Xnvme

------

For details, then see the commit-messages, for highlights see below.

* API Extensions

- Add helper `xnvme_nvm_compare()`

- Plus emulation via ramdisk

* API Refactoring

These are the changes you need to account for if you are using the following
functions defined in the public xNVMe API:

- `xnvme_nvm_sanitize()`: arguments 'oipbp' and 'nodas' are now `bool`
- `xnvme_znd_mgmt_recv()`: argument renamed from 'action' to `zra`
- `xnvme_znd_mgmt_send()`: argument renamed from 'action_so' to `zsaso`
- `xnvme_cli_args`

- `{clear,direct,all,save,verbose,ad,idw,idr}*`: changed to `bool`
- `action` renamed to `sanact`
- `zrms` renamed to `zsa`

- `xnvme_pi_generate`

- `dbuf` renamed to `data_buf`
- `mbuf` renamed to `md_buf`

- Renamed `enum xnvme_retreive_opts` to `enum xnvme_retrieve_opts`

* Backends

- The vfio backend now support iovec payloads

* Library

- A version-script now controls library symbols, effectively preventing symbol
leakage from linked libraries.
- The build no longer fails when SPDK dependencies are not satisfied

- Instead of failing the build, the SPDK backend is disabled.
- SPDK is still "special" in the sense that xNVMe builds and links a patched
version. However, the default behavior now is to disable the SPDK backend
instead of failing the build when transient dependencies are missing.
This is a much nicer behavior for users who simply grab xNVMe to consume
`io_uring` command and NVMe driver ioctl interfaces.

- Replaced custom shared/static library logic with default Meson handling

- The default is to build both the static and shared libraries.
- The tools, examples, and tests are by default linked with the shared
version of the library.
- To build only a single version, use '--default-library' specifying either
'static' or 'shared'.

* Infrastructure

- The ramdisk workflow is now running on macOS.
- Expanded automated performance evaluation to include Windows and FreeBSD.
- Latency report

- Overhead per command evaluated on Linux, FreeBSD, and Windows.
- Uses `fio`.

- Scalability report

- Single-core peak performance when using xNVMe via SPDK/bdev_xnvme.

* Documentation

- The Sphinx-doc project theme now uses the (in)famous PyData Sphinx-theme.
- Major overhaul: the documentation and xNVMe website are now unified as a
Sphinx-doc project.
- A complete rewrite of the getting-started, toolchain, and API sections.

------

A lot of minor fixes, reduction of technical debt, and fixes in preperation for
Debian packaging. See the commits for details.

* Packaging, see subsection "packaging" in the Contributor section of the docs

* feat: Delayed identification, upon xnvme_dev_open() then a device was
"identified" and its geometry "derived", this is dropped in favor of "adhoc" /
"implicit" action when the data is requested.

* feat: The SPDK backend now supports iovec payloads

* feat: end-to-end data-protection is now available with helpers in the public
API

* feat: Support for completion-notification via eventfd() by using helper
function xnvme_queue_get_completion_fd()

------

* Pseudo Commands

- Encapsulation of functionality not NVMe-spec defined, yet common for
drivers etc. encapsulated for backend-handling as "pseudo-commands" these
are

- xnvme_controller_reset()
- xnvme_controller_get_registers()
- xnvme_namespace_rescan()
- xnvme_subsystem_reset()

- Implemented in the SPDK and Linux backends
- Usage via cli-tools is available

* Controller Handles

- Having device-handles to NVMe-controllers is a necessity for e.g. reading
controller-registers as provided via xnvme_controller_get_registers()

* Backend: SPDK

- Support for the KV Command-Set over NVMe/TCP

------

* API Refactoring

- refactor(api): hoist inline-struct 'xnvme_opts.css'
- refactor(api)!: hoist "xnvme_opts.oflags" and drop int-version
- refactor(api): hoist and define xnvme_cmd_ctx_async
- refactor(api): hoist and define xnvme_lba_range_attr

* Backends: libvfn/vfio

- Fix use of the libvfn API (memory-mapping)
- Bumping of the libvfn to libvfn 3.0.0-rc2, bumped to support
eventfd-notification and fix errors with memory-mapping

* Backend: SPDK

- feat(build/spdk): add libarchive dependency
- feat(build/spdk): bump to v23.09

* Backends: Windows

- Added support for SPDK in Windows via WPDK

Backend: linux / liburing

- feat(be/liburing): turn on batching by default

* Feature: Pseudo-commands

- Backend interface expanded with "pseudo-commands", this is to unify aspects
which are not command-encapsulated; reading controller-registers, resetting
subsystems etc.
- api: add xnvme_subsystem_reset() / xnvme_controller_reset() /
xnvme_namespace_rescan(), these construct "pseudo-commands" to instruct the
backend to e.g. reset.

* Rust

- xNVMe now has experimental Rust bindings via crate 'xnvme-sys'
- feat(rust/xnvme-sys): add bindgen-emitted wrapper for libxnvme
- feat(rust/xnvme_sys): add simplest example of call via bindings
- feat(git/ignore): add 'rust/target' to ignore
- feat(pcf,gha): add build of Rust crates


* Misc. Fixes

- fix: format-strings (use PRI-macros instead of e.g. lu-specifiers)
- fix(cli,enum): use xnvme_buf_virt_{alloc|free}() instead of malloc/free
- fix: use zu format-specifier for size_t
- fix(cli): change assignment for create_mode
- fix(spec): adjust format-specifier for comp_temp
- fix(be/libaio): remove comparison warning
- refactor(toolbox/xnvmec_generator): emit to subfolders
- refactor(build/manpages)!: only install manpages for installed binaries
- refactor(build/completions)!: only install completions for installed binaries
- fix(meson/options): remove unused option shared_library
- fix(meson/options): remove unused option enable-ysnp
- fix(toolbox/pkgs): build libvfn as release

* Build

- Cleanup helper targets

* cijoe

- feat(cijoe): add workflow for provisioning via git

* Documentation

- Added Tutorial for FDP
- Added Overview of the xNVMe CI environment

------

* API
- Introduced memory-mapping API (libxnvme_mem.h), that is, when the user
manages memory and thus does not want to use xnvme_buf_alloc() as doing so
would introduce bounce-buffers.

* CLI
- The passthru cli-interfaces now use --cdwXY arguments instead of
"command-files", this alignes with nvme-cli and is arguably simpler

* Backends: Linux
- Performance improvments in io_uring and io_uring_cmd backends due to the
addition batching via delayed submission
- Performance improvements to libaio due to the addition of the "ring-hack"

* Backends: Windows
- Support added for writing via "ioring" on Windows, previously only batched
reads were possible via this interface.

* Infrastructure; github-actions, docker-images, third-party etc. bump the
reference toolchain platforms, that is
- Debian is now Trixie, Bookworm and Bullseye.
- Ubuntu is now Lunar, Jammy and Focal
- Added Rocky Linux 9.2
- Added Oracle Linux 9.
- Dropped CentOS 7
- Dropped CentOS Stream 8
- Dropped openSUSE Leap 15.3 and 15.4, Tumbleweed remains

* Removal of a bunch of deprecated files and code. General *cleanup*.

------

This release got a whole lot bigger than it ought to. Aiming for more
frequent releases in the future. A bunch of changes to API,
implementation, and even the license.

Regarding the license. For compatibility with GPL-licensed software.
That is, consumption of xNVMe from GPL-licences software, then xNVMe is
changed from APACHE to BSD-3-Clause. To better determine the license,
the project has aligned with the golden practice of REUSE-compliance
(https://reuse.software/).

* API
* Refactored to provide a single "entry-point" header
* Headers no longer include other headers (except for the entry-point)
* Renamed the command-line api from xnvmec to xnvme_cli

* API / Command-Sets
* Support for FDP and DSM
* Support for Key-Value SSDs

* Backends
* The POSIX backend is replaced by CBI -- Common Backend Implementation
* Instead of "POSIX" then a handful of commonly useful implementations
are provided, being "strictly" POSIX was an impractical restriction,
such as lacking support for features which are provided on modern
operating systems but not defined by POSIX.

* Backends: FreeBSD
* Support for kqueue based aio

* Backends: SPDK
* Now has options to control Admin and I/O command timeout
* Removed patches no longer needed (available upstream)

* Backends: vfio
* Removed as subproject and instead links "properly" with the
system-provided libvfn

* tools
* switched fio from "external" to "internal" / "upstream" fio engine

For additional details then please have a look at the commit-history,
the v0.7.0 related issue on GitHUB and PR.