There are multiple empty nodes, where no memory resides in, are allowed in virtual machine (VM) backed by QEMU. I don't find anywhere to document how the corresponding device nodes are populated. This series adds one section in Documentation/devicetree/bindings/numa.txt to document how the empty NUMA nodes are handled: no device nodes are existing for these empty NUMA nodes, but the NUMA IDs and distance map are still valid in "numa-distance-map-v1" compatible device node. PATCH[1] adds one section in Documentation/devicetree/bindings/numa.txt to specify how device nodes are populated for these empty NUMA nodes. PATCH[2] fetches NUMA IDs and distance maps from "numa-distance-map-v1" compatible device node. Changelog ========= * No device nodes for empty NUMA nodes (Rob) * Add patch to fetch NUMA IDs and distance map from the "numa-distance-map-v1" compatible device node (Rob) Gavin Shan (2): Documentation, dt, numa: Add note to empty NUMA node of, numa: Fetch empty NUMA node ID from distance map Documentation/devicetree/bindings/numa.txt | 46 +++++++++++++++++++++- drivers/of/of_numa.c | 2 + 2 files changed, 47 insertions(+), 1 deletion(-) -- 2.23.0