Re: [Qemu-devel] [PATCH 5/8] virtio-serial-bus: Add support for buffering guest output, throttling guests

[Markus Armbruster]

Anthony Liguori <address@hidden> writes:

> On 01/12/2010 01:16 AM, Amit Shah wrote:
>> BTW I don't really want this too, I can get rid of it if everyone agrees
>> we won't support clipboard writes>  4k over vnc or if there's a better
>> idea.
>>    
>
> Why bother trying to preserve message boundaries?   I think that's the
> fundamental question.

Yes.  Either it's a datagram or a stream pipe.  I always thought it
would be a stream pipe, as the name "serial" suggests.

As to the clipboard use case: same problem exists with any old stream
pipe, including TCP, same solutions apply.  If you told the peer "I'm
going to send you 12345 bytes now", and your stream pipe chokes after
7890 bytes, you retry until everything got through.  If you want to be
able to abort a partial transfer and start a new one, you layer a
protocol suitable for that on top of your stream pipe.