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Re: [PATCH] x86/cpuid: Deal with broken firmware once more

From Boris Ostrovsky <boris.ostrovsky@oracle.com>
Newsgroups linux.kernel
Subject Re: [PATCH] x86/cpuid: Deal with broken firmware once more
Date 2016-11-10 15:10 +0100
Message-ID <sBYdc-7fw-9@gated-at.bofh.it> (permalink)
References (7 earlier) <sBg2u-2e5-21@gated-at.bofh.it> <sBhrz-3gP-1@gated-at.bofh.it> <sBD8K-HA-35@gated-at.bofh.it> <sBOGW-8w1-5@gated-at.bofh.it> <sBVyG-5qG-23@gated-at.bofh.it>
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On 11/10/2016 06:13 AM, Thomas Gleixner wrote:
> On Thu, 10 Nov 2016, M. Vefa Bicakci wrote:
>
>> I have found that your patch unfortunately does not improve the situation
>> for me. Here is an excerpt obtained from the dmesg of a kernel compiled
>> with this patch *as well as* Sebastian's patch:
>> [    0.002561] CPU: Physical Processor ID: 0
>> [    0.002566] CPU: Processor Core ID: 0
>> [    0.002572] [Firmware Bug]: CPU0: APIC id mismatch. Firmware: ffff CPUID: 2
> So apic->cpu_present_to_apicid() gives us a completely bogus APIC id which
> translates to a bogus package id. And looking at the XEN code:
>
>    xen_pv_apic.cpu_present_to_apicid = xen_cpu_present_to_apicid,
>
> and xen_cpu_present_to_apicid does:
>
> static int xen_cpu_present_to_apicid(int cpu)
> {
>         if (cpu_present(cpu))
>                 return xen_get_apic_id(xen_apic_read(APIC_ID));
>         else
>                 return BAD_APICID;
> }
>
> So independent of which present CPU we query we get just some random
> information, in the above case we get BAD_APICID from xen_apic_read() not
> from the else path as this CPU _IS_ present.
>
> What's so wrong with storing the fricking firmware supplied APICid as
> everybody else does and report it back when queried?

By firmware you mean ACPI? It is most likely not available to PV guests.
How about returning cpu_data(cpu).initial_apicid?

And what was the original problem?

-boris

>
> This damned attitude of we just hack the code into submission and let
> everybody else deal with the outcoming is utterly annoying.
>
> Thanks,
>
> 	tglx

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Thread

[RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-11-02 13:30 +0100
  Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-02 23:50 +0100
    Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-11-03 18:50 +0100
      Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-04 13:30 +0100
        Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-11-04 19:10 +0100
          Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-04 21:50 +0100
            Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-11-04 22:00 +0100
    Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate  memory Thomas Gleixner <tglx@linutronix.de> - 2016-11-07 17:30 +0100
      Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-07 18:10 +0100
        Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate  memory Thomas Gleixner <tglx@linutronix.de> - 2016-11-07 21:30 +0100
          Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-08 15:30 +0100
            Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate  memory Thomas Gleixner <tglx@linutronix.de> - 2016-11-08 15:40 +0100
              Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate memory "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-08 16:00 +0100
                Re: [RFC PATCH] perf/x86/intel/rapl: avoid access unallocate  memory Thomas Gleixner <tglx@linutronix.de> - 2016-11-08 17:30 +0100
                [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-09 16:40 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-09 16:50 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Peter Zijlstra <peterz@infradead.org> - 2016-11-09 17:10 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-09 17:40 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-09 19:50 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-09 19:20 +0100
                [tip:x86/urgent] x86/cpu: Deal with broken firmware (VMWare/XEN) tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2016-11-09 21:30 +0100
                Re: [tip:x86/urgent] x86/cpu: Deal with broken firmware (VMWare/XEN) Alok Kataria <akataria@vmware.com> - 2016-11-11 07:00 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more "M. Vefa Bicakci" <m.v.b@runbox.com> - 2016-11-10 05:00 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-10 12:00 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-10 12:20 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-10 12:20 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Peter Zijlstra <peterz@infradead.org> - 2016-11-10 12:50 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-11-10 15:10 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more "Charles (Chas) Williams" <ciwillia@brocade.com> - 2016-11-10 16:10 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-11-10 16:40 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2016-11-10 17:00 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-10 18:20 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-10 16:20 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-11-10 16:40 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Thomas Gleixner <tglx@linutronix.de> - 2016-11-10 18:20 +0100
                Re: [PATCH] x86/cpuid: Deal with broken firmware once more Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-11-10 19:10 +0100

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