Maximum QMP reply size

[John Snow <jsnow@redhat.com>]

Hi, I suspect I have asked this before, but I didn't write it down in
a comment, so I forget my justification...

In the QMP lib, we need to set a buffering limit for how big a QMP
message can be -- In practice, I found that the largest possible
response was the QAPI schema reply, and I set the code to this:

    # Maximum allowable size of read buffer
    _limit = (64 * 1024)

However, I didn't document if this was a reasonable limit or just a
"worksforme" one. I assume that there's no hard limit for the protocol
or the implementation thereof in QEMU. Is there any kind of value here
that would be more sensible than another?

I'm worried that if replies get bigger in the future (possibly in some
degenerate case I am presently unaware of) that the library default
will become nonsensical.

Any pointers/tips?

--js