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[Qemu-devel] [RFC] AMD IOMMU: emulate multiple devices

From: David Kiarie
Subject: [Qemu-devel] [RFC] AMD IOMMU: emulate multiple devices
Date: Wed, 8 Jun 2016 13:00:31 +0300

Hello all,

This patch tries to solve a problem whereby real AMD IOMMUs exhibit both PCI 
and Platform device properties. AMD IOMMU properties that conflict with 
conventional PCI devices' features include the fact that its not a BusMaster 
device and reserves MMIO region without a BAR register among others.

There is some already ongoing work on Intel IOMMU Interrupt remapping with 
implements an IOMMU base class[1], as a platform device(which means the moment 
I inherit from this class my device loses it's PCI properties). I am therefore 
forced to find a way to combine both PCI and platform features(which I had 
previously avoided) into AMD IOMMU.
                                                X86-IOMMU(common code)
                                                   / \
                                                  /   \
                                        Intel IOMMU   AMD IOMMU

This patch implements a stripped down sample of how I plan to solve this issue. 
It basically implements PCI device which serves to 'steal' PCI config space 
while the main device remains a platform device. The platform device maintains 
a reference to the PCI device and hence the relevant PCI config space. This 
device will also require [2] to work.

Looking forward to your comments!

[1] http://thread.gmane.org/gmane.comp.emulators.qemu/414510
[2] http://thread.gmane.org/gmane.comp.emulators.qemu/413018

David Kiarie (1):
  hw/i386: Composite Bus and PCI device

 hw/i386/compositedevice.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 hw/i386/compositedevice.c


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