From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f48.google.com (mail-wm0-f48.google.com [74.125.82.48]) by dpdk.org (Postfix) with ESMTP id 1ACD311A2 for ; Thu, 17 Dec 2015 00:18:44 +0100 (CET) Received: by mail-wm0-f48.google.com with SMTP id p187so283706wmp.0 for ; Wed, 16 Dec 2015 15:18:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:organization:user-agent :in-reply-to:references:mime-version:content-transfer-encoding :content-type; bh=mekfGgZJcEXKEpkz+1wARge+Lz2Rirwsp5toYWmQnJs=; b=o6VUozoPozQDVUE1fCvxlxhG+Jp/AJWJliTLuP9kXh1asQZL0OpalVRmBNeJXxarg9 8H3E0N/kwOMa/TlWcTO/cOkSijop6PvJNhlPF811J5A5rGowE3gwvyZ3bydJD0d3YXY8 /9+lMSsiNKgy7ok1GIHwitD63h/UUzWReK/GmvcKpnJAS2MA/yPRi/2CvDdqU/JvyYX0 ZfJT2/bJ4d3t6vd8IpaZfDr/snQpOH4WSam2Ttrcemzv/TI1TN+wDodFnYhNGaiN3dIp R3APR0dPkzB7+G1Zuqn2HUiCTMhJXk0yxBLor+AqNZ4CGTZ6SDC9YRwr2KaQi8nYL9/7 KfxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=mekfGgZJcEXKEpkz+1wARge+Lz2Rirwsp5toYWmQnJs=; b=LahHgpbBIUmJ0vOGi0C3I6L4NPFjkN8Kf3pS6arTgrGbrCIJ4Ybp0Kww3svPIVQM+9 Ajtroz96NHv0qHqrciTDd7SmQgErCJMLh79VKhSP4hpxgMRvx/K87OB0w3cRcmpuLlIk zUx6t3ijxQwLIQAdHGwBLI2HLcx5mnE1FunLP1MbJn5ToKPam3pOie3+7L27ApdT9hQV U1pbOsNS/aIuFYDzGvdYdlhjH/ZZE+pMWVetSNOypBIWSK1SuM8wgMPUgbFKJzz/1Jx5 qW5+7grmv2WtKjvM7to/3JK+1L6GPtKNiwyjOlDty6FGZMb0TgOIROpVevDtapHkMx1I vlHA== X-Gm-Message-State: ALoCoQnm2yEqfN8byAfsXlu1CFASIIckJCgcVKEcrHvfh3ZbdRVJy3lZ7s7akNMcmjnMh8J2822ehOOUiPe+mj9nj/47HAhIFw== X-Received: by 10.28.136.149 with SMTP id k143mr303510wmd.57.1450307923932; Wed, 16 Dec 2015 15:18:43 -0800 (PST) Received: from xps13.localnet (guy78-1-82-235-116-147.fbx.proxad.net. [82.235.116.147]) by smtp.gmail.com with ESMTPSA id c13sm27234598wmd.14.2015.12.16.15.18.42 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 16 Dec 2015 15:18:43 -0800 (PST) From: Thomas Monjalon To: "Burakov, Anatoly" Date: Thu, 17 Dec 2015 00:17:21 +0100 Message-ID: <17700135.Qc9aIsHGGP@xps13> Organization: 6WIND User-Agent: KMail/4.14.10 (Linux/4.1.6-1-ARCH; KDE/4.14.11; x86_64; ; ) In-Reply-To: References: <60420822.AbcfvjLZCk@xps13> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] VFIO no-iommu X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Dec 2015 23:18:44 -0000 2015-12-16 16:23, Burakov, Anatoly: > Hi Thomas, > > > > On Tue, Dec 15, 2015 at 09:53:18AM -0700, Alex Williamson wrote: > > > So it works. Is it acceptable? Useful? Sufficiently complete? Does > > > it imply deprecating the uio interface? I believe the feature that > > > started this discussion was support for MSI/X interrupts so that VFs > > > can support some kind of interrupt (uio only supports INTx since it > > > doesn't allow DMA). Implementing that would be the ultimate test of > > > whether this provides dpdk with not only a more consistent interface, > > > but the feature dpdk wants that's missing in uio. Thanks, > > Ferruh has done a great job so far testing Alex's patch, very few changes from DPDK side seem to be required as far as existing functionality goes (not sure about VF interrupts mentioned by Alex). However, one thing that concerns me is usability. While it is true that no-IOMMU mode in VFIO would mean uio interfaces could be deprecated in time, the no-iommu mode is way more hassle than using igb_uio/uio_pci_generic because it will require a kernel recompile as opposed to simply compiling and insmod'ding an out-of-tree driver. So, in essence, if you don't want an IOMMU, it's becoming that much harder to use DPDK. Would that be something DPDK is willing to live with in the absence of uio interfaces? Excuse me if I missed something obvious. Why a kernel compilation is needed?