/* Context: QEMU global mutex held */ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); VirtIOBlock *vblk = VIRTIO_BLK(s->vdev); unsigned i; unsigned nvqs = s->conf->num_queues; if (!vblk->dataplane_started || s->stopping) { return; } /* Better luck next time. */ if (vblk->dataplane_disabled) { vblk->dataplane_disabled = false; vblk->dataplane_started = false; return; } s->stopping = true; trace_virtio_blk_data_plane_stop(s); aio_context_acquire(s->ctx); /* Stop notifications for new requests from guest */ for (i = 0; i < nvqs; i++) { VirtQueue *vq = virtio_get_queue(s->vdev, i); virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, NULL); } /* Drain and switch bs back to the QEMU main loop */ blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context()); aio_context_release(s->ctx); for (i = 0; i < nvqs; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } /* Clean up guest notifier (irq) */ k->set_guest_notifiers(qbus->parent, nvqs, false); vblk->dataplane_started = false; s->stopping = false; }
static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n, void (*fn)(VirtIODevice *vdev, VirtQueue *vq)) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); int rc; /* Set up virtqueue notify */ rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), n, true); if (rc != 0) { fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n", rc); s->dataplane_fenced = true; return rc; } virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, fn); return 0; }
/* Context: QEMU global mutex held */ void virtio_scsi_dataplane_stop(VirtIOSCSI *s) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); int i; if (!s->dataplane_started || s->dataplane_stopping) { return; } /* Better luck next time. */ if (s->dataplane_fenced) { s->dataplane_fenced = false; s->dataplane_started = false; return; } s->dataplane_stopping = true; assert(s->ctx == iothread_get_aio_context(vs->conf.iothread)); aio_context_acquire(s->ctx); virtio_scsi_clear_aio(s); blk_drain_all(); /* ensure there are no in-flight requests */ aio_context_release(s->ctx); for (i = 0; i < vs->conf.num_queues + 2; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } /* Clean up guest notifier (irq) */ k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false); s->dataplane_stopping = false; s->dataplane_started = false; }
/* Context: QEMU global mutex held */ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); VirtIOBlock *vblk = VIRTIO_BLK(s->vdev); unsigned i; unsigned nvqs = s->conf->num_queues; int r; if (vblk->dataplane_started || s->starting) { return; } s->starting = true; /* Set up guest notifier (irq) */ r = k->set_guest_notifiers(qbus->parent, nvqs, true); if (r != 0) { fprintf(stderr, "virtio-blk failed to set guest notifier (%d), " "ensure -enable-kvm is set\n", r); goto fail_guest_notifiers; } /* Set up virtqueue notify */ for (i = 0; i < nvqs; i++) { r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, true); if (r != 0) { fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r); while (i--) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } goto fail_guest_notifiers; } } s->starting = false; vblk->dataplane_started = true; trace_virtio_blk_data_plane_start(s); blk_set_aio_context(s->conf->conf.blk, s->ctx); /* Kick right away to begin processing requests already in vring */ for (i = 0; i < nvqs; i++) { VirtQueue *vq = virtio_get_queue(s->vdev, i); event_notifier_set(virtio_queue_get_host_notifier(vq)); } /* Get this show started by hooking up our callbacks */ aio_context_acquire(s->ctx); for (i = 0; i < nvqs; i++) { VirtQueue *vq = virtio_get_queue(s->vdev, i); virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, virtio_blk_data_plane_handle_output); } aio_context_release(s->ctx); return; fail_guest_notifiers: vblk->dataplane_disabled = true; s->starting = false; vblk->dataplane_started = true; }
/* Context: QEMU global mutex held */ void virtio_scsi_dataplane_start(VirtIOSCSI *s) { int i; int rc; BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s); if (s->dataplane_started || s->dataplane_starting || s->dataplane_fenced || s->ctx != iothread_get_aio_context(vs->conf.iothread)) { return; } s->dataplane_starting = true; /* Set up guest notifier (irq) */ rc = k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, true); if (rc != 0) { fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), " "ensure -enable-kvm is set\n", rc); goto fail_guest_notifiers; } aio_context_acquire(s->ctx); rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0, virtio_scsi_data_plane_handle_ctrl); if (rc) { goto fail_vrings; } rc = virtio_scsi_vring_init(s, vs->event_vq, 1, virtio_scsi_data_plane_handle_event); if (rc) { goto fail_vrings; } for (i = 0; i < vs->conf.num_queues; i++) { rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2, virtio_scsi_data_plane_handle_cmd); if (rc) { goto fail_vrings; } } s->dataplane_starting = false; s->dataplane_started = true; aio_context_release(s->ctx); return; fail_vrings: virtio_scsi_clear_aio(s); aio_context_release(s->ctx); for (i = 0; i < vs->conf.num_queues + 2; i++) { virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false); } k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false); fail_guest_notifiers: s->dataplane_fenced = true; s->dataplane_starting = false; s->dataplane_started = true; }