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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 DC038C433E0 for ; Wed, 17 Mar 2021 17:22:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A12DC64EED for ; Wed, 17 Mar 2021 17:22:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231184AbhCQRWW (ORCPT ); Wed, 17 Mar 2021 13:22:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232094AbhCQRVz (ORCPT ); Wed, 17 Mar 2021 13:21:55 -0400 Received: from mail-il1-x12a.google.com (mail-il1-x12a.google.com [IPv6:2607:f8b0:4864:20::12a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1B71C06174A for ; Wed, 17 Mar 2021 10:21:54 -0700 (PDT) Received: by mail-il1-x12a.google.com with SMTP id c17so2242336ilj.7 for ; Wed, 17 Mar 2021 10:21:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=CC7Mf0q3EnAE5rDEZdcJka8pLybrmwi+35ZtT7cRNpY=; b=R8f/RSCPIzz9NYQuI5TblmZ75ivWjoBIXluRtO7AEotdMv7v7KHCvEai003M94RWSH l7ILlTeFi0m1sdeTXej8XNycu+0HFhG6iNN3ZHXCR/4bjs9eo67PDUYjkLZD9x4Y74vb OKdz6O6CIbjhSB2kmfLYXL/bOtf6+fmgvHPvvsE9YEdRoMDY+0jEMRjwoOEKaWo+P147 WAd7wWzTJhC2SZTVkAjqUP+rhpB0cZ4l/w73CkqZMiEj42SrMqdZXG1xDawpQZHR1BVR R+kPCGhZLsdQ8NIowpoztRaT8kUyq1r0pVG2oYvOmVRGH4p0yYAmhvxkMfTKFCjkpCBK S+jg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=CC7Mf0q3EnAE5rDEZdcJka8pLybrmwi+35ZtT7cRNpY=; b=nYaJCkk0QNQkT3DtWpbSBz357GQqRERofOVCkMRHxc4K3bBVYZLhuvUm9g2tBoqGvs iR92o1N76/34f6bZy0n9vqCltFPRXftk817X0TWzq2PMZCbgEuwaNhCeMx3ljfGgQH7o am7Vsl5bOClyTl2gr8M4xFqlubxwOSQxK92+urPSdYqqN2BkcVl+ytj9LCoaMGlVR+Zl fghv+Ji/M3eaoxe5xX5xAJo4iHdncEOwDr8D54MG89LuImoQuS1SzJUh1geIIFjqWAsr hgvpFWtYOxDCbwDJ+rd2n18piRZQr/00fpAvYG0E8iwE6o/OKA8P+m8mAZvqRzvmQKZj GbCQ== X-Gm-Message-State: AOAM5320Fy4XZw56XxMEw/VSb9JPZsdHpOMpQhGNLqyyb38T5OXvA7Fl es9knUNsSFa97uK8npEtu7yX5A== X-Google-Smtp-Source: ABdhPJybXw8bDKBlONIbtrQr8SGL+GEIUjjPZXAv+okD787KixQ5uvITZ2lF3f2Rihl32Q2eFqYSNw== X-Received: by 2002:a05:6e02:1bc2:: with SMTP id x2mr8024672ilv.205.1616001714337; Wed, 17 Mar 2021 10:21:54 -0700 (PDT) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id d22sm10108387iof.48.2021.03.17.10.21.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 17 Mar 2021 10:21:53 -0700 (PDT) Subject: Re: [RFC PATCH v3 3/3] nvme: wire up support for async passthrough To: Christoph Hellwig Cc: Kanchan Joshi , kbusch@kernel.org, chaitanya.kulkarni@wdc.com, io-uring@vger.kernel.org, linux-nvme@lists.infradead.org, anuj20.g@samsung.com, javier.gonz@samsung.com, nj.shetty@samsung.com, selvakuma.s1@samsung.com References: <20210316140126.24900-1-joshi.k@samsung.com> <20210316140126.24900-4-joshi.k@samsung.com> <20210317085258.GA19580@lst.de> <149d2bc7-ec80-2e51-7db1-15765f35a27f@kernel.dk> <20210317165959.GA25097@lst.de> From: Jens Axboe Message-ID: <3b383e8e-b248-b8c4-2eea-6f5708845604@kernel.dk> Date: Wed, 17 Mar 2021 11:21:53 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210317165959.GA25097@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 3/17/21 10:59 AM, Christoph Hellwig wrote: > On Wed, Mar 17, 2021 at 10:49:28AM -0600, Jens Axboe wrote: >> I will post it soon, only reason I haven't reposted is that I'm not that >> happy with how the sqe split is done (and that it's done in the first >> place). But I'll probably just post the current version for comments, >> and hopefully we can get it to where it needs to be soon. > > Yes, I don't like that at all either. I almost wonder if we should > use an entirely different format after opcode and flags, although > I suspect fd would be nice to have in the same spot as well. Exactly - trying to think of how best to do this. It's somewhat a shame that I didn't place user_data right after fd, or even at the end of the struct. But oh well. One idea would be to have io_uring_sqe_hdr and have that be op/flags/prio/fd as we should have those for anything, and just embed that at the top of both io_uring_sqe (our general command), and io_uring_whatever which is what the passthrough stuff would use. Not sure, I need to dabble in the code a bit and see how we can make it the cleanest. > On a related note: I think it really should have a generic cmd > dispatching mechanism like ioctls have, preferably even enforcing > the _IO* mechanism. Yes, we could certainly do that. I don't want to turn it into a free-for-all and the wild west of passthrough, some notion of coherent definitions would be prudent. -- Jens Axboe