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Date: Wed, 14 Sep 2011 19:28:38 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>, Don Zickus <dzickus@redhat.com>,
        Jeremy Fitzhardinge <jeremy@goop.org>,
        Peter Zijlstra <peterz@infradead.org>,
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        Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
        Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH 08/13] xen/pvticketlock: disable interrupts while blocking
Message-ID: <20110914172838.GV7761@one.firstfloor.org>
References: <20110907155657.GX5795@redhat.com> <4E679AF4.50209@redhat.com> <20110907165203.GQ6838@redhat.com> <4E67A551.4000502@redhat.com> <20110913184044.GN5795@redhat.com> <20110913190320.GR7761@one.firstfloor.org> <20110913192152.GO5795@redhat.com> <4E7050F7.3000208@redhat.com> <20110914144926.GU7761@one.firstfloor.org> <4E70C1BE.7060209@redhat.com>
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> If an NMI hits in an interrupt handler, or in the "after hlt" section 
> before the write-to-last-nmi-rip, then we'll see that %rip has changed.  
> If it hits after the write-to-last-nmi-rip instruction (or in the hlt 
> itself), then we'll also see that %rip has changed, due to the effect of 
> that instruction.

It won't handle multiple NMIs in halt. I assume that's reasonable common.

-Andi