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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 E59F9C04AB1 for ; Thu, 9 May 2019 09:13:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACF20206A3 for ; Thu, 9 May 2019 09:13:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CDkwyiO6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726449AbfEIJNA (ORCPT ); Thu, 9 May 2019 05:13:00 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52184 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725821AbfEIJNA (ORCPT ); Thu, 9 May 2019 05:13:00 -0400 Received: by mail-wm1-f65.google.com with SMTP id o189so2268800wmb.1; Thu, 09 May 2019 02:12:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=UcO77C1d2oPlXYkp6CkiRlKtVOMkq5wxTIYeAm1syxo=; b=CDkwyiO65SSVbxmKPkBw+7CcNdsw7cmG/lXhK57rnCu5hWuqjioqvSYy2l9aUikO5M /nW8VgaATNCzJhdIcK9nIZxH0TZfYz86n0vwCqqh1C//E0g2pG660CNOtzmxqm6EqpgK ZWIpx5vT9WYGFEmAXUpEgd/buHjfmaAOtX6UH2Bw+XR37DkBzqcVhOmXL2ZHV4oI4jxf Q6v6TKLWoy9BL+/a+HF5QnTS14Sj1q9oOGmb1RYruBTgAgXTxEzipUKxBtN49pQAYrNG 4uZj/gIv9bT4vK48zVMSQsSJ5yDQ1b2WgQORXIz4ZaauynohR8iJft+JXpAWii7StqKO 1cXQ== 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:user-agent; bh=UcO77C1d2oPlXYkp6CkiRlKtVOMkq5wxTIYeAm1syxo=; b=GHbMDfYvEaa6C85q8xjApQegAkKhNKpwdC6JFwukJP2D41N3ADfvFSiMwiftpU/ygr dLYpYxEnSca9u0vi66vbWGvoDKqsVyeThGPIR03kQD/CGLY5w4MGmTulB5MjGCxF2Gla ljcySJ0VOnSWMm4vEDeCukIvofeQTZd3ilhOOxk8s8JGWkNcC859OcfM54ZHSskaH5WA jwJnUC3zsiy0HYpbnjicb+GnVje5Lr4GZFK/K7p+AkbCLCy8qFhd4kM0oRWYVtmPbkf+ P6TvvNujlFahf63BlUDRRGOr3NnnSdPlmdV0s1BMDCaqUAlUMOY3qIpgK0Yogdff0VQd ytPw== X-Gm-Message-State: APjAAAX1QshsvAAJyC1SghQ8O+4OlEpkBzNraqZVk6jqHAYEmvp3PICF fDGYMpB/NdnioOKjYXfDtYo= X-Google-Smtp-Source: APXvYqw0VKhI0WziMTaFb1wtWXZnzZOn5XxmOI7BEJXN6voxMBVpcjaeQu+MCIZq24v6HE7IT31/cQ== X-Received: by 2002:a1c:b756:: with SMTP id h83mr1888506wmf.64.1557393177619; Thu, 09 May 2019 02:12:57 -0700 (PDT) Received: from localhost ([51.15.41.238]) by smtp.gmail.com with ESMTPSA id e8sm4815404wrc.34.2019.05.09.02.12.56 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 09 May 2019 02:12:56 -0700 (PDT) Date: Thu, 9 May 2019 10:12:55 +0100 From: Stefan Hajnoczi To: Maxim Levitsky Cc: Christoph Hellwig , Fam Zheng , Keith Busch , Sagi Grimberg , kvm@vger.kernel.org, Wolfram Sang , Greg Kroah-Hartman , Liang Cunming , Nicolas Ferre , linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, "David S . Miller" , Jens Axboe , Alex Williamson , Kirti Wankhede , Mauro Carvalho Chehab , Paolo Bonzini , Liu Changpeng , "Paul E . McKenney" , Amnon Ilan , John Ferlan Subject: Re: [PATCH v2 00/10] RFC: NVME MDEV Message-ID: <20190509091255.GB15331@stefanha-x1.localdomain> References: <20190502114801.23116-1-mlevitsk@redhat.com> <20190503121838.GA21041@lst.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qlTNgmc+xy1dBmNv" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --qlTNgmc+xy1dBmNv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, May 06, 2019 at 12:04:06PM +0300, Maxim Levitsky wrote: > On top of that, it is expected that newer hardware will support the PASID based > device subdivision, which will allow us to _directly_ pass through the > submission queues of the device and _force_ us to use the NVME protocol for the > frontend. I don't understand the PASID argument. The data path will be 100% passthrough and this driver won't be necessary. In the meantime there is already SPDK for users who want polling. This driver's main feature is that the host can still access the device at the same time as VMs, but I'm not sure that's useful in performance-critical use cases and for non-performance use cases this driver isn't necessary. Stefan --qlTNgmc+xy1dBmNv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAlzT7xcACgkQnKSrs4Gr c8h67Qf/cCzGWh6iM657Q87QZaDIfXuEdFC5VBJt+JUTAJrD1K+vJeppmlITSNe9 7i6nrm+Y7G2icJW5PZmv7Ym7Pl9na4VDNU+G13f/ErGEniwuY8YdvW5VyO7v8Ilo ShnXoNT6DY0yhSi7TZalmpq/o9GAw/i0A/QEoMs89A1jQgcnbYZjXemlRTuy+RaT NcXQxGSVvjW3QXT/qSiwD2GgeNVWbGTp5pCFME/GBY5tlad9blpJJIKkQQLHyhdW U/UqokQr4hAbb1C1W+Y4nzQsGaHxB8AN+mQoD3luyDs0qqYNeHLiQCAm3mXdRna5 A/tkfOjwvZxT/OhJqWDcjIHB9NsWmA== =YaAX -----END PGP SIGNATURE----- --qlTNgmc+xy1dBmNv--