Re: feature suggestion: DMAR table emulation for Xen

[Barde Kaushik 00901718 <kbarde@huawei.com>]

Sure, you can but I think, you may have issues if RMRR reports both existent and non-existent device scopes, and if ignored, existent device may be impacted along with non-existent one's.

-Kaushik

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----- Original Message -----
From: Joanna Rutkowska <joanna@invisiblethingslab.com>
Date: Friday, May 14, 2010 3:13 am
Subject: Re: [Xen-devel] feature suggestion: DMAR table emulation for Xen
To: Barde Kaushik 00901718 <kbarde@huawei.com>
Cc: "Kay, Allen M" <allen.m.kay@intel.com>, "Cihula, Joseph" <joseph.cihula@intel.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, "Han, Weidong" <weidong.han@intel.com>

> On 05/14/2010 11:41 AM, Barde Kaushik 00901718 wrote:
> > << So, if we took a DMAR from a platform, say PM45+ICH9M w/ Intel
> > BIOS, it should also work fine on any other laptop with this chipset
> > (and probably other variants too), just minus the potential 
> > BIOS-specific-dirty-tricks...?
> >>> 
> > 
> > Bringing-up mobile variants with same base BIOS may not work, at
> > least in my experience, as OEMs tend to add various custom features
> > (GPIO). These features may to over-ride RMRR assumptions from base
> > BIOS. This tends to be the most prominant cause behind RMRR issues.
> > 
> And what would happen if we ignore RMRRs on such a system?
> 
> j.
> 
>