Messages in this thread | | | Date | Mon, 13 Jun 2011 09:34:44 +0800 | From | Huang Ying <> | Subject | Re: [RFC] x86, NMI, Treat unknown NMI as hardware error |
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On 06/09/2011 08:09 PM, Don Zickus wrote: > On Fri, May 20, 2011 at 04:13:25PM +0800, Huang Ying wrote: >> Hi, Don, >> >> On 05/18/2011 03:07 AM, Don Zickus wrote: >>> On Tue, May 17, 2011 at 11:18:59AM -0700, Andi Kleen wrote: >>>>> Random thought, in the Firmware first mode of HEST (which is the only way >>>>> GHES records get produced??), does an SCI happen first to jump into the >>>>> firmware for processing, then an NMI? >>>> >>>> Either that or there is a separate service processor which handles it. >>>> Presumably it depends a lot on the particular system. >>> >>> Ah interesting. I was going to suggest somehow setting a bit when an SCI >>> comes in and check that bit in the unknown NMI path as a possible hint >>> that the NMI might be related to HEST (sorta how we flag unknown NMIs in >>> the perf code). >>> >>> It was just an idea. Obviously a service processor will make that more >>> difficult. :-) >> >> Hmm, what's the conclusion? Do you think unknown NMI should be seen as >> hardware error? At least on some white listed machines? > > I still sorta have the opinion that a hardware error should be able be > recognizable either through a GHES record or a bit in the southbridge. > Whereas an unknown NMI is something lost and has no owner as the result of > either a buggy NMI handler or an unimplemented NMI handler. > > Yeah, I can see hardware errors coming in through an unknown NMI but to me > (from what I am reading about with APEI/GHES) is those should be trapped > by the firmware and if they aren't then the firmware is broken. In those > cases it should be up to the OEM to provide proper firmware (even certify > them) to allow the proper experience, which includes being properly > trapped by an NMI handler. > > Perhaps I am a bit naive in my belief but I am a little nervous panicing > all the time on unknown NMIs when we are still chasing missed perf NMIs on > a loaded box.
I think things SHOULD go this way too. This just is not the reality.
Best Regards, Huang Ying
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