linux-kernel - RFC: can we kill the KEEP

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Message-ID: <4D4AE3AE.7000009@zytor.com>
Date:	Thu, 03 Feb 2011 09:19:42 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
CC:	Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	"Pan, Jacob jun" <jacob.jun.pan@...el.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Andres Salomon <dilinger@...ued.net>
Subject: RFC: can we kill the KEEP_SEGMENTS bzImage flag?

>   Bit 6 (write): KEEP_SEGMENTS
>         Protocol: 2.07+
>         - If 0, reload the segment registers in the 32bit entry point.
>         - If 1, do not reload the segment registers in the 32bit entry point.
>                 Assume that %cs %ds %ss %es are all set to flat segments with
>                 a base of 0 (or the equivalent for their environment).

Does anything actually rely on this bit or can we kill it?  I think it
was added as a crutch for paravirtualization, but I'm being told it is
not used...

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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