From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out3-smtp.messagingengine.com (out3-smtp.messagingengine.com [66.111.4.27]) by dpdk.org (Postfix) with ESMTP id 5C38671B4 for ; Fri, 12 Jan 2018 01:13:05 +0100 (CET) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id D06F52087E; Thu, 11 Jan 2018 19:13:04 -0500 (EST) Received: from frontend1 ([10.202.2.160]) by compute1.internal (MEProxy); Thu, 11 Jan 2018 19:13:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=mesmtp; bh=dFAY/LTalKBFZ/ASj69SMUFisc tuAQAuIefg5q8FYRg=; b=h+jq/DyqSqtXacUMi/F2oiPQWkIDWK0oUm8/YlQpCi Z+D7yx7p89kElkpbtSxm18aGYoL1ffW2RdtrGG+YWInPVdqHDgKqUQd/RYdNJ1Lu izwFFOjlFgTfIssw5VGNcEcUtVMj0aqTQb5Y8TLQJIx5HE9ouIdkWfJAlTvYf1jh I= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=dFAY/L TalKBFZ/ASj69SMUFisctuAQAuIefg5q8FYRg=; b=LMOJwm8XaC8JyOYhxVgYbv BRe+4DgoHJD+c/C3WhK2YieUkdwBTT/BXcY6m57wFG1P18NZ1vGcMPSKlsJovEjF Xp7NhrW8UYLcvPPZ871xwNXIq5y/WlQOE5leLl+dOT2Wj2OLtD/sIn5eEzWzMaHN 5ehzTgbxpfVMOsKWEZylFu7waJ+B8CA8IFnwjqvxWNGuG+o5LemX8fM+mQFVu3+K 1NcQrFbFiSZtPf1wkJrVIyzaAa30+w9Lu57NvMD2s+ZTx3SrBrnZkr15rVuwApWX EPoqMJDqUO/lw+mFuOwamD8zHrGBMJo2feoDaYI95bPHVVTWMEDRcO/mugvpCu7w == X-ME-Sender: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 7B5507E354; Thu, 11 Jan 2018 19:13:04 -0500 (EST) From: Thomas Monjalon To: Chas Williams <3chas3@gmail.com>, Chas Williams Cc: dev@dpdk.org, anatoly.burakov@intel.com Date: Fri, 12 Jan 2018 01:12:36 +0100 Message-ID: <1773541.G656isd0hF@xps> In-Reply-To: References: <20171130025739.4349-1-3chas3@gmail.com> <2600590.OO5gESNU7Y@xps> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH] eal: add option to force IOVA as PA mode 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, 12 Jan 2018 00:13:05 -0000 03/12/2017 01:23, Chas Williams: > The particular machine in my case is a Dell Optiplex 790 which is fairly > similar to another system that has basically the same problem. The IOMMU > advertises that is can only handle 39 bits of addressing. The DMAR address > tables have a width of 36 bits, so all is well when using IOVA physical > addresses. With IOVA virtual addresses, they sometimes go beyond the 39 > bit boundary. I was under the impression that IOMMU widths are more > typically 48 bits, but I appear to have some low end systems with a simpler > IOMMU. > > I could make it a runtime option. > > On Thu, Nov 30, 2017 at 4:17 AM, Thomas Monjalon > wrote: > > > 30/11/2017 03:57, Chas Williams: > > > From: Chas Williams > > > > > > The IOMMU in some machines report that they can only support > > > limited widths. IOVA virtual addresses may exceed this width > > > making the use of IOVA virtual addresses difficult. The option > > > CONFIG_RTE_LIBRTE_USE_PHYS_IOVA can used to force IOVA physical > > > address usage. > > > > Which machines are you talking about? > > A run-time option may be a better solution. Please check the patch from Maxime: https://dpdk.org/dev/patchwork/patch/33192/