Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging
[qemu.git] / hw / virtio / virtio-bus.c
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 "hw/hw.h"
27 #include "qemu/error-report.h"
28 #include "hw/qdev.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
52 DPRINTF("%s: plug device.\n", qbus->name);
53
54 if (klass->pre_plugged != NULL) {
55 klass->pre_plugged(qbus->parent, errp);
56 }
57
58 /* Get the features of the plugged device. */
59 assert(vdc->get_features != NULL);
60 vdev->host_features = vdc->get_features(vdev, vdev->host_features,
61 errp);
62
63 if (klass->device_plugged != NULL) {
64 klass->device_plugged(qbus->parent, errp);
65 }
66
67 if (klass->get_dma_as != NULL && has_iommu) {
68 virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
69 vdev->dma_as = klass->get_dma_as(qbus->parent);
70 } else {
71 vdev->dma_as = &address_space_memory;
72 }
73 }
74
75 /* Reset the virtio_bus */
76 void virtio_bus_reset(VirtioBusState *bus)
77 {
78 VirtIODevice *vdev = virtio_bus_get_device(bus);
79
80 DPRINTF("%s: reset device.\n", BUS(bus)->name);
81 if (vdev != NULL) {
82 virtio_reset(vdev);
83 }
84 }
85
86 /* A VirtIODevice is being unplugged */
87 void virtio_bus_device_unplugged(VirtIODevice *vdev)
88 {
89 DeviceState *qdev = DEVICE(vdev);
90 BusState *qbus = BUS(qdev_get_parent_bus(qdev));
91 VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
92
93 DPRINTF("%s: remove device.\n", qbus->name);
94
95 if (vdev != NULL) {
96 if (klass->device_unplugged != NULL) {
97 klass->device_unplugged(qbus->parent);
98 }
99 }
100 }
101
102 /* Get the device id of the plugged device. */
103 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
104 {
105 VirtIODevice *vdev = virtio_bus_get_device(bus);
106 assert(vdev != NULL);
107 return vdev->device_id;
108 }
109
110 /* Get the config_len field of the plugged device. */
111 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
112 {
113 VirtIODevice *vdev = virtio_bus_get_device(bus);
114 assert(vdev != NULL);
115 return vdev->config_len;
116 }
117
118 /* Get bad features of the plugged device. */
119 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
120 {
121 VirtIODevice *vdev = virtio_bus_get_device(bus);
122 VirtioDeviceClass *k;
123
124 assert(vdev != NULL);
125 k = VIRTIO_DEVICE_GET_CLASS(vdev);
126 if (k->bad_features != NULL) {
127 return k->bad_features(vdev);
128 } else {
129 return 0;
130 }
131 }
132
133 /* Get config of the plugged device. */
134 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
135 {
136 VirtIODevice *vdev = virtio_bus_get_device(bus);
137 VirtioDeviceClass *k;
138
139 assert(vdev != NULL);
140 k = VIRTIO_DEVICE_GET_CLASS(vdev);
141 if (k->get_config != NULL) {
142 k->get_config(vdev, config);
143 }
144 }
145
146 /* Set config of the plugged device. */
147 void virtio_bus_set_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->set_config != NULL) {
155 k->set_config(vdev, config);
156 }
157 }
158
159 /* On success, ioeventfd ownership belongs to the caller. */
160 int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
161 {
162 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
163
164 /* vhost can be used even if ioeventfd=off in the proxy device,
165 * so do not check k->ioeventfd_enabled.
166 */
167 if (!k->ioeventfd_assign) {
168 return -ENOSYS;
169 }
170
171 if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
172 virtio_bus_stop_ioeventfd(bus);
173 /* Remember that we need to restart ioeventfd
174 * when ioeventfd_grabbed becomes zero.
175 */
176 bus->ioeventfd_started = true;
177 }
178 bus->ioeventfd_grabbed++;
179 return 0;
180 }
181
182 void virtio_bus_release_ioeventfd(VirtioBusState *bus)
183 {
184 assert(bus->ioeventfd_grabbed != 0);
185 if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
186 /* Force virtio_bus_start_ioeventfd to act. */
187 bus->ioeventfd_started = false;
188 virtio_bus_start_ioeventfd(bus);
189 }
190 }
191
192 int virtio_bus_start_ioeventfd(VirtioBusState *bus)
193 {
194 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
195 DeviceState *proxy = DEVICE(BUS(bus)->parent);
196 VirtIODevice *vdev = virtio_bus_get_device(bus);
197 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
198 int r;
199
200 if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
201 return -ENOSYS;
202 }
203 if (bus->ioeventfd_started) {
204 return 0;
205 }
206
207 /* Only set our notifier if we have ownership. */
208 if (!bus->ioeventfd_grabbed) {
209 r = vdc->start_ioeventfd(vdev);
210 if (r < 0) {
211 error_report("%s: failed. Fallback to userspace (slower).", __func__);
212 return r;
213 }
214 }
215 bus->ioeventfd_started = true;
216 return 0;
217 }
218
219 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
220 {
221 VirtIODevice *vdev;
222 VirtioDeviceClass *vdc;
223
224 if (!bus->ioeventfd_started) {
225 return;
226 }
227
228 /* Only remove our notifier if we have ownership. */
229 if (!bus->ioeventfd_grabbed) {
230 vdev = virtio_bus_get_device(bus);
231 vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
232 vdc->stop_ioeventfd(vdev);
233 }
234 bus->ioeventfd_started = false;
235 }
236
237 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
238 {
239 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
240 DeviceState *proxy = DEVICE(BUS(bus)->parent);
241
242 return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
243 }
244
245 /*
246 * This function switches ioeventfd on/off in the device.
247 * The caller must set or clear the handlers for the EventNotifier.
248 */
249 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
250 {
251 VirtIODevice *vdev = virtio_bus_get_device(bus);
252 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
253 DeviceState *proxy = DEVICE(BUS(bus)->parent);
254 VirtQueue *vq = virtio_get_queue(vdev, n);
255 EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
256 int r = 0;
257
258 if (!k->ioeventfd_assign) {
259 return -ENOSYS;
260 }
261
262 if (assign) {
263 r = event_notifier_init(notifier, 1);
264 if (r < 0) {
265 error_report("%s: unable to init event notifier: %s (%d)",
266 __func__, strerror(-r), r);
267 return r;
268 }
269 r = k->ioeventfd_assign(proxy, notifier, n, true);
270 if (r < 0) {
271 error_report("%s: unable to assign ioeventfd: %d", __func__, r);
272 goto cleanup_event_notifier;
273 }
274 return 0;
275 } else {
276 k->ioeventfd_assign(proxy, notifier, n, false);
277 }
278
279 cleanup_event_notifier:
280 /* Test and clear notifier after disabling event,
281 * in case poll callback didn't have time to run.
282 */
283 virtio_queue_host_notifier_read(notifier);
284 event_notifier_cleanup(notifier);
285 return r;
286 }
287
288 static char *virtio_bus_get_dev_path(DeviceState *dev)
289 {
290 BusState *bus = qdev_get_parent_bus(dev);
291 DeviceState *proxy = DEVICE(bus->parent);
292 return qdev_get_dev_path(proxy);
293 }
294
295 static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
296 {
297 return NULL;
298 }
299
300 static void virtio_bus_class_init(ObjectClass *klass, void *data)
301 {
302 BusClass *bus_class = BUS_CLASS(klass);
303 bus_class->get_dev_path = virtio_bus_get_dev_path;
304 bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
305 }
306
307 static const TypeInfo virtio_bus_info = {
308 .name = TYPE_VIRTIO_BUS,
309 .parent = TYPE_BUS,
310 .instance_size = sizeof(VirtioBusState),
311 .abstract = true,
312 .class_size = sizeof(VirtioBusClass),
313 .class_init = virtio_bus_class_init
314 };
315
316 static void virtio_register_types(void)
317 {
318 type_register_static(&virtio_bus_info);
319 }
320
321 type_init(virtio_register_types)