nova-specs/specs/newton/approved/pci-passthrough-whitelist-regex.rst

PCI Pass-through Whitelist Regex

https://blueprints.launchpad.net/nova/+spec/pci-passthrough-whitelist-regex

Enhance PCI pass-through whitelist to support regular expression for address attributes.

Problem description

Current PCI pass-through whitelist address entry is defined as: ["address": "[[<domain>]:]<bus>]:][<slot>][.[<function>", where the address uses the same syntax as it's in lspci or aggregated declaration of PCI devices by using '*'. Therefore there is no way to exclude specific VF(s) from the PCI pass-through whitelist address.

Use Cases

Deployer may want to exclude specific VF(s) to be used for other purposes. For instance VF can be used to connect compute node to storage node by running iSER (iSCSI Extensions for RDMA) transport.

Proposed change

Enhance PCI pass-through whitelist to support regular expression syntax for address attributes. A new syntax will be introduced for the address key: "address":{ "domain": <domain>, "bus": <bus>, "slot": <slot>, "function": <function> } The traditional glob style will still be supported: "address": "<domain>:<bus>:<slot>.<function>"

Example for the regular expression syntax:

This allows allocation of VFs whose functions are from 2 upwards: pci_passthrough_whitelist= {"address":{"domain": ".*", "bus": "02", "slot": "01", "function": "[2-7]"}, "physical_network":"net1"}

This allows allocation of VFs whose functions are from 2 downwards: pci_passthrough_whitelist= {"address":{"domain": ".*", "bus": "02", "slot": "01", "function": "[0-2]"}, "physical_network":"net1"}

This allows allocation of VFs whose slots are between 1 and 2: pci_passthrough_whitelist= {"address":{"domain": ".", "bus": "02", "slot": "0[1-2]", "function": "."}, "physical_network":"net1"}

Alternatives

• Instead of whitelist regular expression we could add multiple PCI pass-through whitelist entries per host. These entries include all the VFs that can be used. This is already supported.
• Instead of whitelist regular expression we could add PCI pass-through blacklist to sit alongside the whitelist to exclude specific PCI addresses.

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: moshele (moshele@mellanox.com)

Work Items

• Add regular expression syntax support to PciAddress in devspec.py.

Dependencies

None

Testing

• Unit tests will be added.
• Mellanox third party CI will be updated to test this feature. https://wiki.openstack.org/wiki/ThirdPartySystems/Mellanox_CI

Documentation Impact

Added regular expression syntax to pci_passthrough_whitelist entry as documented above.

References

[1] https://review.openstack.org/#/c/99043/ [2] https://wiki.openstack.org/wiki/SR-IOV-Passthrough-For-Networking