From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <jbeulich@novell.com>
Subject: Re: NMI deferral on i386
Date: Wed, 16 May 2007 12:10:17 +0200
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To: Keir Fraser <keir@xensource.com>
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>It sounds a bit painful. Also it's the exit-to-guest path that is more of =
a
>pain to deal with. In this case we may have restored a segment register =
by
>the time we take the NMI. What do we do in this case about restoring the
>segment register safely? Races in updating GDT/LDT may mean that the =
reload
>still may fault, even though it didn't just before; also we may need to =
do
>work in Xen (e.g., shadow-mode stuff) in interrupts-enabled context to =
fix
>up a #GP or #PG.

Indeed. Nevertheless, for non-restartable MCEs, deferral is impossible, =
and
hence some mechanism would still be needed (unless we say the machine's
going down anyway in this case and we don't care about getting a proper
reason logged).

Jan