Re: vnc clipboard support

[Daniel P . Berrangé]

On Tue, Feb 02, 2021 at 12:10:15PM +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > > How do you rate-limit intelligently to avoid overflowing the guest 
> > > keyboard buffers?
> > 
> > Like I said earlier in this thread, this is a big problem with
> > keyboard injection.
> 
> It's a solved problem though, the qemu vnc server has throttling
> implemented already.  There even is an option to configure the delay
> (key-delay-ms).

Depends on your view of "solved" really. If I've highlighted a region
of text in openoffice that is 100 KB in size, and press "Ctrl-V" in
the VNC window for the VM, with a 10 ms delay, i'll be waiting 15
minutes for it to finish injecting keystrokes.

Anything longer than 1 second is unacceptable. If you make the delay
too short the guest keyboard handler will loose keys. So realistically
I think keyboard injection is limted to about 100 characters of text.

Regards,
Daniel
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