Messages in this thread | | | Date | Mon, 12 Mar 2012 13:16:44 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 1/2] boot: ignore early NMIs |
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On 03/12/2012 01:04 PM, H. Peter Anvin wrote: > On 03/12/2012 01:01 PM, Eric W. Biederman wrote: >> >> The basic problem is which source do we block this at? How many >> sources are their? And architecturally last I looked x86 no longer >> has a NMI disable EFI and similar systems want to get away without >> a CMOS legacy clock because designers so often get them wrong. >> > > On all processors which have an LAPIC you can block all NMI sources at > the LAPIC. I think it's safe to assume that if you don't have an LAPIC > -- an ancient system by now -- you have port 70h. >
One thing: *disabling* the LAPIC will allow external NMIs coming in on LINT1 through, since the LAPIC in the disabled state tries to mimic the no-LAPIC configuration. So I don't think you want to disable LAPIC as much as disable the interrupt vectors within.
-hpa
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