Messages in this thread | | | Date | Wed, 15 Dec 2021 19:33:47 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v8 01/40] x86/compressed/64: detect/setup SEV/SME features earlier in boot |
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On Wed, Dec 15, 2021 at 12:17:44PM -0600, Venu Busireddy wrote: > Boris & Tom, which implementation would you prefer?
I'd like to see how that sme_sev_parse_cpuid() would look like. And that function should be called sev_parse_cpuid(), btw.
Because if that function turns out to be a subset of your suggestion, functionality-wise, then we should save us the churn and simply do one generic helper.
Btw 2, that helper should be in arch/x86/kernel/sev-shared.c so that it gets shared by both kernel stages instead having an inline function in some random header.
Btw 3, I'm not crazy about the feature testing with the @features param either. Maybe that function should return the eYx register directly, like the cpuid_eYx() variants in the kernel do, where Y in { a, b, c, d }.
The caller can than do its own testing:
eax = sev_parse_cpuid(RET_EAX, ...) if (eax > 0) { if (eax & BIT(1)) ...
Something along those lines, for example.
But I'd have to see a concrete diff from Michael to get a better idea how that CPUID parsing from the CPUID page is going to look like.
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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