Re: [linux-kernel] Re: [PATCH] x86: provide a DMI based port 0x80I/O delay override.

From: H. Peter Anvin
Date: Wed Jan 09 2008 - 00:21:22 EST


Zachary Amsden wrote:

BTW, it isn't ever safe to pass port 0x80 through to hardware from a
virtual machine; some OSes use port 0x80 as a hardware available scratch
register (I believe Darwin/x86 did/does this during boot).

That's funny, because there is definitely no guarantee that you get back what you read (well, perhaps there is on Apple.)

-hpa
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