From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir@xensource.com>
Subject: Re: NMI delivery not correctly working
Date: Tue, 24 Jul 2007 18:07:53 +0100
Message-ID: <C2CBF079.12F6E%keir@xensource.com>
References: <200707241747.23720.Christoph.Egger@amd.com>
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On 24/7/07 16:47, "Christoph Egger" <Christoph.Egger@amd.com> wrote:

> I know, there is a line "current->nmi_masked = 0;" in do_iret() in
> xen/arch/x86/x86_(32|64)/traps.c, but this is actually never called
> after NMI delivery.

Guests *must* use the iret hypercall when returning from their NMI handler.
This is giving a virtualised equivalent of the 'NMI-blocking' latch
implemented in x86 processors, which is reset by the IRET instruction.

 -- Keir