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From:   Andy Lutomirski <luto@kernel.org>
Date:   Tue, 7 Jul 2020 09:36:15 -0700
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Subject: Re: [PATCH v2 1/4] x86/cpufeatures: Add enumeration for SERIALIZE instruction
To:     Cathy Zhang <cathy.zhang@intel.com>
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On Mon, Jul 6, 2020 at 7:21 PM Cathy Zhang <cathy.zhang@intel.com> wrote:
>
> This instruction gives software a way to force the processor to complete
> all modifications to flags, registers and memory from previous instructions
> and drain all buffered writes to memory before the next instruction is
> fetched and executed.
>
> The same effect can be obtained using the cpuid instruction. However,
> cpuid causes modification on the eax, ebx, ecx, and ecx regiters; it
> also causes a VM exit.
>
> A processor supports SERIALIZE instruction if CPUID.0x0x.0x0:EDX[14] is
> present. The CPU feature flag is shown as "serialize" in /proc/cpuinfo.
>
> Detailed information on the instructions and CPUID feature flag SERIALIZE
> can be found in the latest Intel Architecture Instruction Set Extensions
> and Future Features Programming Reference and Intel 64 and IA-32
> Architectures Software Developer's Manual.

Can you also wire this up so sync_core() uses it?

Thanks,
Andy