hw/pci: introduce PCI Expander Bridge (PXB)

PXB is a "light-weight" host bridge whose purpose is to enable
the main host bridge to support multiple PCI root buses
for pc machines.

As oposed to PCI-2-PCI bridge's secondary bus, PXB's bus
is a primary bus and can be associated with a NUMA node
(different from the main host bridge) allowing the guest OS
to recognize the proximity of a pass-through device to
other resources as RAM and CPUs.

The PXB is composed from:
 - A primary PCI bus (can be associated with a NUMA node)
   Acts like a normal pci bus and from the functionality point
   of view is an "expansion" of the bus behind the
   main host bridge.
 - A pci-2-pci bridge behind the primary PCI bus where the actual
   devices will be attached.
 - A host-bridge PCI device
   Situated on the bus behind the main host bridge, allows
   the BIOS to configure the bus number and IO/mem resources.
   It does not have its own config/data register for configuration
   cycles, this being handled by the main host bridge.
-  A host-bridge sysbus to comply with QEMU current design.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/pci-bridge/Makefile.objs b/hw/pci-bridge/Makefile.objs
index 96c596eb31..f2adfe348c 100644
--- a/hw/pci-bridge/Makefile.objs
+++ b/hw/pci-bridge/Makefile.objs
@@ -1,4 +1,5 @@
 common-obj-y += pci_bridge_dev.o
+common-obj-y += pci_expander_bridge.o
 common-obj-$(CONFIG_XIO3130) += xio3130_upstream.o xio3130_downstream.o
 common-obj-$(CONFIG_IOH3420) += ioh3420.o
 common-obj-$(CONFIG_I82801B11) += i82801b11.o