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     bool vdev_has_iommu;
  52     Error *local_err = NULL;
  53
  54     DPRINTF("%s: plug device.\n", qbus->name);
  55
  56     if (klass->pre_plugged != NULL) {
  57         klass->pre_plugged(qbus->parent, &local_err);
  58         if (local_err) {
  59             error_propagate(errp, local_err);
  60             return;
  61         }
  62     }
  63
  64     /* Get the features of the plugged device. */
  65     assert(vdc->get_features != NULL);
  66     vdev->host_features = vdc->get_features(vdev, vdev->host_features,
  67                                             &local_err);
  68     if (local_err) {
  69         error_propagate(errp, local_err);
  70         return;
  71     }
  72
  73     if (klass->device_plugged != NULL) {
  74         klass->device_plugged(qbus->parent, &local_err);
  75     }
  76     if (local_err) {
  77         error_propagate(errp, local_err);
  78         return;
  79     }
  80
  81     vdev_has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
  82     if (klass->get_dma_as != NULL && has_iommu) {
  83         virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
  84         vdev->dma_as = klass->get_dma_as(qbus->parent);
  85         if (!vdev_has_iommu && vdev->dma_as != &address_space_memory) {
  86             error_setg(errp,
  87                        "iommu_platform=true is not supported by the device");
  88             return;
  89         }
  90     } else {
  91         vdev->dma_as = &address_space_memory;
  92     }
  93 }
  94
  95 /* Reset the virtio_bus */
  96 void virtio_bus_reset(VirtioBusState *bus)
  97 {
  98     VirtIODevice *vdev = virtio_bus_get_device(bus);
  99
 100     DPRINTF("%s: reset device.\n", BUS(bus)->name);
 101     if (vdev != NULL) {
 102         virtio_reset(vdev);
 103     }
 104 }
 105
 106 /* A VirtIODevice is being unplugged */
 107 void virtio_bus_device_unplugged(VirtIODevice *vdev)
 108 {
 109     DeviceState *qdev = DEVICE(vdev);
 110     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
 111     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
 112
 113     DPRINTF("%s: remove device.\n", qbus->name);
 114
 115     if (vdev != NULL) {
 116         if (klass->device_unplugged != NULL) {
 117             klass->device_unplugged(qbus->parent);
 118         }
 119     }
 120 }
 121
 122 /* Get the device id of the plugged device. */
 123 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
 124 {
 125     VirtIODevice *vdev = virtio_bus_get_device(bus);
 126     assert(vdev != NULL);
 127     return vdev->device_id;
 128 }
 129
 130 /* Get the config_len field of the plugged device. */
 131 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
 132 {
 133     VirtIODevice *vdev = virtio_bus_get_device(bus);
 134     assert(vdev != NULL);
 135     return vdev->config_len;
 136 }
 137
 138 /* Get bad features of the plugged device. */
 139 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
 140 {
 141     VirtIODevice *vdev = virtio_bus_get_device(bus);
 142     VirtioDeviceClass *k;
 143
 144     assert(vdev != NULL);
 145     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 146     if (k->bad_features != NULL) {
 147         return k->bad_features(vdev);
 148     } else {
 149         return 0;
 150     }
 151 }
 152
 153 /* Get config of the plugged device. */
 154 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
 155 {
 156     VirtIODevice *vdev = virtio_bus_get_device(bus);
 157     VirtioDeviceClass *k;
 158
 159     assert(vdev != NULL);
 160     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 161     if (k->get_config != NULL) {
 162         k->get_config(vdev, config);
 163     }
 164 }
 165
 166 /* Set config of the plugged device. */
 167 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
 168 {
 169     VirtIODevice *vdev = virtio_bus_get_device(bus);
 170     VirtioDeviceClass *k;
 171
 172     assert(vdev != NULL);
 173     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 174     if (k->set_config != NULL) {
 175         k->set_config(vdev, config);
 176     }
 177 }
 178
 179 /* On success, ioeventfd ownership belongs to the caller.  */
 180 int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
 181 {
 182     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 183
 184     /* vhost can be used even if ioeventfd=off in the proxy device,
 185      * so do not check k->ioeventfd_enabled.
 186      */
 187     if (!k->ioeventfd_assign) {
 188         return -ENOSYS;
 189     }
 190
 191     if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
 192         virtio_bus_stop_ioeventfd(bus);
 193         /* Remember that we need to restart ioeventfd
 194          * when ioeventfd_grabbed becomes zero.
 195          */
 196         bus->ioeventfd_started = true;
 197     }
 198     bus->ioeventfd_grabbed++;
 199     return 0;
 200 }
 201
 202 void virtio_bus_release_ioeventfd(VirtioBusState *bus)
 203 {
 204     assert(bus->ioeventfd_grabbed != 0);
 205     if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
 206         /* Force virtio_bus_start_ioeventfd to act.  */
 207         bus->ioeventfd_started = false;
 208         virtio_bus_start_ioeventfd(bus);
 209     }
 210 }
 211
 212 int virtio_bus_start_ioeventfd(VirtioBusState *bus)
 213 {
 214     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 215     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 216     VirtIODevice *vdev = virtio_bus_get_device(bus);
 217     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 218     int r;
 219
 220     if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
 221         return -ENOSYS;
 222     }
 223     if (bus->ioeventfd_started) {
 224         return 0;
 225     }
 226
 227     /* Only set our notifier if we have ownership.  */
 228     if (!bus->ioeventfd_grabbed) {
 229         r = vdc->start_ioeventfd(vdev);
 230         if (r < 0) {
 231             error_report("%s: failed. Fallback to userspace (slower).", __func__);
 232             return r;
 233         }
 234     }
 235     bus->ioeventfd_started = true;
 236     return 0;
 237 }
 238
 239 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
 240 {
 241     VirtIODevice *vdev;
 242     VirtioDeviceClass *vdc;
 243
 244     if (!bus->ioeventfd_started) {
 245         return;
 246     }
 247
 248     /* Only remove our notifier if we have ownership.  */
 249     if (!bus->ioeventfd_grabbed) {
 250         vdev = virtio_bus_get_device(bus);
 251         vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 252         vdc->stop_ioeventfd(vdev);
 253     }
 254     bus->ioeventfd_started = false;
 255 }
 256
 257 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
 258 {
 259     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 260     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 261
 262     return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
 263 }
 264
 265 /*
 266  * This function switches ioeventfd on/off in the device.
 267  * The caller must set or clear the handlers for the EventNotifier.
 268  */
 269 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
 270 {
 271     VirtIODevice *vdev = virtio_bus_get_device(bus);
 272     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 273     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 274     VirtQueue *vq = virtio_get_queue(vdev, n);
 275     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
 276     int r = 0;
 277
 278     if (!k->ioeventfd_assign) {
 279         return -ENOSYS;
 280     }
 281
 282     if (assign) {
 283         r = event_notifier_init(notifier, 1);
 284         if (r < 0) {
 285             error_report("%s: unable to init event notifier: %s (%d)",
 286                          __func__, strerror(-r), r);
 287             return r;
 288         }
 289         r = k->ioeventfd_assign(proxy, notifier, n, true);
 290         if (r < 0) {
 291             error_report("%s: unable to assign ioeventfd: %d", __func__, r);
 292             virtio_bus_cleanup_host_notifier(bus, n);
 293         }
 294     } else {
 295         k->ioeventfd_assign(proxy, notifier, n, false);
 296     }
 297
 298     if (r == 0) {
 299         virtio_queue_set_host_notifier_enabled(vq, assign);
 300     }
 301
 302     return r;
 303 }
 304
 305 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n)
 306 {
 307     VirtIODevice *vdev = virtio_bus_get_device(bus);
 308     VirtQueue *vq = virtio_get_queue(vdev, n);
 309     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
 310
 311     /* Test and clear notifier after disabling event,
 312      * in case poll callback didn't have time to run.
 313      */
 314     virtio_queue_host_notifier_read(notifier);
 315     event_notifier_cleanup(notifier);
 316 }
 317
 318 static char *virtio_bus_get_dev_path(DeviceState *dev)
 319 {
 320     BusState *bus = qdev_get_parent_bus(dev);
 321     DeviceState *proxy = DEVICE(bus->parent);
 322     return qdev_get_dev_path(proxy);
 323 }
 324
 325 static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
 326 {
 327     return NULL;
 328 }
 329
 330 bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev)
 331 {
 332     DeviceState *qdev = DEVICE(vdev);
 333     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
 334     VirtioBusState *bus = VIRTIO_BUS(qbus);
 335     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
 336
 337     if (!klass->iommu_enabled) {
 338         return false;
 339     }
 340
 341     return klass->iommu_enabled(qbus->parent);
 342 }
 343
 344 static void virtio_bus_class_init(ObjectClass *klass, void *data)
 345 {
 346     BusClass *bus_class = BUS_CLASS(klass);
 347     bus_class->get_dev_path = virtio_bus_get_dev_path;
 348     bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
 349 }
 350
 351 static const TypeInfo virtio_bus_info = {
 352     .name = TYPE_VIRTIO_BUS,
 353     .parent = TYPE_BUS,
 354     .instance_size = sizeof(VirtioBusState),
 355     .abstract = true,
 356     .class_size = sizeof(VirtioBusClass),
 357     .class_init = virtio_bus_class_init
 358 };
 359
 360 static void virtio_register_types(void)
 361 {
 362     type_register_static(&virtio_bus_info);
 363 }
 364
 365 type_init(virtio_register_types)