vfio: Add PCI device driver

Add PCI device support for VFIO.  PCI devices expose regions
for accessing config space, I/O port space, and MMIO areas
of the device.  PCI config access is virtualized in the kernel,
allowing us to ensure the integrity of the system, by preventing
various accesses while reducing duplicate support across various
userspace drivers.  I/O port supports read/write access while
MMIO also supports mmap of sufficiently sized regions.  Support
for INTx, MSI, and MSI-X interrupts are provided using eventfds to
userspace.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Author: Alex Williamson

drivers/vfio/Kconfig

@@ -12,3 +12,5 @@ menuconfig VFIO
 	  See Documentation/vfio.txt for more details.
 
 	  If you don't know what to do here, say N.
+
+source "drivers/vfio/pci/Kconfig"

drivers/vfio/pci/Kconfig

@@ -0,0 +1,8 @@
+config VFIO_PCI
+	tristate "VFIO support for PCI devices"
+	depends on VFIO && PCI && EVENTFD
+	help
+	  Support for the PCI VFIO bus driver.  This is required to make
+	  use of PCI drivers using the VFIO framework.
+
+	  If you don't know what to do here, say N.

drivers/vfio/pci/Makefile

@@ -0,0 +1,4 @@
+
+vfio-pci-y := vfio_pci.o vfio_pci_intrs.o vfio_pci_rdwr.o vfio_pci_config.o
+
+obj-$(CONFIG_VFIO_PCI) += vfio-pci.o