From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f66.google.com (mail-ed1-f66.google.com [209.85.208.66]) by dpdk.org (Postfix) with ESMTP id 76E821BEE3 for ; Tue, 3 Jul 2018 12:08:09 +0200 (CEST) Received: by mail-ed1-f66.google.com with SMTP id g12-v6so1193667edi.9 for ; Tue, 03 Jul 2018 03:08:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=PSuVYSVAFVGB8G96bLeiiN6Kte7LTEDhTnf1R7jDqmU=; b=KrGdsPsI0McuFBz71Yu/surHYj6xQZ/CNm0qcq3HLslxfrwjWSnqXrhhybu8GuK4Hn 1fnSVlQTy6MgW7guUJlM34sMfdsO5eHRWcCJDEQCwDc8m5BZh/BZXLmTDkG1aVTPiWgb sJ3/xGyOVA5aJW1quvunPwDeB9nAcdp1sF/zD9JKqoOwi6E+W9dCFF8/6XKgiszO9AJg thnaSIaZkDyLNYEe2ix6MwlVcYRSIzxdumawR7YeX4bxKq3wDWwNcyncRp7StmdIEDrZ jI4g1b8v5s4c5wCsuO4nmfDkMg1YOSiXI/ut78yBZ9hIxA4TnIcnRpPz6XfTmHJdJgB+ U8oA== 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=PSuVYSVAFVGB8G96bLeiiN6Kte7LTEDhTnf1R7jDqmU=; b=SB/ISuce/HI5ag6mng2xd4kN+YltP9xgMd3/2zQaKMrcGJmTfZlw8fy56+DmyBjykW l5PmDo3bKQsyxYRQbkTyHw3ZiA6gfFb+FoRwDD/S2bf2HWMY9c1hRyPdvJmPT31qEBXg swF4qqJnlwzF094trh4FJEKyiqQVPF7fGe6g2Yb6R9wdml5qvo6Fa9QOFLfR6bWNQ1o2 ue2x2hADF2M4wzjnR5O/guFWjp1JThyrQnL7b6QuHvpT8PqZQonu3crpHhsF7YVQlUka KCmnQoo+cJ2StPBqP09MJ7zZtBDHRQXhqm7MEIUFzY/nWjcxCYMs38xiilMEKwulHtZO dtcQ== X-Gm-Message-State: APt69E0m09dKkI+41npM816i5vZ5lHsbwuAerDNpIrfJu/WncI1vm2Vm siRaHw1qDfWRumYEgxFa16pbCaDXV0Rp3K9LJhVtuOTH X-Google-Smtp-Source: AAOMgpeGrbHJmfaIJDYtn5a5+PAa1QQKzlZxNJ6Jm9zFylbyecbUCfgYfdXaWCCycI1hvwE627J7J/AOtrirfc40Ijc= X-Received: by 2002:a50:f098:: with SMTP id v24-v6mr28259850edl.90.1530612489303; Tue, 03 Jul 2018 03:08:09 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a50:b194:0:0:0:0:0 with HTTP; Tue, 3 Jul 2018 03:08:08 -0700 (PDT) In-Reply-To: <544f7536-9140-850a-8a01-7b6e15909ae4@intel.com> References: <1530552423-32301-1-git-send-email-alejandro.lucero@netronome.com> <1530552423-32301-4-git-send-email-alejandro.lucero@netronome.com> <544f7536-9140-850a-8a01-7b6e15909ae4@intel.com> From: Alejandro Lucero Date: Tue, 3 Jul 2018 11:08:08 +0100 Message-ID: To: "Burakov, Anatoly" Cc: dev , stable@dpdk.org, Maxime Coquelin Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH 3/6] bus/pci: use IOVAs check when setting IOVA 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: Tue, 03 Jul 2018 10:08:09 -0000 On Tue, Jul 3, 2018 at 10:10 AM, Burakov, Anatoly wrote: > On 02-Jul-18 6:27 PM, Alejandro Lucero wrote: > >> Although VT-d emulation currently only supports 39 bits, it could >> be iovas being within that supported range. This patch allows >> IOVA mode in such a case. >> >> Indeed, memory initialization code can be modified for using lower >> virtual addresses than those used by the kernel for 64 bits processes >> by default, and therefore memsegs iovas can use 39 bits or less for >> most system. And this is likely 100% true for VMs. >> >> Signed-off-by: Alejandro Lucero >> --- >> > > General question - is this issue only applicable to PCI? Do other buses > need this? > > I think there could be other buses or devices with those limitations. Ideally, we could do more things like just discarding those memsegs out of range, but that would imply other changes. IMHO, this is good enough and just if it turns out this is causing problems, other solution should be implemented. But with most current systems out there, I do not think this is a priority. > -- > Thanks, > Anatoly >