enable CONFIG_INTEL_TDX_HOST in linux >= 6.7 for noble

[Andrea Righi]

[Impact]

Intel Trust Domain Extensions (TDX) protects guest VMs from malicious host and certain physical attacks.
Linux 6.7 introduced the TDX support for the host to run confidential VMs (TDX guests).

[Test case]

We should probably define with Intel a proper test case to test this feature, since it requires special hardware/firmware support.

[Fix]

Enable CONFIG_INTEL_TDX_HOST in our generic kernel.

[Regression potential]

The TDX host support may introduce potential performance regressions, so we should probably do some performance evaluation with vs without CONFIG_INTEL_TDX_HOST enabled.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 6.8.0-11.11

---------------
linux (6.8.0-11.11) noble; urgency=medium

  * noble/linux: 6.8.0-11.11 -proposed tracker (LP: #2053094)

  * Miscellaneous Ubuntu changes
    - [Packaging] riscv64: disable building unnecessary binary debs

 -- Paolo Pisati <email address hidden> Wed, 14 Feb 2024 00:04:31 +0100

[Thibf (thibf)]

When switching to 6.8-rc1, this commit was introduced:

cb8eb06d50fcf4 x86/virt/tdx: Disable TDX host support when kexec is enabled

Which led to this config to be removed with this commit:

ca03be74737277 UBUNTU: [Config] updateconfigs following v6.8-rc1 rebase

So this isn't fixed in 6.8

[Andrea Righi (arighi)]

Changing the state to Won't fix, because of LP: #2059762.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-nvidia-6.8/6.8.0-1006.6~22.04.2 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-jammy-linux-nvidia-6.8' to 'verification-done-jammy-linux-nvidia-6.8'. If the problem still exists, change the tag 'verification-needed-jammy-linux-nvidia-6.8' to 'verification-failed-jammy-linux-nvidia-6.8'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!