Re: [PATCH v7 05/22] x86/sev: Move GHCB page based HV communication out of startup code

Ard Biesheuvel
2025-09-01T14:26:53Z

On Mon, 1 Sept 2025 at 16:26, Borislav Petkov <bp@alien8.de> wrote:
>
> On Mon, Sep 01, 2025 at 04:02:04PM +0200, Ard Biesheuvel wrote:
> > Are you sure this can be removed? It is tested in other places too
> > (arch/x86/coco/sev/core.c), and AIUI, it is a Linux defined CPU
> > feature so it will never be set automatically.
>
> It it set in scattered.c for the "late" code like sev/core.c:
>
> arch/x86/kernel/cpu/scattered.c:51: { X86_FEATURE_COHERENCY_SFW_NO, CPUID_EBX, 31, 0x8000001f, 0 },
>
> Tom added it to boot/cpuflags.c, in addition, for the early testing which
> we're doing differently now.
>

Ah ok, yes that makes sense.