| Message ID | 1363184055-8610-1-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Mar 13, 2013 at 03:14:15PM +0100, Paolo Bonzini wrote: > 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> > --- > hw/dataplane/virtio-blk.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) Thanks, tested and applied to my block tree: https://github.com/stefanha/qemu/commits/block Stefan
On Wed, Mar 13, 2013 at 03:14:15PM +0100, Paolo Bonzini wrote: > 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. This also fixes the problem we were seeing on s390x. regards Jens > > 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> > --- > hw/dataplane/virtio-blk.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/hw/dataplane/virtio-blk.c b/hw/dataplane/virtio-blk.c > index aa9b040..24994fa 100644 > --- a/hw/dataplane/virtio-blk.c > +++ b/hw/dataplane/virtio-blk.c > @@ -261,6 +261,11 @@ 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, > @@ -340,6 +345,14 @@ 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, > @@ -470,7 +483,7 @@ 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); > @@ -478,7 +491,7 @@ 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); > -- > 1.8.1.4 > >
diff --git a/hw/dataplane/virtio-blk.c b/hw/dataplane/virtio-blk.c index aa9b040..24994fa 100644 --- a/hw/dataplane/virtio-blk.c +++ b/hw/dataplane/virtio-blk.c @@ -261,6 +261,11 @@ 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, @@ -340,6 +345,14 @@ 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, @@ -470,7 +483,7 @@ 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); @@ -478,7 +491,7 @@ 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);
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> --- hw/dataplane/virtio-blk.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)