Re: [patch] x86/smpboot: Disable parallel bootup if cc_vendor != NONE

Tom Lendacky
2023-05-30T21:14:07Z

On 5/30/23 15:39, Thomas Gleixner wrote:
> On Tue, May 30 2023 at 15:03, Tom Lendacky wrote:
>> On 5/30/23 14:51, Thomas Gleixner wrote:
>>> That aside. From a semantical POV making this decision about parallel
>>> bootup based on some magic CC encryption attribute is questionable.
>>>
>>> I'm tending to just do the below and make this CC agnostic (except that
>>> I couldn't find the right spot for SEV-ES to clear that flag.)
>>
>> Maybe in sme_sev_setup_real_mode() in arch/x86/realmode/init.c? You could
>> clear the flag within the CC_ATTR_GUEST_STATE_ENCRYPT check.
>
> Eeew.
>
> Can we please have a AMD SEV-ES init specific place and not hijack some
> random code which has to check CC_ATTR_GUEST_STATE_ENCRYPT?

As long as it's not too early, you could try sme_early_init() in
arch/x86/mm/mem_encrypt_amd.c. Add a check for sev_status &
MSR_AMD64_SEV_ES_ENABLED and clear the flag.

Thanks,
Tom

>
> Thanks,
>
> tglx