changelog: add bdev QoS and iSCSI VPP support

# Changelog

## v18.04: (Upcoming Release)

## v18.04: Logical Volume Snapshot/Clone, iSCSI Initiator, Bdev QoS, VPP Userspace TCP/IP

### vhost

Please see this [security advisory](https://access.redhat.com/security/cve/cve-2018-1059)

for additional information on the DPDK vulnerability.

Workarounds have been added to ensure vhost compatibility with QEMU 2.12.

EXPERIMENTAL: Support for vhost-nvme has been added to the SPDK vhost target. See the

[vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.

### Unified Target Application

A new unified SPDK target application, `spdk_tgt`, has been added. This application combines the

functionality of several existing SPDK applications, including the iSCSI target, NVMe-oF target,

and vhost target. The new application can be managed through the existing configuration file and

[JSON-RPC](http://www.spdk.io/doc/jsonrpc.html) methods.

### Env

Add wrapper for DPDK rte_mempool_get_bulk() via spdk_mempool_get_bulk().

spdk_mempool_get_bulk() has been added to wrap DPDK rte_mempool_get_bulk().

New memory management functions spdk_malloc(), spdk_zmalloc(), and spdk_free() have been added.

These new functions have a `flags` parameter that allows the user to specify whether the allocated

### Bdev

Add new optional bdev module interface function, init_complete, to notify bdev modules

when the bdev subsystem initialization is complete. Useful for virtual bdevs that require

A new optional bdev module interface function, `init_complete`, has been added to notify bdev modules

when the bdev subsystem initialization is complete. This may be useful for virtual bdevs that require

notification that the set of initialization examine() calls is complete.

The bdev layer now allows modules to provide an optional per-bdev UUID, which can be retrieved with

the spdk_bdev_get_uuid() function.

Enforcement of IOPS limits for quality of service (QoS) has been added to the bdev layer. See the

[set_bdev_qos_limit_iops](http://www.spdk.io/doc/jsonrpc.html#rpc_set_bdev_qos_limit_iops) documentation

for more details.

### RPC

The Rpc configuration file section, which was deprecated in v18.01, has been removed.

The `[Rpc]` configuration file section, which was deprecated in v18.01, has been removed.

Users should switch to the `-r` command-line parameter instead.

The JSON-RPC server implementation now allows up to 32 megabyte responses, growing as

### NVMe Driver

EXPERIMENTAL: Adds support for WDS and RDS capable CMBs in NVMe controllers. This support is

EXPERIMENTAL: Support for WDS and RDS capable CMBs in NVMe controllers has been added. This support is

experimental pending a functional allocator to free and reallocate CMB buffers.

spdk_nvme_ns_get_uuid() has been added to allow retrieval of per-namespace UUIDs when available.

Added spdk_nvme_ctrlr_get_first_active_ns() and spdk_nvme_ctrlr_get_next_active_ns() to iterate

active namespaces and spdk_nvme_ctrlr_is_active_ns() to check if a ns id is active.

New API functions spdk_nvme_ctrlr_get_first_active_ns() and spdk_nvme_ctrlr_get_next_active_ns()

have been added to iterate active namespaces, as well as spdk_nvme_ctrlr_is_active_ns() to check if

a namespace ID is active.

### NVMe-oF Target

Namespaces may now be assigned unique identifiers via new optional "eui64" and "nguid" parameters

to the `nvmf_subsystem_add_ns` RPC method.

Namespaces may now be assigned unique identifiers via new optional `eui64` and `nguid` parameters

to the `nvmf_subsystem_add_ns` RPC method. Additionally, the NVMe-oF target automatically exposes

the backing bdev's UUID as the namespace UUID when available.

`spdk_nvmf_subsystem_remove_ns` is now asynchronous and requires two additional arguments, cb_fn and cb_arg.

cb_fn is a function pointer of type spdk_channel_for_each_cpl and cb_arg is a void pointer.

spdk_nvmf_subsystem_remove_ns() is now asynchronous and requires a callback to indicate completion.

### Blobstore

See the [lvol snapshots](http://www.spdk.io/doc/logical_volumes.html#lvol_snapshots) documentation

for more details.

Resizing logical volumes is now supported via the `resize_lvol_bdev` RPC method.

### Lib

A set of changes were made in the SPDK's lib code altering,

A set of changes were made in the SPDK's lib code altering

instances of calls to `exit()` and `abort()` to return a failure instead

wherever reasonably possible.

whether or not the poller did any work.  Existing pollers will need to be updated to

return a value.

### iSCSI Target

The SPDK iSCSI target now supports the fd.io Vector Packet Processing (VPP) framework userspace

TCP/IP stack. See the [iSCSI VPP documentation](http://www.spdk.io/doc/iscsi.html#vpp) for more

details.

### iSCSI initiator

An iSCSI initiator bdev module has been added to SPDK.  This module should be considered

### PMDK

The persistent memory (PMDK) bdev module is now enabled using --with-pmdk instead of

--with-nvml.  This reflects the renaming of the persistent memory library from NVML to

The persistent memory (PMDK) bdev module is now enabled using `--with-pmdk` instead of

`--with-nvml`.  This reflects the renaming of the persistent memory library from NVML to

PMDK.

### Virtio Block driver

### Virtio with 2MB hugepages

Previous 1GB hugepage limitation has now been lifted. A new '-g' command-line option

The previous 1GB hugepage limitation has now been lifted. A new `-g` command-line option

enables SPDK Virtio to work with 2MB hugepages.

See [2MB hugepages](http://www.spdk.io/doc/virtio.html#virtio_2mb) for details.