]>
Commit | Line | Data |
---|---|---|
16c915ba AS |
1 | /* |
2 | * A virtio device implementing a hardware random number generator. | |
3 | * | |
4 | * Copyright 2012 Red Hat, Inc. | |
5 | * Copyright 2012 Amit Shah <amit.shah@redhat.com> | |
6 | * | |
7 | * This work is licensed under the terms of the GNU GPL, version 2 or | |
8 | * (at your option) any later version. See the COPYING file in the | |
9 | * top-level directory. | |
10 | */ | |
11 | ||
1de7afc9 | 12 | #include "qemu/iov.h" |
83c9f4ca | 13 | #include "hw/qdev.h" |
b4a42f81 | 14 | #include "qapi/qmp/qerror.h" |
0d09e41a PB |
15 | #include "hw/virtio/virtio.h" |
16 | #include "hw/virtio/virtio-rng.h" | |
dccfcd0e | 17 | #include "sysemu/rng.h" |
57d3e1b3 | 18 | #include "qom/object_interfaces.h" |
16c915ba | 19 | |
16c915ba AS |
20 | static bool is_guest_ready(VirtIORNG *vrng) |
21 | { | |
611aa333 | 22 | VirtIODevice *vdev = VIRTIO_DEVICE(vrng); |
16c915ba | 23 | if (virtio_queue_ready(vrng->vq) |
611aa333 | 24 | && (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) { |
16c915ba AS |
25 | return true; |
26 | } | |
27 | return false; | |
28 | } | |
29 | ||
e1f7b481 | 30 | static size_t get_request_size(VirtQueue *vq, unsigned quota) |
16c915ba | 31 | { |
14417039 | 32 | unsigned int in, out; |
16c915ba | 33 | |
e1f7b481 | 34 | virtqueue_get_avail_bytes(vq, &in, &out, quota, 0); |
14417039 | 35 | return in; |
16c915ba AS |
36 | } |
37 | ||
904d6f58 AL |
38 | static void virtio_rng_process(VirtIORNG *vrng); |
39 | ||
16c915ba AS |
40 | /* Send data from a char device over to the guest */ |
41 | static void chr_read(void *opaque, const void *buf, size_t size) | |
42 | { | |
43 | VirtIORNG *vrng = opaque; | |
611aa333 | 44 | VirtIODevice *vdev = VIRTIO_DEVICE(vrng); |
14417039 | 45 | VirtQueueElement elem; |
16c915ba AS |
46 | size_t len; |
47 | int offset; | |
48 | ||
49 | if (!is_guest_ready(vrng)) { | |
50 | return; | |
51 | } | |
52 | ||
904d6f58 AL |
53 | vrng->quota_remaining -= size; |
54 | ||
16c915ba AS |
55 | offset = 0; |
56 | while (offset < size) { | |
14417039 | 57 | if (!virtqueue_pop(vrng->vq, &elem)) { |
16c915ba AS |
58 | break; |
59 | } | |
14417039 | 60 | len = iov_from_buf(elem.in_sg, elem.in_num, |
16c915ba AS |
61 | 0, buf + offset, size - offset); |
62 | offset += len; | |
63 | ||
14417039 | 64 | virtqueue_push(vrng->vq, &elem, len); |
16c915ba | 65 | } |
611aa333 | 66 | virtio_notify(vdev, vrng->vq); |
16c915ba AS |
67 | } |
68 | ||
904d6f58 | 69 | static void virtio_rng_process(VirtIORNG *vrng) |
16c915ba | 70 | { |
14417039 | 71 | size_t size; |
e1f7b481 | 72 | unsigned quota; |
904d6f58 AL |
73 | |
74 | if (!is_guest_ready(vrng)) { | |
75 | return; | |
76 | } | |
16c915ba | 77 | |
e1f7b481 MT |
78 | if (vrng->quota_remaining < 0) { |
79 | quota = 0; | |
80 | } else { | |
81 | quota = MIN((uint64_t)vrng->quota_remaining, (uint64_t)UINT32_MAX); | |
82 | } | |
83 | size = get_request_size(vrng->vq, quota); | |
904d6f58 | 84 | size = MIN(vrng->quota_remaining, size); |
14417039 | 85 | if (size) { |
16c915ba AS |
86 | rng_backend_request_entropy(vrng->rng, size, chr_read, vrng); |
87 | } | |
88 | } | |
89 | ||
904d6f58 AL |
90 | static void handle_input(VirtIODevice *vdev, VirtQueue *vq) |
91 | { | |
611aa333 | 92 | VirtIORNG *vrng = VIRTIO_RNG(vdev); |
904d6f58 AL |
93 | virtio_rng_process(vrng); |
94 | } | |
95 | ||
16c915ba AS |
96 | static uint32_t get_features(VirtIODevice *vdev, uint32_t f) |
97 | { | |
98 | return f; | |
99 | } | |
100 | ||
101 | static void virtio_rng_save(QEMUFile *f, void *opaque) | |
102 | { | |
611aa333 | 103 | VirtIODevice *vdev = opaque; |
16c915ba | 104 | |
611aa333 | 105 | virtio_save(vdev, f); |
16c915ba AS |
106 | } |
107 | ||
108 | static int virtio_rng_load(QEMUFile *f, void *opaque, int version_id) | |
109 | { | |
110 | VirtIORNG *vrng = opaque; | |
611aa333 | 111 | VirtIODevice *vdev = VIRTIO_DEVICE(vrng); |
16c915ba AS |
112 | |
113 | if (version_id != 1) { | |
114 | return -EINVAL; | |
115 | } | |
611aa333 | 116 | virtio_load(vdev, f); |
16c915ba | 117 | |
904d6f58 | 118 | /* We may have an element ready but couldn't process it due to a quota |
42015c9a AS |
119 | * limit. Make sure to try again after live migration when the quota may |
120 | * have been reset. | |
121 | */ | |
904d6f58 AL |
122 | virtio_rng_process(vrng); |
123 | ||
16c915ba AS |
124 | return 0; |
125 | } | |
126 | ||
904d6f58 AL |
127 | static void check_rate_limit(void *opaque) |
128 | { | |
611aa333 | 129 | VirtIORNG *vrng = opaque; |
904d6f58 | 130 | |
611aa333 FK |
131 | vrng->quota_remaining = vrng->conf.max_bytes; |
132 | virtio_rng_process(vrng); | |
bc72ad67 AB |
133 | timer_mod(vrng->rate_limit_timer, |
134 | qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vrng->conf.period_ms); | |
904d6f58 AL |
135 | } |
136 | ||
a8d57dfb | 137 | static void virtio_rng_device_realize(DeviceState *dev, Error **errp) |
16c915ba | 138 | { |
a8d57dfb | 139 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
af7671fd | 140 | VirtIORNG *vrng = VIRTIO_RNG(dev); |
16c915ba AS |
141 | Error *local_err = NULL; |
142 | ||
d44bb860 | 143 | if (!vrng->conf.period_ms > 0) { |
a8d57dfb AF |
144 | error_set(errp, QERR_INVALID_PARAMETER_VALUE, "period", |
145 | "a positive number"); | |
146 | return; | |
d44bb860 AK |
147 | } |
148 | ||
46a5a89d FK |
149 | if (vrng->conf.rng == NULL) { |
150 | vrng->conf.default_backend = RNG_RANDOM(object_new(TYPE_RNG_RANDOM)); | |
151 | ||
57d3e1b3 IM |
152 | user_creatable_complete(OBJECT(vrng->conf.default_backend), |
153 | &local_err); | |
154 | if (local_err) { | |
155 | error_propagate(errp, local_err); | |
156 | object_unref(OBJECT(vrng->conf.default_backend)); | |
157 | return; | |
158 | } | |
159 | ||
af7671fd | 160 | object_property_add_child(OBJECT(dev), |
46a5a89d FK |
161 | "default-backend", |
162 | OBJECT(vrng->conf.default_backend), | |
163 | NULL); | |
164 | ||
af7671fd | 165 | object_property_set_link(OBJECT(dev), |
46a5a89d FK |
166 | OBJECT(vrng->conf.default_backend), |
167 | "rng", NULL); | |
6eac8aec | 168 | } |
16c915ba | 169 | |
46a5a89d FK |
170 | virtio_init(vdev, "virtio-rng", VIRTIO_ID_RNG, 0); |
171 | ||
172 | vrng->rng = vrng->conf.rng; | |
16c915ba | 173 | if (vrng->rng == NULL) { |
a8d57dfb AF |
174 | error_set(errp, QERR_INVALID_PARAMETER_VALUE, "rng", "a valid object"); |
175 | return; | |
16c915ba AS |
176 | } |
177 | ||
16c915ba | 178 | vrng->vq = virtio_add_queue(vdev, 8, handle_input); |
6eac8aec | 179 | |
af1a8ad6 FK |
180 | assert(vrng->conf.max_bytes <= INT64_MAX); |
181 | vrng->quota_remaining = vrng->conf.max_bytes; | |
904d6f58 | 182 | |
bc72ad67 | 183 | vrng->rate_limit_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, |
904d6f58 AL |
184 | check_rate_limit, vrng); |
185 | ||
bc72ad67 AB |
186 | timer_mod(vrng->rate_limit_timer, |
187 | qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + vrng->conf.period_ms); | |
904d6f58 | 188 | |
af7671fd | 189 | register_savevm(dev, "virtio-rng", -1, 1, virtio_rng_save, |
16c915ba | 190 | virtio_rng_load, vrng); |
6eac8aec FK |
191 | } |
192 | ||
306ec6c3 | 193 | static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp) |
6eac8aec | 194 | { |
306ec6c3 AF |
195 | VirtIODevice *vdev = VIRTIO_DEVICE(dev); |
196 | VirtIORNG *vrng = VIRTIO_RNG(dev); | |
6eac8aec | 197 | |
bc72ad67 AB |
198 | timer_del(vrng->rate_limit_timer); |
199 | timer_free(vrng->rate_limit_timer); | |
306ec6c3 | 200 | unregister_savevm(dev, "virtio-rng", vrng); |
6a1a8cc7 | 201 | virtio_cleanup(vdev); |
6eac8aec FK |
202 | } |
203 | ||
204 | static Property virtio_rng_properties[] = { | |
205 | DEFINE_VIRTIO_RNG_PROPERTIES(VirtIORNG, conf), | |
206 | DEFINE_PROP_END_OF_LIST(), | |
207 | }; | |
208 | ||
209 | static void virtio_rng_class_init(ObjectClass *klass, void *data) | |
210 | { | |
211 | DeviceClass *dc = DEVICE_CLASS(klass); | |
212 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass); | |
a8d57dfb | 213 | |
6eac8aec | 214 | dc->props = virtio_rng_properties; |
125ee0ed | 215 | set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
a8d57dfb | 216 | vdc->realize = virtio_rng_device_realize; |
306ec6c3 | 217 | vdc->unrealize = virtio_rng_device_unrealize; |
6eac8aec FK |
218 | vdc->get_features = get_features; |
219 | } | |
220 | ||
221 | static void virtio_rng_initfn(Object *obj) | |
222 | { | |
223 | VirtIORNG *vrng = VIRTIO_RNG(obj); | |
224 | ||
225 | object_property_add_link(obj, "rng", TYPE_RNG_BACKEND, | |
9561fda8 | 226 | (Object **)&vrng->conf.rng, |
39f72ef9 | 227 | qdev_prop_allow_set_link_before_realize, |
9561fda8 | 228 | OBJ_PROP_LINK_UNREF_ON_RELEASE, NULL); |
6eac8aec FK |
229 | } |
230 | ||
231 | static const TypeInfo virtio_rng_info = { | |
232 | .name = TYPE_VIRTIO_RNG, | |
233 | .parent = TYPE_VIRTIO_DEVICE, | |
234 | .instance_size = sizeof(VirtIORNG), | |
235 | .instance_init = virtio_rng_initfn, | |
236 | .class_init = virtio_rng_class_init, | |
237 | }; | |
238 | ||
239 | static void virtio_register_types(void) | |
240 | { | |
241 | type_register_static(&virtio_rng_info); | |
242 | } | |
243 | ||
244 | type_init(virtio_register_types) |