Re: [PATCH v4 01/11] liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option

[email protected] writes:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] The patch introduces the `LIVEUPDATE_GUEST_MEMFD` Kconfig option claiming to enable a new feature, but there is no actual implementation provided.
> --
>
> --- Patch [1]: [PATCH v4 01/11] liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option ---
> commit e0c3fde657d56c548cd9a7467d2143f0f42c5242
> Author: Tarun Sahu <[email protected]>
>
> liveupdate: Add LIVEUPDATE_GUEST_MEMFD config option
>
> This commit introduces the LIVEUPDATE_GUEST_MEMFD Kconfig option, which aims
> to enable live update support for KVM guest_memfd files.
>
>> diff --git a/kernel/liveupdate/Kconfig b/kernel/liveupdate/Kconfig
>> index 1a8513f16ef7c..0bbc4037192e9 100644
>> --- a/kernel/liveupdate/Kconfig
>> +++ b/kernel/liveupdate/Kconfig
>> @@ -88,4 +88,19 @@ config LIVEUPDATE_MEMFD
>>
>>  	  If unsure, say N.
>>
>> +config LIVEUPDATE_GUEST_MEMFD
>> +	bool "Live update support for guest_memfd"
>> +	depends on LIVEUPDATE
>> +	depends on KVM_GUEST_MEMFD
>> +	default LIVEUPDATE
>
> [Severity: Medium]
> Is the implementation for this feature missing from this patch?
>
> The commit message notes that this patch enables live update support for KVM
> guest_memfd files, but the newly added LIVEUPDATE_GUEST_MEMFD symbol appears
> to be unreferenced in the tree. Since there are no Makefiles, C files, or
> preprocessor checks that use it, this currently acts as dead code.
>
> Could the implementation be missing, or was this intended to be introduced as
> part of a larger series where the symbol is used in a subsequent patch?
>

Sashiko is right here, I think this patch should be squashed with the
first usage.

>> +	help
>> +	  Enable live update support for KVM guest_memfd files. This allows
>> +	  preserving VM Memory backed by guest_memfd file across kernel live
>> +	  updates.
>> +
>> +	  This can only be used for the guest_memfd that are fully-shared
>> +	  and pre-faulted.
>> +
>> +	  If unsure, say N.
>> +
>>  endmenu
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1