cd7fdfe59f
When dataplane is stopping, the s->vdev->binding->set_host_notifier(..., false) call can invoke the virtqueue handler if an ioeventfd notification is pending. This causes hw/virtio-blk.c to invoke virtio_blk_data_plane_start() before virtio_blk_data_plane_stop() returns! The result is that we try to restart dataplane while trying to stop it and the following assertion is raised: msix_set_mask_notifier: Assertion `!dev->msix_mask_notifier' failed. Although the code was intended to prevent this scenario, the s->started boolean isn't enough. Add s->stopping so that we can postpone clearing s->started until we've completely stopped dataplane. This way, virtqueue handler calls during virtio_blk_data_plane_stop() are ignored. When dataplane is legitimately started again later we already self-kick ourselves to resume processing. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Read the documentation in qemu-doc.html or on http://wiki.qemu.org - QEMU team