Re: [Qemu-devel] Is network backend netmap worth keeping?

[Giuseppe Lettieri]

Dear Markus,

the netmap project is alive and well, if a bit understuffed. We have 
moved to github:

https://github.com/luigirizzo/netmap

We have users from FreeBSD, where it is part of the official kernel, and 
Linux, both from Academia and industry.

But you asked about the netmap backend in QEMU, in particular. When it 
was merged, the decision was made to disable it by default because it 
was not supported upstream in Linux. As Jason Wang says, this support is 
even more unlikely now than it was then.

The fact the the backend has to be explicitly enabled and built from the 
sources has obviously cut down the number of potential users. However, 
we still think it is useful and we have pending updates for it. If it's 
causing problems in the workflow, I am willing to help as much as I can.

Cheers,
Giuseppe

Il 08/08/19 06:48, Markus Armbruster ha scritto:
> Please excuse the attention-grabbing subject.
>
> Philippe Mathieu-Daudé <address@hidden> writes:
>
> > On 8/7/19 10:16 PM, Markus Armbruster wrote:
> [...]
> > > Can you tell me offhand what I have to install so configure enables
> > > CONFIG_NETMAP?
> >
> > The steps are listed in tests/docker/dockerfiles/debian-amd64.docker,
> > but you can get to this point running:
> >
> >    $ make docker-image-debian-amd64 V=1 DEBUG=1
> >
> > This will build the docker image with netmap (so you don't have to mess
> > with your workstation setup), then build QEMU within the image.
>
> So, to make use of QEMU's netmap backend (CONFIG_NETMAP), you have to
> build and install netmap software from sources.  Which pretty much
> ensures nobody uses it.  It was added in commit 58952137b0b (Nov 2013).
> The commit message points to <http://info.iet.unipi.it/~luigi/netmap/>,
> which gives me "connection timed out" right now.
>
> On the other hand, it's covered in MAINTAINERS, and has seen
> non-janitorial activity as late as Dec 2018 (commit c693fc748a).
>
> Luigi, Giuseppe, Vincenzo, what's the status of the netmap project?
>
> Why is the QEMU netmap backend worth keeping?
>
> Who is using the netmap backend?
>
> How do they obtain a netmap-enabled QEMU?  Compile it from sources
> themselves?
>
> Would it make sense to have netmap packaged in common Linux distros?


--
Dr. Ing. Giuseppe Lettieri
Dipartimento di Ingegneria della Informazione
Universita' di Pisa
Largo Lucio Lazzarino 1, 56122 Pisa - Italy
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e-mail: address@hidden