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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6670BC76196 for ; Tue, 11 Apr 2023 14:55:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230114AbjDKOzR (ORCPT ); Tue, 11 Apr 2023 10:55:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230191AbjDKOy4 (ORCPT ); Tue, 11 Apr 2023 10:54:56 -0400 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB6214C07 for ; Tue, 11 Apr 2023 07:54:51 -0700 (PDT) Received: by mail-io1-xd2c.google.com with SMTP id ca18e2360f4ac-7606cf9c551so2751939f.0 for ; Tue, 11 Apr 2023 07:54:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; t=1681224891; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=n1/uakkZjv9cQF6P7up1HAscrfLZ1PckVlhhE3kXYRA=; b=i2M7Gt5eHTm8Zs3MHrk2JXdsmGkyZeCGjw4sJo9A0tJ26iSzx4aGtypYqkuS6DYNUz lv1RUSJkcY1cOnuVLJs4ky1/FBfMdyPk/UbAr++vHYTxtv9pREyb/taP47PWOFzlSuMd u2X+Rt6tRRnnS6EJ6xBsDnWIVJG5kzFKGBG5C34Rf8brfoKsgQR70flgDtlaTr4hkMtK 40GCjDp8pq2KkGHK2ikm830ZQw/BPjREs1RKfJNSmVi1XbgCbldOvyTDewUFzkQmuKs/ AERVqGet/CWXA1fCNIa0kcXhEBm1pVqsYVUPejuHM9u2J0G9iMPDz/RN2vBo+F8bg4R/ zszg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681224891; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=n1/uakkZjv9cQF6P7up1HAscrfLZ1PckVlhhE3kXYRA=; b=fRMaroH7+tMrTuSwbF6rXN+V8IW0b1LUGQIyuWXN+IWntI05TVJbQ4DKn3CTs0fpD0 3NeewvK5oKTfb2l0qOawR7WPpYtNesHO/iVqBQQy910/wlV5juDhGBNW1JEyA0UUHkfO kNhj/SKaFKqXHNTHCkIuyNKmpo7EHpHOqHfQHkDQUx+JcdqE8sB8tR/S/ouxz5mw6/WT 3dbYO3VQm6CPfXZILfRsMPw5daJ8fOCLtBp7+JYKEa4qPk0yMjNfWZnmOtesbgnsw3PI bI1Xt7htX55wvzsXtDsFpvw9zoZEBt61rlIpybHu1eUfgqgXL/J6lIkveSoHM0cZcezL K33A== X-Gm-Message-State: AAQBX9fSB/lmkI53Sp0SL80B55WLUWz+rpT2aeTi7TOAuzdpPjO3Dh4c GLWG5oCuE0muSWRuwJtTp7a6ZgnySlbeMt4n3N4= X-Google-Smtp-Source: AKy350ZNd1GN2qGTn8k0KmKiar/rBVtqQ95KVwEH4VZ0jhuU+wlCTFTF5pf6yJ2PAMLuldmKwNN0IA== X-Received: by 2002:a6b:8d84:0:b0:740:7d21:d96f with SMTP id p126-20020a6b8d84000000b007407d21d96fmr4946123iod.1.1681224890937; Tue, 11 Apr 2023 07:54:50 -0700 (PDT) Received: from [192.168.1.94] ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id y32-20020a029523000000b0040bd91e4803sm980367jah.155.2023.04.11.07.54.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 Apr 2023 07:54:50 -0700 (PDT) Message-ID: <036c80e5-4844-5c84-304c-7e553fe17a9b@kernel.dk> Date: Tue, 11 Apr 2023 08:54:49 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH 0/5] add initial io_uring_cmd support for sockets Content-Language: en-US To: Willem de Bruijn , David Ahern , Breno Leitao Cc: Willem de Bruijn , io-uring@vger.kernel.org, netdev@vger.kernel.org, kuba@kernel.org, asml.silence@gmail.com, leit@fb.com, edumazet@google.com, pabeni@redhat.com, davem@davemloft.net, dccp@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org, matthieu.baerts@tessares.net, marcelo.leitner@gmail.com References: <20230406144330.1932798-1-leitao@debian.org> <75e3c434-eb8b-66e5-5768-ca0f906979a1@kernel.org> <67831406-8d2f-feff-f56b-d0f002a95d96@kernel.dk> <643573df81e20_11117c2942@willemb.c.googlers.com.notmuch> From: Jens Axboe In-Reply-To: <643573df81e20_11117c2942@willemb.c.googlers.com.notmuch> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 4/11/23 8:51?AM, Willem de Bruijn wrote: > Jens Axboe wrote: >> On 4/11/23 8:36?AM, David Ahern wrote: >>> On 4/11/23 6:00 AM, Breno Leitao wrote: >>>> I am not sure if avoiding io_uring details in network code is possible. >>>> >>>> The "struct proto"->uring_cmd callback implementation (tcp_uring_cmd() >>>> in the TCP case) could be somewhere else, such as in the io_uring/ >>>> directory, but, I think it might be cleaner if these implementations are >>>> closer to function assignment (in the network subsystem). >>>> >>>> And this function (tcp_uring_cmd() for instance) is the one that I am >>>> planning to map io_uring CMDs to ioctls. Such as SOCKET_URING_OP_SIOCINQ >>>> -> SIOCINQ. >>>> >>>> Please let me know if you have any other idea in mind. >>> >>> I am not convinced that this io_uring_cmd is needed. This is one >>> in-kernel subsystem calling into another, and there are APIs for that. >>> All of this set is ioctl based and as Willem noted a little refactoring >>> separates the get_user/put_user out so that in-kernel can call can be >>> made with existing ops. >> >> How do you want to wire it up then? We can't use fops->unlocked_ioctl() >> obviously, and we already have ->uring_cmd() for this purpose. > > Does this suggestion not work? Not sure I follow, what suggestion? >>> I was thinking just having sock_uring_cmd call sock->ops->ioctl, like >>> sock_do_ioctl. > >> I do think the right thing to do is have a common helper that returns >> whatever value you want (or sets it), and split the ioctl parts into a >> wrapper around that that simply copies in/out as needed. Then >> ->uring_cmd() could call that, or you could some exported function that >> does supports that. >> >> This works for the basic cases, though I do suspect we'll want to go >> down the ->uring_cmd() at some point for more advanced cases or cases >> that cannot sanely be done in an ioctl fashion. > > Right now the two examples are ioctls that return an integer. Do you > already have other calls in mind? That would help estimate whether > ->uring_cmd() indeed will be needed and we might as well do it now. Right, it's a proof of concept. But we'd want to support anything that setsockopt/getsockopt would do. This is necessary so that direct descriptors (eg ones that describe a struct file that isn't in the process file table or have a regular fd) can be used for anything that a regular file can. Beyond that, perhaps various things necessary for efficient zero copy rx. I do think we can make the ->uring_cmd() hookup a bit more palatable in terms of API. It really should be just a sub-opcode and then arguments to support that. The grunt of the work is really refactoring the ioctl and set/getsockopt bits so that they can be called in-kernel rather than assuming copy in/out is needed. Once that is done, the actual uring_cmd hookup should be simple and trivial. -- Jens Axboe