PCI passthrough testing frame work considration

PCI passthrough testing frame work considration

Currently pci passthrough had no testing cover all logic cuase need special test machine setup. we try to add some test case into temptest to cover the pci passthrough module.

fake libvirt call

this solution tying create a special things for pci alias and white list wihch contain 'debug' in the extra info, pci logic code trate such request and device as a fake one.

• pro:

 1) no change in testing infrastructure
 2) don't need the special setup for testing machine

• cons:

  can not cover the libvirt driver.

fake pci device or bus

a faked device or bus develeping is time consuming , it also face some tough situation:
  1) kernel won’t accept it
  2) vendor won’t need it

modify testing frame work allow special machine schedule

  1) setup compute node which the pci passthrough is ready to use
  2) modify the testing schedule logic allow the pci testing case be scheduled to that machine (already supported?? fix me)

QEMU IOMMU emulator

  QEMU provide the emulation of pci devices. 
  problem: iommu emulation is on the way.