From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <3chas3@gmail.com> Received: from mail-it0-f46.google.com (mail-it0-f46.google.com [209.85.214.46]) by dpdk.org (Postfix) with ESMTP id 06B7E29C8 for ; Sun, 3 Dec 2017 01:25:07 +0100 (CET) Received: by mail-it0-f46.google.com with SMTP id f143so161497itb.0 for ; Sat, 02 Dec 2017 16:25:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=5aPbn0U+ovVYu1k03PcfCDEJ6t5UVlXfJFJzDkExoWw=; b=XjAXuEaIfG7T0w6WrNiDTqktxd42eKtIn2Z+jWfa28e4BvGNdIgiieo0eMmgqrfTt9 LLTXE15BTAfx9zk435OctjMaQfFzFV8X8WkOfdV4bhUmgATgctZ2orSjH6Wwb8G0I08j SWeaDPGS9Y3cO3cN8lV7TprA07qd/5x4ynorYTwvOQpKJr6/5F1Nh9/6sUh27ITBlYlY wYqzHsYoKTZXB9FQclNsh8OpWM8qwuLuuXqnxg99fnxcckkRRqlk1Fa37WmdIcd5NvHe t8P5oSgIzabQwLNKU0GUVswOE/ImI6v9GDkg2YJoCbLYnCk2vJ5R2HYuNLNM5dWzIM/q bGhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=5aPbn0U+ovVYu1k03PcfCDEJ6t5UVlXfJFJzDkExoWw=; b=MhFZ9+9yJz34OJl5ufFMW6LKcwGkvqePs+rc9Lp+gBc0TRuR032PRmn85QKYw5ZnVp EYw6ma2HRg3Sa3G74fRq6Fg4XnS0vtXoNMA/kywULVTfFL7I1eknLqpDWIpRXGSqyuOx wcYD4WFOM3l43op4HAVx6a/D0tdHzO+fI3gdoHH4MHNq7izq0V9OM6n9Nx3VAm6/lPFT Bsso//HIpJ6mS6HkpeDqwww/g5dmJbur543IA6lAS4TS2zTY5eWsAdoC43dVF4mEd4B5 MTxzmOnS2s1unkI6h18cYXfleYWyJbxbtCwekGmzqBygZjiDaoEVhLs0Kk0XVQnetxyq U7oA== X-Gm-Message-State: AKGB3mIDUhKddBHAqGCsx9KNCONTIXV+t5BONS8RDS2noY1HuA2vLHzr UrS2ZeSlGRi79VqC/rAe75uWjn/q0I+mkI1GiLw= X-Google-Smtp-Source: AGs4zMaCvfRalovjuey1cBbRwjVkg0WpQHZV3TQn7oQoJ1mZ50L9ae52qveSwYWEAcV223NoYGPaHEkiFcMrjHMVg4M= X-Received: by 10.36.68.76 with SMTP id o73mr7272186ita.4.1512260706475; Sat, 02 Dec 2017 16:25:06 -0800 (PST) MIME-Version: 1.0 Received: by 10.107.2.5 with HTTP; Sat, 2 Dec 2017 16:25:06 -0800 (PST) In-Reply-To: <5c919800-d135-6cac-1385-d1d0c58808d8@nxp.com> References: <20171130025739.4349-1-3chas3@gmail.com> <5c919800-d135-6cac-1385-d1d0c58808d8@nxp.com> From: Chas Williams <3chas3@gmail.com> Date: Sat, 2 Dec 2017 19:25:06 -0500 Message-ID: To: Hemant Agrawal Cc: dev@dpdk.org, anatoly.burakov@intel.com, Thomas Monjalon , Chas Williams Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 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: Sun, 03 Dec 2017 00:25:07 -0000 On Fri, Dec 1, 2017 at 12:48 AM, Hemant Agrawal wrote: > On 11/30/2017 8:27 AM, Chas Williams wrote: > >> 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. >> >> > Is it possible to dynamically detect the machine limitation in bus iova > code instead of compile time option? > > Yes, I think you can examine the "cap" of the IOMMU group in /sys and determine the bit width. I will have to check on that.