Re: [Qemu-devel] [PATCH v3] add input-send-event command

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

> > 'console' is mandatory; I guess that's okay.
> > 
> > Are we guaranteed that either all events are sent? Or is there a need to
> 
> Events can be dropped at hardware level if the event queue is full, for 
> example. Would have to modify individual drivers to return error codes, 
> i suppose. Gerd?

Events can be dropped at hardware level indeed.  Hard to check
beforehand, and we don't even return errors today as the ui code (which
would see the error) can't do much about it.  Not sure this is worth
changing, this usually only happens in case the guest has trouble
driving the device, in which case you have bigger problems anyway.

Events can also be dropped because there is no device they can be
delivered to.  This can easily be checked for the whole event list
before you start sending the events, just call qemu_input_find_handler()
and see whenever it returns a handler or not.  So we can go for a
"all-or-nothing" model here.  In the x86 world this can happen with
absolute mouse moves only because there is always a ps2 kbd+mouse.

cheers,
  Gerd