On 14/09/2016 19:08, Konstantin Belousov wrote: > Well, the following might work, but I have no good idea what to do > when BIOS does handoff with x2APIC enabled and directs us to not > enable it. Switching to xAPIC mode is not an option, I suspect.
The specification describes a way to transition from x2APIC to xAPIC mode, but it's not trivial, because it requires checking all CPU IDs and disabling CPUs with too high ones. Personally, I am not comfortable with your patch. First, it seems that the patch does not cover hw.x2apic_enable=0. And I don't like that we leave x2APIC mode enabled even when we otherwise would not enable it just because BIOS. All in all, if we can't go x2APIC -> xAPIC, then I would prefer a meaningful panic over a "compromise". Just my opinion. The topic probably warrants a wider discussion and a proper review. Slawa, thank you for your persistence and testing. -- Andriy Gapon _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
