Re: [PATCH] Enable K8 GART as an IOMMU

[Muli Ben-Yehuda <muli@il.ibm.com>]

On Mon, Feb 12, 2007 at 11:47:09AM -0600, Langsdorf, Mark wrote:

> AMD Opteron and Athlon 64 processors have an AGP aperture and GART
> built into the processor.  Linux has used the AGP GART as an IOMMU
> to improve the performance of 32-bit only PCI devices when DMA'ing
> into physical memory above 0xffffffff.  This patch provides a
> similar capability for Xen dom0.
>
> Most of the code simply migrates the native Linux aperture.c and
> pci-gart.c to dom0.  A new memory op is added to clear the aperture
> mapping from the hypervisor's page tables, which is necessary to
> prevent cache alias issues resulting from processor speculation.

Could you please split it up into two patches, one of which does the
bulk movement around and the other which adds GART support, to make
reviewing easier?

Thanks,
Muli