From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21A0EC4338F for ; Sun, 22 Aug 2021 22:31:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC5716128A for ; Sun, 22 Aug 2021 22:31:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232300AbhHVWcM (ORCPT ); Sun, 22 Aug 2021 18:32:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230172AbhHVWcM (ORCPT ); Sun, 22 Aug 2021 18:32:12 -0400 Received: from mail-qt1-x82f.google.com (mail-qt1-x82f.google.com [IPv6:2607:f8b0:4864:20::82f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7DE46C061575 for ; Sun, 22 Aug 2021 15:31:30 -0700 (PDT) Received: by mail-qt1-x82f.google.com with SMTP id c19so1518621qte.7 for ; Sun, 22 Aug 2021 15:31:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Jknhhatu+ClTZ3AhFRUou0UJJsz++z+Or8pfjtihPEA=; b=fIK/UZK3d8gwf6UaP4hmp1Sy2g/FqP7jbNQFwit2ocdzmLW9gki5mV2o+s3lWsbWxC eRtFY/GD/AW0LNq7gTEtdlzv7Lj1gzVSEwgqzvsVcjGkmwPJ4yHTwdQ7NlvKiQjItmHS 124hIqL2q/heqwxPnwc/HpwVFp9Zm/FwNAAXy6X3NbQP/qmIJ20rAZ9Lf7QzvBkq5AKP 67wHqDd5B9y1UgFBMtC7pHSnc2+uqEdZrh858ZQ3Tzw4/DOrKNmjDAL2I6CpDAyq/sm0 sLUIAZeMD1KmzafIQ9ctdAb3Bkic9YpdtCKMYw569m4ck9os9zF4V/tps0k9W8rUUH2p 4kLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Jknhhatu+ClTZ3AhFRUou0UJJsz++z+Or8pfjtihPEA=; b=FMq1rqFGYAB6zrBb1OorC1eabBEM9R2m4ILWc620mVOWSg1px+j4wDvafTKtPncFjK hUL7w9bNqSo+4Q6edxMRqa6MYdhBTNV99xEA/KBUpbi/LoS3IIhHlSZac2APrjTLIEeh WvfEfxqDKBnYF9lnB60GCT734nen+3tYIE7xnf6HgoeqlHCJFCXLxDnsEbGla6YnqkzJ AkVpp9wOqo+ABp0uA5G4KRAZY31m1Cg5ZdpiNC52bvIg45B7Sjcp3cfmGqvLtLxib4kf NKoQ+8+wqcC69+likANvCj3ze2aH1BxWtZrOz/a42zdJ9cL0W7fVsKmtnWIa09Zt5nBs 335g== X-Gm-Message-State: AOAM532MVdULfgZ5d9PMewMz2C9ZnA7uCc/wd9SoF6gfKZIlK8+loA/6 Ir5nRhMzxswbvUGOsLKVwnSMqkvOnACRlA== X-Google-Smtp-Source: ABdhPJyjJDH6c+7ZIvo0q0HBYtMB5RDfYgWlv5mfo6XdM0RMEIzatlwvBroS/yiLCrSBL1VNA21FHw== X-Received: by 2002:ac8:6054:: with SMTP id k20mr26557500qtm.237.1629671489673; Sun, 22 Aug 2021 15:31:29 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-142-162-113-129.dhcp-dynamic.fibreop.ns.bellaliant.net. [142.162.113.129]) by smtp.gmail.com with ESMTPSA id bl26sm6943270qkb.34.2021.08.22.15.31.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 22 Aug 2021 15:31:29 -0700 (PDT) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1mHw00-0035Th-C5; Sun, 22 Aug 2021 19:31:28 -0300 Date: Sun, 22 Aug 2021 19:31:28 -0300 From: Jason Gunthorpe To: Oded Gabbay Cc: linux-rdma , Greg Kroah-Hartman Subject: Re: Creating new RDMA driver for habanalabs Message-ID: <20210822223128.GZ543798@ziepe.ca> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Sun, Aug 22, 2021 at 12:40:26PM +0300, Oded Gabbay wrote: > Hi Jason, > > I think that about a year ago we talked about the custom RDMA code of > habanalabs. I tried to upstream it and you, rightfully, rejected that. > > Now that I have enough b/w to do this work, I want to start writing a > proper RDMA driver for the habanalabs Gaudi device, which I will be > able to upstream to the infiniband subsystem. > > I don't know if you remember but the Gaudi h/w is somewhat limited in > its RDMA capabilities. We are not selling a stand-alone NIC :) We just > use RDMA (or more precisely, ROCEv2) to connect between Gaudi devices. > > I'm sure I will have more specific questions down the line, but I had > hoped you could point me to a basic/not-too-complex existing driver > that I can use as a modern template. I'm also aware that I will need > to write matching code in rdma-core. > > Also, I would like to add we will use the auxiliary bus feature to > connect between this driver, the main (compute) driver and the > Ethernet driver (which we are going to publish soon I hope). It sounds fine, as Leon mentions EFA is a good starting point for something simple but non-spec compliant If I recall properly you'll want to have some special singular PD for the HW and some specialty QPs? Jason