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_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 316E3C43381 for ; Thu, 21 Mar 2019 16:20:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00DBB218E2 for ; Thu, 21 Mar 2019 16:20:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553185245; bh=IhPIrhq8W8Q87S/POuATveJFR7fESaBnfudF5pTg+A8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=tIIq/eDtfJ98QN7pQ3Qrg2SbVtzftsZ16RPOtTJa2eQXk3tqT2B7FGBs35zMyyh3U pfov+h1l9qKYI2ThRyY1eIfd+VW3UKLZfBoAd0GDjRFaiJjWqIGGT3TR+uDTCYp8O/ hcjgj2F8T0vVqvCh0EzWYervImwP3D1sTIevoUe4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728537AbfCUQUo (ORCPT ); Thu, 21 Mar 2019 12:20:44 -0400 Received: from mga03.intel.com ([134.134.136.65]:37556 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727829AbfCUQUn (ORCPT ); Thu, 21 Mar 2019 12:20:43 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Mar 2019 09:20:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,253,1549958400"; d="scan'208";a="144019210" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by orsmga002.jf.intel.com with ESMTP; 21 Mar 2019 09:20:41 -0700 Date: Thu, 21 Mar 2019 10:21:40 -0600 From: Keith Busch To: Stefan Hajnoczi Cc: Maxim Levitsky , Fam Zheng , "kvm@vger.kernel.org" , Wolfram Sang , "linux-nvme@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Keith Busch , Kirti Wankhede , Mauro Carvalho Chehab , "Paul E . McKenney" , Christoph Hellwig , Sagi Grimberg , "Harris, James R" , Felipe Franciosi , Liang Cunming , Jens Axboe , Alex Williamson , Thanos Makatos , John Ferlan , Liu Changpeng , Greg Kroah-Hartman , Nicolas Ferre , Paolo Bonzini , Amnon Ilan , "David S . Miller" Subject: Re: Message-ID: <20190321162140.GA29342@localhost.localdomain> References: <20190319144116.400-1-mlevitsk@redhat.com> <488768D7-1396-4DD1-A648-C86E5CF7DB2F@nutanix.com> <42f444d22363bc747f4ad75e9f0c27b40a810631.camel@redhat.com> <20190321161239.GH31434@stefanha-x1.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190321161239.GH31434@stefanha-x1.localdomain> 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 Thu, Mar 21, 2019 at 04:12:39PM +0000, Stefan Hajnoczi wrote: > mdev-nvme seems like a duplication of SPDK. The performance is not > better and the features are more limited, so why focus on this approach? > > One argument might be that the kernel NVMe subsystem wants to offer this > functionality and loading the kernel module is more convenient than > managing SPDK to some users. > > Thoughts? Doesn't SPDK bind a controller to a single process? mdev binds to namespaces (or their partitions), so you could have many mdev's assigned to many VMs accessing a single controller.