Add requirements for Raspberry Pi

[darox]

Add documentation for running Cilium on a Raspberry Pi.

Signed-off-by: darox 9934402+darox@users.noreply.github.com

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docs: Add requirements for installing Cilium on Raspberry Pi

[qmonnet]

Please, can you also consider using a real email address in the commit's Signed-off-by: tag? Although this doesn't happen often, we've had to reach out to some contributors in the past.

[darox]

Please, can you also consider using a real email address in the commit's Signed-off-by: tag? Although this doesn't happen often, we've had to reach out to some contributors in the past.

Done

[gentoo-root]

Suggested change

	sudo apt install linux-modules-extra-$(uname -r)
	sudo apt install linux-modules-extra-raspi

As far as I understand (correct me if I'm wrong), linux-modules-extra-raspi pulls in the latest version of linux-modules-extra-*, updating it automatically with kernel updates. If you just install linux-modules-extra-$(uname -r), Cilium will break again after a kernel update.

(Also I checked Ubuntu for amd64, and it doesn't require linux-modules-extra for xfrm_user and xfrm_interfaces, which were apparently missing here, so the "Ubuntu 22.04 on Raspberry Pi" header looks good to me.)

[qmonnet]

Thanks! Looks good to me assuming Maxim's comment gets addressed

[gentoo-root]

Thanks!

[fmunteanu]

@darox your documentation covers only Ubuntu, what about default RaspiOS?

[darox]

@darox your documentation covers only Ubuntu, what about default RaspiOS?

I expect the default OS to require the same package. However, I don't have one at hand to test it.

[fmunteanu]

@darox it does not. This is a major roadblock since the kernel developers will not modify it, just to accommodate a third party app, as they describe Cilium in raspberrypi/linux#5354. And they are correct. Right now RaspiOS users need to recompile the kernel, in order to accommodate the Cilium requirements, which is unrealistic for updates. I opened #23640 with Cilium.

[darox]

I didnt't know that. Thank you for the clarification.

[fmunteanu]

@darox not sure if you could help bring this to the attention of Cilium devs, it should be an easy fix. Cilium binary should accept default CONFIG_ARM64_VA_BITS_39 value.

[joestringer]

@fmunteanu Is there some change that you could propose as a PR? It's not clear to me how Cilium interacts with the kernel flag CONFIG_ARM64_VA_BITS_39.

[fmunteanu]

@joestringer is it possible to continue this discussion into #23640?

[joestringer]

@fmunteanu ah yes, that would be better than discussing on this PR. 👍