net sched missing from Jammy KVM image

[Nathan Ward]

The net/sched modules are not included in the KVM image, but are in other images (for example AWS, if I install `linux-modules-5.15.0-1020-aws`.

Can these modules be included in the KVM image + modules package?

Additionally, I note that there seems to be no `linux-modules-extra` for KVM?

```
$ dpkg -L linux-modules-5.15.0-1020-kvm | grep net/sched | wc -l
0
$ dpkg -L linux-modules-5.15.0-1020-aws | grep net/sched | wc -l
72
```

[John Chittum (jchittum)]

Thanks for reporting this. I'm going to send this along to our Kernel team for them to triage

Do you know if this module was available in previous KVM modules sets, or if it we should add and backport this to all supported KVM kernels?

[Dimitri John Ledkov (xnox)]

linux-kvm config is very minimal, and it doesn't build most of the drivers.

there are many similar deficiencies in the linux-kvm kernel like that. It would be nice for us to come with definition as to which purpose linux-kvm is supposed to fix, and then yield from that.

[Luke Nowakowski-Krijger (lukenow)]

@xnox brings up a good question of what the purposed of the linux-kvm kernel is. Its supposed to be the minimal kernel (minimal boot time and minimal size), and I think the main use case is to bootstrap cloud images so that they can then install other kernels as quickly as possible, right? So Im not sure what other use cases outside of that we care about.

[Luke Nowakowski-Krijger (lukenow)]

@Nathan Ward We do not build modules-extra for linux-kvm. I would recommend installing one of the other cloud-optimized kernels or just the linux-generic kernel as it has those configs you care about.

Can I ask what use case you're trying to use this kernel for?

[John Chittum (jchittum)]

> I think the main use case is to bootstrap cloud images so that they can then install other kernels as quickly as possible, right?

This is incorrect. the linux-kvm kernel is lightweight kernel meant for minimal applications running in virtualized environments. The only image it is present on currently (from a cloud-images perspective) are

1. x86 based minimal cloud images in 20.04 forward, downloadable here: http://cloud-images.ubuntu.com/minimal/
2. x86 based server cloud images labeled as `kvm`, such as : focal-server-cloudimg-amd64-disk-kvm.img , from 20.04 forward

These are useful for, say, a local VM or creating a highly tailored cloud VM in an openstack environment. But there is little public documentation on the KVM kernel

being said, it looks like this has gone stale. Considering the focus of the KVM kernel, it is probably worth defining one of two things

1. if the linux-kvm kernel based x86 minimal images are meant to work out of the box with a general Openstack setup. If so, what do we need to do to improve this experience? or
2. if a linux-virutal based x86 minimal image for download should be created.