1 | /* |
2 | * VirtioBus |
3 | * |
4 | * Copyright (C) 2012 : GreenSocs Ltd |
5 | * http://www.greensocs.com/ , email: info@greensocs.com |
6 | * |
7 | * Developed by : |
8 | * Frederic Konrad <fred.konrad@greensocs.com> |
9 | * |
10 | * This program is free software; you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License as published by |
12 | * the Free Software Foundation, either version 2 of the License, or |
13 | * (at your option) any later version. |
14 | * |
15 | * This program is distributed in the hope that it will be useful, |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
18 | * GNU General Public License for more details. |
19 | * |
20 | * You should have received a copy of the GNU General Public License along |
21 | * with this program; if not, see <http://www.gnu.org/licenses/>. |
22 | * |
23 | */ |
24 | |
25 | #include "qemu/osdep.h" |
26 | #include "qemu/error-report.h" |
27 | #include "qemu/module.h" |
28 | #include "qapi/error.h" |
29 | #include "hw/virtio/virtio-bus.h" |
30 | #include "hw/virtio/virtio.h" |
31 | #include "exec/address-spaces.h" |
32 | |
33 | /* #define DEBUG_VIRTIO_BUS */ |
34 | |
35 | #ifdef DEBUG_VIRTIO_BUS |
36 | #define DPRINTF(fmt, ...) \ |
37 | do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0) |
38 | #else |
39 | #define DPRINTF(fmt, ...) do { } while (0) |
40 | #endif |
41 | |
42 | /* A VirtIODevice is being plugged */ |
43 | void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp) |
44 | { |
45 | DeviceState *qdev = DEVICE(vdev); |
46 | BusState *qbus = BUS(qdev_get_parent_bus(qdev)); |
47 | VirtioBusState *bus = VIRTIO_BUS(qbus); |
48 | VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus); |
49 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); |
50 | bool has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM); |
51 | Error *local_err = NULL; |
52 | |
53 | DPRINTF("%s: plug device.\n" , qbus->name); |
54 | |
55 | if (klass->pre_plugged != NULL) { |
56 | klass->pre_plugged(qbus->parent, &local_err); |
57 | if (local_err) { |
58 | error_propagate(errp, local_err); |
59 | return; |
60 | } |
61 | } |
62 | |
63 | /* Get the features of the plugged device. */ |
64 | assert(vdc->get_features != NULL); |
65 | vdev->host_features = vdc->get_features(vdev, vdev->host_features, |
66 | &local_err); |
67 | if (local_err) { |
68 | error_propagate(errp, local_err); |
69 | return; |
70 | } |
71 | |
72 | if (klass->device_plugged != NULL) { |
73 | klass->device_plugged(qbus->parent, &local_err); |
74 | } |
75 | if (local_err) { |
76 | error_propagate(errp, local_err); |
77 | return; |
78 | } |
79 | |
80 | if (klass->get_dma_as != NULL && has_iommu) { |
81 | virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM); |
82 | vdev->dma_as = klass->get_dma_as(qbus->parent); |
83 | } else { |
84 | vdev->dma_as = &address_space_memory; |
85 | } |
86 | } |
87 | |
88 | /* Reset the virtio_bus */ |
89 | void virtio_bus_reset(VirtioBusState *bus) |
90 | { |
91 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
92 | |
93 | DPRINTF("%s: reset device.\n" , BUS(bus)->name); |
94 | if (vdev != NULL) { |
95 | virtio_reset(vdev); |
96 | } |
97 | } |
98 | |
99 | /* A VirtIODevice is being unplugged */ |
100 | void virtio_bus_device_unplugged(VirtIODevice *vdev) |
101 | { |
102 | DeviceState *qdev = DEVICE(vdev); |
103 | BusState *qbus = BUS(qdev_get_parent_bus(qdev)); |
104 | VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus); |
105 | |
106 | DPRINTF("%s: remove device.\n" , qbus->name); |
107 | |
108 | if (vdev != NULL) { |
109 | if (klass->device_unplugged != NULL) { |
110 | klass->device_unplugged(qbus->parent); |
111 | } |
112 | } |
113 | } |
114 | |
115 | /* Get the device id of the plugged device. */ |
116 | uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus) |
117 | { |
118 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
119 | assert(vdev != NULL); |
120 | return vdev->device_id; |
121 | } |
122 | |
123 | /* Get the config_len field of the plugged device. */ |
124 | size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus) |
125 | { |
126 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
127 | assert(vdev != NULL); |
128 | return vdev->config_len; |
129 | } |
130 | |
131 | /* Get bad features of the plugged device. */ |
132 | uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus) |
133 | { |
134 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
135 | VirtioDeviceClass *k; |
136 | |
137 | assert(vdev != NULL); |
138 | k = VIRTIO_DEVICE_GET_CLASS(vdev); |
139 | if (k->bad_features != NULL) { |
140 | return k->bad_features(vdev); |
141 | } else { |
142 | return 0; |
143 | } |
144 | } |
145 | |
146 | /* Get config of the plugged device. */ |
147 | void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config) |
148 | { |
149 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
150 | VirtioDeviceClass *k; |
151 | |
152 | assert(vdev != NULL); |
153 | k = VIRTIO_DEVICE_GET_CLASS(vdev); |
154 | if (k->get_config != NULL) { |
155 | k->get_config(vdev, config); |
156 | } |
157 | } |
158 | |
159 | /* Set config of the plugged device. */ |
160 | void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config) |
161 | { |
162 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
163 | VirtioDeviceClass *k; |
164 | |
165 | assert(vdev != NULL); |
166 | k = VIRTIO_DEVICE_GET_CLASS(vdev); |
167 | if (k->set_config != NULL) { |
168 | k->set_config(vdev, config); |
169 | } |
170 | } |
171 | |
172 | /* On success, ioeventfd ownership belongs to the caller. */ |
173 | int virtio_bus_grab_ioeventfd(VirtioBusState *bus) |
174 | { |
175 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); |
176 | |
177 | /* vhost can be used even if ioeventfd=off in the proxy device, |
178 | * so do not check k->ioeventfd_enabled. |
179 | */ |
180 | if (!k->ioeventfd_assign) { |
181 | return -ENOSYS; |
182 | } |
183 | |
184 | if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) { |
185 | virtio_bus_stop_ioeventfd(bus); |
186 | /* Remember that we need to restart ioeventfd |
187 | * when ioeventfd_grabbed becomes zero. |
188 | */ |
189 | bus->ioeventfd_started = true; |
190 | } |
191 | bus->ioeventfd_grabbed++; |
192 | return 0; |
193 | } |
194 | |
195 | void virtio_bus_release_ioeventfd(VirtioBusState *bus) |
196 | { |
197 | assert(bus->ioeventfd_grabbed != 0); |
198 | if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) { |
199 | /* Force virtio_bus_start_ioeventfd to act. */ |
200 | bus->ioeventfd_started = false; |
201 | virtio_bus_start_ioeventfd(bus); |
202 | } |
203 | } |
204 | |
205 | int virtio_bus_start_ioeventfd(VirtioBusState *bus) |
206 | { |
207 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); |
208 | DeviceState *proxy = DEVICE(BUS(bus)->parent); |
209 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
210 | VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev); |
211 | int r; |
212 | |
213 | if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) { |
214 | return -ENOSYS; |
215 | } |
216 | if (bus->ioeventfd_started) { |
217 | return 0; |
218 | } |
219 | |
220 | /* Only set our notifier if we have ownership. */ |
221 | if (!bus->ioeventfd_grabbed) { |
222 | r = vdc->start_ioeventfd(vdev); |
223 | if (r < 0) { |
224 | error_report("%s: failed. Fallback to userspace (slower)." , __func__); |
225 | return r; |
226 | } |
227 | } |
228 | bus->ioeventfd_started = true; |
229 | return 0; |
230 | } |
231 | |
232 | void virtio_bus_stop_ioeventfd(VirtioBusState *bus) |
233 | { |
234 | VirtIODevice *vdev; |
235 | VirtioDeviceClass *vdc; |
236 | |
237 | if (!bus->ioeventfd_started) { |
238 | return; |
239 | } |
240 | |
241 | /* Only remove our notifier if we have ownership. */ |
242 | if (!bus->ioeventfd_grabbed) { |
243 | vdev = virtio_bus_get_device(bus); |
244 | vdc = VIRTIO_DEVICE_GET_CLASS(vdev); |
245 | vdc->stop_ioeventfd(vdev); |
246 | } |
247 | bus->ioeventfd_started = false; |
248 | } |
249 | |
250 | bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus) |
251 | { |
252 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); |
253 | DeviceState *proxy = DEVICE(BUS(bus)->parent); |
254 | |
255 | return k->ioeventfd_assign && k->ioeventfd_enabled(proxy); |
256 | } |
257 | |
258 | /* |
259 | * This function switches ioeventfd on/off in the device. |
260 | * The caller must set or clear the handlers for the EventNotifier. |
261 | */ |
262 | int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign) |
263 | { |
264 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
265 | VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus); |
266 | DeviceState *proxy = DEVICE(BUS(bus)->parent); |
267 | VirtQueue *vq = virtio_get_queue(vdev, n); |
268 | EventNotifier *notifier = virtio_queue_get_host_notifier(vq); |
269 | int r = 0; |
270 | |
271 | if (!k->ioeventfd_assign) { |
272 | return -ENOSYS; |
273 | } |
274 | |
275 | if (assign) { |
276 | r = event_notifier_init(notifier, 1); |
277 | if (r < 0) { |
278 | error_report("%s: unable to init event notifier: %s (%d)" , |
279 | __func__, strerror(-r), r); |
280 | return r; |
281 | } |
282 | r = k->ioeventfd_assign(proxy, notifier, n, true); |
283 | if (r < 0) { |
284 | error_report("%s: unable to assign ioeventfd: %d" , __func__, r); |
285 | virtio_bus_cleanup_host_notifier(bus, n); |
286 | } |
287 | } else { |
288 | k->ioeventfd_assign(proxy, notifier, n, false); |
289 | } |
290 | |
291 | return r; |
292 | } |
293 | |
294 | void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n) |
295 | { |
296 | VirtIODevice *vdev = virtio_bus_get_device(bus); |
297 | VirtQueue *vq = virtio_get_queue(vdev, n); |
298 | EventNotifier *notifier = virtio_queue_get_host_notifier(vq); |
299 | |
300 | /* Test and clear notifier after disabling event, |
301 | * in case poll callback didn't have time to run. |
302 | */ |
303 | virtio_queue_host_notifier_read(notifier); |
304 | event_notifier_cleanup(notifier); |
305 | } |
306 | |
307 | static char *virtio_bus_get_dev_path(DeviceState *dev) |
308 | { |
309 | BusState *bus = qdev_get_parent_bus(dev); |
310 | DeviceState *proxy = DEVICE(bus->parent); |
311 | return qdev_get_dev_path(proxy); |
312 | } |
313 | |
314 | static char *virtio_bus_get_fw_dev_path(DeviceState *dev) |
315 | { |
316 | return NULL; |
317 | } |
318 | |
319 | static void virtio_bus_class_init(ObjectClass *klass, void *data) |
320 | { |
321 | BusClass *bus_class = BUS_CLASS(klass); |
322 | bus_class->get_dev_path = virtio_bus_get_dev_path; |
323 | bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path; |
324 | } |
325 | |
326 | static const TypeInfo virtio_bus_info = { |
327 | .name = TYPE_VIRTIO_BUS, |
328 | .parent = TYPE_BUS, |
329 | .instance_size = sizeof(VirtioBusState), |
330 | .abstract = true, |
331 | .class_size = sizeof(VirtioBusClass), |
332 | .class_init = virtio_bus_class_init |
333 | }; |
334 | |
335 | static void virtio_register_types(void) |
336 | { |
337 | type_register_static(&virtio_bus_info); |
338 | } |
339 | |
340 | type_init(virtio_register_types) |
341 | |