Enable SR-IOV physical functions assignment with Neutron port¶
https://blueprints.launchpad.net/nova/+spec/sriov-pf-passthrough-neutron-port
Relying on the sriov-physical-function-passthrough spec [1], which describes an implementation of a SR-IOV physical functions passthough support in Nova; This spec will address the need for SR-IOV physical functions to be associated with Neutron ports.
Problem description¶
Current implementation of the Physical Function (PF) passthrough lacks any network awareness. It is exposing the physical hardware to the instances without an integration with Neutron, unlike the way it is implemented for the SR-IOV Virtual Functions (VFs).
Physical Function can only be exposed as a libvirt’s <hostdev> definition in the domain XML and not as a “<interface type=’hostdev’…” element that can receive a MAC address and a virtual port definition.
In general, it is not possible to configure a MAC address for a PF, nor to assign a VLAN tag via it’s driver on the host. Therefore, additional steps will be needed to update Neutron with an actual MAC address of a seleced PF.
Use Cases¶
Workloads requiring to have full access to a physical function will also need to have the ability to manipulate the network settings, in the same manner and flexibility that is currently available for VFs.
Project Priority¶
None
Proposed change¶
Allow the users to specify a new vnic_type, with the neutron port creation, which would be used by Nova to select a Physical Function on a host and properly passthrough it to a guest, using a new VIF type. Nova will update the neutron port with a MAC address of the selected PF on the host.
Alternatives¶
None
Data model impact¶
None
REST API impact¶
None
Security impact¶
None
Notifications impact¶
None
Other end user impact¶
None
Performance Impact¶
None
Other deployer impact¶
None
Developer impact¶
None
Implementation¶
Assignee(s)¶
- Primary assignee:
Vladik Romanovsky <vromanso@redhat.com>
- Other contributors:
Nikola Đipanov <ndipanov@redhat.com>
Work Items¶
Introduce a new vnic_type to request PF selection - VNIC_DIRECT_PHYSICAL
Introduce a new vif type to configure the PF attachment with as a hostdev.
Update the Neutron port with a MAC of a selected PF.
Dependencies¶
Depending on a neutron support of a new VNIC type. https://review.openstack.org/#/c/246923 https://bugs.launchpad.net/neutron/+bug/1500993
There is also a dependency on the actual implementation of the sriov-physical-function-passthrough spec [1]
Testing¶
New unit and functional tests will be written to cover the changes.
Documentation Impact¶
Documentation of a new vnic_type should be documented.
References¶
History¶
Optional section for Mitaka intended to be used each time the spec is updated to describe new design, API or any database schema updated. Useful to let reader understand what’s happened along the time.
Release Name |
Description |
|---|---|
Mitaka |
Introduced |
Newton |
Re-proposed |
