Messages in this thread | | | Date | Tue, 2 Nov 2021 17:53:15 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v6 14/42] x86/sev: Register GHCB memory when SEV-SNP is active |
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On Fri, Oct 08, 2021 at 01:04:25PM -0500, Brijesh Singh wrote: > + /* SEV-SNP guest requires that GHCB must be registered. */ > + if (cc_platform_has(CC_ATTR_SEV_SNP)) > + snp_register_ghcb(data, __pa(ghcb));
This looks like more of that "let's register a GHCB at the time the first #VC fires".
And there already is setup_ghcb() which is called in the #VC handler. And that thing registers a GHCB GPA.
But then you have to do it here again.
I think this should be changed together with the CPUID page detection stuff we talked about earlier, where, after you've established that this is an SNP guest, you call setup_ghcb() *once* and after that you have everything set up, including the GHCB GPA. And then the #VC exceptions can come.
Right?
Or is there a chicken-and-an-egg issue here which I'm not thinking about?
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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