Messages in this thread | | | Subject | Re: [V5][PATCH 4/6] x86, nmi: add in logic to handle multiple events and unknown NMIs | From | Peter Zijlstra <> | Date | Wed, 21 Sep 2011 17:33:52 +0200 |
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On Wed, 2011-09-21 at 17:18 +0200, Robert Richter wrote: > 1. The cpu executes some microcode or SMM code. > 2. HW triggers the first NMI, an NMI is pending. > 3. HW triggers a second NMI, the NMI is still pending. > 4. The cpu finished microcode or SMM code. > 5. NMI handler is called, no NMI pending anymore. > 6. Return from NMI handler.
Even without SMM, all you need is two different NMI users to trigger while an NMI is in flight.
Wouldn't be entirely impossible to trigger if you have non-fatal-MCE/hardware-NMI-switch/PMI all active.
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