Re: 3.2.1 Unable to reset IRR messages on boot

[Suresh Siddha <suresh.b.siddha@intel.com>]

On Tue, 2012-03-20 at 05:40 -0400, Konrad Rzeszutek Wilk wrote:
> I think there are three ways of fixing this:
> 
>  1). Revert Suresh's patch and look at just removing the "Unable to reset IRR" warning
>     (perhaps by being conditional on running in kexec-env?).
> 
>  2). Make the Xen layer fake out an IOAPIC - so instead of 0xffffff, make sure to
>      clear the three bits that Suresh' patch is testing for (Ewwwww, I don't actually
>      like that - that stinks of a hack).
> 
>  3). Rework Suresh's patch - to only remove the IOAPIC entry if there is no
>      INT_SRV_OVR that depend on it. I made a stab at it and here is draft patch, that
>      looks to work on my boxes that have more than one IOAPIC and are booting under Xen:
>      But I am not 100% confident about it so would appreciate somebody looking at it.
> 

Thanks for looking at this Konrad. This issue is not just specific to
INT_SRC_OVR per-say.

Issue is that Xen though it doesn't use IO-APIC, it does depend on
proper IO-APIC parsing for various things like getting proper gsi_top,
INT_SRV_OVR entries etc.

I think Xen should be setting up a valid dummy IO-APIC mapping instead
of working around.

thanks,
suresh