linux-drivers/
drivers/nvdimm

LIBNVDIMM persistent memory, virtio-pmem, and CXL PMEM bridge

The kernel's persistent-memory stack: NVDIMM modules described by ACPI NFIT (Intel Optane and similar battery-backed DIMMs from the late 2010s), the virtio-pmem paravirtual device that exposes persistent memory to VMs, and the bridge that lets newer CXL-attached persistent memory plug into the same namespace and region machinery.

keep conf=0.84 deploy=medium replacement=none subsystem=nvdimm category=memory
84%

recommendation

It should stay because the subsystem is actively maintained, with patches landing in 2024 and stable backports for virtio-pmem queued into 2026. Far from being legacy, LIBNVDIMM is the foundation that the modern CXL persistent-memory stack plugs into, QEMU's virtio-pmem still relies on it for VM guests, and vendors like Micron continue shipping new CXL memory products in 2025 that ultimately surface through this code.

repository signals

31 files
15,236 source lines
173 commits, 5y
+2,869 / −3,151 lines added / removed, 5y
65 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 173 total · active in 48/61 months
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sources

  1. lore.kernel.org

    Recent upstream maintenance in 2024 touched drivers/nvdimm directly ("drivers/nvdimm: Assign parent for event_source device").

  2. lore.kernel.org

    The subsystem still receives fixes in 2026, including virtio_pmem bugfix backports ("nvdimm: virtio_pmem: serialize flush requests").

  3. docs.kernel.org

    Kernel documentation describes LIBNVDIMM PMEM, regions, namespaces, BTT, and ongoing kernel-facing functionality for persistent-memory devices.

  4. kernel.org

    Current kernel CXL documentation says the CXL PMEM infrastructure serves as a bridge to the LIBNVDIMM subsystem, so new CXL persistent-memory deployments still depend on this stack.

  5. qemu.org

    QEMU documents virtio-pmem as a current paravirtual persistent-memory device, indicating ongoing VM/guest deployments for the Linux nvdimm stack.

  6. micron.com

    Micron currently markets CXL-based memory-expansion products, supporting the conclusion that new deployments in 2025 still exist in the broader persistent-memory/CXL space that feeds into libnvdimm.

codex reasoning notes (technical)

Keep: the directory is active kernel driver code with recent file-level lore activity, including a 2024 direct nvdimm change and a 2026 virtio_pmem stable backport. Web search found current kernel docs for LIBNVDIMM and CXL showing CXL PMEM bridges into LIBNVDIMM rather than replacing it, plus current QEMU virtio-pmem docs and a current Micron CXL memory product page. Sources obtained via lore_activity (first two URLs) and web search/open on kernel/QEMU/vendor docs (remaining URLs). No credible removal signal surfaced from the sampled lore evidence; this looks like a maintained core stack for legacy NFIT PMEM, VM virtio-pmem, and newer CXL-backed persistent-memory flows.