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Adding SR-IOV to Tripleo

Blueprint URL:
https://blueprints.launchpad.net/tripleo/+spec/tripleo-sriov

SR-IOV is a specification that extends the PCI Express specification and allows a PCIe device to appear to be multiple separate physical PCIe devices.

SR-IOV provides one or more Virtual Functions (VFs) and a Physical Function(PF)

  • Virtual Functions (VF’s) are ‘lightweight’ PCIe functions that contain the resources necessary for data movement but have a carefully minimized set of configuration resources.
  • Physical Function (PF) are full PCIe functions that include the SR-IOV Extended Capability. This capability is used to configure and manage the SR-IOV functionality.

The VF’s could be attached to VMs like a dedicated PCIe device and thereby the usage of SR-IOV NICs boosts the networking performance considerably.

Problem Description

  • Today the installation and configuration of SR-IOV feature is done manually after overcloud deployment. It shall be automated via tripleo.
  • Identification of the hardware capabilities for SR-IOV were all done manually today and the same shall be automated during introspection. The hardware detection also provides the operator, the data needed for configuring Heat templates.

Proposed Change

Overview

  • Ironic Python Agent will discover the below hardware details and store it in swift blob -

    • SR-IOV capable NICs: Shall read /sys/bus/pci/devices/.../sriov_totalvfs and check if its non zero, inorder to identify if the NIC is SR-IOV capable
    • VT-d or IOMMU support in BIOS: The CPU flags shall be read to identify the support.
  • DIB shall include the package by default - openstack-neutron-sriov-nic-agent.

  • The nodes without any of the above mentioned capabilities can’t be used for COMPUTE role with SR-IOV

  • SR-IOV drivers shall be loaded during bootup via persistent module loading scripts. These persistent module loading scripts shall be created by the puppet manifests.

  • T-H-T shall provide the below details

    • supported_pci_vendor_devs - configure the vendor-id/product-id couples in the nodes running neutron-server
    • max number of vf’s - persistent across reboots
    • physical device mappings - Add physical device mappings ml2_conf_sriov.ini file in compute node
  • On the nodes running the Neutron server, puppet shall

    • enable sriovnicswitch in the /etc/neutron/plugin.ini file mechanism_drivers = openvswitch,sriovnicswitch This configuration enables the SR-IOV mechanism driver alongside OpenvSwitch.
    • Set the VLAN range for SR-IOV in the file /etc/neutron/plugin.ini, present in the network node network_vlan_ranges = <physical network name SR-IOV interface>:<VLAN min> :<VLAN max> Ex : network_vlan_ranges = fabric0:15:20
    • Configure the vendor-id/product-id couples if it differs from “15b3:1004,8086:10ca” in /etc/neutron/plugins/ml2/ml2_conf_sriov.ini supported_pci_vendor_devs = 15b3:1004,8086:10ca,<vendor-id:product-id>
    • Configure neutron-server.service to use the ml2_conf_sriov.ini file [Service] Type=notify User=neutron ExecStart=/usr/bin/neutron-server –config-file /usr/share/neutron/neutron-dist.conf –config-file /etc/neutron/neutron.conf –config-file /etc/neutron/plugin.ini –config-file /etc/neutron/plugins/ml2/ml2_conf_sriov.ini –log-file /var/log/neutron/server.log
  • In the nodes running nova scheduler, puppet shall

    • add PciPassthroughFilter filter to the list of scheduler_default_filters. This needs to be done to allow proper scheduling of SR-IOV devices
  • On each COMPUTE+SRIOV node, puppet shall configure /etc/nova/nova.conf

    • Associate the available VFs with each physical network Ex: pci_passthrough_whitelist={“devname”: “enp5s0f1”, “physical_network”:”fabric0”}

      PCI passthrough whitelist entries use the following syntax: [“device_id”: “<id>”,] [“product_id”: “<id>”,] [“address”: “[[[[<domain>]:]<bus>]:][<slot>][.[<function>]]” | “devname”: “Ethernet Interface Name”,] “physical_network”:”Network label string”

      VF’s that needs to be excluded from agent configuration shall be added in [sriov_nic]/exclude_devices. T-H-T shall configure this.

      Multiple whitelist entries per host are supported.

  • Puppet shall

    • Setup max number of VF’s to be configured by the operator echo required_max_vfs > /sys/bus/pci/devices/.../sriov_numvfs Puppet will also validate the required_max_vfs, so that it does not go beyond the supported max on the device.

    • Enable NoopFirewallDriver in the ‘/etc/neutron/plugins/ml2/sriov_agent.ini’ file.

      [securitygroup] firewall_driver = neutron.agent.firewall.NoopFirewallDriver

    • Add mappings to the /etc/neutron/plugins/ml2/sriov_agent.ini file. Ex: physical_device_mappings = fabric0:enp4s0f1 In this example, fabric0 is the physical network, and enp4s0f1 is the physical function

  • Puppet shall start the SR-IOV agent on Compute

    • systemctl enable neutron-sriov-nic-agent.service
    • systemctl start neutron-sriov-nic-agent.service

Alternatives

None

Security impact

  • We have no firewall drivers which support SR-IOV at present. Security groups will be disabled only for SR-IOV ports in compute hosts.

Other End User Impact

None

Performance Impact

  • SR-IOV provides near native I/O performance for each virtual machine on a physical server. Refer - http://goo.gl/HxZvXX

Other Deployer Impact

  • The operator shall ensure that the BIOS supports VT-d/IOMMU virtualization technology on the compute nodes.
  • IOMMU needs to be enabled in the Compute+SR-IOV nodes. Boot parameters (intel_iommu=on or amd_iommu=pt) shall be added in the grub.conf, using the first boot scripts (THT).
  • Post deployment, operator shall
    • Create neutron ports prior to creating VM’s (nova boot) neutron port-create fabric0_0 –name sr-iov –binding:vnic-type direct
    • Create the VM with the required flavor and SR-IOV port id Ex: nova boot –flavor m1.small –image <image id> –nic port-id=<port id> vnf0

Developer Impact

None

Implementation

Assignee(s)

Primary assignees:

  • karthiks
  • sanjayu

Work Items

  • Documented above in the Proposed changes

Dependencies

Testing

  • Since SR-IOV needs specific hardware support, this feature cant be tested under CI. We will need third party CI for validating it.

Documentation Impact

  • Manual steps that needs to be done by the operator shall be documented. Ex: configuring BIOS for VT-d, IOMMU, post deploymenent configurations.

Refrences