Re: [PATCH v1 1/3] x86/cpu/AMD: Make LFENCE a serializing instruction

[Tom Lendacky]

On 1/5/2018 10:35 AM, Brian Gerst wrote:
> On Fri, Jan 5, 2018 at 11:07 AM, Tom Lendacky <thomas.lendacky@xxxxxxx> wrote:
>> To aid in speculation control, make LFENCE a serializing instruction.
>> This is done by setting bit 1 of MSR 0xc0011029 (DE_CFG).  Some families
>> that support LFENCE do not have this MSR.  For these families, the LFENCE
>> instruction is already serializing.
> 
> Does this require a microcode update?

No, it doesn't.

Thanks,
Tom

> 
> --
> Brian Gerst
>