Remote Direct Memory Access (RDMA) Protocol Extensions
RFC 7306
Internet Engineering Task Force (IETF) H. Shah
Request for Comments: 7306 Broadcom Corporation
Category: Standards Track F. Marti
ISSN: 2070-1721 W. Noureddine
A. Eiriksson
Chelsio Communications, Inc.
R. Sharp
Intel Corporation
June 2014
Remote Direct Memory Access (RDMA) Protocol Extensions
Abstract
This document specifies extensions to the IETF Remote Direct Memory
Access Protocol (RDMAP) as specified in RFC 5040. RDMAP provides
read and write services directly to applications and enables data to
be transferred directly into Upper-Layer Protocol (ULP) Buffers
without intermediate data copies. The extensions specified in this
document provide the following capabilities and/or improvements:
Atomic Operations and Immediate Data.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7306.
Shah, et al. Standards Track [Page 1]
RFC 7306 RDMA Protocol Extensions June 2014
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Shah, et al. Standards Track [Page 2]
RFC 7306 RDMA Protocol Extensions June 2014
Table of Contents
1. Introduction ....................................................4
1.1. Discovery of RDMAP Extensions ..............................5
2. Requirements Language ...........................................5
3. Glossary ........................................................6
4. Header Format Extensions ........................................7
4.1. RDMAP Control and Invalidate STag Fields ...................7
4.2. RDMA Message Definitions ...................................9
5. Atomic Operations ...............................................9
5.1. Atomic Operation Details ..................................10
5.1.1. FetchAdd ...........................................10
5.1.2. CmpSwap ............................................12
5.2. Atomic Operations .........................................13
5.2.1. Atomic Operation Request Message ...................14
5.2.2. Atomic Operation Response Message ..................17
5.3. Atomicity Guarantees ......................................18
5.4. Atomic Operations Ordering and Completion Rules ...........18
6. Immediate Data .................................................20
6.1. RDMAP Interactions with ULP for Immediate Data ............20
6.2. Immediate Data Header Format ..............................21
6.3. Immediate Data or Immediate Data with SE Message ..........21
6.4. Ordering and Completions ..................................22
7. Ordering and Completions Table .................................22
8. Error Processing ...............................................25
8.1. Errors Detected at the Local Peer .........................25
8.2. Errors Detected at the Remote Peer ........................26
9. Security Considerations ........................................26
10. IANA Considerations ...........................................27
10.1. RDMAP Message Atomic Operation Subcodes ..................27
10.2. RDMAP Queue Numbers ......................................28
11. References ....................................................29
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