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[Xen-devel] NMI deferral on i386

To: <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] NMI deferral on i386
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Tue, 15 May 2007 16:46:00 +0200
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Looking at cloning this logic to more properly support MCE, I see two issues
with this code:

- by using iret, the NMI is being acknowledged to the CPU, and since nothing
  was done to address its reason, I can't see why it shouldn't re-trigger right
  after that iret (unless it was sent as an IPI)
- by re-issuing it on vector 31, the resulting interrupt will have lower 
priority
  than any external interrupt, hence all pending interrupts will be serviced
  before getting to actually handle the NMI; ideally this should use the highest
  possible vector, but since priorities are grouped anyway, at least allocating
  the vector from the high priority pool would seem necessary

Thanks, Jan


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