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
