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>
The .io_flush() handler no longer exists and has no users. Drop the
io_flush argument to aio_set_fd_handler() and related functions.
The AioFlushEventNotifierHandler and AioFlushHandler typedefs are no
longer used and are dropped too.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Check exit conditions before entering blocking aio_poll(). This is
mainly for consistency since it's unlikely that we are stopping in the
first event loop iteration.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Dataplane must check whether a block device is in use before launching
the dataplane thread. This is necessary since the thread does not
synchronize with the main loop and I/O requests could cause corruption.
One example is when a drive is added and a block job is started before
hotplugging the virtio-blk-pci adapter. In this case we must not use
dataplane mode.
Cc: qemu-stable@nongnu.org
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Although the dataplane thread does not cooperate with dirty memory
logging yet it's fairly easy to temporarily disable dataplane during
live migration. This way virtio-blk can live migrate when
x-data-plane=on.
The dataplane thread will restart after migration is cancelled or if the
guest resuming virtio-blk operation after migration completes.
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Load the virtio.c state into vring.c when we start dataplane mode and
vice versa when stopping dataplane mode. This patch makes it possible
to start and stop dataplane any time while the guest is running.
This will eventually allow us to go back to QEMU main loop for
bdrv_drain_all() and live migration. In the meantime, this patch makes
the dataplane lifecycle more robust but should make no visible
difference. It may be useful in the virtio-net dataplane effort.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This remove virtio-bindings, and use class instead.
Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-id: 1366791683-5350-6-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
