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->dma_as = &address_space_memory;
  82     if (has_iommu) {
  83         vdev_has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
  84         /*
  85          * Present IOMMU_PLATFORM to the driver iff iommu_plattform=on and
  86          * device operational. If the driver does not accept IOMMU_PLATFORM
  87          * we fail the device.
  88          */
  89         virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
  90         if (klass->get_dma_as) {
  91             vdev->dma_as = klass->get_dma_as(qbus->parent);
  92             if (!vdev_has_iommu && vdev->dma_as != &address_space_memory) {
  93                 error_setg(errp,
  94                        "iommu_platform=true is not supported by the device");
  95                 return;
  96             }
  97         }
  98     }
  99 }
 100
 101 /* Reset the virtio_bus */
 102 void virtio_bus_reset(VirtioBusState *bus)
 103 {
 104     VirtIODevice *vdev = virtio_bus_get_device(bus);
 105
 106     DPRINTF("%s: reset device.\n", BUS(bus)->name);
 107     virtio_bus_stop_ioeventfd(bus);
 108     if (vdev != NULL) {
 109         virtio_reset(vdev);
 110     }
 111 }
 112
 113 /* A VirtIODevice is being unplugged */
 114 void virtio_bus_device_unplugged(VirtIODevice *vdev)
 115 {
 116     DeviceState *qdev = DEVICE(vdev);
 117     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
 118     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
 119
 120     DPRINTF("%s: remove device.\n", qbus->name);
 121
 122     if (vdev != NULL) {
 123         if (klass->device_unplugged != NULL) {
 124             klass->device_unplugged(qbus->parent);
 125         }
 126     }
 127 }
 128
 129 /* Get the device id of the plugged device. */
 130 uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
 131 {
 132     VirtIODevice *vdev = virtio_bus_get_device(bus);
 133     assert(vdev != NULL);
 134     return vdev->device_id;
 135 }
 136
 137 /* Get the config_len field of the plugged device. */
 138 size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
 139 {
 140     VirtIODevice *vdev = virtio_bus_get_device(bus);
 141     assert(vdev != NULL);
 142     return vdev->config_len;
 143 }
 144
 145 /* Get bad features of the plugged device. */
 146 uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
 147 {
 148     VirtIODevice *vdev = virtio_bus_get_device(bus);
 149     VirtioDeviceClass *k;
 150
 151     assert(vdev != NULL);
 152     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 153     if (k->bad_features != NULL) {
 154         return k->bad_features(vdev);
 155     } else {
 156         return 0;
 157     }
 158 }
 159
 160 /* Get config of the plugged device. */
 161 void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
 162 {
 163     VirtIODevice *vdev = virtio_bus_get_device(bus);
 164     VirtioDeviceClass *k;
 165
 166     assert(vdev != NULL);
 167     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 168     if (k->get_config != NULL) {
 169         k->get_config(vdev, config);
 170     }
 171 }
 172
 173 /* Set config of the plugged device. */
 174 void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
 175 {
 176     VirtIODevice *vdev = virtio_bus_get_device(bus);
 177     VirtioDeviceClass *k;
 178
 179     assert(vdev != NULL);
 180     k = VIRTIO_DEVICE_GET_CLASS(vdev);
 181     if (k->set_config != NULL) {
 182         k->set_config(vdev, config);
 183     }
 184 }
 185
 186 /* On success, ioeventfd ownership belongs to the caller.  */
 187 int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
 188 {
 189     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 190
 191     /* vhost can be used even if ioeventfd=off in the proxy device,
 192      * so do not check k->ioeventfd_enabled.
 193      */
 194     if (!k->ioeventfd_assign) {
 195         return -ENOSYS;
 196     }
 197
 198     if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
 199         virtio_bus_stop_ioeventfd(bus);
 200         /* Remember that we need to restart ioeventfd
 201          * when ioeventfd_grabbed becomes zero.
 202          */
 203         bus->ioeventfd_started = true;
 204     }
 205     bus->ioeventfd_grabbed++;
 206     return 0;
 207 }
 208
 209 void virtio_bus_release_ioeventfd(VirtioBusState *bus)
 210 {
 211     assert(bus->ioeventfd_grabbed != 0);
 212     if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
 213         /* Force virtio_bus_start_ioeventfd to act.  */
 214         bus->ioeventfd_started = false;
 215         virtio_bus_start_ioeventfd(bus);
 216     }
 217 }
 218
 219 int virtio_bus_start_ioeventfd(VirtioBusState *bus)
 220 {
 221     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 222     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 223     VirtIODevice *vdev = virtio_bus_get_device(bus);
 224     VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 225     int r;
 226
 227     if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
 228         return -ENOSYS;
 229     }
 230     if (bus->ioeventfd_started) {
 231         return 0;
 232     }
 233
 234     /* Only set our notifier if we have ownership.  */
 235     if (!bus->ioeventfd_grabbed) {
 236         r = vdc->start_ioeventfd(vdev);
 237         if (r < 0) {
 238             error_report("%s: failed. Fallback to userspace (slower).", __func__);
 239             return r;
 240         }
 241     }
 242     bus->ioeventfd_started = true;
 243     return 0;
 244 }
 245
 246 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
 247 {
 248     VirtIODevice *vdev;
 249     VirtioDeviceClass *vdc;
 250
 251     if (!bus->ioeventfd_started) {
 252         return;
 253     }
 254
 255     /* Only remove our notifier if we have ownership.  */
 256     if (!bus->ioeventfd_grabbed) {
 257         vdev = virtio_bus_get_device(bus);
 258         vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 259         vdc->stop_ioeventfd(vdev);
 260     }
 261     bus->ioeventfd_started = false;
 262 }
 263
 264 bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
 265 {
 266     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 267     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 268
 269     return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
 270 }
 271
 272 /*
 273  * This function switches ioeventfd on/off in the device.
 274  * The caller must set or clear the handlers for the EventNotifier.
 275  */
 276 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
 277 {
 278     VirtIODevice *vdev = virtio_bus_get_device(bus);
 279     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
 280     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 281     VirtQueue *vq = virtio_get_queue(vdev, n);
 282     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
 283     int r = 0;
 284
 285     if (!k->ioeventfd_assign) {
 286         return -ENOSYS;
 287     }
 288
 289     if (assign) {
 290         r = event_notifier_init(notifier, 1);
 291         if (r < 0) {
 292             error_report("%s: unable to init event notifier: %s (%d)",
 293                          __func__, strerror(-r), r);
 294             return r;
 295         }
 296         r = k->ioeventfd_assign(proxy, notifier, n, true);
 297         if (r < 0) {
 298             error_report("%s: unable to assign ioeventfd: %d", __func__, r);
 299             virtio_bus_cleanup_host_notifier(bus, n);
 300         }
 301     } else {
 302         k->ioeventfd_assign(proxy, notifier, n, false);
 303     }
 304
 305     if (r == 0) {
 306         virtio_queue_set_host_notifier_enabled(vq, assign);
 307     }
 308
 309     return r;
 310 }
 311
 312 void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n)
 313 {
 314     VirtIODevice *vdev = virtio_bus_get_device(bus);
 315     VirtQueue *vq = virtio_get_queue(vdev, n);
 316     EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
 317
 318     /* Test and clear notifier after disabling event,
 319      * in case poll callback didn't have time to run.
 320      */
 321     virtio_queue_host_notifier_read(notifier);
 322     event_notifier_cleanup(notifier);
 323 }
 324
 325 static char *virtio_bus_get_dev_path(DeviceState *dev)
 326 {
 327     BusState *bus = qdev_get_parent_bus(dev);
 328     DeviceState *proxy = DEVICE(bus->parent);
 329     return qdev_get_dev_path(proxy);
 330 }
 331
 332 static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
 333 {
 334     return NULL;
 335 }
 336
 337 bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev)
 338 {
 339     DeviceState *qdev = DEVICE(vdev);
 340     BusState *qbus = BUS(qdev_get_parent_bus(qdev));
 341     VirtioBusState *bus = VIRTIO_BUS(qbus);
 342     VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
 343
 344     if (!klass->iommu_enabled) {
 345         return false;
 346     }
 347
 348     return klass->iommu_enabled(qbus->parent);
 349 }
 350
 351 static void virtio_bus_class_init(ObjectClass *klass, void *data)
 352 {
 353     BusClass *bus_class = BUS_CLASS(klass);
 354     bus_class->get_dev_path = virtio_bus_get_dev_path;
 355     bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
 356 }
 357
 358 static const TypeInfo virtio_bus_info = {
 359     .name = TYPE_VIRTIO_BUS,
 360     .parent = TYPE_BUS,
 361     .instance_size = sizeof(VirtioBusState),
 362     .abstract = true,
 363     .class_size = sizeof(VirtioBusClass),
 364     .class_init = virtio_bus_class_init
 365 };
 366
 367 static void virtio_register_types(void)
 368 {
 369     type_register_static(&virtio_bus_info);
 370 }
 371
 372 type_init(virtio_register_types)