Upgrading from x86_64-v2

[Dwid]

Hi, what are the consequences if I change the CPU architecture of a VM from x86_64-v2 to x86_64-v3?
From my testing I reall can't see any issues, everything seems to be running fine. But I guess given the changes that Redhat have introduces with RHEL 10 and setting x86_64-v3 as a requirement for upgrading it seems relevant to ask the question.
I would assume that it would prove problematic going from x86_64-v3 to x86_64-v2 and not the other way.
Anyone who might shed some light on this, and maybe have some experience in this?

Dwid.

 

[bbgeek17]

You can find functional differences between CPU feature sets across x86-64 microarchitectures here: x86-64 Feature Levels – Wikipedia

Changing the CPU type in a VM requires a cold start (full power-off and restart) for the new settings to take effect.

Most modern operating systems, including Windows, handle such changes without issue. However, some software (including OS licensing mechanisms) may tie activation to a hardware fingerprint, which could be affected by the CPU change.

Take a snapshot of the VM before testing any changes.

Good luck

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[SteveITS]

Adding to the above reply, we haven't noticed anything when changing CPU types.

There's a CPU compatibility list at https://qemu-project.gitlab.io/qemu/system/qemu-cpu-models.html