target/ppc: Detect erroneous condition in interrupt delivery
[qemu/ar7.git] / backends / rng-egd.c
blobd2b9ce6cbf1089c555acb1879409a1d2b57a4672
1 /*
2 * QEMU Random Number Generator Backend
4 * Copyright IBM, Corp. 2012
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
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.
13 #include "qemu/osdep.h"
14 #include "sysemu/rng.h"
15 #include "chardev/char-fe.h"
16 #include "qapi/error.h"
17 #include "qapi/qmp/qerror.h"
19 #define TYPE_RNG_EGD "rng-egd"
20 #define RNG_EGD(obj) OBJECT_CHECK(RngEgd, (obj), TYPE_RNG_EGD)
22 typedef struct RngEgd
24 RngBackend parent;
26 CharBackend chr;
27 char *chr_name;
28 } RngEgd;
30 static void rng_egd_request_entropy(RngBackend *b, RngRequest *req)
32 RngEgd *s = RNG_EGD(b);
33 size_t size = req->size;
35 while (size > 0) {
36 uint8_t header[2];
37 uint8_t len = MIN(size, 255);
39 /* synchronous entropy request */
40 header[0] = 0x02;
41 header[1] = len;
43 /* XXX this blocks entire thread. Rewrite to use
44 * qemu_chr_fe_write and background I/O callbacks */
45 qemu_chr_fe_write_all(&s->chr, header, sizeof(header));
47 size -= len;
51 static int rng_egd_chr_can_read(void *opaque)
53 RngEgd *s = RNG_EGD(opaque);
54 RngRequest *req;
55 int size = 0;
57 QSIMPLEQ_FOREACH(req, &s->parent.requests, next) {
58 size += req->size - req->offset;
61 return size;
64 static void rng_egd_chr_read(void *opaque, const uint8_t *buf, int size)
66 RngEgd *s = RNG_EGD(opaque);
67 size_t buf_offset = 0;
69 while (size > 0 && !QSIMPLEQ_EMPTY(&s->parent.requests)) {
70 RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);
71 int len = MIN(size, req->size - req->offset);
73 memcpy(req->data + req->offset, buf + buf_offset, len);
74 buf_offset += len;
75 req->offset += len;
76 size -= len;
78 if (req->offset == req->size) {
79 req->receive_entropy(req->opaque, req->data, req->size);
81 rng_backend_finalize_request(&s->parent, req);
86 static void rng_egd_opened(RngBackend *b, Error **errp)
88 RngEgd *s = RNG_EGD(b);
89 Chardev *chr;
91 if (s->chr_name == NULL) {
92 error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
93 "chardev", "a valid character device");
94 return;
97 chr = qemu_chr_find(s->chr_name);
98 if (chr == NULL) {
99 error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
100 "Device '%s' not found", s->chr_name);
101 return;
103 if (!qemu_chr_fe_init(&s->chr, chr, errp)) {
104 return;
107 /* FIXME we should resubmit pending requests when the CDS reconnects. */
108 qemu_chr_fe_set_handlers(&s->chr, rng_egd_chr_can_read,
109 rng_egd_chr_read, NULL, NULL, s, NULL, true);
112 static void rng_egd_set_chardev(Object *obj, const char *value, Error **errp)
114 RngBackend *b = RNG_BACKEND(obj);
115 RngEgd *s = RNG_EGD(b);
117 if (b->opened) {
118 error_setg(errp, QERR_PERMISSION_DENIED);
119 } else {
120 g_free(s->chr_name);
121 s->chr_name = g_strdup(value);
125 static char *rng_egd_get_chardev(Object *obj, Error **errp)
127 RngEgd *s = RNG_EGD(obj);
128 Chardev *chr = qemu_chr_fe_get_driver(&s->chr);
130 if (chr && chr->label) {
131 return g_strdup(chr->label);
134 return NULL;
137 static void rng_egd_init(Object *obj)
139 object_property_add_str(obj, "chardev",
140 rng_egd_get_chardev, rng_egd_set_chardev,
141 NULL);
144 static void rng_egd_finalize(Object *obj)
146 RngEgd *s = RNG_EGD(obj);
148 qemu_chr_fe_deinit(&s->chr, false);
149 g_free(s->chr_name);
152 static void rng_egd_class_init(ObjectClass *klass, void *data)
154 RngBackendClass *rbc = RNG_BACKEND_CLASS(klass);
156 rbc->request_entropy = rng_egd_request_entropy;
157 rbc->opened = rng_egd_opened;
160 static const TypeInfo rng_egd_info = {
161 .name = TYPE_RNG_EGD,
162 .parent = TYPE_RNG_BACKEND,
163 .instance_size = sizeof(RngEgd),
164 .class_init = rng_egd_class_init,
165 .instance_init = rng_egd_init,
166 .instance_finalize = rng_egd_finalize,
169 static void register_types(void)
171 type_register_static(&rng_egd_info);
174 type_init(register_types);