Extended

This section describes some options for where to go next after you have gained familiarity with xNVMe and the Core API.

Different command sets

If your device has support for more than just the NVM command set, then libxnvme_kvs.h and libxnvme_znd.h will be of interest. These include functions for constructing and submitting commands for their respective command set.

Alternatively, if you want to interact with a file, you can use the API in libxnvme_file.h.

Quality of life

xNVMe has a number of header files for making programming NVMe easier to manage, some of these are described below.

libxnvme_geo.h and libxnvme_ident.h include structs to make accessing useful information about the namespace (or controller) easier. xnvme_geo includes the maximum data transfer size (mdts_nbytes), the size of a logical block address (lba_nbytes), and more. xnvme_ident includes the namespace identifier (nsid), command set identifier, and more.

libxnvme_lba.h includes functions for constructing a xnvme_lba_range, which is a struct representing a range of logical block addresses (LBAs).

NVMe specification

libxnvme_spec.h is a C representation of the NVMe specification. This includes most of the structures described across the base, NVM, ZNS, and KV specifications.

In line with this, libxnvme_pi.h and libxnvme_topology.h provides functions for NVMe operations which aren’t commands. libxnvme_pi.h has functions for generating and verifying protection info. libxnvme_topology.h has functions for subsystem (or controller) reset, namespace rescan, and getting controller registers.

Command-line interface

libxnvme_cli.h provides functionality to create command-line interfaces for xNVMe related applications. Most of the xNVMe examples, tools, and tests use this header to provide a coherent command-line interface with bash-completion-scripts and man-pages.