blockdev: acquire AioContext in block_set_io_throttle The block_set_io_throttle QMP and HMP commands modify I/O throttling limits for block devices. Acquire the BlockDriverState's AioContext to protect against race conditions with an IOThread that is running I/O for this device. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>