Re: [BUG] x86 kenel won't boot under Virtual PC

From: H. Peter Anvin
Date: Mon Sep 08 2008 - 11:39:50 EST


Ingo Molnar wrote:

I thought you agreed that CPU virtualization can be a problem? That was the whole excuse for why the dynamic code was changed. Why would it not be true for the static code?

The fact is, if you want to run on a Core2 or other modern CPU, then "Virtual PC" is apparently buggy in this respect. You worked around it for the dynamic choice - but that's totally _pointless_ if you then don't want to work around it for the static one.

yes. X86_P6_NOPS is a totally insignificant optimization and if it makes _any_ CPU not boot (be that virtual or real), then it's frankly not worth it.

David, exactly how does the kernel fail to boot with latest -git? (v2.6.27-rc5-313-g64f996f or later) Does detect_nopl() run? It really should, and it should detect the non-working instructions.


It almost certainly never gets as far as detect_nopl().

-hpa
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