Solved KVM QEMU --Change CPU topography to pass W11 install CPU limitation

jimbo45 · Apr 29, 2024

Hi folks

question also for @cereberus (you seem to have become the current guy to ask on all things HYPER-V these days).

Not sure if HYPER-V can do this but if creating a Windows 11 VM or updating one on KVM/QEMU on typical Linux hosts then setting the CPU topography from the drop down lists to Ivy Sandy Bridge then install proceeds properly and no message from Windows Update if using the insider builds (via WU, not the ISO from UUPDUMP etc).

Host is a laptop running i5 gen 6 processor - but in the VM config : set as an Intel XEON E3-12xx (v2). Works perfectly -- I selected 2 virtual cpu's.

Can Hyper-V do this even if the config needs to be changed manually.

and the config :

Actual physical machine : (tested on opensuse tumbleweed)

Cheers

jimbo

Hopachi · May 5, 2024

From what I experienced so far, the CPU topography in KVM/QEMU allows you to select older models for compatibility purposes.

Your host is Intel gen6, while on your screenshot you have IvyBridge which is gen3 and SandyBridge is gen2, even older.

Here for instance I have a gen3 host Intel i7-3632QM that in the past was presented to VMs as Intel XEON E3-12xx (same gen3) on older KVM, where now with cpu-passthrough will be presented exactly like that (Intel i7) to the VM.

Hyper-V does cpu-passthrough by default and I don't think it's possible to change that. Maybe in some very advanced configs (just assuming) but not on regular installs.

cereberus · May 5, 2024

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jimbo45 said:
Hi folks

question also for @cereberus (you seem to have become the current guy to ask on all things HYPER-V these days).

Not sure if HYPER-V can do this but if creating a Windows 11 VM or updating one on KVM/QEMU on typical Linux hosts then setting the CPU topography from the drop down lists to Ivy Sandy Bridge then install proceeds properly and no message from Windows Update if using the insider builds (via WU, not the ISO from UUPDUMP etc).

Host is a laptop running i5 gen 6 processor - but in the VM config : set as an Intel XEON E3-12xx (v2). Works perfectly -- I selected 2 virtual cpu's.

Can Hyper-V do this even if the config needs to be changed manually.

View attachment 94696

and the config :
View attachment 94697

Actual physical machine : (tested on opensuse tumbleweed)

View attachment 94698

Cheers

jimbo

Sorry I do not know but I do know I use it with W11 on a W10 laptop that is not W11 compatible.

I have tried it on several non compatible devices and it just works.

I don't think Hyper-V really cares what the host CPU is. It wil be interesting to see what happens when forthcoming hardware constraint is introduced.