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
  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 static 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)