From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 08/13] xen/pvticketlock: disable interrupts while blocking
Date: Wed, 14 Sep 2011 22:26:21 +0300
Message-ID: <4E70FFDD.80405@redhat.com>
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> <20110914172838.GV7761@one.firstfloor.org>
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To: Andi Kleen <andi@firstfloor.org>
Cc: Don Zickus <dzickus@redhat.com>, Jeremy Fitzhardinge <jeremy@goop.org>, Peter Zijlstra <peterz@infradead.org>, "H. Peter Anvin" <hpa@zytor.com>, Linus Torvalds <torvalds@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>, the arch/x86 maintainers <x86@kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Nick Piggin <npiggin@kernel.dk>, Marcelo Tosatti <mtosatti@redhat.com>, KVM <kvm@vger.kernel.org>, Xen Devel <xen-devel@lists.xensource.com>, Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On 09/14/2011 08:28 PM, Andi Kleen wrote:
> >  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.
>

Why not?

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.