Merge remote-tracking branch 'remotes/alistair23/tags/pull-riscv-to-apply-20211022...
[qemu.git] / backends / rng-builtin.c
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 #include "qom/object.h"
13 #include "sysemu/replay.h"
14
15 OBJECT_DECLARE_SIMPLE_TYPE(RngBuiltin, RNG_BUILTIN)
16
17 struct RngBuiltin {
18 RngBackend parent;
19 QEMUBH *bh;
20 };
21
22 static void rng_builtin_receive_entropy_bh(void *opaque)
23 {
24 RngBuiltin *s = opaque;
25
26 while (!QSIMPLEQ_EMPTY(&s->parent.requests)) {
27 RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);
28
29 qemu_guest_getrandom_nofail(req->data, req->size);
30
31 req->receive_entropy(req->opaque, req->data, req->size);
32
33 rng_backend_finalize_request(&s->parent, req);
34 }
35 }
36
37 static void rng_builtin_request_entropy(RngBackend *b, RngRequest *req)
38 {
39 RngBuiltin *s = RNG_BUILTIN(b);
40
41 replay_bh_schedule_event(s->bh);
42 }
43
44 static void rng_builtin_init(Object *obj)
45 {
46 RngBuiltin *s = RNG_BUILTIN(obj);
47
48 s->bh = qemu_bh_new(rng_builtin_receive_entropy_bh, s);
49 }
50
51 static void rng_builtin_finalize(Object *obj)
52 {
53 RngBuiltin *s = RNG_BUILTIN(obj);
54
55 qemu_bh_delete(s->bh);
56 }
57
58 static void rng_builtin_class_init(ObjectClass *klass, void *data)
59 {
60 RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
61
62 rbc->request_entropy = rng_builtin_request_entropy;
63 }
64
65 static const TypeInfo rng_builtin_info = {
66 .name = TYPE_RNG_BUILTIN,
67 .parent = TYPE_RNG_BACKEND,
68 .instance_size = sizeof(RngBuiltin),
69 .instance_init = rng_builtin_init,
70 .instance_finalize = rng_builtin_finalize,
71 .class_init = rng_builtin_class_init,
72 };
73
74 static void register_types(void)
75 {
76 type_register_static(&rng_builtin_info);
77 }
78
79 type_init(register_types);