hw/virtio/vhost-vsock-common.c

   1 /*
   2  * Parent class for vhost-vsock devices
   3  *
   4  * Copyright 2015-2020 Red Hat, Inc.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or
   7  * (at your option) any later version.  See the COPYING file in the
   8  * top-level directory.
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "standard-headers/linux/virtio_vsock.h"
  13 #include "qapi/error.h"
  14 #include "hw/virtio/virtio-access.h"
  15 #include "qemu/error-report.h"
  16 #include "hw/qdev-properties.h"
  17 #include "hw/virtio/vhost.h"
  18 #include "hw/virtio/vhost-vsock.h"
  19 #include "qemu/iov.h"
  20 #include "monitor/monitor.h"
  21
  22 const int feature_bits[] = {
  23     VIRTIO_VSOCK_F_SEQPACKET,
  24     VIRTIO_F_RING_RESET,
  25     VHOST_INVALID_FEATURE_BIT
  26 };
  27
  28 uint64_t vhost_vsock_common_get_features(VirtIODevice *vdev, uint64_t features,
  29                                          Error **errp)
  30 {
  31     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
  32
  33     if (vvc->seqpacket != ON_OFF_AUTO_OFF) {
  34         virtio_add_feature(&features, VIRTIO_VSOCK_F_SEQPACKET);
  35     }
  36
  37     features = vhost_get_features(&vvc->vhost_dev, feature_bits, features);
  38
  39     if (vvc->seqpacket == ON_OFF_AUTO_ON &&
  40         !virtio_has_feature(features, VIRTIO_VSOCK_F_SEQPACKET)) {
  41         error_setg(errp, "vhost-vsock backend doesn't support seqpacket");
  42     }
  43
  44     return features;
  45 }
  46
  47 int vhost_vsock_common_start(VirtIODevice *vdev)
  48 {
  49     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
  50     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
  51     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
  52     int ret;
  53     int i;
  54
  55     if (!k->set_guest_notifiers) {
  56         error_report("binding does not support guest notifiers");
  57         return -ENOSYS;
  58     }
  59
  60     ret = vhost_dev_enable_notifiers(&vvc->vhost_dev, vdev);
  61     if (ret < 0) {
  62         error_report("Error enabling host notifiers: %d", -ret);
  63         return ret;
  64     }
  65
  66     ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, true);
  67     if (ret < 0) {
  68         error_report("Error binding guest notifier: %d", -ret);
  69         goto err_host_notifiers;
  70     }
  71
  72     vvc->vhost_dev.acked_features = vdev->guest_features;
  73     ret = vhost_dev_start(&vvc->vhost_dev, vdev);
  74     if (ret < 0) {
  75         error_report("Error starting vhost: %d", -ret);
  76         goto err_guest_notifiers;
  77     }
  78
  79     /*
  80      * guest_notifier_mask/pending not used yet, so just unmask
  81      * everything here.  virtio-pci will do the right thing by
  82      * enabling/disabling irqfd.
  83      */
  84     for (i = 0; i < vvc->vhost_dev.nvqs; i++) {
  85         vhost_virtqueue_mask(&vvc->vhost_dev, vdev, i, false);
  86     }
  87
  88     return 0;
  89
  90 err_guest_notifiers:
  91     k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
  92 err_host_notifiers:
  93     vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
  94     return ret;
  95 }
  96
  97 void vhost_vsock_common_stop(VirtIODevice *vdev)
  98 {
  99     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 100     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
 101     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
 102     int ret;
 103
 104     if (!k->set_guest_notifiers) {
 105         return;
 106     }
 107
 108     vhost_dev_stop(&vvc->vhost_dev, vdev);
 109
 110     ret = k->set_guest_notifiers(qbus->parent, vvc->vhost_dev.nvqs, false);
 111     if (ret < 0) {
 112         error_report("vhost guest notifier cleanup failed: %d", ret);
 113         return;
 114     }
 115
 116     vhost_dev_disable_notifiers(&vvc->vhost_dev, vdev);
 117 }
 118
 119
 120 static void vhost_vsock_common_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 121 {
 122     /* Do nothing */
 123 }
 124
 125 static void vhost_vsock_common_guest_notifier_mask(VirtIODevice *vdev, int idx,
 126                                             bool mask)
 127 {
 128     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 129
 130     vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask);
 131 }
 132
 133 static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev,
 134                                                int idx)
 135 {
 136     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 137
 138     return vhost_virtqueue_pending(&vvc->vhost_dev, idx);
 139 }
 140
 141 static void vhost_vsock_common_send_transport_reset(VHostVSockCommon *vvc)
 142 {
 143     VirtQueueElement *elem;
 144     VirtQueue *vq = vvc->event_vq;
 145     struct virtio_vsock_event event = {
 146         .id = cpu_to_le32(VIRTIO_VSOCK_EVENT_TRANSPORT_RESET),
 147     };
 148
 149     elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
 150     if (!elem) {
 151         error_report("vhost-vsock missed transport reset event");
 152         return;
 153     }
 154
 155     if (elem->out_num) {
 156         error_report("invalid vhost-vsock event virtqueue element with "
 157                      "out buffers");
 158         goto err;
 159     }
 160
 161     if (iov_from_buf(elem->in_sg, elem->in_num, 0,
 162                      &event, sizeof(event)) != sizeof(event)) {
 163         error_report("vhost-vsock event virtqueue element is too short");
 164         goto err;
 165     }
 166
 167     virtqueue_push(vq, elem, sizeof(event));
 168     virtio_notify(VIRTIO_DEVICE(vvc), vq);
 169
 170     g_free(elem);
 171     return;
 172
 173 err:
 174     virtqueue_detach_element(vq, elem, 0);
 175     g_free(elem);
 176 }
 177
 178 static void vhost_vsock_common_post_load_timer_cleanup(VHostVSockCommon *vvc)
 179 {
 180     if (!vvc->post_load_timer) {
 181         return;
 182     }
 183
 184     timer_free(vvc->post_load_timer);
 185     vvc->post_load_timer = NULL;
 186 }
 187
 188 static void vhost_vsock_common_post_load_timer_cb(void *opaque)
 189 {
 190     VHostVSockCommon *vvc = opaque;
 191
 192     vhost_vsock_common_post_load_timer_cleanup(vvc);
 193     vhost_vsock_common_send_transport_reset(vvc);
 194 }
 195
 196 int vhost_vsock_common_pre_save(void *opaque)
 197 {
 198     VHostVSockCommon *vvc = opaque;
 199
 200     /*
 201      * At this point, backend must be stopped, otherwise
 202      * it might keep writing to memory.
 203      */
 204     assert(!vhost_dev_is_started(&vvc->vhost_dev));
 205
 206     return 0;
 207 }
 208
 209 int vhost_vsock_common_post_load(void *opaque, int version_id)
 210 {
 211     VHostVSockCommon *vvc = opaque;
 212     VirtIODevice *vdev = VIRTIO_DEVICE(vvc);
 213
 214     if (virtio_queue_get_addr(vdev, 2)) {
 215         /*
 216          * Defer transport reset event to a vm clock timer so that virtqueue
 217          * changes happen after migration has completed.
 218          */
 219         assert(!vvc->post_load_timer);
 220         vvc->post_load_timer =
 221             timer_new_ns(QEMU_CLOCK_VIRTUAL,
 222                          vhost_vsock_common_post_load_timer_cb,
 223                          vvc);
 224         timer_mod(vvc->post_load_timer, 1);
 225     }
 226     return 0;
 227 }
 228
 229 void vhost_vsock_common_realize(VirtIODevice *vdev)
 230 {
 231     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 232
 233     virtio_init(vdev, VIRTIO_ID_VSOCK, sizeof(struct virtio_vsock_config));
 234
 235     /* Receive and transmit queues belong to vhost */
 236     vvc->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
 237                                       vhost_vsock_common_handle_output);
 238     vvc->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
 239                                        vhost_vsock_common_handle_output);
 240
 241     /* The event queue belongs to QEMU */
 242     vvc->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
 243                                        vhost_vsock_common_handle_output);
 244
 245     vvc->vhost_dev.nvqs = ARRAY_SIZE(vvc->vhost_vqs);
 246     vvc->vhost_dev.vqs = vvc->vhost_vqs;
 247
 248     vvc->post_load_timer = NULL;
 249 }
 250
 251 void vhost_vsock_common_unrealize(VirtIODevice *vdev)
 252 {
 253     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 254
 255     vhost_vsock_common_post_load_timer_cleanup(vvc);
 256
 257     virtio_delete_queue(vvc->recv_vq);
 258     virtio_delete_queue(vvc->trans_vq);
 259     virtio_delete_queue(vvc->event_vq);
 260     virtio_cleanup(vdev);
 261 }
 262
 263 static struct vhost_dev *vhost_vsock_common_get_vhost(VirtIODevice *vdev)
 264 {
 265     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 266     return &vvc->vhost_dev;
 267 }
 268
 269 static Property vhost_vsock_common_properties[] = {
 270     DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket,
 271                             ON_OFF_AUTO_AUTO),
 272     DEFINE_PROP_END_OF_LIST(),
 273 };
 274
 275 static void vhost_vsock_common_class_init(ObjectClass *klass, void *data)
 276 {
 277     DeviceClass *dc = DEVICE_CLASS(klass);
 278     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
 279
 280     device_class_set_props(dc, vhost_vsock_common_properties);
 281     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 282     vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask;
 283     vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending;
 284     vdc->get_vhost = vhost_vsock_common_get_vhost;
 285 }
 286
 287 static const TypeInfo vhost_vsock_common_info = {
 288     .name = TYPE_VHOST_VSOCK_COMMON,
 289     .parent = TYPE_VIRTIO_DEVICE,
 290     .instance_size = sizeof(VHostVSockCommon),
 291     .class_init = vhost_vsock_common_class_init,
 292     .abstract = true,
 293 };
 294
 295 static void vhost_vsock_common_register_types(void)
 296 {
 297     type_register_static(&vhost_vsock_common_info);
 298 }
 299
 300 type_init(vhost_vsock_common_register_types)