Re: [PATCH 2/3] ps2: use a separate keyboard command reply queue

[Gerd Hoffmann]

  Hi,

> A PS/2 keyboard has a separate command reply queue that is
> independant of the key queue. This prevents that command replies
> and keyboard input mix. Keyboard command replies take precedence
> over queued keystrokes. A new keyboard command removes any
> remaining command replies from the command reply queue.
> 
> Implement a separate keyboard command reply queue and clear the
> command reply queue before command execution. This brings the
> PS/2 keyboard emulation much closer to a real PS/2 keyboard.

It seems you place both queues in the existing 256-byte buffer,
probably to avoid breaking live migration.

Could you explain the logic a bit more, how the three pointers q->*ptr
variables play together here?

thanks,
  Gerd