uefi-{arm64|x86}-edge (6.18): CONFIG_HYPER=y (from =m)

[rpardini]

• this is to workaround torvalds/linux@e3ec97c
  • I talked to the maintainer (Wei Liu) upstream, they are aware of the problem, but haven't a solution
• the cloud variants are not affected (already had =y)

Summary by CodeRabbit

• Chores
  • Hyper-V support is now built-in and enabled by default on ARM64 and x86 UEFI systems, improving compatibility in virtualized environments.

[coderabbitai]

Walkthrough

Two Linux kernel configuration files (ARM64 and x86 UEFI edge variants) are updated to change Hyper-V support from modular (m) to built-in (y) configuration. This promotes Hyper-V from an optional kernel module to mandatory, compiled-in support.

Changes

Cohort / File(s)	Summary
Hyper-V kernel configuration config/kernel/linux-uefi-arm64-edge.config, config/kernel/linux-uefi-x86-edge.config	Changed CONFIG_HYPERV from module (m) to built-in (y) at two locations in ARM64 edge config and one location in x86 edge config

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

• Simple, repetitive kernel configuration option changes across two files
• No logic changes, functional code modifications, or complex interactions
• Straightforward verification: confirm CONFIG_HYPERV setting and consistency across both files

Suggested labels

Patches

Suggested reviewers

• igorpecovnik
• amazingfate
• ahoneybun
• clee
• adeepn

Poem

🐰 Hyper-V leaps from module to core,
No longer optional, now forever more!
Built right into the kernel's heart,
A mandatory, steadfast part. 🚀

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The title contains a typo: 'CONFIG_HYPER' instead of 'CONFIG_HYPERV'. The actual changes modify 'CONFIG_HYPERV' in two kernel config files, making the title misleading and inaccurate.	Correct the title to 'uefi-{arm64|x86}-edge (6.18): CONFIG_HYPERV=y (from =m)' to accurately reflect the config option being changed.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

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📥 Commits

Reviewing files that changed from the base of the PR and between 97924fb and 536494c.

📒 Files selected for processing (2)

• config/kernel/linux-uefi-arm64-edge.config (1 hunks)
• config/kernel/linux-uefi-x86-edge.config (1 hunks)

🧰 Additional context used

🧠 Learnings (10)

📓 Common learnings

Learnt from: rpardini
Repo: armbian/build PR: 8879
File: config/sources/families/uefi-x86.conf:0-0
Timestamp: 2025-11-06T15:36:04.606Z
Learning: As of PR #8879, the uefi-x86 family in the Armbian build system now includes kernel patches for the first time. The current and edge branches for uefi-x86 are specifically configured for Apple T2-based x86 machines, including T2-specific patches from the linux-t2 project and custom kernel configuration options for Apple hardware drivers.

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-199
Timestamp: 2025-09-25T18:37:00.330Z
Learning: In PR armbian/build#8661, line 235 of lib/functions/compilation/armbian-kernel.sh already contains the corrected comment "BPF link support for netfilter hooks" for NETFILTER_BPF_LINK, not the misleading "BPF_SYSCALL" comment that was flagged during review.

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-199
Timestamp: 2025-09-25T18:37:00.330Z
Learning: In PR armbian/build#8661, line 235 of lib/functions/compilation/armbian-kernel.sh already contains the corrected comment "BPF link support for netfilter hooks" for NETFILTER_BPF_LINK, not the misleading "BPF_SYSCALL" comment that was flagged during review.

Learnt from: tabrisnet
Repo: armbian/build PR: 8746
File: config/sources/families/filogic.conf:61-68
Timestamp: 2025-10-13T02:26:18.249Z
Learning: In the Armbian build system, the "edge" kernel branch is intended to be bleeding-edge and experimental. It does not require hardware testing or stability verification before merging, as it's expected to contain potentially unstable or untested code for early adopters and developers.

Learnt from: EvilOlaf
Repo: armbian/build PR: 8428
File: config/boards/lckfb-taishanpi.csc:5-9
Timestamp: 2025-07-25T03:51:50.830Z
Learning: When reviewing PRs in the Armbian build system, U-Boot defconfig files and patches may be added as part of the PR changes but might not be visible in the current repository clone state during review. It's important to check the actual PR file changes directly via GitHub API (https://api.github.com/repos/armbian/build/pulls/{pr_number}/files) to get the complete picture of what files are being added or modified, especially for U-Boot patches that will be applied during the build process.

Learnt from: EvilOlaf
Repo: armbian/build PR: 8428
File: config/boards/lckfb-taishanpi.csc:5-9
Timestamp: 2025-07-25T03:51:50.830Z
Learning: When reviewing PRs in the Armbian build system, U-Boot defconfig files and patches may be added as part of the PR changes but might not be visible in the current repository clone state during review. It's important to check the actual PR file changes directly via GitHub or the PR API to get the complete picture of what files are being added or modified.

Learnt from: igorpecovnik
Repo: armbian/build PR: 8789
File: config/kernel/linux-sunxi64-edge.config:839-839
Timestamp: 2025-10-22T07:56:19.424Z
Learning: In Linux kernel configuration, some `=y` (builtin) options are infrastructure or feature flags that enable subsystems or features for modular drivers, rather than directly compiling code into the kernel. For example, in Armbian wireless configs, options like CONFIG_SPARD_WLAN_SUPPORT=y, CONFIG_SC23XX=y, CONFIG_WCN_BSP_DRIVER_BUILDIN=y, CONFIG_UNISOC_WIFI_PS=y are module infrastructure/feature enablers, while the actual drivers (CONFIG_WLAN_UWE5621=m, CONFIG_WLAN_UWE5622=m) remain as loadable modules. These infrastructure options don't cause kernel bloat.

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-201
Timestamp: 2025-09-22T21:52:01.225Z
Learning: The kernel_config_set_m function in lib/functions/compilation/armbian-kernel.sh preserves existing 'y' (built-in) settings and only sets options to 'm' (module) when they are not already built-in, achieving "prefer modules but allow built-ins" behavior.

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-201
Timestamp: 2025-09-22T21:52:01.225Z
Learning: The kernel_config_set_m function in lib/functions/compilation/armbian-kernel.sh preserves existing 'y' (built-in) settings and only sets options to 'm' (module) when they are not already built-in, achieving "prefer modules but allow built-ins" behavior.

Learnt from: pyavitz
Repo: armbian/build PR: 8421
File: config/kernel/linux-sunxi64-edge.config:2664-2671
Timestamp: 2025-07-27T13:03:53.146Z
Learning: In the Armbian build system's kernel configuration, when CONFIG_EXT2_FS=y and CONFIG_EXT3_FS=y are both set to built-in, EXT4 filesystem support becomes automatically available/hard-coded without requiring an explicit CONFIG_EXT4_FS line in the configuration file. This is specific to how Armbian handles kernel configuration and differs from typical standalone Linux kernel configuration behavior.

Learnt from: tabrisnet
Repo: armbian/build PR: 0
File: :0-0
Timestamp: 2025-08-30T06:56:33.372Z
Learning: In Armbian kernel configuration, the BTRFS configuration logic preserves existing settings (whether built-in 'y' or module 'm') and only sets BTRFS_FS to module when it was previously disabled or not set, achieving "allow but not require" flexibility while maintaining backward compatibility.

Learnt from: pyavitz
Repo: armbian/build PR: 8421
File: config/kernel/linux-sunxi64-edge.config:2664-2671
Timestamp: 2025-07-27T13:03:53.146Z
Learning: In Linux kernel configuration for the Armbian build system, when CONFIG_EXT2_FS and CONFIG_EXT3_FS are both set to =y (built-in), CONFIG_EXT4_FS is automatically enabled/hard-coded and does not need to be explicitly specified in the configuration file. This dependency relationship means that EXT4 support is implicitly included when EXT2 and EXT3 are built into the kernel.

Learnt from: igorpecovnik
Repo: armbian/build PR: 8849
File: config/boards/radxa-e54c.csc:14-28
Timestamp: 2025-11-02T20:49:56.719Z
Learning: In Armbian board configuration files (config/boards/*.conf, *.csc, etc.), do not use kernel_config_set, kernel_config_set_m, kernel_config_set_y, or custom_kernel_config__* functions to modify kernel configuration. Kernel configuration is associated with LINUXFAMILY/BOARDFAMILY, not individual BOARD. Board-specific kernel modifications cause inconsistency in kernel packages published to the apt repository because boards within a family share the same kernel packages. Kernel configuration changes must be made in the appropriate kernel config file (e.g., config/kernel/linux-*-*.config) or in family configuration files (config/sources/families/*.conf, *.inc) instead.

Learnt from: rafayahmed317
Repo: armbian/build PR: 8484
File: config/kernel/linux-rk35xx-vendor.config:904-906
Timestamp: 2025-08-11T22:00:13.411Z
Learning: In the linux-rk35xx-vendor kernel, the LTE driver options (CONFIG_LTE, CONFIG_LTE_RM310, CONFIG_LTE_EM05) are defined as boolean in drivers/net/lte/Kconfig and cannot be built as modules - they must be either built-in (=y) or disabled.

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-201
Timestamp: 2025-09-22T21:52:01.225Z
Learning: In lib/functions/compilation/armbian-kernel.sh, the kernel_config_modifying_hashes array is not universally required for all kernel configuration functions - some functions like armbian_kernel_config__netkit() operate without it, and adding entries with '=m' would be incorrect when the actual result might be '=y' for options already built-in.

📚 Learning: 2025-11-06T15:36:04.606Z

Learnt from: rpardini
Repo: armbian/build PR: 8879
File: config/sources/families/uefi-x86.conf:0-0
Timestamp: 2025-11-06T15:36:04.606Z
Learning: As of PR #8879, the uefi-x86 family in the Armbian build system now includes kernel patches for the first time. The current and edge branches for uefi-x86 are specifically configured for Apple T2-based x86 machines, including T2-specific patches from the linux-t2 project and custom kernel configuration options for Apple hardware drivers.

Applied to files:

• config/kernel/linux-uefi-x86-edge.config

📚 Learning: 2025-10-22T07:56:19.424Z

Learnt from: igorpecovnik
Repo: armbian/build PR: 8789
File: config/kernel/linux-sunxi64-edge.config:839-839
Timestamp: 2025-10-22T07:56:19.424Z
Learning: In Linux kernel configuration, some `=y` (builtin) options are infrastructure or feature flags that enable subsystems or features for modular drivers, rather than directly compiling code into the kernel. For example, in Armbian wireless configs, options like CONFIG_SPARD_WLAN_SUPPORT=y, CONFIG_SC23XX=y, CONFIG_WCN_BSP_DRIVER_BUILDIN=y, CONFIG_UNISOC_WIFI_PS=y are module infrastructure/feature enablers, while the actual drivers (CONFIG_WLAN_UWE5621=m, CONFIG_WLAN_UWE5622=m) remain as loadable modules. These infrastructure options don't cause kernel bloat.

Applied to files:

• config/kernel/linux-uefi-x86-edge.config
• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-22T21:52:01.225Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-201
Timestamp: 2025-09-22T21:52:01.225Z
Learning: The kernel_config_set_m function in lib/functions/compilation/armbian-kernel.sh preserves existing 'y' (built-in) settings and only sets options to 'm' (module) when they are not already built-in, achieving "prefer modules but allow built-ins" behavior.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-27T21:47:58.020Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8678
File: config/kernel/linux-bcm2711-edge.config:859-861
Timestamp: 2025-09-27T21:47:58.020Z
Learning: In the Armbian build system, kernel configuration files in config/kernel/ are generated through an automated process: taking previous config → applying scripted changes from armbian-kernel.sh → running kernel's `make oldconfig` → processing by Armbian machinery back into config files. This automated process properly handles kernel configuration dependencies and reduces the likelihood of manual configuration errors.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-22T21:52:01.225Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8661
File: lib/functions/compilation/armbian-kernel.sh:194-201
Timestamp: 2025-09-22T21:52:01.225Z
Learning: In lib/functions/compilation/armbian-kernel.sh, the kernel_config_modifying_hashes array is not universally required for all kernel configuration functions - some functions like armbian_kernel_config__netkit() operate without it, and adding entries with '=m' would be incorrect when the actual result might be '=y' for options already built-in.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-27T21:50:04.845Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8678
File: config/kernel/linux-sm8250-edge.config:80-82
Timestamp: 2025-09-27T21:50:04.845Z
Learning: In the Armbian build system, kernel configuration files are generated through this automated process: taking previous config → applying scripted changes from armbian-kernel.sh → running kernel's `make oldconfig` → processing by Armbian machinery back into config files. This automated process properly handles kernel configuration dependencies and reduces the likelihood of manual configuration errors.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-27T21:49:55.796Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8678
File: config/kernel/linux-sm8250-current.config:78-80
Timestamp: 2025-09-27T21:49:55.796Z
Learning: In the Armbian build system, kernel configuration files are generated through an automated process: taking previous config → applying scripted changes from armbian-kernel.sh → running kernel's `make oldconfig` → processing by Armbian machinery back into config files. This automated process properly handles kernel configuration dependencies and reduces the likelihood of manual configuration errors.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-09-27T21:50:15.915Z

Learnt from: tabrisnet
Repo: armbian/build PR: 8678
File: config/kernel/linux-sunxi64-current.config:94-94
Timestamp: 2025-09-27T21:50:15.915Z
Learning: When kernel config files are generated through Armbian's automated process (previous config → armbian-kernel.sh changes → make oldconfig → Armbian machinery processing), manual config file edits are not appropriate since they would be overwritten. Deprecated option handling should be implemented in the automated tooling instead.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

📚 Learning: 2025-11-02T20:49:56.719Z

Learnt from: igorpecovnik
Repo: armbian/build PR: 8849
File: config/boards/radxa-e54c.csc:14-28
Timestamp: 2025-11-02T20:49:56.719Z
Learning: In Armbian board configuration files (config/boards/*.conf, *.csc, etc.), do not use kernel_config_set, kernel_config_set_m, kernel_config_set_y, or custom_kernel_config__* functions to modify kernel configuration. Kernel configuration is associated with LINUXFAMILY/BOARDFAMILY, not individual BOARD. Board-specific kernel modifications cause inconsistency in kernel packages published to the apt repository because boards within a family share the same kernel packages. Kernel configuration changes must be made in the appropriate kernel config file (e.g., config/kernel/linux-*-*.config) or in family configuration files (config/sources/families/*.conf, *.inc) instead.

Applied to files:

• config/kernel/linux-uefi-arm64-edge.config

🔇 Additional comments (2)

config/kernel/linux-uefi-x86-edge.config (1)

4766-4766: CONFIG_HYPERV promotion to built-in is justified and follows precedent.

Changing CONFIG_HYPERV from =m (module) to =y (built-in) aligns with the PR objective to work around the upstream kernel issue in commit e3ec97c3abaf2fb68cc755cae3229288696b9f3d. This is consistent with the existing cloud variant configuration (which already uses =y) and follows the pattern established in config/kernel/linux-uefi-arm64-edge.config. The upstream maintainer Wei Liu is aware of the underlying issue.

config/kernel/linux-uefi-arm64-edge.config (1)

4983-4983: Config change approved, but verify consistency across variants.

The change looks correct: CONFIG_HYPERV=y promotes Hyper-V support from a loadable module to built-in. This aligns with the PR objective as a workaround for upstream commit e3ec97c3abaf2fb68cc755cae3229288696b9f3d.

However, ensure that the corresponding x86 UEFI edge config file (linux-uefi-x86-edge.config) has the identical change, since the PR title mentions both uefi-{arm64|x86}-edge variants should be updated consistently.

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[github-actions]

✅ This PR has been reviewed and approved — all set for merge!