Re: [PATCH PATCH 9/9] x86/rfds: Exclude P-only parts from the RFDS affected list

From: Dave Hansen
Date: Mon Jun 17 2024 - 11:20:08 EST


On 6/17/24 02:43, Andrew Cooper wrote:
> On 17/06/2024 10:12 am, Pawan Gupta wrote:
>> + VULNBL_INTEL_CPU_TYPE (RAPTORLAKE, X86_CPU_TYPE_INTEL_ATOM, RFDS),
>> + VULNBL_INTEL_CPU_TYPE (ALDERLAKE, X86_CPU_TYPE_INTEL_ATOM, RFDS),
>
> How does this work?
>
> Being __initconst, this is only evaluated on the BSP.
>
> P-only and mixed P/E systems won't see X86_CPU_TYPE_INTEL_ATOM, even if
> there are ATOM APs to bring up later.

The X86_CPU_TYPE_* is only used on the boot CPU on non-hybrids. Hybrids
(independent of the boot CPU type) should be considered vulnerable no
matter what.