From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Kicinski Subject: Re: [PATCH rdma-next 0/8] User space steering Date: Mon, 1 Apr 2019 11:32:21 -0700 Message-ID: <20190401113221.6fbba319@cakuba.hsd1.ca.comcast.net> References: <20190331164450.23618-1-leon@kernel.org> <20190331140633.33df25a7@cakuba.hsd1.ca.comcast.net> <20190401062816.GC8348@mtr-leonro.mtl.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190401062816.GC8348@mtr-leonro.mtl.com> Sender: netdev-owner@vger.kernel.org To: Leon Romanovsky Cc: Doug Ledford , Jason Gunthorpe , RDMA mailing list , Ariel Levkovich , Eli Cohen , Mark Bloch , Saeed Mahameed , linux-netdev List-Id: linux-rdma@vger.kernel.org On Mon, 1 Apr 2019 09:28:16 +0300, Leon Romanovsky wrote: > On Sun, Mar 31, 2019 at 02:06:33PM -0700, Jakub Kicinski wrote: > > On Sun, 31 Mar 2019 19:44:42 +0300, Leon Romanovsky wrote: > > > From: Leon Romanovsky > > > > > > From Ariel, > > > > > > This series of patches adds user space managed steering infrastructure > > > to the mlx5_ib driver. > > > > > > User space managed steering requires the means to access a dedicated > > > memory space that is used by the device to store the packet steering > > > and header modification tables and rules in order to manage them directly > > > without the device's firmware involvement. This dedicated memory is part > > > of the ICM memory space. > > > > > > The changes are introducing the mlx5_ib API to allocate, deallocate and > > > register this dedicated SW ICM memory via the existing device memory API > > > using a private attribute which specifies the memory type. > > > > > > The allocated memory itself is not IO mapped and user can only access it > > > using remote RDMA operations. > > > > > > In addition, the series exposed the ICM address of the receive transport > > > interface (TIR) of Raw Packet and RSS QPs to user since they are required > > > to properly create and insert steering rules that direct flows to these QPs. > > > > Hi Leon! Out of curiosity what protocols are you guys steering here? > > Is this some form of RoCE or IB? Is there a good resource to read up on > > the DEVX stuff? (I presume this series is related?) > > mlx5 devices steering operates on packets without relation to specific > protocol. The decision to steer is based on HW capabilities and user > configuration for matching specific fields. Such configuration is done > through kernel and through DEVX. > > General description of DEVX can be found in manuals of libmlx5. > https://github.com/linux-rdma/rdma-core/blob/master/providers/mlx5/man/mlx5dv_devx_obj_create.3.md > https://github.com/linux-rdma/rdma-core/blob/master/providers/mlx5/man/ Thanks for those, looks quite powerful. What's your primary use case here? Is there some flow steering and encapsulation going on in RDMA world?