SPDK v25.09: NVMe 1.4 support in NVMe-oF target, NVMe-oF NSSR

bdev

spdk_bdev_get_preferred_write_alignment, spdk_bdev_get_preferred_write_granularity,
spdk_bdev_get_optimal_write_size, spdk_bdev_get_preferred_unmap_alignment and
spdk_bdev_get_preferred_unmap_granularity APIs were added.

bdev_compress

The deprecated bdev_compress module was removed.

bdev_null

Support was added to set the bdev's preferred write alignment, preferred write
granularity, optimal write size, preferred unmap alignment and preferred unmap
granularity. These can be set by users using new parameters to the bdev_null_create
RPC.

bdev_nvme

Add NVMe flush support to the bdev_nvme module. This support is optional and can be
enabled using the new enable_flush parameter to the bdev_nvme_set_options RPC.
The flush command is only sent to the namespace if the namespace reported that it
had a volatile write cache.

Support was added to set the bdev's preferred write alignment, preferred write
granularity, optimal write size, preferred unmap alignment and preferred unmap
granularity, if the NVMe namespace reports the associated values in its
IDENTIFY data.

bdev_rbd

Support was added for read-only RBD bdevs. Users can make an RBD bdev read-only
by using the -r or --readonly flag with the bdev_rbd_create RPC.

blobfs

The deprecated blobfs library was removed.

env_dpdk

The DPDK submodule was updated to DPDK 25.07.

Support was added for memory registration at a 4KB granularity.

The deprecated spdk_env_get_socket_id() and spdk_pci_device_get_socket_id()
APIs were removed. Users should use spdk_env_get_numa_id() and
spdk_pci_device_get_numa_id() instead.

nvme

Logging was significantly enhanced as part of this release. Transport address
is now shown for fabrics controllers. QP related log messages now include
information about the QP and its controller.

nvmf

(CVE-2025-57275) Fixed (8981ddb) an array-out-of-bounds access during update of registrants
for a namespace when PTPL (Persist through power loss) was enabled.
If number of registrants exceeded 16 (SPDK_NVMF_MAX_NUM_REGISTRANTS) memory after
the array ended could have been written with data provided in Reservation Register
command by the initiator. PTPL needed to be enabled explicitly, as it is disabled by default.
Affected NVMe-oF transports include TCP and RDMA NVMe-oF in SPDK NVMe-oF target.

Add NSSR support (NVMe Subsytem Reset) to NVMe-oF target. Once NSSR is issued - it is passed to all
underlying namespaces (bdevs). Currenly only bdevs with PCIe transport would handle NSSR.
See the NVMe Subsystem Reset (NSSR) section of nvmf.md for more information.

Passthrough handlers for vendor-specific admin commands were added to the NVMe-oF target.
They can be enabled using the optional vendor_specific parameter to the nvmf_set_config
RPC.

Vfio-user migration code was removed. This code was in a non-working state, and upstream
libvfio-user has moved to a new v2-style interface which is significantly different.
QEMU 10.1 has no live migration support currently, and when it does it will be v2-style
based. This allows SPDK to use latest vfio-user and its vfio-user migration support
is planned to be re-added at a later time.

A namespace's IDENTIFY data is now populated with the preferred write alignment,
preferred write granularity, optimal write size, preferred unmap alignment and
preferred unmap granularity if they were specified by the underlying bdev.

The nvmf target now reports support for NVMe version 1.4. To enable this upgrade,
improved NSID and log page offset validation was added to the target.

python

Moved all cli code inside the python package for easier generation and packaging.
Split large rpc python file into modules.

Deprecate python.spdk.rpc modules and use JSONRPCClient object directly.

reduce

The deprecated reduce library was removed.

rocksdb

The deprecated RocksDB plugin was removed.

sock

Simplified spdk_sock_[listen|connect] impl_name handling. Previously, if NULL was provided and the
connection or listen operation failed the code would continue checking other sock implementations.
This behavior is no longer necessary, as VPP sock module was removed. The remaining uring and posix
implementations both rely on network kernel stack and upcoming XLIO support shares the same
addressing. This legacy behavior complicates the implementation of asynchronous connect,
particularly when the socket object is returned immediately. Now, when NULL is provided, the default
implementation is selected and terminates on failure without iterating over other sock
implementations.

Changed the return behavior of spdk_sock_flush. The function now returns 0 on success, as relying
on the number of bytes returned was not recommended.

Added spdk_sock_connect_async to enable asynchronous connect operations.

thread

The spdk_io_channel_ref API was added to more efficiently take a reference to an
existing and known I/O channel.

util

The spdk_bit_pool_set_bit_allocated API was added to enable setting an spdk_bit_pool
to a previously known state.