Re: x86, microcode: BUG: microcode update that changes x86_capability

[Borislav Petkov]

On Thu, Sep 18, 2014 at 06:00:12PM -0700, Andy Lutomirski wrote:
> Yes, but how?  I assume that BIOS isn't switching between two
> different ucode blobs, and I don't know about any wrcpuid instruction.
> So there must be *some* way, at least on new ucode (and maybe on old
> ucode) to change that bit.

I'd venture a guess that WRMSR to some reg should give you that, if they
expose it.

-- 
Regards/Gruss,
    Boris.
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