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Subject: Re: [PATCH] x86/cpu: clear X86_BUG_SPECTRE_V2 on Zhaoxin family 7
 CPUs
To:     Thomas Gleixner <tglx@linutronix.de>, <mingo@redhat.com>,
        <bp@alien8.de>, <hpa@zytor.com>, <x86@kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <DavidWang@zhaoxin.com>, <CooperYan@zhaoxin.com>,
        <QiyuanWang@zhaoxin.com>, <HerryYang@zhaoxin.com>
References: <1579075500-7065-1-git-send-email-TonyWWang-oc@zhaoxin.com>
 <87h80wxsze.fsf@nanos.tec.linutronix.de>
From:   Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Message-ID: <d85ca29e-2249-a55d-5f2a-0cefc10772b2@zhaoxin.com>
Date:   Thu, 16 Jan 2020 11:51:39 +0800
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On 16/01/2020 06:19, Thomas Gleixner wrote:
> Tony W Wang-oc <TonyWWang-oc@zhaoxin.com> writes:
> 
>> These CPUs are not affected by spectre_v2, so clear spectre_v2 bug flag
>> in their specific initialization code.
>>  
>>  	if (cpu_has(c, X86_FEATURE_VMX))
>>  		centaur_detect_vmx_virtcap(c);
>> +
>> +	if (c->x86 == 7) {
>> +		setup_clear_cpu_cap(X86_BUG_SPECTRE_V2);
>> +		clear_bit(X86_BUG_SPECTRE_V2, (unsigned long *)cpu_caps_set);
> 
> No. Please use cpu_vuln_whitelist. It exists for exactly this
> purpose. You just need to extend it with a NO_SPECTRE_V2 bit.

Got, done.

Sincerely
TonyWWang-oc