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 43C12C77B6F for ; Tue, 11 Apr 2023 15:11:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230128AbjDKPLM (ORCPT ); Tue, 11 Apr 2023 11:11:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230422AbjDKPKw (ORCPT ); Tue, 11 Apr 2023 11:10:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 662AC59ED; Tue, 11 Apr 2023 08:10:35 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 010F062835; Tue, 11 Apr 2023 15:10:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7478C4339B; Tue, 11 Apr 2023 15:10:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1681225834; bh=DJwe6UzJsaev9ajZujQ5NHkfDfsVI0n/WkKr9BI449U=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=DzE+Q4O7O00+JC7HVvTuKE+IE498IDbddKmq9X9Euwh1PTxJ7PhyxRkZblRxsU1fI GpEiJce7E4J1DQRSyckcpAErj9AxAKoGoCfGxxpvdQRLeiM64Vf0ZxmwIQLkZHQ6ZJ egPKxdTUZZgKlMr50LZFM3QUOugoZYHPqt7YJ+y+VuyNzPotdX4CYAbVwl+UKv6sjM JtNgX4swzADyQR7yARHl3sicy224kzDIqvhuvMwZwgGUaLEMAAI4WrmnLIAO4X04uy +3Tn3wftfpcyiBbQKj6Q6LSVDqO+DtZWCjuPOSY3F6GvyRXyHizLBH/dz7+vTsIkMc 8pvziXG0GEUPg== Message-ID: Date: Tue, 11 Apr 2023 09:10:32 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH 0/5] add initial io_uring_cmd support for sockets Content-Language: en-US To: Jens Axboe , 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, willemdebruijn.kernel@gmail.com, 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> From: David Ahern In-Reply-To: <67831406-8d2f-feff-f56b-d0f002a95d96@kernel.dk> 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 8:41 AM, 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. > > 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. > My meta point is that there are uapis today to return this information to applications (and I suspect this is just the start of more networking changes - both data retrieval and adjusting settings). io_uring is wanting to do this on behalf of the application without a syscall. That makes io_uring yet another subsystem / component managing a socket. Any change to the networking stack required by io_uring should be usable by all other in-kernel socket owners or managers. ie., there is no reason for io_uring specific code here.