VirtIO-PMEM Driver Added To Linux 5.3 For Paravirtualized Persistent Memory

In addition to Linux 5.3 bringing a VirtIO-IOMMU driver, this next kernel version is bringing another new VirtIO virtual device implementation: PMEM for para-virtualized persistent memory support for the likes of Intel Optane DC persistent memory.

This new driver is "virtio-pmem" and was developed at Red Hat for supporting persistent memory devices over VirtIO for use by KVM+QEMU guests. VirtIO-PMEM leverages existing persistent memory driver infrastructure for supporting DAX-capable file-systems.

This driver exposes a fake persistent memory NVDIMM to guests that does bypass the guest page cache. Concurrently Red Hat has been working on the VirtIO persistent memory specification and documented here. Likewise, the QEMU bits can be found here.

The VirtIO-PMEM driver for Linux 5.3 is part of the libnvdimm pull request.