+static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
+ uint32_t event, uint32_t reason)
+{
+ VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
+ VirtIOSCSIEvent *evt;
+ int in_size;
+
+ if (!req) {
+ s->events_dropped = true;
+ return;
+ }
+
+ if (req->elem.out_num || req->elem.in_num != 1) {
+ virtio_scsi_bad_req();
+ }
+
+ if (s->events_dropped) {
+ event |= VIRTIO_SCSI_T_EVENTS_MISSED;
+ s->events_dropped = false;
+ }
+
+ in_size = req->elem.in_sg[0].iov_len;
+ if (in_size < sizeof(VirtIOSCSIEvent)) {
+ virtio_scsi_bad_req();
+ }
+
+ evt = req->resp.event;
+ memset(evt, 0, sizeof(VirtIOSCSIEvent));
+ evt->event = event;
+ evt->reason = reason;
+ if (!dev) {
+ assert(event == VIRTIO_SCSI_T_NO_EVENT);
+ } else {
+ evt->lun[0] = 1;
+ evt->lun[1] = dev->id;
+
+ /* Linux wants us to keep the same encoding we use for REPORT LUNS. */
+ if (dev->lun >= 256) {
+ evt->lun[2] = (dev->lun >> 8) | 0x40;
+ }
+ evt->lun[3] = dev->lun & 0xFF;
+ }
+ virtio_scsi_complete_req(req);
+}
+
+static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOSCSI *s = (VirtIOSCSI *)vdev;
+
+ if (s->events_dropped) {
+ virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
+ }
+}
+
+static void virtio_scsi_change(SCSIBus *bus, SCSIDevice *dev, SCSISense sense)
+{
+ VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
+
+ if (((s->vdev.guest_features >> VIRTIO_SCSI_F_CHANGE) & 1) &&
+ (s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+ dev->type != TYPE_ROM) {
+ virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_PARAM_CHANGE,
+ sense.asc | (sense.ascq << 8));
+ }
+}
+
+static void virtio_scsi_hotplug(SCSIBus *bus, SCSIDevice *dev)
+{
+ VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
+
+ if (((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) &&
+ (s->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+ virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
+ VIRTIO_SCSI_EVT_RESET_RESCAN);
+ }
+}
+
+static void virtio_scsi_hot_unplug(SCSIBus *bus, SCSIDevice *dev)
+{
+ VirtIOSCSI *s = container_of(bus, VirtIOSCSI, bus);
+
+ if ((s->vdev.guest_features >> VIRTIO_SCSI_F_HOTPLUG) & 1) {
+ virtio_scsi_push_event(s, dev, VIRTIO_SCSI_T_TRANSPORT_RESET,
+ VIRTIO_SCSI_EVT_RESET_REMOVED);
+ }
+}
+