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[Xen-devel] c/s 19576 vs. AMD systems

To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
Subject: [Xen-devel] c/s 19576 vs. AMD systems
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Wed, 29 Apr 2009 09:53:01 +0100
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I'm afraid this change is going to hurt on AMD systems where memory extends
beyond the 4Gb boundary: Both such systems that I have direct access to
have their Intel MTRRs only defined up to the 4Gb boundary, yet through
the use of AMD specific MSRs (SYS_CFG.Tom2ForceMemTypeWB and TOM2)
the default memory type for everything beyond the 4Gb boundary is WB.
On these systems there shouldn't be any clipping. I certainly can put together
a patch for this, but it'll take me a couple of days until I'd get to it.


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