Re: [PATCH] db: add Hyper-V leaf 0x40000001

Hi Ahmed,

On Tue, Aug 18, 2026 at 08:50:40PM +0200, Ahmed S. Darwish wrote:
>Hi Luigi,
>
>On Fri, 07 Aug 2026, Luigi Leonardi wrote:
>>
>> Thanks for the patch, this would be very useful for SVSM!
>>
>
>Sorry for the late response.
>
>Could you point me please to the kernel patch queue in need of this?
>
>So far, no hypervisor leaf callsites are converted. See:
>
>https://msgid.link/[email protected]
>
>

Thanks for sharing this link!

SVSM[1] is a firmware used for confidential computing written in rust.
In this project we consume a rust crate called cpufeature[2] that is
automatically generated from the x86-cpuid-db, that exports the cpuid
leaves to rust structures. Our plan is to upstream the conversion script
once we finalize the crate design.

In SVSM we do use the HV leaf[3] to detect if the code is running on an
hyper-v system.

Hope that helps!

Thanks,
Luigi


[1]https://github.com/coconut-svsm/svsm/
[2]https://github.com/coconut-svsm/cpufeature/
[3]https://github.com/coconut-svsm/svsm/blob/ec10d69313742cc337b696a800f6863b12c9f824/kernel/src/cpu/features.rs#L41