dataplane: fail notifier setting gracefully

The dataplane code is currently doing a hard exit if it fails to set
up either guest or host notifiers. In practice, this may mean that a
guest suddenly dies after a dataplane device failed to come up (e.g.,
when a file descriptor limit is hit for tne nth device).

Let's just try to unwind the setup instead and return.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Cornelia Huck 2014-07-25 14:10:47 +02:00 committed by Stefan Hajnoczi
parent 267e1a204c
commit f9907ebc4c

View File

@ -232,8 +232,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
vq = virtio_get_queue(s->vdev, 0);
if (!vring_setup(&s->vring, s->vdev, 0)) {
s->starting = false;
return;
goto fail_vring;
}
/* Set up guest notifier (irq) */
@ -241,7 +240,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
if (r != 0) {
fprintf(stderr, "virtio-blk failed to set guest notifier (%d), "
"ensure -enable-kvm is set\n", r);
exit(1);
goto fail_guest_notifiers;
}
s->guest_notifier = virtio_queue_get_guest_notifier(vq);
@ -249,7 +248,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
r = k->set_host_notifier(qbus->parent, 0, true);
if (r != 0) {
fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
exit(1);
goto fail_host_notifier;
}
s->host_notifier = *virtio_queue_get_host_notifier(vq);
@ -269,6 +268,14 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
aio_context_acquire(s->ctx);
aio_set_event_notifier(s->ctx, &s->host_notifier, handle_notify);
aio_context_release(s->ctx);
return;
fail_host_notifier:
k->set_guest_notifiers(qbus->parent, 1, false);
fail_guest_notifiers:
vring_teardown(&s->vring, s->vdev, 0);
fail_vring:
s->starting = false;
}
/* Context: QEMU global mutex held */