linux-kernel - Re: [PATCH v1 1/1] x86: Skip WBINVD instruction for VM guest

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Date:   Tue, 16 Nov 2021 08:36:53 -0800
From:   Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H . Peter Anvin" <hpa@...or.com>, Tony Luck <tony.luck@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 1/1] x86: Skip WBINVD instruction for VM guest

Hi,

On 11/16/21 8:24 AM, Borislav Petkov wrote:
> On Mon, Nov 15, 2021 at 04:50:27PM -0800, Kuppuswamy Sathyanarayanan wrote:
>> -#define ACPI_FLUSH_CPU_CACHE()	wbinvd()
>> +#define ACPI_FLUSH_CPU_CACHE()				\
>> +do {							\
>> +	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))	\
> 
> cpu_feature_enabled()
> 
> If you wanna query a X86_FEATURE_* bit, from now on, use only this
> function.
> 

Ok. I will change it in next version.

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer