Standard Device Attributes for Dynamic Resource Allocation

Kubernetes defines a set of standard device attributes under the resource.kubernetes.io domain for use with Dynamic Resource Allocation (DRA). These attributes have well-defined semantics so that matchAttribute constraints work across devices from different DRA drivers without requiring driver-specific knowledge.

DRA drivers are encouraged to publish these attributes when applicable. The Kubernetes DRA helper library (k8s.io/dynamic-resource-allocation/deviceattribute) provides functions that drivers can call to derive the correct values from sysfs.

Standard attributes

resource.kubernetes.io/numaNode

Identifies the NUMA topology of a device. This attribute can be either:

• A scalar integer: the device's physical NUMA node, read from the kernel's numa_node sysfs entry. This form works without any feature gate.
• An integer list (requires the DRAListTypeAttributes feature gate): the physical NUMA node followed by same-socket NUMA nodes at the minimum ACPI SLIT distance. For example, on an AMD EPYC system with 4 NUMA nodes per socket, a device on NUMA node 5 may publish [5, 4, 6, 7] to indicate that NUMA nodes 4, 6, and 7 are on the same socket and equidistant.

Use matchAttribute with this attribute to co-locate devices from different drivers on the same NUMA node. When list-type values are used, the scheduler performs set intersection: two devices match as long as their NUMA node lists share at least one value.

Devices with no NUMA affinity (numa_node = -1 in sysfs) must not publish this attribute.

Helper functions for DRA driver authors:

• GetNUMANodeAttributeByPCIBusID(pciBusID, attrForm): for PCI devices (GPUs, NICs, NVMe controllers). Reads numa_node from sysfs and, when attrForm is ListAttribute, computes the SLIT-based list.
• GetNUMANodeAttribute(numaNode, attrForm): for devices that already know their NUMA node (CPUs, memory).
• GetNUMANodeForCPU(cpuID): returns the NUMA node for a CPU core.

resource.kubernetes.io/pciBusID

The PCI bus address of a PCI device in extended BDF notation (Domain:Bus:Device.Function). This attribute uniquely identifies a PCI device on a node.

resource.kubernetes.io/pcieRoot

The PCIe Root Complex of a PCI device, in the format pci<domain>:<bus>. Devices that share the same PCIe Root Complex are connected to the same PCIe switch hierarchy. Use matchAttribute with this attribute to co-locate devices under the same PCIe root for lowest-latency communication.