Date: Tue, 09 Dec 2025 15:58:12 +0000 From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: e2b8be511e90 - main - nvmf_che: Add a manual page for the Chelsio NVMe/TCP PDU offload driver Message-ID: <69384714.35ba6.6608b41c@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=e2b8be511e9064de29a847e7c1cfc9200e69394b commit e2b8be511e9064de29a847e7c1cfc9200e69394b Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2025-12-09 15:57:44 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2025-12-09 15:57:44 +0000 nvmf_che: Add a manual page for the Chelsio NVMe/TCP PDU offload driver Sponsored by: Chelsio Communications Differential Revision: https://reviews.freebsd.org/D53764 --- share/man/man4/Makefile | 1 + share/man/man4/nvmf_che.4 | 80 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 81 insertions(+) diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index 722ee2bc9334..4084fa55dc69 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -442,6 +442,7 @@ MAN= aac.4 \ ${_nvdimm.4} \ nvme.4 \ nvmf.4 \ + nvmf_che.4 \ nvmf_tcp.4 \ nvmft.4 \ ${_nvram.4} \ diff --git a/share/man/man4/nvmf_che.4 b/share/man/man4/nvmf_che.4 new file mode 100644 index 000000000000..8960cda9c506 --- /dev/null +++ b/share/man/man4/nvmf_che.4 @@ -0,0 +1,80 @@ +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.\" Copyright (c) 2025 Chelsio Communications, Inc. +.\" +.Dd November 14, 2025 +.Dt NVMF_CHE 4 +.Os +.Sh NAME +.Nm nvmf_che +.Nd TCP transport for NVM Express over Fabrics on Chelsio NICs +.Sh SYNOPSIS +In +.Xr loader.conf 5 : +.Bd -literal -offset indent +nvmf_che_load="YES" +.Ed +.Sh DESCRIPTION +The +.Nm +module implements the a TCP/IP transport for NVM Express over Fabrics +using PDU offload on Chelsio T7 adapters. +It can be used by either the in-kernel NVMeoF host driver or controller. +In order to use PDU offload, +the initial socket connection must be using the TCP offload engine (TOE) +on a supported network interface. +In addition, +controller connections must negotiate a suitable +.Dv MAXH2CDATA +limit to ensure that received PDUs do not exceeed the maximum size +supported by the adapter. +.Sh SYSCTL VARIABLES +The following variables are available as both +.Xr sysctl 8 +variables and +.Xr loader 8 +tunables: +.Bl -tag -width indent +.It Va kern.nvmf.che.max_transmit_pdu +The maximum size of a transmitted PDU including all headers, payload, +and checksums. +This is an upper limit enforced when queues are created. +Individual adapters may empose a smaller limit. +The default size is 32 kilobytes. +.It Va kern.nvmf.che.max_receive_pdu +As above, but for received PDUs. +.It Va kern.nvmf.che.use_dsgl +Enable the use of a S/G list for large writes into adapter memory when +writing control structures for DDP (not used for PDU payload data). +S/G lists are enabled by default. +.It Va kern.nvmf.che.inline_threshold +Writes of control structures into adapter memory use a S/G list instead +of immediate data placed in work requests. +The default threshold is 256 bytes. +.It Va kern.nvmf.che.ddp_tags_per_qp +The number of STAGs reserved for use by DDP buffers for each queue pair. +Each command sent on a queue that requests data from the remote peer can +use DDP to place received data directly into the associated data buffer. +Each buffer requires a STAG to enable DDP. +If an STAG is not available when command requesting remote data is sent, +the data will be received in free list buffers and copied into the data +buffer by the driver instead. +The default size is 256 kilobytes. +.El +.Sh SEE ALSO +.Xr cxgbe 4 , +.Xr nvmf 4 , +.Xr nvmf_tcp 4 , +.Xr nvmft 4 +.Sh HISTORY +The +.Nm +module first appeared in +.Fx 16.0 . +.Sh AUTHORS +The +.Nm +module was developed by +.An John Baldwin Aq Mt jhb@FreeBSD.org +under sponsorship from Chelsio Communications, Inc.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?69384714.35ba6.6608b41c>