From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 5DA09591E for ; Fri, 17 Feb 2017 13:29:47 +0100 (CET) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Feb 2017 04:29:46 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,171,1484035200"; d="scan'208";a="226519559" Received: from fyigit-mobl1.ger.corp.intel.com (HELO [10.237.220.137]) ([10.237.220.137]) by fmsmga004.fm.intel.com with ESMTP; 17 Feb 2017 04:29:44 -0800 To: Alejandro Lucero , dev@dpdk.org References: <1484742475-41005-1-git-send-email-alejandro.lucero@netronome.com> Cc: Thomas Monjalon From: Ferruh Yigit Message-ID: <6b4adfde-4e43-07d9-6fcb-43454f1d2d20@intel.com> Date: Fri, 17 Feb 2017 12:29:44 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <1484742475-41005-1-git-send-email-alejandro.lucero@netronome.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] igb_uio: map dummy dma forcing iommu domain attachment X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2017 12:29:47 -0000 On 1/18/2017 12:27 PM, Alejandro Lucero wrote: > For using a DPDK app when iommu is enabled, it requires to > add iommu=pt to the kernel command line. But using igb_uio driver > makes DMAR errors because the device has not an IOMMU domain. > > Since kernel 3.15, iommu=pt requires to use the internal kernel > DMA API for attaching the device to the IOMMU 1:1 mapping, aka > si_domain. Previous versions did attach the device to that > domain when intel iommu notifier was called. > > This is not a problem if the driver does later some call to the > DMA API because the mapping can be done then. But DPDK apps do > not use that DMA API at all. > > Doing this dma map and unmap is harmless even when iommu is not > enabled at all. > > Signed-off-by: Alejandro Lucero Acked-by: Ferruh Yigit (I suggest getting this early in 17.05 release, so it can be tested more)