Merge tag 'edgar/xilinx-next-2022-09-21.for-upstream' of https://github.com/edgarigl...
[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 "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 (has_iommu && !virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM)) {
73 error_setg(errp, "iommu_platform=true is not supported by the device");
74 return;
75 }
76
77 if (klass->device_plugged != NULL) {
78 klass->device_plugged(qbus->parent, &local_err);
79 }
80 if (local_err) {
81 error_propagate(errp, local_err);
82 return;
83 }
84
85 if (klass->get_dma_as != NULL && has_iommu) {
86 virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
87 vdev->dma_as = klass->get_dma_as(qbus->parent);
88 } else {
89 vdev->dma_as = &address_space_memory;
90 }
91 }
92
93 /* Reset the virtio_bus */
94 void virtio_bus_reset(VirtioBusState *bus)
95 {
96 VirtIODevice *vdev = virtio_bus_get_device(bus);
97
98 DPRINTF("%s: reset device.\n", BUS(bus)->name);
99 if (vdev != NULL) {
100 virtio_reset(vdev);
101 }
102 }
103
104 /* A VirtIODevice is being unplugged */
105 void virtio_bus_device_unplugged(VirtIODevice *vdev)
106 {
107 DeviceState *qdev = DEVICE(vdev);
108 BusState *qbus = BUS(qdev_get_parent_bus(qdev));
109 VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
110
111 DPRINTF("%s: remove device.\n", qbus->name);
112
113 if (vdev != NULL) {
114 if (klass->device_unplugged != NULL) {
115 klass->device_unplugged(qbus->parent);
116 }
117 }
118 }
119
120 /* Get the device id of the plugged device. */
121 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
122 {
123 VirtIODevice *vdev = virtio_bus_get_device(bus);
124 assert(vdev != NULL);
125 return vdev->device_id;
126 }
127
128 /* Get the config_len field of the plugged device. */
129 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
130 {
131 VirtIODevice *vdev = virtio_bus_get_device(bus);
132 assert(vdev != NULL);
133 return vdev->config_len;
134 }
135
136 /* Get bad features of the plugged device. */
137 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
138 {
139 VirtIODevice *vdev = virtio_bus_get_device(bus);
140 VirtioDeviceClass *k;
141
142 assert(vdev != NULL);
143 k = VIRTIO_DEVICE_GET_CLASS(vdev);
144 if (k->bad_features != NULL) {
145 return k->bad_features(vdev);
146 } else {
147 return 0;
148 }
149 }
150
151 /* Get config of the plugged device. */
152 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
153 {
154 VirtIODevice *vdev = virtio_bus_get_device(bus);
155 VirtioDeviceClass *k;
156
157 assert(vdev != NULL);
158 k = VIRTIO_DEVICE_GET_CLASS(vdev);
159 if (k->get_config != NULL) {
160 k->get_config(vdev, config);
161 }
162 }
163
164 /* Set config of the plugged device. */
165 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
166 {
167 VirtIODevice *vdev = virtio_bus_get_device(bus);
168 VirtioDeviceClass *k;
169
170 assert(vdev != NULL);
171 k = VIRTIO_DEVICE_GET_CLASS(vdev);
172 if (k->set_config != NULL) {
173 k->set_config(vdev, config);
174 }
175 }
176
177 /* On success, ioeventfd ownership belongs to the caller. */
178 int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
179 {
180 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
181
182 /* vhost can be used even if ioeventfd=off in the proxy device,
183 * so do not check k->ioeventfd_enabled.
184 */
185 if (!k->ioeventfd_assign) {
186 return -ENOSYS;
187 }
188
189 if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
190 virtio_bus_stop_ioeventfd(bus);
191 /* Remember that we need to restart ioeventfd
192 * when ioeventfd_grabbed becomes zero.
193 */
194 bus->ioeventfd_started = true;
195 }
196 bus->ioeventfd_grabbed++;
197 return 0;
198 }
199
200 void virtio_bus_release_ioeventfd(VirtioBusState *bus)
201 {
202 assert(bus->ioeventfd_grabbed != 0);
203 if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
204 /* Force virtio_bus_start_ioeventfd to act. */
205 bus->ioeventfd_started = false;
206 virtio_bus_start_ioeventfd(bus);
207 }
208 }
209
210 int virtio_bus_start_ioeventfd(VirtioBusState *bus)
211 {
212 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
213 DeviceState *proxy = DEVICE(BUS(bus)->parent);
214 VirtIODevice *vdev = virtio_bus_get_device(bus);
215 VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
216 int r;
217
218 if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
219 return -ENOSYS;
220 }
221 if (bus->ioeventfd_started) {
222 return 0;
223 }
224
225 /* Only set our notifier if we have ownership. */
226 if (!bus->ioeventfd_grabbed) {
227 r = vdc->start_ioeventfd(vdev);
228 if (r < 0) {
229 error_report("%s: failed. Fallback to userspace (slower).", __func__);
230 return r;
231 }
232 }
233 bus->ioeventfd_started = true;
234 return 0;
235 }
236
237 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
238 {
239 VirtIODevice *vdev;
240 VirtioDeviceClass *vdc;
241
242 if (!bus->ioeventfd_started) {
243 return;
244 }
245
246 /* Only remove our notifier if we have ownership. */
247 if (!bus->ioeventfd_grabbed) {
248 vdev = virtio_bus_get_device(bus);
249 vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
250 vdc->stop_ioeventfd(vdev);
251 }
252 bus->ioeventfd_started = false;
253 }
254
255 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
256 {
257 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
258 DeviceState *proxy = DEVICE(BUS(bus)->parent);
259
260 return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
261 }
262
263 /*
264 * This function switches ioeventfd on/off in the device.
265 * The caller must set or clear the handlers for the EventNotifier.
266 */
267 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
268 {
269 VirtIODevice *vdev = virtio_bus_get_device(bus);
270 VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
271 DeviceState *proxy = DEVICE(BUS(bus)->parent);
272 VirtQueue *vq = virtio_get_queue(vdev, n);
273 EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
274 int r = 0;
275
276 if (!k->ioeventfd_assign) {
277 return -ENOSYS;
278 }
279
280 if (assign) {
281 r = event_notifier_init(notifier, 1);
282 if (r < 0) {
283 error_report("%s: unable to init event notifier: %s (%d)",
284 __func__, strerror(-r), r);
285 return r;
286 }
287 r = k->ioeventfd_assign(proxy, notifier, n, true);
288 if (r < 0) {
289 error_report("%s: unable to assign ioeventfd: %d", __func__, r);
290 virtio_bus_cleanup_host_notifier(bus, n);
291 }
292 } else {
293 k->ioeventfd_assign(proxy, notifier, n, false);
294 }
295
296 if (r == 0) {
297 virtio_queue_set_host_notifier_enabled(vq, assign);
298 }
299
300 return r;
301 }
302
303 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n)
304 {
305 VirtIODevice *vdev = virtio_bus_get_device(bus);
306 VirtQueue *vq = virtio_get_queue(vdev, n);
307 EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
308
309 /* Test and clear notifier after disabling event,
310 * in case poll callback didn't have time to run.
311 */
312 virtio_queue_host_notifier_read(notifier);
313 event_notifier_cleanup(notifier);
314 }
315
316 static char *virtio_bus_get_dev_path(DeviceState *dev)
317 {
318 BusState *bus = qdev_get_parent_bus(dev);
319 DeviceState *proxy = DEVICE(bus->parent);
320 return qdev_get_dev_path(proxy);
321 }
322
323 static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
324 {
325 return NULL;
326 }
327
328 bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev)
329 {
330 DeviceState *qdev = DEVICE(vdev);
331 BusState *qbus = BUS(qdev_get_parent_bus(qdev));
332 VirtioBusState *bus = VIRTIO_BUS(qbus);
333 VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
334
335 if (!klass->iommu_enabled) {
336 return false;
337 }
338
339 return klass->iommu_enabled(qbus->parent);
340 }
341
342 static void virtio_bus_class_init(ObjectClass *klass, void *data)
343 {
344 BusClass *bus_class = BUS_CLASS(klass);
345 bus_class->get_dev_path = virtio_bus_get_dev_path;
346 bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
347 }
348
349 static const TypeInfo virtio_bus_info = {
350 .name = TYPE_VIRTIO_BUS,
351 .parent = TYPE_BUS,
352 .instance_size = sizeof(VirtioBusState),
353 .abstract = true,
354 .class_size = sizeof(VirtioBusClass),
355 .class_init = virtio_bus_class_init
356 };
357
358 static void virtio_register_types(void)
359 {
360 type_register_static(&virtio_bus_info);
361 }
362
363 type_init(virtio_register_types)