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, ...) \
37do { 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 */
43void 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 */
89void 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 */
100void 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. */
116uint16_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. */
124size_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. */
132uint32_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. */
147void 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. */
160void 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. */
173int 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
195void 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
205int 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
232void 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
250bool 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 */
262int 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
294void 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
307static 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
314static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
315{
316 return NULL;
317}
318
319static 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
326static 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
335static void virtio_register_types(void)
336{
337 type_register_static(&virtio_bus_info);
338}
339
340type_init(virtio_register_types)
341