PCI: Enable quirks for PCIe ACS on Intel PCH root ports
Many of the currently available Intel PCH-based root ports do not provide PCIe ACS capabilities. Without this, we must assume that peer-to-peer traffic between multifunction root ports and between devices behind root ports is possible. This lack of isolation is exposed by grouping the devices together in the same IOMMU group. If we want to expose these devices to userspace, vfio uses IOMMU groups as the unit of ownership, thus making it very difficult to assign individual devices to separate users. The good news is that the chipset does provide ACS-like isolation capabilities, but we do need to verify and enable those capabilities if the BIOS has not done so. This patch implements the device specific enabling and testing of equivalent ACS function for these devices. Signed-off-by:Alex Williamson <alex.williamson@redhat.com> Signed-off-by: