[PATCH 0 of 6 V6] amd iommu: support ats-gpu passthru on iommuv2 systems

[PATCH 0 of 6 V6] amd iommu: support ats-gpu passthru on iommuv2 systems

[Wei Wang]

This is a resend of patch set v6 after xen-unstable reopened for new 
features. Please review it. Thanks.

For more details, please refer to old threads.
http://lists.xen.org/archives/html/xen-devel/2012-02/msg00889.html
http://lists.xen.org/archives/html/xen-devel/2012-01/msg01646.html

and, for an overview of the design, please refer to
http://www.amd64.org/pub/iommuv2.png

======================================================================
changes in v6:
* Fix indentation issues.
* Fix definition of iommu_set_msi.
* Rebase on top of tip.

changes in v5:
* Remove patch 2 after upstream c/s 24729:6f6a6d1d2fb6

changes in v4:
* Only tool part in this version, since hypervisor patches have already 
been committed.
* rename guest config option from "iommu = {0,1}" to "guest_iommu = {0,1}"
* add description into docs/man/xl.cfg.pod.5


changes in v3:
* Use xenstore to receive guest iommu configuration instead of adding in 
a new field in hvm_info_table.
* Support pci segment in vbdf to mbdf bind.
* Make hypercalls visible for non-x86 platforms.
* A few code cleanups according to comments from Jan and Ian.

Changes in v2:
* Do not use linked list to access guest iommu tables.
* Do not parse iommu parameter in libxl_device_model_info again.
* Fix incorrect logical calculation in patch 11.
* Fix hypercall definition for non-x86 systems.


Thanks,
Wei