PCI passthrough SRIOV support

Back Groud

PCI devices has not only PCI standard property like BDF, vendor_id etc, it also has some extra information which may be application specific. For example, attached network switch for NIC, or resolution for GPU etc.These information can't be achieved through hypervisor, and may be provided externally through like configuration file.

Currently nova PCI support has basic support for such extra information in database and object layer. But we need more effort to it, including: get such information from configuration file, group devices with same extra information value etc.

Requements from SRIOV

• group device

  for SRIOV, all VFs belong to same PF share same physical network reachability. so if you want, say, deploy a vlan network, you need choose the right PF's VF, otherwise network does not work for you.

• tracking device alloced to the NIC

  networking or other special deive is not as simple as pass though to the VM, there is need more configration. to acheive this, SRIOV must know the device infomation allocation to the specific NIC.

group the devices

  spec: a filter defined by (k,v) paris
  extra_spec: the filter defined by (k, v) and k not in the pci object fileds. 

pci utils/objects support grouping

      * pci utils k,v match support the list values
      * objects provide a class level extrac interface to extract base spec and extra spec

white list import address set

      * white list support 'address':[bdf1, ....]
      * white list support  any other (k,v) pair to group or store special infomation 
      * object extrac specs and extra_info, specs use as whitelist spec, extra info will be updated to device's extra_info fields

enable alias request extra property

      * alis can specify extra (k,v) pairs 
      * pci manager use extrac method extrac the specs and extra_specs, match them agains  the pci object  object.extra_info.

pci stats grouping device on demand

        * pci_grouping_key configration option define a set of key name which will used to group the device to stats
        * default value is  [vendor_id, product_id], this current implemtation
        * limited support to 3 keys grouping for algorithm simplicity.

tracking device allocated to alias

here is the idea how user can identify which device allocated for the pci alias.

    * while allocated such device, user put a  marker into the device ( in the pci device extra_info fileds) 
    *after finised allocation, user can seach a instance's pci devices to find the specific marker

   the way marker data transfer from user to device utilize the pci_request, which convert from the pci alias.