Re: [PATCH v16 8/8] x86/smpboot: Allow parallel bringup for SEV-ES

Tom Lendacky
2023-03-23T18:28:50Z

On 3/23/23 10:34, Woodhouse, David wrote:
> On Thu, 2023-03-23 at 08:16 -0500, Tom Lendacky wrote:
>>
>> Maybe call this sev_early_get_cpuid_0b() or such to imply that the MSR
>> protocol is being used and only retrieving / returning edx.
>
> Or indeed sev_early_get_apicid() since that's what it's actually doing,
> and the caller doesn't care *how*.

Sounds good.

>
>> Also, since it is a function now and can be used at any point, the current
>> GHCB MSR should be saved on entry and restored on exit.
>
> Well, I don't know that it should be callable at any point. This is
> only supposed to be called from head_64.S.

I agree. But once it's there, someone somewhere in the future may look and
go, oh, I can call this. So I think it either needs a nice comment above
it about how it is currently used/called and what to do if it needs to be
called from someplace other than head_64.S or the MSR needs to be
saved/restored.

Thanks,
Tom

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