Re: [Qemu-devel] [RFC] Future goals for autotest and virtualization tests

[Lucas Meneghel Rodrigues]

On 03/08/2012 03:57 PM, Anthony Liguori wrote:
> On 03/08/2012 09:19 AM, Lucas Meneghel Rodrigues wrote:
> > Before I forget, I'd like to ask you about this:
> >
> > On 03/08/2012 10:36 AM, Anthony Liguori wrote:
> > > I'm really not a fan of buildroot. Note that in order to ship binaries,
> > > full source needs to be provided in order to comply with the GPL. The
> > > FSF at least states that referring to another website for source that's
> > > not under your control doesn't satisfy the requirements of the GPL.
> >
> > About using buildroot, what is up with it, since it is mature and
> > works well?
> > You mentioned than providing all the sources is harder than it looks
> > like, and I
> > surely think this might be the case.
>
> buildroot is a full blown distribution. But instead of distributing
> binaries, it only distributes source code. Think of it like Gentoo--.
>
> It relies on third party links to fetch said source code which means
> that it's not unusual

By this definition, qemu test fetch source code from 3rd party 
repositories just as much, after all you have to fetch your linux and 
busybox code from somewhere, I assume.

at all for buildroot to straight out fail. Because
> it needs a GCC that can build shared libraries, it also requires
> rebuilding GCC which increases the build time even for a minimalistic
> configuration.

But is this additional build time a problem? Is the person expected to 
be messing around with re-creating the minimal guest images all the time?

> Having a JeOS it not meant to replace having proper guests (like Fedora
> or Ubuntu). As I've said in other notes, the point of having a JeOS is
> to essentially use Linux as a libOS when writing unit tests.

That is why we would have a reference binary jeos image that can be 
downloaded (although not a replacement, having a small guest makes setup 
time smaller, as well as smaller time to run the tests). If people need 
to tweak kernel, etc for some reason, I'm assuming that person would 
have their own clone of the repo and rebuild the images with the 
modification, and use that for the tests, I guess just the way you would 
do with qemu-jeos.

> > But in all my naiveness, if the problem is to ship the exact source
> > with the
> > images have been built, couldn't I just ask buildroot to fetch all the
> > tarball
> > sources (there's a function to perform source download only) and add
> > them to the
> > appropriate git branch?
>
> Okay, let's say I'm a developer and I want to use a new Linux kernel to
> test the new virtio-pci feature I added with buildroot. Where do I
> begin? What patch do I submit?

You change the configuration file to build your linux from git rather 
than the tarball, change the linux config and type 'make'. At the end, 
you'll have a patch that can be sent and kept in another 
autotest-buildroot branch, if it's proven to be useful *for other people*.

All in all, I don't see what is the big difference between this workflow 
and qemu-jeos.