1/*
2 * QEMU Builtin Random Number Generator Backend
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
5 * See the COPYING file in the top-level directory.
6 */
7
8#include "qemu/osdep.h"
9#include "sysemu/rng.h"
10#include "qemu/main-loop.h"
11#include "qemu/guest-random.h"
12
13#define RNG_BUILTIN(obj) OBJECT_CHECK(RngBuiltin, (obj), TYPE_RNG_BUILTIN)
14
15typedef struct RngBuiltin {
16 RngBackend parent;
17 QEMUBH *bh;
18} RngBuiltin;
19
20static void rng_builtin_receive_entropy_bh(void *opaque)
21{
22 RngBuiltin *s = opaque;
23
24 while (!QSIMPLEQ_EMPTY(&s->parent.requests)) {
25 RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);
26
27 qemu_guest_getrandom_nofail(req->data, req->size);
28
29 req->receive_entropy(req->opaque, req->data, req->size);
30
31 rng_backend_finalize_request(&s->parent, req);
32 }
33}
34
35static void rng_builtin_request_entropy(RngBackend *b, RngRequest *req)
36{
37 RngBuiltin *s = RNG_BUILTIN(b);
38
39 qemu_bh_schedule(s->bh);
40}
41
42static void rng_builtin_init(Object *obj)
43{
44 RngBuiltin *s = RNG_BUILTIN(obj);
45
46 s->bh = qemu_bh_new(rng_builtin_receive_entropy_bh, s);
47}
48
49static void rng_builtin_finalize(Object *obj)
50{
51 RngBuiltin *s = RNG_BUILTIN(obj);
52
53 qemu_bh_delete(s->bh);
54}
55
56static void rng_builtin_class_init(ObjectClass *klass, void *data)
57{
58 RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
59
60 rbc->request_entropy = rng_builtin_request_entropy;
61}
62
63static const TypeInfo rng_builtin_info = {
64 .name = TYPE_RNG_BUILTIN,
65 .parent = TYPE_RNG_BACKEND,
66 .instance_size = sizeof(RngBuiltin),
67 .instance_init = rng_builtin_init,
68 .instance_finalize = rng_builtin_finalize,
69 .class_init = rng_builtin_class_init,
70};
71
72static void register_types(void)
73{
74 type_register_static(&rng_builtin_info);
75}
76
77type_init(register_types);
78