From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f41.google.com (mail-wg0-f41.google.com [74.125.82.41]) by dpdk.org (Postfix) with ESMTP id 326437E89 for ; Mon, 20 Oct 2014 23:51:01 +0200 (CEST) Received: by mail-wg0-f41.google.com with SMTP id b13so6429112wgh.0 for ; Mon, 20 Oct 2014 14:59:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:from:date:message-id:subject:to:content-type; bh=Lmeu64scZTwvvOxnrGX7oz8CXYfIXMBA1g/tb3SsDgw=; b=KS2ZfkxZkY/zZTznkCBYJ6069V7BOgGK/yWFMjmrod1d+MLME3WhZ6Vn3/x1bMtCAI VYFRxqIMtjbVc38wZoaqecqEuXFzkYQXi9/glKsA6Qsj1Y4w8bFNPoUg7B/+o3k3Zhij Qco94vt0S7BrlZv9zdXlsfLTVWthm41WD9yhSKMpTrauZ63SaPv4KIFiAYmscIJIp1NK ZT0QL0u81MQTgv2Sm7ZeqxcXf1nOUK4Z98S9aJbZJ/4Ghq6zBJYa/DbnOkJ4eEcuR8RQ mWWxievHg9Myp3U6r8wr4ZJpuv+sZ+lkoNaNhVtRLbIYuHUPg2JDvYFvIPuD0pB55yFX iFPw== X-Received: by 10.180.104.8 with SMTP id ga8mr23299276wib.78.1413842354292; Mon, 20 Oct 2014 14:59:14 -0700 (PDT) MIME-Version: 1.0 Received: by 10.180.9.68 with HTTP; Mon, 20 Oct 2014 14:58:54 -0700 (PDT) From: Shivapriya Hiremath Date: Mon, 20 Oct 2014 14:58:54 -0700 Message-ID: To: dev@dpdk.org Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-dev] Why do we need iommu=pt? 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: Mon, 20 Oct 2014 21:51:01 -0000 Hi, My question is that if the Poll mode driver used the DMA kernel interface to set up its mappings appropriately, would it still require that iommu=pt be set? What is the purpose of setting iommu=pt ? Thank you.