Re: lapic detection at runtime for kernel modules

Le 21/03/2025 à 08:48, Emile `iMil' Heitor a écrit :
> Hey Jean-Yves!

Greetings!

> On Thu, 20 Mar 2025, Jean-Yves Migeon (NetBSD) wrote:
> 
> After some back and forth, mlelstv@ came with the most elegant idea:
> https://imil.net/NetBSD/has_lapic.patch
> Basically an #ifdef function translation, as the point is only to know
> if we have LAPIC support enabled in the kernel,

Brutal, but indeed works (:

This "tests" whether LAPIC support is compiled in (instead of checking 
the PIC routines) though.

 > which AFAIK is only false in Xen...

And old buggy hardware (...) On which there is no risk you would load or 
run nvmm(4) on it.

> but do we build nvmm module for Xen?

Nope (at least not yet) -- IMHO it has limited interest besides attempts 
at nesting hypervisors (which has its uses but quite niche)

Cheers!

-- 
jym@