Can't use EPYC-ROME CPU after update

[jaytee129]

@jaytee129

can you run lscpu and ensure that xsave is enabled for EPYC.
also compare the features with and without migitations being enabled and see if you also losing other features.

the host should only pass through to windows whats actually present on the host.

is your bios up-to-date and are all the virt features fully enabled in it including nested virtualisation which will be required now for some windows features like VBS/HVCI which might be active in your VM because they was enabled when it was created but are now missing when you run it.

Yes, lscpu shows xsave listed as one of the "Flags" (meaning, I assume, enabled), and is not mentioned for any of the Vulnerability mitigations listed - see attached lscpu output.

What I can't tell is what the difference is between "host" and "EPYC" as a CPU, and why the Windows VM struggles with the former but not the latter. Is there a way to tell what features shown at proxmox host level (via lscpu) make it to the VM?

I have no idea where to look to say if

all the virt features fully enabled in it including nested virtualisation which will be required now for some windows features like VBS/HVCI which might be active in your VM because they was enabled when it was created but are now missing when you run it.

Yes, BIOS is up to date