Phase out support for Linux kernel 4.14

[pb8o]

Linux 4.14 has been EOL since 2024-01-10.

It is no longer receiving security fixes, so as part of our security tenets we should not continue supporting it
Linux 4.14 host support was removed in #4689 and the new minimum supported kernel is 5.10.

Supported versions v1.8 and v1.7 still run on Linux 4.14. After we phase out support for those the Firecracker project will no longer support running on 4.14.

[kanpov]

Would this also entail 6.1 becoming a supported guest kernel version?

[xmarcalx]

Hi @kanpov,

We currently deprecated only host OS kernel version 4.14, and planning to deprecate guest OS kernel version 4.14 soon too.
We already support host OS kernel version 6.1 (https://github.com/firecracker-microvm/firecracker/blob/main/docs/kernel-policy.md) and definitely working on supporting guest OS kernel version 6.1 as substitute of 4.14.

[roypat]

We have finished deprecation of support for Linux 4.14 with Firecracker 1.10, released on November 7th 2024