linux-kernel - Re: [PATCH v5 13/19] x86/cpufeatures: Add flag to track whether MSR IA32_FEAT

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Message-ID: <1eaf6fbe-0adb-5074-3bc4-1e8327e0cdb3@intel.com>
Date:   Tue, 25 Feb 2020 14:52:32 -0800
From:   Jacob Keller <jacob.e.keller@...el.com>
To:     Sean Christopherson <sean.j.christopherson@...el.com>
Cc:     TonyWWang-oc@...oxin.com, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, bp@...en8.de, bp@...e.de,
        hpa@...or.com, jacob.jun.pan@...ux.intel.com,
        jarkko.sakkinen@...ux.intel.com, jmattson@...gle.com,
        jolsa@...hat.com, joro@...tes.org, kvm@...r.kernel.org,
        lenb@...nel.org, linux-edac@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org,
        linux-pm@...r.kernel.org, mark.rutland@....com, mingo@...hat.com,
        namhyung@...nel.org, pbonzini@...hat.com, peterz@...radead.org,
        rkrcmar@...hat.com, shuah@...nel.org, tglx@...utronix.de,
        tony.luck@...el.com, vkuznets@...hat.com, wanpengli@...cent.com,
        x86@...nel.org
Subject: Re: [PATCH v5 13/19] x86/cpufeatures: Add flag to track whether MSR
 IA32_FEAT_CTL is configured

On 2/25/2020 2:12 PM, Sean Christopherson wrote:
> On Tue, Feb 25, 2020 at 01:49:13PM -0800, Jacob Keller wrote:
>> Hi Sean,
>>
>> I suspect something is wrong and the features are enabled even though
>> the BIOS has it disabled, leading to later failure because of this.
> 
> Hrm.  On the failing kernel, what are the values of MSR 0x3a for all CPUs,
> i.e. what's the output of 'sudo rdmsr -a 0x3a'?
> 

On the old (fedora 30) kernel, every cpu reports as '1'.

I can't easily test the failing kernel because it crashes during boot.

Thanks,
Jake