From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <alejandro.lucero@netronome.com>
Received: from mail-ob0-f173.google.com (mail-ob0-f173.google.com
 [209.85.214.173]) by dpdk.org (Postfix) with ESMTP id DAB41370
 for <dev@dpdk.org>; Tue, 15 Dec 2015 12:20:47 +0100 (CET)
Received: by mail-ob0-f173.google.com with SMTP id sd4so3998344obb.0
 for <dev@dpdk.org>; Tue, 15 Dec 2015 03:20:47 -0800 (PST)
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:date:message-id:subject:from:to
 :cc:content-type;
 bh=747TfoVM6tVy7Yl3YgPWJkZnW2/exLAz7WKg5NIBOaM=;
 b=w9zLLEsFaLbpFjbQoaGzzAwN6fO6lOkcDtEHpPwUVFvgQAlxm4gylqzgmm1hFgyqBZ
 77YI+qd4hCncf2Yl1gTVOjXVJuxxMgT+zi9avMeca3WhYRKJUv7kze7EFvbFTKPs32a6
 MLPo3o9glPTjeFyebiDuFQ+KNCUG9vSU8ZBdSjKEynrQcq6Q2qonLGSlzrIWY40twhgL
 s5KHLHoXXBZR3wSGr62bHuNfEnum3kCQozDssI53E80G2gz1iamf1OXoBkWW4C6fB1py
 fU/ht7GHsME4jamRSXEQbf8R0qHqp3YXd3SADBUTC+xpGKj/sOnnOIGWSuA4Dmm8Uwt+
 IOdw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20130820;
 h=x-gm-message-state:mime-version:in-reply-to:references:date
 :message-id:subject:from:to:cc:content-type;
 bh=747TfoVM6tVy7Yl3YgPWJkZnW2/exLAz7WKg5NIBOaM=;
 b=HyaC5MjApfXk13rBDbVC/CI5rSE0eh5FLyoz0VB7jmTaImfWwFOT737M0q/YxIeSl8
 3jr5s5fztsrBt8abT4r+OGxwxWQ8iKQ5Z2+8NE79GwWMyolUpupmWAHqr5+Q2GkO3Igy
 LlHIgM2C91Ey4V9cliXb9J8OZe9S7Vtux+VP2I/Rpq6yB4xUghUXkKojpxtjrYAU3yja
 vqLZs6vxkjx5+h2h+7jht5tlWCEYOGtFu0eUfU3Ifa5DmruUezfRF1GEK18kEq1pwYlS
 Zhl7LQREK8rYYyg771zA1wQypefPpHufnzlCWcxDJb4/jKl5pdWYot50LJ3BdHdsbfuv
 I4gw==
X-Gm-Message-State: ALoCoQkcQ4o7bX/gekMbINQr42asD6s1HU8jZcLu5gqy/n2WNQImuhV+zwOBWiMf7cywSNuGGRVoAUpL6mYwW1CQQGqfojm0e4slGStOLBU0NfrWxvd9Gt4=
MIME-Version: 1.0
X-Received: by 10.60.95.67 with SMTP id di3mr29061921oeb.5.1450178447184; Tue,
 15 Dec 2015 03:20:47 -0800 (PST)
Received: by 10.76.150.99 with HTTP; Tue, 15 Dec 2015 03:20:47 -0800 (PST)
In-Reply-To: <20151212002051.68708a38@jvn>
References: <60420822.AbcfvjLZCk@xps13>
	<20151212002051.68708a38@jvn>
Date: Tue, 15 Dec 2015 11:20:47 +0000
Message-ID: <CAD+H992b183d9tdz70JsgkRtV9GGpa1OL-PsY80izMcjsEwydw@mail.gmail.com>
From: Alejandro Lucero <alejandro.lucero@netronome.com>
To: Jan Viktorin <viktorin@rehivetech.com>
Content-Type: text/plain; charset=UTF-8
X-Content-Filtered-By: Mailman/MimeDel 2.1.15
Cc: dev <dev@dpdk.org>, Alex Williamson <alex.williamson@redhat.com>
Subject: Re: [dpdk-dev] VFIO no-iommu
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Tue, 15 Dec 2015 11:20:48 -0000

Hi,

I know a bit about VFIO implementation, have been debugging IOMMU (intel)
problems,  know how QEMU/KVM work about using legacy or vfio attached
devices, and I'm the maintainer of a DPDK PMD recently accepted upstream
which requires our particular UIO driver (not maintained upstream). So I
guess I could help with this effort and testing the code with our card. Of
course, I can not be full time on this but I will be happy to contribute.


On Fri, Dec 11, 2015 at 11:20 PM, Jan Viktorin <viktorin@rehivetech.com>
wrote:

> Hello,
>
> I am not involved in the vfio very much, however, I was watching some
> vfio-related code in last few weeks. It looks promising to me and
> IMHO it seems to the best way to bring a support of integrated Ethernet
> MACs into DPDK (related to many SoCs). Unfortunately, the ARMv7 SoCs (I
> know) lacks of an IOMMU... The only protection there is the TrustZone
> technology but I have no idea of its support in the kernel. It's also
> far from being a replacement of an IOMMU. When using FPGAs, it is
> possible to put an IOMMU engine there (I've got such a prototype
> somewhere in my VHDL library) but nobody will probably do use because
> of saving on-chip resources.
>
> The X-Gene SoC (ARM 64) contains 2x 10 Gbps EMACs on the chip. I have no
> idea about IOMMUs there. Thus, this platform can probably benefit of
> such driver as well. The question is whether there is some interest to
> have this kind of support in DPDK.
>
> Thus, I'd like to have the vfio/no-iommu to support the ARMv7 (otherwise
> it would be effectively dead in DPDK). Unfortunately, it's not my
> primary job at the moment.
>
> Regards
> Jan
>
> Note: as far as I know, it is discouraged to refer to lkml.org as
> it is often very slow - my case today :).
>
> On Fri, 11 Dec 2015 17:28:43 +0100
> Thomas Monjalon <thomas.monjalon@6wind.com> wrote:
>
> > Recently there were some discussions to have an upstream replacement
> > for our igb_uio module.
> > Several solutions were discussed (new uio driver, uio_pci_generic, vfio):
> >       https://lkml.org/lkml/2015/10/16/700
> >
> > Alex Williamson (maintainer of VFIO driver), submitted a solution
> > and was waiting some feedback. Unfortunately, nobody caught it and
> > he has reverted his work:
> >
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ae5515d
> >
> > It is an important challenge to remove our out-of-tree modules and
> > especially igb_uio. It is a long way to have a standard solution
> integrated
> > in every distributions.
> > The current cooking Linux kernel is 4.4 and will have a long term
> maintenance:
> >       https://kernel.org/releases.html
> > So it is a pity to miss this opportunity.
> >
> > Stephen has fixed a bug to use the IOMMU group zero:
> >       http://dpdk.org/browse/dpdk/commit/?id=22215f141b1
> >
> > Is there someone interested to work on VFIO no-iommu and provide
> > some feedbacks?
> > We also need to prepare a documentation patch to explain its usage
> > compared to the standard VFIO mode.
> >
> > Thanks
>
>