[PATCH v2] Xen PCI backend driver.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

Attached is set of patches for the Xen PCI backend driver. Lot of driver pieces
have been reviewed in the past, but I don't recall it being sent to xen-devel.
The infrastructure parts (patches #1-#6) were posted at some point.

The Xen PCI back driver patch (#7) was squished from the git tree
(devel/xen-pciback-0.2) as some of them were just boring (supporting 2.6.18
driver to work, checkpatch), and some already posted/reviewed. The 
full tree is available at:

git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git devel/xen-pciback-0.2

.. and that is the tree I will use when asking Linus to pull the
driver.

So what is Xen PCI backend? It is a simple driver that utilizes the
ring-buffer to exchange 0xcf8 inb/outb commands from the guest to
the control domain. The backend carries out sanitized PCI configuration
reads/writes on behest of the guest. It also has some extra commands
for enabling/disabling MSI/MSI-X interrupts.

Please take a look at the patches (or even just a couple of them)
and provide feedback.

The patch set depends on stable/xenbus, which is back-port of XenBus
backend driver done by Ian Campbell. A merge of this tree along with
stable/xenbus is available as:

git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git master

The diffstat:

 arch/x86/include/asm/xen/pci.h                  |   16 +
 arch/x86/pci/xen.c                              |   73 ++
 drivers/xen/Kconfig                             |   65 ++
 drivers/xen/Makefile                            |    1 +
 drivers/xen/events.c                            |   68 ++-
 drivers/xen/pciback/Makefile                    |   17 +
 drivers/xen/pciback/conf_space.c                |  435 +++++++
 drivers/xen/pciback/conf_space.h                |  126 +++
 drivers/xen/pciback/conf_space_capability.c     |   66 ++
 drivers/xen/pciback/conf_space_capability.h     |   26 +
 drivers/xen/pciback/conf_space_capability_msi.c |  111 ++
 drivers/xen/pciback/conf_space_capability_pm.c  |  113 ++
 drivers/xen/pciback/conf_space_capability_vpd.c |   40 +
 drivers/xen/pciback/conf_space_header.c         |  385 +++++++
 drivers/xen/pciback/conf_space_quirks.c         |  140 +++
 drivers/xen/pciback/conf_space_quirks.h         |   35 +
 drivers/xen/pciback/controller.c                |  442 ++++++++
 drivers/xen/pciback/passthrough.c               |  178 +++
 drivers/xen/pciback/pci_stub.c                  | 1371 +++++++++++++++++++++++
 drivers/xen/pciback/pciback.h                   |  142 +++
 drivers/xen/pciback/pciback_ops.c               |  241 ++++
 drivers/xen/pciback/slot.c                      |  191 ++++
 drivers/xen/pciback/vpci.c                      |  244 ++++
 drivers/xen/pciback/xenbus.c                    |  726 ++++++++++++
 include/xen/events.h                            |    9 +
 25 files changed, 5258 insertions(+), 3 deletions(-)