accel: move qtest CpusAccel functions to a common location
[qemu.git] / include / sysemu / rng.h
1 /*
2 * QEMU Random Number Generator Backend
3 *
4 * Copyright IBM, Corp. 2012
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.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 #ifndef QEMU_RNG_H
14 #define QEMU_RNG_H
15
16 #include "qemu/queue.h"
17 #include "qom/object.h"
18
19 #define TYPE_RNG_BACKEND "rng-backend"
20 OBJECT_DECLARE_TYPE(RngBackend, RngBackendClass,
21 RNG_BACKEND)
22
23 #define TYPE_RNG_BUILTIN "rng-builtin"
24
25 typedef struct RngRequest RngRequest;
26
27 typedef void (EntropyReceiveFunc)(void *opaque,
28 const void *data,
29 size_t size);
30
31 struct RngRequest
32 {
33 EntropyReceiveFunc *receive_entropy;
34 uint8_t *data;
35 void *opaque;
36 size_t offset;
37 size_t size;
38 QSIMPLEQ_ENTRY(RngRequest) next;
39 };
40
41 struct RngBackendClass
42 {
43 ObjectClass parent_class;
44
45 void (*request_entropy)(RngBackend *s, RngRequest *req);
46
47 void (*opened)(RngBackend *s, Error **errp);
48 };
49
50 struct RngBackend
51 {
52 Object parent;
53
54 /*< protected >*/
55 bool opened;
56 QSIMPLEQ_HEAD(, RngRequest) requests;
57 };
58
59
60 /**
61 * rng_backend_request_entropy:
62 * @s: the backend to request entropy from
63 * @size: the number of bytes of data to request
64 * @receive_entropy: a function to be invoked when entropy is available
65 * @opaque: data that should be passed to @receive_entropy
66 *
67 * This function is used by the front-end to request entropy from an entropy
68 * source. This function can be called multiple times before @receive_entropy
69 * is invoked with different values of @receive_entropy and @opaque. The
70 * backend will queue each request and handle appropriately.
71 *
72 * The backend does not need to pass the full amount of data to @receive_entropy
73 * but will pass a value greater than 0.
74 */
75 void rng_backend_request_entropy(RngBackend *s, size_t size,
76 EntropyReceiveFunc *receive_entropy,
77 void *opaque);
78
79 /**
80 * rng_backend_free_request:
81 * @s: the backend that created the request
82 * @req: the request to finalize
83 *
84 * Used by child rng backend classes to finalize requests once they've been
85 * processed. The request is removed from the list of active requests and
86 * deleted.
87 */
88 void rng_backend_finalize_request(RngBackend *s, RngRequest *req);
89 #endif