Override start_ioeventfd and stop_ioeventfd to start/stop the
whole dataplane logic. This has some positive side effects:
- no need anymore for virtio_add_queue_aio (i.e. a revert of
commit 0ff841f6d138904d514efa1d885bcaf54583852d)
- no need anymore to switch from generic ioeventfd handlers to
dataplane
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/block/dataplane/virtio-blk.c | 67 ++++++++++++++++++++++++-----------------
hw/block/dataplane/virtio-blk.h | 6 ++--
hw/block/virtio-blk.c | 16 ++++------
hw/virtio/virtio-bus.c | 2 +-
4 files changed, 50 insertions(+), 41 deletions(-)
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 9b268f4..73781e9 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -83,38 +83,44 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev,
VirtIOBlkConf *conf,
Error **errp)
{
VirtIOBlockDataPlane *s;
- BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+ BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
*dataplane = NULL;
- if (!conf->iothread) {
+ if (!virtio_device_ioeventfd_enabled(vdev)) {
return;
}
/* Don't try if transport does not support notifiers. */
- if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
- error_setg(errp,
- "device is incompatible with dataplane "
- "(transport does not support notifiers)");
- return;
- }
+ if (conf->iothread) {
+ if (!k->set_guest_notifiers || !k->ioeventfd_assign) {
+ error_setg(errp,
+ "device is incompatible with dataplane "
+ "(transport does not support notifiers)");
+ return;
+ }
- /* If dataplane is (re-)enabled while the guest is running there could be
- * block jobs that can conflict.
- */
- if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
- error_prepend(errp, "cannot start dataplane thread: ");
- return;
+ /* If dataplane is (re-)enabled while the guest is running there could
+ * be block jobs that can conflict.
+ */
+ if (blk_op_is_blocked(conf->conf.blk, BLOCK_OP_TYPE_DATAPLANE, errp)) {
+ error_prepend(errp, "cannot start dataplane thread: ");
+ return;
+ }
}
s = g_new0(VirtIOBlockDataPlane, 1);
s->vdev = vdev;
s->conf = conf;
- s->iothread = conf->iothread;
- object_ref(OBJECT(s->iothread));
- s->ctx = iothread_get_aio_context(s->iothread);
+ if (conf->iothread) {
+ s->iothread = conf->iothread;
+ object_ref(OBJECT(s->iothread));
+ s->ctx = iothread_get_aio_context(s->iothread);
+ } else {
+ s->ctx = qemu_get_aio_context();
+ }
s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
s->batch_notify_vqs = bitmap_new(conf->num_queues);
@@ -124,14 +130,18 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev,
VirtIOBlkConf *conf,
/* Context: QEMU global mutex held */
void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
{
+ VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
+
if (!s) {
return;
}
- virtio_blk_data_plane_stop(s);
+ assert(!vblk->dataplane_started);
g_free(s->batch_notify_vqs);
qemu_bh_delete(s->bh);
- object_unref(OBJECT(s->iothread));
+ if (s->iothread) {
+ object_unref(OBJECT(s->iothread));
+ }
g_free(s);
}
@@ -147,17 +157,18 @@ static void
virtio_blk_data_plane_handle_output(VirtIODevice *vdev,
}
/* Context: QEMU global mutex held */
-void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
+int virtio_blk_data_plane_start(VirtIODevice *vdev)
{
- BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
+ VirtIOBlock *vblk = VIRTIO_BLK(vdev);
+ VirtIOBlockDataPlane *s = vblk->dataplane;
+ BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vblk)));
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;
+ return 0;
}
s->starting = true;
@@ -204,20 +215,22 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
virtio_blk_data_plane_handle_output);
}
aio_context_release(s->ctx);
- return;
+ return 0;
fail_guest_notifiers:
vblk->dataplane_disabled = true;
s->starting = false;
vblk->dataplane_started = true;
+ return -ENOSYS;
}
/* Context: QEMU global mutex held */
-void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
+void virtio_blk_data_plane_stop(VirtIODevice *vdev)
{
- BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
+ VirtIOBlock *vblk = VIRTIO_BLK(vdev);
+ VirtIOBlockDataPlane *s = vblk->dataplane;
+ BusState *qbus = qdev_get_parent_bus(DEVICE(vblk));
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
- VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
unsigned i;
unsigned nvqs = s->conf->num_queues;
diff --git a/hw/block/dataplane/virtio-blk.h b/hw/block/dataplane/virtio-blk.h
index b1f0b95..db3f47b 100644
--- a/hw/block/dataplane/virtio-blk.h
+++ b/hw/block/dataplane/virtio-blk.h
@@ -23,9 +23,9 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev,
VirtIOBlkConf *conf,
VirtIOBlockDataPlane **dataplane,
Error **errp);
void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_drain(VirtIOBlockDataPlane *s);
void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s, VirtQueue *vq);
+int virtio_blk_data_plane_start(VirtIODevice *vdev);
+void virtio_blk_data_plane_stop(VirtIODevice *vdev);
+
#endif /* HW_DATAPLANE_VIRTIO_BLK_H */
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 331d766..9f09e29 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -604,7 +604,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev,
VirtQueue *vq)
/* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
* dataplane here instead of waiting for .set_status().
*/
- virtio_blk_data_plane_start(s->dataplane);
+ virtio_device_start_ioeventfd(vdev);
if (!s->dataplane_disabled) {
return;
}
@@ -668,11 +668,9 @@ static void virtio_blk_reset(VirtIODevice *vdev)
virtio_blk_free_request(req);
}
- if (s->dataplane) {
- virtio_blk_data_plane_stop(s->dataplane);
- }
aio_context_release(ctx);
+ assert(!s->dataplane_started);
blk_set_enable_write_cache(s->blk, s->original_wce);
}
@@ -770,11 +768,7 @@ static void virtio_blk_set_status(VirtIODevice *vdev,
uint8_t status)
{
VirtIOBlock *s = VIRTIO_BLK(vdev);
- if (s->dataplane && !(status & (VIRTIO_CONFIG_S_DRIVER |
- VIRTIO_CONFIG_S_DRIVER_OK))) {
- virtio_blk_data_plane_stop(s->dataplane);
- }
-
+ assert(!s->dataplane_started);
if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return;
}
@@ -915,7 +909,7 @@ static void virtio_blk_device_realize(DeviceState *dev,
Error **errp)
s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
for (i = 0; i < conf->num_queues; i++) {
- virtio_add_queue_aio(vdev, 128, virtio_blk_handle_output);
+ virtio_add_queue(vdev, 128, virtio_blk_handle_output);
}
virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
if (err != NULL) {
@@ -990,6 +984,8 @@ static void virtio_blk_class_init(ObjectClass *klass, void
*data)
vdc->reset = virtio_blk_reset;
vdc->save = virtio_blk_save_device;
vdc->load = virtio_blk_load_device;
+ vdc->start_ioeventfd = virtio_blk_data_plane_start;
+ vdc->stop_ioeventfd = virtio_blk_data_plane_stop;
}
static const TypeInfo virtio_device_info = {
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index f60efd7..05af529 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -218,7 +218,7 @@ void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
bus->ioeventfd_started = false;
}
-bool virtio_bus_ioeventfd_enabled(VirtIODevice *vdev)
+bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
{
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
DeviceState *proxy = DEVICE(BUS(bus)->parent);
--
2.7.4
