User Manual

Rev 2.2-1.0.1

Mellanox Technologies

MLX5_SCATTER_TO_CQE

• Small buffers are scattered to the completion queue entry and manipulated by the driver.

Valid for RC transport.

• Default is 1, otherwise disabled.

1.3.3 Mid-layer Core

Core services include: management interface (MAD), connection manager (CM) interface, and

Subnet Administrator (SA) interface. The stack includes components for both user-mode and

kernel applications. The core services run in the kernel and expose an interface to user-mode for

verbs, CM and management.

1.3.4 ULPs

IPoIB

The IP over IB (IPoIB) driver is a network interface implementation over InfiniBand. IPoIB

encapsulates IP datagrams over an InfiniBand connected or datagram transport service. IPoIB

pre-appends the IP datagrams with an encapsulation header, and sends the outcome over the

InfiniBand transport service. The transport service is Unreliable Datagram (UD) by default, but it

may also be configured to be Reliable Connected (RC). The interface supports unicast, multicast

and broadcast. For details, see

Chapter 4.4, “IP over InfiniBand”.

iSER

iSCSI Extensions for RDMA (iSER) extends the iSCSI protocol to RDMA. It permits data to be

transferred directly into and out of SCSI buffers without intermediate data copies. For further

information, please refer to

Chapter 4.2, “iSCSI Extensions for RDMA (iSER)”.

SRP

SCSI RDMA Protocol (SRP) is designed to take full advantage of the protocol offload and

RDMA features provided by the InfiniBand architecture. SRP allows a large body of SCSI soft

ware to be readily used on InfiniBand architecture. The SRP driver—known as the SRP Initia-

tor—differs from traditional low-level SCSI drivers in Linux. The SRP Initiator does not control

a local HBA; instead, it controls a connection to an I/O controller—known as the SRP Target—to

provide access to remote storage devices across an InfiniBand fabric. The SRP Target resides in

an I/O unit and provides storage services. See

Chapter 4.1, “SCSI RDMA Protocol” and Appen-

dix A, “SRP Target Driver”.

uDAPL

User Direct Access Programming Library (uDAPL) is a standard API that promotes data center

application data messaging performance, scalability, and reliability over RDMA interconnects:

InfiniBand and RoCE. The uDAPL interface is defined by the DAT collaborative.

This release of the uDAPL reference implementation package for both DAT 1.2 and 2.0 specifi-

cation is timed to coincide with OFED release of the Open Fabrics (www.openfabrics.org) soft-

ware stack.

For more information about the DAT collaborative, go to the following site:

http://www.datcollaborative.org