10.2.3. Using the QEMU Guest Agent

The qemu-guest-agent cannot detect whether or not a client has connected to the channel.

There is no way for a client to detect whether or not qemu-guest-agent has disconnected or reconnected to the back-end.

If the virtio-serial device resets and qemu-guest-agent has not connected to the channel (generally caused by a reboot or hot plug), data from the client will be dropped.

If qemu-guest-agent has connected to the channel following a virtio-serial device reset, data from the client will be queued (and eventually throttled if available buffers are exhausted), regardless of whether or not qemu-guest-agent is still running or connected.