[Qemu-devel] Re: [Bug 453617] Re: kvm hangs at 100% cpu when connecting to forwarded ports (when listed incorrectly on the command line)

[Michael Tokarev <mjt@tls.msk.ru>]

21.05.2010 21:16, Jan Kiszka wrote:
> Michael Tokarev wrote:
>> 21.05.2010 19:42, Gleb Natapov wrote:
>>>> ProblemType: Bug
>>>> Architecture: amd64
>>>> Date: Fri Oct 16 17:19:59 2009
>>>> DistroRelease: Ubuntu 9.10
>>> What is the point forwarding distro bugs here? Can we have upstream bug
>>> tracker to report upstream issues?
>>
>> Um, this _is_ upstream issue, as far as I can see.
>> It exists in qemu-kvm-0.12.4 at least, I just verified.
>
> Well, this particular bug rather looks like a potential documentation
> insufficiency:
>
> Instantiating two user space networking stacks on the _same_ vlan with
> _identical_ parameters is just asking for troubles. If the reporter read
> the manual and then did the mistake, we may have to clarify the docs
> what "-net user" does.

Actually it's solved like that in ubuntu, by updating documentation.

It's a common trap - two pairs of -net nic -net tap without
specifying vlan=NN and voila, you have a loop on your network.
This has been tried/trapped on more than once, that's for sure :)

>> What's wrong with that forwarding?
>
> IMHO so far nothing - as long as the ratio of pure downstream issues
> remains low. I think we should give this channel a chance as it can be
> advantageous to have more "real" end-user reports.

There's very few distro-specific bugreports usually.  At least on
Debian.  Two observations: I forward or notify about bugs filed
against Debian package (I maintain qemu-kvm there) anyway, and
quite some bugs filed actually are either usage/operator errors
or sort of misunderstanding or misuse, not real bugs.

But actually I were asking about this particular bugreport,
not about general forwarding - which - at least - should be
done with care :)

Thanks!

/mjt