Enable SR-IOV physical functions assignment with Neutron port

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

Testing

New unit and functional tests will be written to cover the changes.

Documentation Impact

Documentation of a new vnic_type should be documented.

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.

Revisions

Release Name

Description

Mitaka

Introduced

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nova-specs