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Date: Wed, 25 Jul 2012 15:51:45 +0400
From: Vladimir Davydov <vdavydov@parallels.com>
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To: Andi Kleen <ak@linux.intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Borislav Petkov <borislav.petkov@amd.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] cpu: intel, amd: mask cleared cpuid features
References: <73e09fb43e37de851acda10dc64bc495a5b68357.1342801662.git.vdavydov@parallels.com> <dd185bfa60b6478e7eb1bce455c9d082ec884abe.1342801662.git.vdavydov@parallels.com> <20120720171002.GE13032@tassilo.jf.intel.com>
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On 07/20/2012 09:10 PM, Andi Kleen wrote:
>> +					unsigned int *msr_ext_cpuid_mask)
>> +{
>> +	unsigned int msr, msr_ext;
>> +
>> +	msr = msr_ext = 0;
>> +
>> +	switch (c->x86_model) {
> You have to check the family too.
>
>> +
>> +	return msr;
>> +}
>> +
>> +static void __cpuinit intel_mask_cpu_caps(struct cpuinfo_x86 *c)
>> +{
>> +	u32 low, high;
>> +	unsigned int msr_cpuid_mask, msr_ext_cpuid_mask;
>> +
>> +	msr_cpuid_mask = intel_cpuid_mask_msr(c,&msr_ext_cpuid_mask);
>> +	if (msr_cpuid_mask) {
>> +		set_cpu_cap(c, X86_FEATURE_CPUIDMASK);
>> +
>> +		rdmsr(msr_cpuid_mask, low, high);
> And please use rdmsrl(), rdmsr() is so 90ies
>
> Other than that patch looks good. I presume it will be useful for
> other things than just migration too.
>
> -Andi
>

Thank you for review, but we've decided to drop this since the kernel 
does not seem to be a suitable place for such "tweaking".