From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-x229.google.com (mail-pa0-x229.google.com [IPv6:2607:f8b0:400e:c03::229]) by dpdk.org (Postfix) with ESMTP id 6AA6C9A for ; Mon, 6 Jan 2014 15:08:15 +0100 (CET) Received: by mail-pa0-f41.google.com with SMTP id lf10so18630117pab.14 for ; Mon, 06 Jan 2014 06:09:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=RdMF+puNcORKzL4f2zMPkcLSH+sdowNjWjkmSld5P5M=; b=sTGgKh0BdyrqlrGcaSdXR2fol+xazCJunQu5zlho9mOFH96484F337ynQDIXvJLU4h PXfsQp6WKrglnctncMaO9Ocr5lOcJLj7pLS+eUcR7a+NofSSUvWuxYNi2C9N2KvF/xeb qWd09yuJrCsJrbxMb2NlTLHL+qcApHjp1W2Ac/2doDmeKwoEMa8KiNEYto+DdCX1MyVB uQbpZV7yMmrq8UyT1iitMi48TaXwWX8NvsUxwEqOq9C7YHbpy6gP+jZD93Zmb+a5DspE Ai0eQo49luNJGDdYShEV0JkDb/d/JqGQr/Fr9Q33+ro1nHwwlng8e0Lj0rq+Smo25I8n J4gw== MIME-Version: 1.0 X-Received: by 10.68.130.103 with SMTP id od7mr67682776pbb.87.1389017006217; Mon, 06 Jan 2014 06:03:26 -0800 (PST) Received: by 10.70.53.197 with HTTP; Mon, 6 Jan 2014 06:03:26 -0800 (PST) In-Reply-To: <019901cf0a3b$97b47cd0$c71d7670$@com> References: <019901cf0a3b$97b47cd0$c71d7670$@com> Date: Mon, 6 Jan 2014 19:33:26 +0530 Message-ID: From: Sridhar S To: =?ISO-8859-1?Q?Fran=E7ois=2DFr=E9d=E9ric_Ozog?= , dev@dpdk.org Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] Issue when the kernel parameter intel_iommu=on is being used 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, 06 Jan 2014 14:08:16 -0000 Hi, Thanks for information. If I use kernel parameters intel_iommu=3Don and iommu=3Dpt, then the follow= ing error has been observed. ####ERROR REPORT######## dmar: DRHD: handling fault status reg 2 dmar: DMAR:[DMA Write] Request device [01:00.0] fault addr 4f883000 DMAR:[fault reason 02] Present bit in context entry is clear ########################## Does this mean no context entry hasn't been created for the Connect X3 device? But, as per my understanding , the intel iommu code (intel_iommu.c) creates root entries and context entries as per DMAR table which provided by BIOS to OS.Also, it should create entry for Connect X3 device as well(?). Or the created memory via DPDK API is not belongs to Domain(VT-d) to which Connect X3 device is assigned to? Or does this error code is generic? Can you share your knowledge on this issue. Thanks Sri On Sun, Jan 5, 2014 at 10:58 PM, Fran=E7ois-Fr=E9d=E9ric Ozog = wrote: > Hi, > > To understand the issue, you may have a look at: > > http://www.intel.com/content/www/us/en/intelligent-systems/intel-technolo= gy/ > vt-directed-io-spec.html > > When you have no IOMMU, "physical" address space is accessed directly by > hardware, so your core works. > > When VT-d is active, there is DMA/IRQ remapping hardware layer between th= e > device and the memory/cpu. If you look at =A73.4.3 of the spec, you that = for > each device of each bus there is a context (enumerated at boot time, > leveraging BIOS/ACPI). For each device, you may have address translation > programmed so that DMA produced by hardware is actually mapped to a > physical > address. > > When you use the Linux kernel API for mapping DMA memory, Linux takes car= e > of the "details". > > For DPDK, documentation =A75.6 Using Linux IOMMU Pass-Through to Run Inte= l=AE > DPDK with Intel=AE VT-d says that you should have iommu=3Dpt kernel param= eter > on. Do you have it ? > > FF > > > > -----Message d'origine----- > > De : dev [mailto:dev-bounces@dpdk.org] De la part de Sridhar S > > Envoy=E9 : dimanche 5 janvier 2014 13:38 > > =C0 : dev@dpdk.org > > Objet : [dpdk-dev] Issue when the kernel parameter intel_iommu=3Don is > being > > used > > > > Hello, > > > > > > > > I am using DPDK 1.5 for development of host pmd for device =93Connect X= 3=94. > > > > > > > > I am observing issue while the ConnectX3 device DMA to a memory which = is > > allocated with rte_memzone_reserve_aligned() API . > > > > The issue(please refer ERROR below) has been observed if the system run= s > > with the kernel parameter =93intel_iommu=3Don=94. > > > > > > > > ERROR : > > > > dmar: DRHD: handling fault status reg 302 > > > > dmar: DMAR:[DMA Write] Request device [01:00.0] fault addr 4f883000 > > > > DMAR:[fault reason 01] Present bit in root entry is clear > > > > > > The reported "fault Addr" is the physical address which was returned by > the > > Above API. > > > > > > > > I don=92t see any issue with the same code when the system up with kern= el > > parameter intel_iommu=3Doff. > > > > > > > > > > Can you share your comments on this issue? > > > > > > Thanks in advance > > > > Sri > >