On Tue, Nov 07, 2023 at 12:32:58PM -0600, Tom Lendacky wrote:
> It needs to be called early enough to allow for AutoIBRS to not be disabled
> just because SNP is supported. By calling it where it is currently called,
> the SNP feature can be cleared if, even though supported, SNP can't be used,
> allowing AutoIBRS to be used as a more performant Spectre mitigation.
So far so good.
However, early_rmptable_check -> snp_get_rmptable_info is unnecessary
work which happens on every AP for no reason whatsoever. That's reading
RMP_BASE and RMP_END, doing the same checks which it did on the BSP and
then throwing away the computed rmp_base and rmp_sz, all once per AP.
I don't mind doing early work which needs to be done only once.
I mind doing work which needs to be done only once, on every AP.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
