Soon you will be able to boot across a network with attached computers using NVME over Fabrics. This capability is often called Boot from SAN. Currently, successful storage networking technologies such as Fibre Channel and iSCSI have standardized solutions that allow attached computer systems to boot from OS images stored on attached storage notes. The lack of this capability in NVMe-oF architecture presents a barrier to adoption.

This talk presents the design and implementation of libvfn, a new open-source library for interacting with PCIe-based NVMe devices from user-space using VFIO. The core of the library is excessively low-level and aims to allow NVMe controller verification and testing teams to interact with devices at the register and queue level. While the library ships with a production ready NVMe driver with a high-level API, the library is designed to expose enough low-level VFIO functionality with which custom drivers can be implemented for any PCIe device as required by the application.

Almost 10 years ago, the SPDK userspace polled mode nvme driver showed performance and efficiency far surpassing what was capable with the Linux kernel. But in recent years, Linux has responded with io_uring and asynchronous NVMe passthrough interfaces. The xNVMe project has also helped storage projects and applications adapt to the ever-growing list of Linux storage interfaces. This talk will compare the strengths of the SPDK and Linux NVMe drivers, explain how xNVMe has enabled io_uring NVMe passthrough in SPDK, and share some early performance results.

NVM Express® (NVMe®) technology has become synonymous with high-performance storage seeing widespread adoption in client, cloud and enterprise applications. Since the release of the NVMe 2.0 family of specifications, the NVM Express organization has released a number of new features to allow for faster and simpler development of NVMe solutions in order to support increasingly diverse environments.

NVM Express® is in the process of standardizing the Live Migration of a controller from one server to another. That work has already ratified TP4165 Tracking LBA Allocation with Granularity and has made significant changes to TP4159 PCIe Infrastructure for Live Migration. This presentation details the new capabilities the standardization that allows a host to seamless migrate a Virtual Machine (VM) and associated resources without affecting the user experience for use in datacenter load balancing and system maintenance.