Re: [PATCH v1 2/4] x86/fred: Write to FRED MSRs with wrmsrns()

From: H. Peter Anvin
Date: Thu Jul 04 2024 - 03:59:45 EST


On July 3, 2024 10:57:29 PM PDT, Xin Li <xin@xxxxxxxxx> wrote:
>On 7/3/2024 9:18 AM, Andrew Cooper wrote:
>> On 03/07/2024 5:06 pm, H. Peter Anvin wrote:
>>> I believe tglx declared53 to use them unconditionally since FRED depends on WRMSRNS (and the kernel enforces that.)
>>
>> I know that Linux has chosen to have this as a software-enforced
>> requirement.
>>
>> The dependency does not exist architecturally, and just because it
>> happens to be true on Intel processors doesn't mean it's true of other
>> implementations.
>
>Won't it be way better if we could have all x86 vendors agree on it?
>
>

It was tglx' explicit request to keep it simple unless someone objects. All it would take is for someone to come up with a countercase.