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Date: Mon, 22 Aug 2011 13:51:35 +0300
From: Avi Kivity <avi@redhat.com>
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To: Joerg Roedel <joerg.roedel@amd.com>
Subject: Re: kvm PCI assignment & VFIO ramblings
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Cc: Alexey Kardashevskiy <aik@au1.ibm.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Paul Mackerras <pmac@au1.ibm.com>, qemu-devel <qemu-devel@nongnu.org>,
	iommu <iommu@lists.linux-foundation.org>, chrisw <chrisw@sous-sol.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Anthony Liguori <anthony@codemonkey.ws>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	"benve@cisco.com" <benve@cisco.com>
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On 08/22/2011 01:46 PM, Joerg Roedel wrote:
> >  $ readlink /sys/devices/pci0000:00/0000:00:19.0/iommu_group
> >  ../../../path/to/device/which/represents/the/resource/constraint
> >
> >  (the pci-to-pci bridge on x86, or whatever node represents partitionable
> >  endpoints on power)
>
> 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?

-- 
error compiling committee.c: too many arguments to function