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authorPaolo Bonzini <pbonzini@redhat.com>2013-03-13 15:14:15 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2013-03-15 16:07:51 +0100
commit485e3ce88e8af0e5311dd626f399b3a1e0846dd6 (patch)
tree60ee8446e09e288ae004f05d56513f2106338a77
parent28f082469650a0f4c0e37b4ccd6f9514b1a0698d (diff)
dataplane: fix hang introduced by AioContext transition
The bug is that the EventNotifiers do have a NULL io_flush callback. Because _none_ of the callbacks on the dataplane AioContext have such a callback, aio_poll will simply do nothing. Fixed by adding the callbacks: the ioeventfd will always be polled (this can change in the future to pause/resume the processing during live snapshots or similar operations); the ioqueue will be polled if there are outstanding requests. I must admit I have screwed up my testing somehow, because commit 2c20e71 does not work even if cherry-picked on top of 1.4.0, and this patch fixes it there as well. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--hw/dataplane/virtio-blk.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/hw/dataplane/virtio-blk.c b/hw/dataplane/virtio-blk.c
index dfe5f9b9cd..1242d61e71 100644
--- a/hw/dataplane/virtio-blk.c
+++ b/hw/dataplane/virtio-blk.c
@@ -263,6 +263,11 @@ static int process_request(IOQueue *ioq, struct iovec iov[],
}
}
+static int flush_true(EventNotifier *e)
+{
+ return true;
+}
+
static void handle_notify(EventNotifier *e)
{
VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
@@ -342,6 +347,14 @@ static void handle_notify(EventNotifier *e)
}
}
+static int flush_io(EventNotifier *e)
+{
+ VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
+ io_notifier);
+
+ return s->num_reqs > 0;
+}
+
static void handle_io(EventNotifier *e)
{
VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
@@ -472,7 +485,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
exit(1);
}
s->host_notifier = *virtio_queue_get_host_notifier(vq);
- aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify, NULL);
+ aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify, flush_true);
/* Set up ioqueue */
ioq_init(&s->ioqueue, s->fd, REQ_MAX);
@@ -480,7 +493,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
ioq_put_iocb(&s->ioqueue, &s->requests[i].iocb);
}
s->io_notifier = *ioq_get_notifier(&s->ioqueue);
- aio_set_event_notifier(s->ctx, &s->io_notifier, handle_io, NULL);
+ aio_set_event_notifier(s->ctx, &s->io_notifier, handle_io, flush_io);
s->started = true;
trace_virtio_blk_data_plane_start(s);