Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels

Pekka Enberg
2011-11-07T08:09:55Z

On Mon, Nov 7, 2011 at 10:00 AM, Paolo Bonzini <pbonzini@redhat.com> wrote:
> No, having the source code in Linux kernel tree is perfectly useless for the
> exceptional case, and forces you to go through extra hoops to build only one
> component.  Small hoops such as adding "-- tools/kvm" to "git bisect start"
> perhaps, but still hoops that aren't traded for a practical advantage.  You
> keep saying "oh things have been so much better" because "it's so close to
> the kernel" and "it worked so great for perf", but you haven't brought any
> practical example that we can stare at in admiration.

The _practical example_ is the working software in tools/kvm!

>> I have no idea why you're trying to convince me that it doesn't matter.
>
> I'm not trying to convince you that it doesn't matter, I'm trying to
> convince you that it doesn't *make sense*.
>
>> It's a hypervisor that implements virtio drivers, serial
>> emulation, and mini-BIOS.
>
> ... all of which have a spec against which you should be working.  Save
> perhaps for the mini-BIOS, if you develop against the kernel source rather
> than the spec you're doing it *wrong*.  Very wrong.  But you've been told
> this many times already.

I have zero interest in arguing with you about something you have no
practical experience on. I've tried both out-of-tree and in-tree
development for the KVM tool and I can tell you the latter is much
more productive environment.

We are obviously also using specifications but as you damn well should
know, specifications don't matter nearly as much as working code.
That's why it's important to have easy access to both.

Pekka