I am trying to use PCI pass through to a VM. The host system uses Centos 7.2. The system has several PCIe devices connected behind a fabric of PCIe switches and bridges (typically from PLX). I can pass through our endpoint devices just fine, but our system also needs access to the bridge devices since we use features available on them (they do have a BAR space). However, they are owned by pcieport and trying to detach them results in:
error: Failed to detach device pci_0000_1f_00_0
error: Failed to bind PCI device '0000:1f:00.0' to vfio-pci: No such device
Searching the web, it appears that vfio does not support bridge devices. Is there any other way to be able to access these PCIe devices from the guest VM (typically Centos 6.2)?
Is there a way to bridge access from a driver on the host VM (such as is done for USB devices)?
Is there a guide to write a device driver to bridge access from the guest VM to the host?
