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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 A66B6C3A5A0 for ; Mon, 19 Aug 2019 18:59:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B530214DA for ; Mon, 19 Aug 2019 18:59:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566241194; bh=Wxa6xg07vvb4+S3puGVqgQafgQXeiE6wj03+QbDhvTM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=gF21kSfNI4MOeaX8pBTRHV1FCMOV+BrjnSJDLKyqFyximEjSdSD84VRQCrCfk6PRj b9zsL63Dm1n9NB6xwlGPvR+nvlCS3V80m5O6GE55ljwc7uglF+OVkmCZHk1hoCSpxE oQ1W/EslHEZ+gQGXKOOaOgrOHZdtBz8Fiv7S3qrs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728400AbfHSS7x (ORCPT ); Mon, 19 Aug 2019 14:59:53 -0400 Received: from mga01.intel.com ([192.55.52.88]:29694 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728283AbfHSS7x (ORCPT ); Mon, 19 Aug 2019 14:59:53 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Aug 2019 11:59:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,405,1559545200"; d="scan'208";a="195595817" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by fmsmga001.fm.intel.com with ESMTP; 19 Aug 2019 11:59:52 -0700 Date: Mon, 19 Aug 2019 12:57:49 -0600 From: Keith Busch To: Sagi Grimberg Cc: Marta Rybczynska , Christoph Hellwig , axboe , linux-nvme , linux-kernel , Samuel Jones , Guillaume Missonnier Subject: Re: [PATCH v2] nvme: allow 64-bit results in passthru commands Message-ID: <20190819185749.GA11202@localhost.localdomain> References: <89520652.56920183.1565948841909.JavaMail.zimbra@kalray.eu> <20190816131606.GA26191@lst.de> <469829119.56970464.1566198383932.JavaMail.zimbra@kalray.eu> <20190819144922.GC6883@localhost.localdomain> <1d7819a9-9504-2dc6-fca4-fbde4f99d92c@grimberg.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1d7819a9-9504-2dc6-fca4-fbde4f99d92c@grimberg.me> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 19, 2019 at 11:56:28AM -0700, Sagi Grimberg wrote: > > >> ----- On 16 Aug, 2019, at 15:16, Christoph Hellwig hch@lst.de wrote: > >>> Sorry for not replying to the earlier version, and thanks for doing > >>> this work. > >>> > >>> I wonder if instead of using our own structure we'd just use > >>> a full nvme SQE for the input and CQE for that output. Even if we > >>> reserve a few fields that means we are ready for any newly used > >>> field (at least until the SQE/CQE sizes are expanded..). > >> > >> We could do that, nvme_command and nvme_completion are already UAPI. > >> On the other hand that would mean not filling out certain fields like > >> command_id. Can do an approach like this. > > > > Well, we need to pass user space addresses and lengths, which isn't > > captured in struct nvme_command. > > Isn't simply having a 64 variant simpler? Could you provide more details on what you mean by this?