Subject: Re: kvm PCI assignment & VFIO ramblings

From: "Roedel, Joerg" <[email-masked]>
Date: Mon, 22 Aug 2011 14:36:51 +0200

On Mon, Aug 22, 2011 at 06:51:35AM -0400, Avi Kivity wrote:
> On 08/22/2011 01:46 PM, Joerg Roedel wrote:
> > That does not work. The bridge in question may not even be visible as a
> > PCI device, so you can't link to it. This is the case on a few PCIe
> > cards which only have a PCIx chip and a PCIe-2-PCIx bridge to implement
> > the PCIe interface (yes, I have seen those cards).
> 
> How does the kernel detect that devices behind the invisible bridge must 
> be assigned as a unit?

On the AMD IOMMU side this information is stored in the IVRS ACPI table.
Not sure about the VT-d side, though.

	Joerg

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