Re: [PATCH 1/3] iommu/amd: Add logic to decode AMD IOMMU event flag

[Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>]

On Tue, Apr 02, 2013 at 09:32:40PM +0200, Borislav Petkov wrote:
> On Tue, Apr 02, 2013 at 06:33:18PM +0200, Joerg Roedel wrote:

> > Okay, in theory I could implement a feedback loop between timer-setup
> > and intremap code and try fixups until it works. But that seems not to
> > be worth it to work around a buggy BIOS.
> 
> Yeah, same here. It's not like we really need intremap to work - we're
> only trying to fix the annoying error message currently. :-)

Right :)

> > What I actually thought about was providing an IVRS-override on the
> > kernel command line. So that you can specify the IOAPIC_ID->DEVID
> > mapping there and make it work this way. What do you think?
> 
> I guess that is workable. I can imagine people wanting this if they want
> to do the intremap thing on such b0rked BIOSen. So how do I specify this
> IOAPIC_ID->DEVID mapping on the cmdline exactly?


Don't know yet, probably something like ivrs_ioapic[<apicid>]=0:14.2 and
ivrs_hpet[<hpet-id>]=0:14.2. But not entierly sure yet, at least parsing
shouldn't require lex and yacc ;)

> > Yeah, that's my fear too. So we leave it better as it is...
> 
> Hohumm.

Thus shall it be!


	Joerg