hw/arm/raspi: fix CPRMAN base address
[qemu.git] / hw / ppc / spapr_rng.c
1 /*
2 * QEMU sPAPR random number generator "device" for H_RANDOM hypercall
3 *
4 * Copyright 2015 Thomas Huth, Red Hat Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License,
9 * or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21 #include "qapi/error.h"
22 #include "cpu.h"
23 #include "qemu/error-report.h"
24 #include "qemu/main-loop.h"
25 #include "qemu/module.h"
26 #include "sysemu/device_tree.h"
27 #include "sysemu/rng.h"
28 #include "hw/ppc/spapr.h"
29 #include "hw/qdev-properties.h"
30 #include "kvm_ppc.h"
31 #include "qom/object.h"
32
33 OBJECT_DECLARE_SIMPLE_TYPE(SpaprRngState, SPAPR_RNG)
34
35 struct SpaprRngState {
36 /*< private >*/
37 DeviceState ds;
38 RngBackend *backend;
39 bool use_kvm;
40 };
41
42 struct HRandomData {
43 QemuSemaphore sem;
44 union {
45 uint64_t v64;
46 uint8_t v8[8];
47 } val;
48 int received;
49 };
50 typedef struct HRandomData HRandomData;
51
52 /* Callback function for the RngBackend */
53 static void random_recv(void *dest, const void *src, size_t size)
54 {
55 HRandomData *hrdp = dest;
56
57 if (src && size > 0) {
58 assert(size + hrdp->received <= sizeof(hrdp->val.v8));
59 memcpy(&hrdp->val.v8[hrdp->received], src, size);
60 hrdp->received += size;
61 }
62
63 qemu_sem_post(&hrdp->sem);
64 }
65
66 /* Handler for the H_RANDOM hypercall */
67 static target_ulong h_random(PowerPCCPU *cpu, SpaprMachineState *spapr,
68 target_ulong opcode, target_ulong *args)
69 {
70 SpaprRngState *rngstate;
71 HRandomData hrdata;
72
73 rngstate = SPAPR_RNG(object_resolve_path_type("", TYPE_SPAPR_RNG, NULL));
74
75 if (!rngstate || !rngstate->backend) {
76 return H_HARDWARE;
77 }
78
79 qemu_sem_init(&hrdata.sem, 0);
80 hrdata.val.v64 = 0;
81 hrdata.received = 0;
82
83 while (hrdata.received < 8) {
84 rng_backend_request_entropy(rngstate->backend, 8 - hrdata.received,
85 random_recv, &hrdata);
86 qemu_mutex_unlock_iothread();
87 qemu_sem_wait(&hrdata.sem);
88 qemu_mutex_lock_iothread();
89 }
90
91 qemu_sem_destroy(&hrdata.sem);
92 args[0] = hrdata.val.v64;
93
94 return H_SUCCESS;
95 }
96
97 static void spapr_rng_instance_init(Object *obj)
98 {
99 if (object_resolve_path_type("", TYPE_SPAPR_RNG, NULL) != NULL) {
100 error_report("spapr-rng can not be instantiated twice!");
101 return;
102 }
103
104 object_property_set_description(obj, "rng",
105 "ID of the random number generator backend");
106 }
107
108 static void spapr_rng_realize(DeviceState *dev, Error **errp)
109 {
110
111 SpaprRngState *rngstate = SPAPR_RNG(dev);
112
113 if (rngstate->use_kvm) {
114 if (kvmppc_enable_hwrng() == 0) {
115 return;
116 }
117 /*
118 * If user specified both, use-kvm and a backend, we fall back to
119 * the backend now. If not, provide an appropriate error message.
120 */
121 if (!rngstate->backend) {
122 error_setg(errp, "Could not initialize in-kernel H_RANDOM call!");
123 return;
124 }
125 }
126
127 if (rngstate->backend) {
128 spapr_register_hypercall(H_RANDOM, h_random);
129 } else {
130 error_setg(errp, "spapr-rng needs an RNG backend!");
131 }
132 }
133
134 static Property spapr_rng_properties[] = {
135 DEFINE_PROP_BOOL("use-kvm", SpaprRngState, use_kvm, false),
136 DEFINE_PROP_LINK("rng", SpaprRngState, backend, TYPE_RNG_BACKEND,
137 RngBackend *),
138 DEFINE_PROP_END_OF_LIST(),
139 };
140
141 static void spapr_rng_class_init(ObjectClass *oc, void *data)
142 {
143 DeviceClass *dc = DEVICE_CLASS(oc);
144
145 dc->realize = spapr_rng_realize;
146 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
147 device_class_set_props(dc, spapr_rng_properties);
148 dc->hotpluggable = false;
149 }
150
151 static const TypeInfo spapr_rng_info = {
152 .name = TYPE_SPAPR_RNG,
153 .parent = TYPE_DEVICE,
154 .instance_size = sizeof(SpaprRngState),
155 .instance_init = spapr_rng_instance_init,
156 .class_init = spapr_rng_class_init,
157 };
158
159 static void spapr_rng_register_type(void)
160 {
161 type_register_static(&spapr_rng_info);
162 }
163 type_init(spapr_rng_register_type)