From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 2A30CA00E6 for ; Tue, 9 Jul 2019 17:18:51 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id DA1EB1B95C; Tue, 9 Jul 2019 17:18:49 +0200 (CEST) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id 3977E1B958 for ; Tue, 9 Jul 2019 17:18:48 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jul 2019 08:18:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,470,1557212400"; d="scan'208";a="165791032" Received: from aburakov-mobl1.ger.corp.intel.com (HELO [10.237.220.82]) ([10.237.220.82]) by fmsmga008.fm.intel.com with ESMTP; 09 Jul 2019 08:18:43 -0700 To: Thomas Monjalon Cc: Jerin Jacob Kollanukkaran , David Marchand , dev , Ben Walker References: <20190708142450.51597-1-jerinj@marvell.com> <2514934.U1Lao15di9@xps> From: "Burakov, Anatoly" Message-ID: <9284e5ad-8726-c850-c3a3-a2e0f4d3713e@intel.com> Date: Tue, 9 Jul 2019 16:18:43 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <2514934.U1Lao15di9@xps> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [EXT] Re: [PATCH] bus/pci: fix IOVA as VA mode selection 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 09-Jul-19 4:12 PM, Thomas Monjalon wrote: > 09/07/2019 17:02, Burakov, Anatoly: >> When IOMMU is fully enabled (iommu=on at boot time), igb_uio will simply >> not work. VFIO will work, whichever address mode you use. >> >> When IOMMU is in pass-through mode (iommu=pt at boot time), both igb_uio >> and VFIO will work, although igb_uio will only support IOVA as PA mode. >> Both modes will enable IOMMU, and both can run in IOVA as PA mode >> without losing that protection. >> >> It's only when IOMMU is off, igb_uio will not engage IOMMU, and VFIO >> will only work in no-IOMMU mode (thus not engaging IOMMU either), and >> only then you lack the IOMMU protection. > > Could we try to make IOMMU status clear in DPDK logs? > Then we could check the kernel drivers loaded and give > a compatibility status for each of them as debug logs. > I don't think there is a way to know IOMMU status from DPDK. It's a property of the system. We can kinda-sorta check IOMMU status if we have VFIO driver (there's a API to check for vfio_noiommu i think), and we do log it into debug output, but there is no such facility for igb_uio - we cannot know if it does or does not engage the IOMMU. (not unless we grep dmesg or something) -- Thanks, Anatoly