qemu/hw/block/dataplane
Cornelia Huck 8caf907f07 dataplane: Fix startup race.
Avoid trying to setup dataplane again if dataplane setup is already in
progress. This may happen if an eventfd is triggered during setup.

I saw this occasionally with an experimental s390 irqfd implementation:

virtio_blk_handle_output
-> virtio_blk_data_plane_start
-> virtio_ccw_set_host_notifier
...
-> virtio_queue_set_host_notifier_fd_handler
-> virtio_queue_host_notifier_read
-> virtio_queue_notify_vq
-> virtio_blk_handle_output
-> virtio_blk_data_plane_start
-> vring_setup
-> hostmem_init
-> memory_listener_register
-> BOOM

As virtio-ccw tries to follow what virtio-pci does, it might be triggerable
for other platforms as well.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
..
ioq.c
ioq.h
Makefile.objs
virtio-blk.c dataplane: Fix startup race. 2013-09-06 15:25:09 +02:00
virtio-blk.h