(TYPE_MEMORY_BACKEND_MEMFD, backend->size,
50 m->hugetlb, m->hugetlbsize, m->seal ?
51 F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL : 0,
52 errp);
53 if (fd == -1) {
54 return;
55 }
56
57 name = host_memory_backend_get_name(backend);
58 memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
59 name, backend->size,
60 backend->share, fd, errp);
61 g_free(name);
62}
63
64static bool
65memfd_backend_get_hugetlb(Object *o, Error **errp)
66{
67 return MEMORY_BACKEND_MEMFD(o)->hugetlb;
68}
69
70static void
71memfd_backend_set_hugetlb(Object *o, bool value, Error **errp)
72{
73 MEMORY_BACKEND_MEMFD(o)->hugetlb = value;
74}
75
76static void
77memfd_backend_set_hugetlbsize(Object *obj, Visitor *v, const char *name,
78 void *opaque, Error **errp)
79{
80 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
81 Error *local_err = NULL;
82 uint64_t value;
83
84 if (host_memory_backend_mr_inited(MEMORY_BACKEND(obj))) {
85 error_setg(&local_err, "cannot change property value");
86 goto out;
87 }
88
89 visit_type_size(v, name, &value, &local_err);
90 if (local_err) {
91 goto out;
92 }
93 if (!value) {
94 error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
95 PRIu64 "'", object_get_typename(obj), name, value);
96 goto out;
97 }
98 m->hugetlbsize = value;
99out:
100 error_propagate(errp, local_err);
101}
102
103static void
104memfd_backend_get_hugetlbsize(Object *obj, Visitor *v, const char *name,
105 void *opaque, Error **errp)
106{
107 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
108 uint64_t value = m->hugetlbsize;
109
110 visit_type_size(v, name, &value, errp);
111}
112
113static bool
114memfd_backend_get_seal(Object *o, Error **errp)
115{
116 return MEMORY_BACKEND_MEMFD(o)->seal;
117}
118
119static void
120memfd_backend_set_seal(Object *o, bool value, Error **errp)
121{
122 MEMORY_BACKEND_MEMFD(o)->seal = value;
123}
124
125static void
126memfd_backend_instance_init(Object *obj)
127{
128 HostMemoryBackendMemfd *m = MEMORY_BACKEND_MEMFD(obj);
129
130
131 m->seal = true;
132 MEMORY_BACKEND(m)->share = true;
133}
134
135static void
136memfd_backend_class_init(ObjectClass *oc, void *data)
137{
138 HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
139
140 bc->alloc = memfd_backend_memory_alloc;
141
142 if (qemu_memfd_check(MFD_HUGETLB)) {
143 object_class_property_add_bool(oc, "hugetlb",
144 memfd_backend_get_hugetlb,
145 memfd_backend_set_hugetlb,
146 &error_abort);
147 object_class_property_set_description(oc, "hugetlb",
148 "Use huge pages",
149 &error_abort);
150 object_class_property_add(oc, "hugetlbsize", "int",
151 memfd_backend_get_hugetlbsize,
152 memfd_backend_set_hugetlbsize,
153 NULL, NULL, &error_abort);
154 object_class_property_set_description(oc, "hugetlbsize",
155 "Huge pages size (ex: 2M, 1G)",
156 &error_abort);
157 }
158 object_class_property_add_bool(oc, "seal",
159 memfd_backend_get_seal,
160 memfd_backend_set_seal,
161 &error_abort);
162 object_class_property_set_description(oc, "seal",
163 "Seal growing & shrinking",
164 &error_abort);
165}
166
167static const TypeInfo memfd_backend_info = {
168 .name = TYPE_MEMORY_BACKEND_MEMFD,
169 .parent = TYPE_MEMORY_BACKEND,
170 .instance_init = memfd_backend_instance_init,
171 .class_init = memfd_backend_class_init,
172 .instance_size = sizeof(HostMemoryBackendMemfd),
173};
174
175static void register_types(void)
176{
177 if (qemu_memfd_check(MFD_ALLOW_SEALING)) {
178 type_register_static(&memfd_backend_info);
179 }
180}
181
182type_init(register_types);
183
