.. _config-sriov: ====== SR-IOV ====== The purpose of this page is to describe how to enable SR-IOV functionality available in OpenStack (using OpenStack Networking). This functionality was first introduced in the OpenStack Juno release. This page intends to serve as a guide for how to configure OpenStack Networking and OpenStack Compute to create SR-IOV ports. The basics ~~~~~~~~~~ PCI-SIG Single Root I/O Virtualization and Sharing (SR-IOV) functionality is available in OpenStack since the Juno release. The SR-IOV specification defines a standardized mechanism to virtualize PCIe devices. This mechanism can virtualize a single PCIe Ethernet controller to appear as multiple PCIe devices. Each device can be directly assigned to an instance, bypassing the hypervisor and virtual switch layer. As a result, users are able to achieve low latency and near-line wire speed. The following terms are used throughout this document: .. list-table:: :header-rows: 1 :widths: 10 90 * - Term - Definition * - PF - Physical Function. The physical Ethernet controller that supports SR-IOV. * - VF - Virtual Function. The virtual PCIe device created from a physical Ethernet controller. SR-IOV agent ------------ The SR-IOV agent allows you to set the admin state of ports, configure port security (enable and disable spoof checking), and configure QoS rate limiting and minimum bandwidth. You must include the SR-IOV agent on each compute node using SR-IOV ports. .. note:: The SR-IOV agent was optional before Mitaka, and was not enabled by default before Liberty. .. note:: The ability to control port security and QoS rate limit settings was added in Liberty. Supported Ethernet controllers ------------------------------ The following manufacturers are known to work: - Intel - Mellanox - QLogic - Broadcom For information on **Mellanox SR-IOV Ethernet ConnectX cards**, see the `Mellanox: How To Configure SR-IOV VFs on ConnectX-4 or newer `_. For information on **QLogic SR-IOV Ethernet cards**, see the `User's Guide OpenStack Deployment with SR-IOV Configuration `_. For information on **Broadcom NetXtreme Series Ethernet cards**, see the `Broadcom NetXtreme Product Page `_. Using SR-IOV interfaces ~~~~~~~~~~~~~~~~~~~~~~~ In order to enable SR-IOV, the following steps are required: #. Create Virtual Functions (Compute) #. Configure allow list for PCI devices in nova-compute (Compute) #. Configure neutron-server (Controller) #. Configure nova-scheduler (Controller) #. Enable neutron sriov-agent (Compute) We recommend using VLAN provider networks for segregation. This way you can combine instances without SR-IOV ports and instances with SR-IOV ports on a single network. .. note:: Throughout this guide, ``eth3`` is used as the PF and ``physnet2`` is used as the provider network configured as a VLAN range. These ports may vary in different environments. Create Virtual Functions (Compute) ---------------------------------- Create the VFs for the network interface that will be used for SR-IOV. We use ``eth3`` as PF, which is also used as the interface for the VLAN provider network and has access to the private networks of all machines. .. note:: The steps detail how to create VFs using Mellanox ConnectX-4 and newer/Intel SR-IOV Ethernet cards on an Intel system. Steps may differ for different hardware configurations. #. Ensure SR-IOV and VT-d are enabled in BIOS. #. Enable IOMMU in Linux by adding ``intel_iommu=on`` to the kernel parameters, for example, using GRUB. #. On each compute node, create the VFs via the PCI SYS interface: .. code-block:: console # echo '8' > /sys/class/net/eth3/device/sriov_numvfs .. note:: On some PCI devices, observe that when changing the amount of VFs you receive the error ``Device or resource busy``. In this case, you must first set ``sriov_numvfs`` to ``0``, then set it to your new value. .. note:: A network interface could be used both for PCI passthrough, using the PF, and SR-IOV, using the VFs. If the PF is used, the VF number stored in the ``sriov_numvfs`` file is lost. If the PF is attached again to the operating system, the number of VFs assigned to this interface will be zero. To keep the number of VFs always assigned to this interface, modify the interfaces configuration file adding an ``ifup`` script command. On Ubuntu, modify the ``/etc/network/interfaces`` file: .. code-block:: ini auto eth3 iface eth3 inet dhcp pre-up echo '4' > /sys/class/net/eth3/device/sriov_numvfs On RHEL and derivatives, modify the ``/sbin/ifup-local`` file: .. code-block:: bash #!/bin/sh if [[ "$1" == "eth3" ]] then echo '4' > /sys/class/net/eth3/device/sriov_numvfs fi .. warning:: Alternatively, you can create VFs by passing the ``max_vfs`` to the kernel module of your network interface. However, the ``max_vfs`` parameter has been deprecated, so the PCI SYS interface is the preferred method. You can determine the maximum number of VFs a PF can support: .. code-block:: console # cat /sys/class/net/eth3/device/sriov_totalvfs 63 #. Verify that the VFs have been created and are in ``up`` state. For example: .. code-block:: console # lspci | grep Ethernet 82:00.0 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01) 82:00.1 Ethernet controller: Intel Corporation 82599ES 10-Gigabit SFI/SFP+ Network Connection (rev 01) 82:10.0 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:10.2 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:10.4 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:10.6 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:11.0 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:11.2 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:11.4 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) 82:11.6 Ethernet controller: Intel Corporation 82599 Ethernet Controller Virtual Function (rev 01) .. code-block:: console # ip link show eth3 8: eth3: mtu 1500 qdisc mq state UP mode DEFAULT qlen 1000 link/ether a0:36:9f:8f:3f:b8 brd ff:ff:ff:ff:ff:ff vf 0 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 1 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 2 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 3 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 4 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 5 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 6 MAC 00:00:00:00:00:00, spoof checking on, link-state auto vf 7 MAC 00:00:00:00:00:00, spoof checking on, link-state auto If the interfaces are down, set them to ``up`` before launching a guest, otherwise the instance will fail to spawn: .. code-block:: console # ip link set eth3 up #. Persist created VFs on reboot: .. code-block:: console # echo "echo '7' > /sys/class/net/eth3/device/sriov_numvfs" >> /etc/rc.local .. note:: The suggested way of making PCI SYS settings persistent is through the ``sysfsutils`` tool. However, this is not available by default on many major distributions. Configuring allow list for PCI devices nova-compute (Compute) ------------------------------------------------------------- #. Configure which PCI devices the ``nova-compute`` service may use. Edit the ``nova.conf`` file: .. code-block:: ini [pci] passthrough_whitelist = { "devname": "eth3", "physical_network": "physnet2"} This tells the Compute service that all VFs belonging to ``eth3`` are allowed to be passed through to instances and belong to the provider network ``physnet2``. Alternatively the ``[pci] passthrough_whitelist`` parameter also supports allowing devices by: - PCI address: The address uses the same syntax as in ``lspci`` and an asterisk (``*``) can be used to match anything. .. code-block:: ini [pci] passthrough_whitelist = { "address": "[[[[]:]]:][][.[]]", "physical_network": "physnet2" } For example, to match any domain, bus ``0a``, slot ``00``, and all functions: .. code-block:: ini [pci] passthrough_whitelist = { "address": "*:0a:00.*", "physical_network": "physnet2" } - PCI ``vendor_id`` and ``product_id`` as displayed by the Linux utility ``lspci``. .. code-block:: ini [pci] passthrough_whitelist = { "vendor_id": "", "product_id": "", "physical_network": "physnet2" } If the device defined by the PCI address or ``devname`` corresponds to an SR-IOV PF, all VFs under the PF will match the entry. Multiple ``[pci] passthrough_whitelist`` entries per host are supported. In order to enable SR-IOV to request "trusted mode", the ``[pci] passthrough_whitelist`` parameter also supports a ``trusted`` tag. .. note:: This capability is only supported starting with version 18.0.0 (Rocky) release of the compute service configured to use the libvirt driver. .. important:: There are security implications of enabling trusted ports. The trusted VFs can be set into VF promiscuous mode which will enable it to receive unmatched and multicast traffic sent to the physical function. For example, to allow users to request SR-IOV devices with trusted capabilities on device ``eth3``: .. code-block:: ini [pci] passthrough_whitelist = { "devname": "eth3", "physical_network": "physnet2", "trusted":"true" } The ports will have to be created with a binding profile to match the ``trusted`` tag, see `Launching instances with SR-IOV ports`_. #. Restart the ``nova-compute`` service for the changes to go into effect. .. _configure_sriov_neutron_server: Configure neutron-server (Controller) ------------------------------------- .. note:: This section does not apply to remote-managed ports of SmartNIC DPU devices which also use SR-IOV at the host side but do not rely on the ``sriovnicswitch`` mechanism driver. #. Add ``sriovnicswitch`` as mechanism driver. Edit the ``ml2_conf.ini`` file on each controller: .. code-block:: ini [ml2] mechanism_drivers = openvswitch,sriovnicswitch #. Ensure your physnet is configured for the chosen network type. Edit the ``ml2_conf.ini`` file on each controller: .. code-block:: ini [ml2_type_vlan] network_vlan_ranges = physnet2 #. Add the ``plugin.ini`` file as a parameter to the ``neutron-server`` service. Edit the appropriate initialization script to configure the ``neutron-server`` service to load the plugin configuration file: .. code-block:: bash --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini #. Restart the ``neutron-server`` service. Configure nova-scheduler (Controller) ------------------------------------- #. On every controller node running the ``nova-scheduler`` service, add ``PciPassthroughFilter`` to ``[filter_scheduler] enabled_filters`` to enable this filter. Ensure ``[filter_scheduler] available_filters`` is set to the default of ``nova.scheduler.filters.all_filters``: .. code-block:: ini [filter_scheduler] enabled_filters = AvailabilityZoneFilter, ComputeFilter, ComputeCapabilitiesFilter, ImagePropertiesFilter, ServerGroupAntiAffinityFilter, ServerGroupAffinityFilter, PciPassthroughFilter available_filters = nova.scheduler.filters.all_filters #. Restart the ``nova-scheduler`` service. Enable neutron-sriov-nic-agent (Compute) ---------------------------------------- #. Install the SR-IOV agent, if necessary. #. Edit the ``sriov_agent.ini`` file on each compute node. For example: .. code-block:: ini [securitygroup] firewall_driver = noop [sriov_nic] physical_device_mappings = physnet2:eth3 exclude_devices = .. note:: The ``physical_device_mappings`` parameter is not limited to be a 1-1 mapping between physical networks and NICs. This enables you to map the same physical network to more than one NIC. For example, if ``physnet2`` is connected to ``eth3`` and ``eth4``, then ``physnet2:eth3,physnet2:eth4`` is a valid option. The ``exclude_devices`` parameter is empty, therefore, all the VFs associated with eth3 may be configured by the agent. To exclude specific VFs, add them to the ``exclude_devices`` parameter as follows: .. code-block:: ini exclude_devices = eth1:0000:07:00.2;0000:07:00.3,eth2:0000:05:00.1;0000:05:00.2 #. Ensure the SR-IOV agent runs successfully: .. code-block:: console # neutron-sriov-nic-agent \ --config-file /etc/neutron/neutron.conf \ --config-file /etc/neutron/plugins/ml2/sriov_agent.ini #. Enable the neutron SR-IOV agent service. If installing from source, you must configure a daemon file for the init system manually. (Optional) FDB L2 agent extension ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Forwarding DataBase (FDB) population is an L2 agent extension to OVS agent or Linux bridge. Its objective is to update the FDB table for existing instance using normal port. This enables communication between SR-IOV instances and normal instances. The use cases of the FDB population extension are: * Direct port and normal port instances reside on the same compute node. * Direct port instance that uses floating IP address and network node are located on the same host. For additional information describing the problem, refer to: `Virtual switching technologies and Linux bridge. `_ #. Edit the ``ovs_agent.ini`` or ``linuxbridge_agent.ini`` file on each compute node. For example: .. code-block:: console [agent] extensions = fdb #. Add the FDB section and the ``shared_physical_device_mappings`` parameter. This parameter maps each physical port to its physical network name. Each physical network can be mapped to several ports: .. code-block:: console [FDB] shared_physical_device_mappings = physnet1:p1p1, physnet1:p1p2 Launching instances with SR-IOV ports ------------------------------------- Once configuration is complete, you can launch instances with SR-IOV ports. #. If it does not already exist, create a network and subnet for the chosen physnet. This is the network to which SR-IOV ports will be attached. For example: .. code-block:: console $ openstack network create --provider-physical-network physnet2 \ --provider-network-type vlan --provider-segment 1000 \ sriov-net $ openstack subnet create --network sriov-net \ --subnet-pool shared-default-subnetpool-v4 \ sriov-subnet #. Get the ``id`` of the network where you want the SR-IOV port to be created: .. code-block:: console $ net_id=$(openstack network show sriov-net -c id -f value) #. Create the SR-IOV port. ``vnic-type=direct`` is used here, but other options include ``normal``, ``direct-physical``, and ``macvtap``: .. code-block:: console $ openstack port create --network $net_id --vnic-type direct \ sriov-port Alternatively, to request that the SR-IOV port accept trusted capabilities, the binding profile should be enhanced with the ``trusted`` tag. .. code-block:: console $ openstack port create --network $net_id --vnic-type direct \ --binding-profile trusted=true \ sriov-port #. Get the ``id`` of the created port: .. code-block:: console $ port_id=$(openstack port show sriov-port -c id -f value) #. Create the instance. Specify the SR-IOV port created in step two for the NIC: .. code-block:: console $ openstack server create --flavor m1.large --image ubuntu_18.04 \ --nic port-id=$port_id \ test-sriov .. note:: There are two ways to attach VFs to an instance. You can create an SR-IOV port or use the ``pci_alias`` in the Compute service. For more information about using ``pci_alias``, refer to `nova-api configuration`__. __ https://docs.openstack.org/nova/latest/admin/pci-passthrough.html#configure-nova-api-controller SR-IOV with ConnectX-3/ConnectX-3 Pro Dual Port Ethernet ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In contrast to Mellanox newer generation NICs, ConnectX-3 family network adapters expose a single PCI device (PF) in the system regardless of the number of physical ports. When the device is **dual port** and SR-IOV is enabled and configured we can observe some inconsistencies in linux networking subsystem. .. note:: In the example below ``enp4s0`` represents PF net device associated with physical port 1 and ``enp4s0d1`` represents PF net device associated with physical port 2. **Example:** A system with ConnectX-3 dual port device and a total of four VFs configured, two VFs assigned to port one and two VFs assigned to port two. .. code-block:: console $ lspci | grep Mellanox 04:00.0 Network controller: Mellanox Technologies MT27520 Family [ConnectX-3 Pro] 04:00.1 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] 04:00.2 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] 04:00.3 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] 04:00.4 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] Four VFs are available in the system, however, .. code-block:: console $ ip link show 31: enp4s0: mtu 1500 qdisc noop master ovs-system state DOWN mode DEFAULT group default qlen 1000 link/ether f4:52:14:01:d9:e1 brd ff:ff:ff:ff:ff:ff vf 0 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 1 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 2 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 3 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto 32: enp4s0d1: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether f4:52:14:01:d9:e2 brd ff:ff:ff:ff:ff:ff vf 0 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 1 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 2 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto vf 3 MAC 00:00:00:00:00:00, vlan 4095, spoof checking off, link-state auto **ip** command identifies each PF associated net device as having four VFs *each*. .. note:: Mellanox ``mlx4`` driver allows *ip* commands to perform configuration of *all* VFs from either PF associated network devices. To allow neutron SR-IOV agent to properly identify the VFs that belong to the correct PF network device (thus to the correct network port) Admin is required to provide the ``exclude_devices`` configuration option in ``sriov_agent.ini`` **Step 1**: derive the VF to Port mapping from mlx4 driver configuration file: ``/etc/modprobe.d/mlnx.conf`` or ``/etc/modprobe.d/mlx4.conf`` .. code-block:: console $ cat /etc/modprobe.d/mlnx.conf | grep "options mlx4_core" options mlx4_core port_type_array=2,2 num_vfs=2,2,0 probe_vf=2,2,0 log_num_mgm_entry_size=-1 Where: ``num_vfs=n1,n2,n3`` - The driver will enable ``n1`` VFs on physical port 1, ``n2`` VFs on physical port 2 and ``n3`` dual port VFs (applies only to dual port HCA when all ports are Ethernet ports). ``probe_vfs=m1,m2,m3`` - the driver probes ``m1`` single port VFs on physical port 1, ``m2`` single port VFs on physical port 2 (applies only if such a port exist) ``m3`` dual port VFs. Those VFs are attached to the hypervisor. (applies only if all ports are configured as Ethernet). The VFs will be enumerated in the following order: 1. port 1 VFs 2. port 2 VFs 3. dual port VFs In our example: | 04:00.0 : PF associated to **both** ports. | 04:00.1 : VF associated to port **1** | 04:00.2 : VF associated to port **1** | 04:00.3 : VF associated to port **2** | 04:00.4 : VF associated to port **2** **Step 2:** Update ``exclude_devices`` configuration option in ``sriov_agent.ini`` with the correct mapping Each PF associated net device shall exclude the **other** port's VFs .. code-block:: ini [sriov_nic] physical_device_mappings = physnet1:enp4s0,physnet2:enp4s0d1 exclude_devices = enp4s0:0000:04:00.3;0000:04:00.4,enp4s0d1:0000:04:00.1;0000:04:00.2 SR-IOV with InfiniBand ~~~~~~~~~~~~~~~~~~~~~~ The support for SR-IOV with InfiniBand allows a Virtual PCI device (VF) to be directly mapped to the guest, allowing higher performance and advanced features such as RDMA (remote direct memory access). To use this feature, you must: #. Use InfiniBand enabled network adapters. #. Run InfiniBand subnet managers to enable InfiniBand fabric. All InfiniBand networks must have a subnet manager running for the network to function. This is true even when doing a simple network of two machines with no switch and the cards are plugged in back-to-back. A subnet manager is required for the link on the cards to come up. It is possible to have more than one subnet manager. In this case, one of them will act as the primary, and any other will act as a backup that will take over when the primary subnet manager fails. #. Install the ``ebrctl`` utility on the compute nodes. Check that ``ebrctl`` is listed somewhere in ``/etc/nova/rootwrap.d/*``: .. code-block:: console $ grep 'ebrctl' /etc/nova/rootwrap.d/* If ``ebrctl`` does not appear in any of the rootwrap files, add this to the ``/etc/nova/rootwrap.d/compute.filters`` file in the ``[Filters]`` section. .. code-block:: ini [Filters] ebrctl: CommandFilter, ebrctl, root Known limitations ~~~~~~~~~~~~~~~~~ * When using Quality of Service (QoS), ``max_burst_kbps`` (burst over ``max_kbps``) is not supported. In addition, ``max_kbps`` is rounded to Mbps. * Security groups are not supported when using SR-IOV, thus, the firewall driver must be disabled. This can be done in the ``neutron.conf`` file. .. code-block:: ini [securitygroup] firewall_driver = noop * SR-IOV is not integrated into the OpenStack Dashboard (horizon). Users must use the CLI or API to configure SR-IOV interfaces. * Live migration support has been added to the Libvirt Nova virt-driver in the Train release for instances with neutron SR-IOV ports. Indirect mode SR-IOV interfaces (vnic-type: macvtap or virtio-forwarder) can now be migrated transparently to the guest. Direct mode SR-IOV interfaces (vnic-type: direct or direct-physical) are detached before the migration and reattached after the migration so this is not transparent to the guest. To avoid loss of network connectivy when live migrating with direct mode sriov the user should create a failover bond in the guest with a transparently live migration port type e.g. vnic-type normal or indirect mode SR-IOV. .. note:: SR-IOV features may require a specific NIC driver version, depending on the vendor. Intel NICs, for example, require ixgbe version 4.4.6 or greater, and ixgbevf version 3.2.2 or greater. * Attaching SR-IOV ports to existing servers is supported starting with the Victoria release.