xref: /qemu/hw/virtio/virtio-bus.c (revision e616c2f390634a241f7899ff4c52bed9803103c6) 
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 
32 /* #define DEBUG_VIRTIO_BUS */
33 
34 #ifdef DEBUG_VIRTIO_BUS
35 #define DPRINTF(fmt, ...) \
36 do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
37 #else
38 #define DPRINTF(fmt, ...) do { } while (0)
39 #endif
40 
41 /* A VirtIODevice is being plugged */
42 void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
43 {
44     DeviceState *qdev = DEVICE(vdev);
45     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
46     VirtioBusState *bus = VIRTIO_BUS(qbus);
47     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
48     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
49 
50     DPRINTF("%s: plug device.\n", qbus->name);
51 
52     if (klass->pre_plugged != NULL) {
53         klass->pre_plugged(qbus->parent, errp);
54     }
55 
56     /* Get the features of the plugged device. */
57     assert(vdc->get_features != NULL);
58     vdev->host_features = vdc->get_features(vdev, vdev->host_features,
59                                             errp);
60 
61     if (klass->device_plugged != NULL) {
62         klass->device_plugged(qbus->parent, errp);
63     }
64 }
65 
66 /* Reset the virtio_bus */
67 void virtio_bus_reset(VirtioBusState *bus)
68 {
69     VirtIODevice *vdev = virtio_bus_get_device(bus);
70 
71     DPRINTF("%s: reset device.\n", BUS(bus)->name);
72     if (vdev != NULL) {
73         virtio_reset(vdev);
74     }
75 }
76 
77 /* A VirtIODevice is being unplugged */
78 void virtio_bus_device_unplugged(VirtIODevice *vdev)
79 {
80     DeviceState *qdev = DEVICE(vdev);
81     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
82     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
83 
84     DPRINTF("%s: remove device.\n", qbus->name);
85 
86     if (vdev != NULL) {
87         if (klass->device_unplugged != NULL) {
88             klass->device_unplugged(qbus->parent);
89         }
90     }
91 }
92 
93 /* Get the device id of the plugged device. */
94 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
95 {
96     VirtIODevice *vdev = virtio_bus_get_device(bus);
97     assert(vdev != NULL);
98     return vdev->device_id;
99 }
100 
101 /* Get the config_len field of the plugged device. */
102 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
103 {
104     VirtIODevice *vdev = virtio_bus_get_device(bus);
105     assert(vdev != NULL);
106     return vdev->config_len;
107 }
108 
109 /* Get bad features of the plugged device. */
110 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
111 {
112     VirtIODevice *vdev = virtio_bus_get_device(bus);
113     VirtioDeviceClass *k;
114 
115     assert(vdev != NULL);
116     k = VIRTIO_DEVICE_GET_CLASS(vdev);
117     if (k->bad_features != NULL) {
118         return k->bad_features(vdev);
119     } else {
120         return 0;
121     }
122 }
123 
124 /* Get config of the plugged device. */
125 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
126 {
127     VirtIODevice *vdev = virtio_bus_get_device(bus);
128     VirtioDeviceClass *k;
129 
130     assert(vdev != NULL);
131     k = VIRTIO_DEVICE_GET_CLASS(vdev);
132     if (k->get_config != NULL) {
133         k->get_config(vdev, config);
134     }
135 }
136 
137 /* Set config of the plugged device. */
138 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
139 {
140     VirtIODevice *vdev = virtio_bus_get_device(bus);
141     VirtioDeviceClass *k;
142 
143     assert(vdev != NULL);
144     k = VIRTIO_DEVICE_GET_CLASS(vdev);
145     if (k->set_config != NULL) {
146         k->set_config(vdev, config);
147     }
148 }
149 
150 int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
151                                int n, bool assign)
152 {
153     VirtIODevice *vdev = virtio_bus_get_device(bus);
154     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
155     VirtQueue *vq = virtio_get_queue(vdev, n);
156     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
157     int r = 0;
158 
159     if (assign) {
160         r = event_notifier_init(notifier, 1);
161         if (r < 0) {
162             error_report("%s: unable to init event notifier: %s (%d)",
163                          __func__, strerror(-r), r);
164             return r;
165         }
166         virtio_queue_set_host_notifier_fd_handler(vq, true, false);
167         r = k->ioeventfd_assign(proxy, notifier, n, assign);
168         if (r < 0) {
169             error_report("%s: unable to assign ioeventfd: %d", __func__, r);
170             virtio_queue_set_host_notifier_fd_handler(vq, false, false);
171             event_notifier_cleanup(notifier);
172             return r;
173         }
174     } else {
175         k->ioeventfd_assign(proxy, notifier, n, assign);
176         virtio_queue_set_host_notifier_fd_handler(vq, false, false);
177         event_notifier_cleanup(notifier);
178     }
179     return r;
180 }
181 
182 int virtio_bus_start_ioeventfd(VirtioBusState *bus)
183 {
184     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
185     DeviceState *proxy = DEVICE(BUS(bus)->parent);
186     VirtIODevice *vdev = virtio_bus_get_device(bus);
187     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
188     int r;
189 
190     if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
191         return -ENOSYS;
192     }
193     if (bus->ioeventfd_started) {
194         return 0;
195     }
196     r = vdc->start_ioeventfd(vdev);
197     if (r < 0) {
198         error_report("%s: failed. Fallback to userspace (slower).", __func__);
199         return r;
200     }
201     bus->ioeventfd_started = true;
202     return 0;
203 }
204 
205 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
206 {
207     VirtIODevice *vdev;
208     VirtioDeviceClass *vdc;
209 
210     if (!bus->ioeventfd_started) {
211         return;
212     }
213 
214     vdev = virtio_bus_get_device(bus);
215     vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
216     vdc->stop_ioeventfd(vdev);
217     bus->ioeventfd_started = false;
218 }
219 
220 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
221 {
222     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
223     DeviceState *proxy = DEVICE(BUS(bus)->parent);
224 
225     return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
226 }
227 
228 /*
229  * This function switches ioeventfd on/off in the device.
230  * The caller must set or clear the handlers for the EventNotifier.
231  */
232 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
233 {
234     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
235     DeviceState *proxy = DEVICE(BUS(bus)->parent);
236 
237     if (!k->ioeventfd_assign) {
238         return -ENOSYS;
239     }
240     if (assign) {
241         assert(!bus->ioeventfd_started);
242     } else {
243         if (!bus->ioeventfd_started) {
244             return 0;
245         }
246     }
247     return set_host_notifier_internal(proxy, bus, n, assign);
248 }
249 
250 static char *virtio_bus_get_dev_path(DeviceState *dev)
251 {
252     BusState *bus = qdev_get_parent_bus(dev);
253     DeviceState *proxy = DEVICE(bus->parent);
254     return qdev_get_dev_path(proxy);
255 }
256 
257 static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
258 {
259     return NULL;
260 }
261 
262 static void virtio_bus_class_init(ObjectClass *klass, void *data)
263 {
264     BusClass *bus_class = BUS_CLASS(klass);
265     bus_class->get_dev_path = virtio_bus_get_dev_path;
266     bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
267 }
268 
269 static const TypeInfo virtio_bus_info = {
270     .name = TYPE_VIRTIO_BUS,
271     .parent = TYPE_BUS,
272     .instance_size = sizeof(VirtioBusState),
273     .abstract = true,
274     .class_size = sizeof(VirtioBusClass),
275     .class_init = virtio_bus_class_init
276 };
277 
278 static void virtio_register_types(void)
279 {
280     type_register_static(&virtio_bus_info);
281 }
282 
283 type_init(virtio_register_types)
284