From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua0-f173.google.com (mail-ua0-f173.google.com [209.85.217.173]) by dpdk.org (Postfix) with ESMTP id 74DD198 for ; Wed, 8 Feb 2017 16:48:42 +0100 (CET) Received: by mail-ua0-f173.google.com with SMTP id 96so112268495uaq.3 for ; Wed, 08 Feb 2017 07:48:42 -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:from:date:message-id:subject:to :cc; bh=OLbHwC/GrWtm5XzyG5AkALakoclvXPBn7u7Ff+WrBUQ=; b=GGlSJ7Ybcprr4C7n5fMKB7T4NsosGj5D2E2kBVG/0Yfq6N3NwUg7Ud8Tx2xcpkEg3w IVn1vlnXtateTyV/hJyKWk7q2cqrFBRDcXUWaQe4MUBGp7is6tWibUA1w/GarH4FWwJD a2KN8kCsn3MxjhFwNk9a0M9xM9cIg031XPf+84WpYiblZOYTfqBK6OOEH4xwsHjBRom/ JUQAUTe7rOnWA3mz1p8FUlOopsnZyNI+dFqaKU4wJys45Lw7/L3QnS8S4bsOClaTLo9u EMshnC9p9tol5+dxvn4n+AcQh/TAnRClnn/r1oOVl20ZiaOdHeCWjZ1rdvPkwvpxJvyy mMXQ== 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=OLbHwC/GrWtm5XzyG5AkALakoclvXPBn7u7Ff+WrBUQ=; b=FfxyU0KEYY7RFC/XNa2ocdGCiXaGeQqlJXZtbWpaddjm8WFh/NNUwa1H7Bf3esFOWi 1u9ajrzwxhOhqPZKiWvLXOhQHgpWazvWeHZW8tTD+zNyVT0GhfcxmEuzBRRXtF4PvzbA k53J0EKxA+L8vHRyQV1LD85eJLr8v0MIayRYux/n4oGgxOahqxcMt1Bcy7cxP2U2uJEm /A+UQmp8RbGfgPDnHVcDwWHD5KLE+76VGAzLgfxFWEpdZ2uKxPsvWbDmfZkLm02chy56 qcUoEWSAC268n0OIFCYCNU4tcSFrRw5xJr7emo7sr7cirow9C+FlBa0ARcEZSdYJKkHN k/2Q== X-Gm-Message-State: AIkVDXJBIQs6EZF2inriMKTcGnjjXFEyCTtB9NDJdG9qN+nqqwgh006W2ib1ACKqQWPlcM2dL+pnpKboQJSdVRBP X-Received: by 10.159.36.73 with SMTP id 67mr11497304uaq.124.1486568921812; Wed, 08 Feb 2017 07:48:41 -0800 (PST) MIME-Version: 1.0 Received: by 10.103.146.141 with HTTP; Wed, 8 Feb 2017 07:48:41 -0800 (PST) In-Reply-To: References: <1eca3907-39e6-2b09-a8fc-fe894988cc79@redhat.com> <2ce1bbcd-f3f2-bf8f-7b86-f04072139c4b@redhat.com> From: Alejandro Lucero Date: Wed, 8 Feb 2017 15:48:41 +0000 Message-ID: To: echaudron@redhat.com Cc: Eelco Chaudron , dev , mtetsuyah@gmail.com Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] Hotplug support for VFIO 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: Wed, 08 Feb 2017 15:48:42 -0000 I just wanted to clarify the hotplug VFIO is not the problem, as I can see it, but the unplug. When attaching a device the current VFIO code will be used, but there is no code for doing the IOMMU unmapping when unplugging. On Wed, Feb 8, 2017 at 3:43 PM, Alejandro Lucero < alejandro.lucero@netronome.com> wrote: > Hi Eelco, > > On Wed, Feb 8, 2017 at 9:41 AM, Eelco Chaudron > wrote: > >> Hi Anatoly, >> >> This will be great... If you want I can do some testing on (early) >> patches if required. >> >> Also do you know why it is currently not supported, i.e. what are the >> limitations? >> >> Thanks, >> > > I assume your reply was to my previous email and not to Anatoly's one. My > apologies if this assumption is wrong. > By the way, you did not reply to the list, but I'm doing to do so because > this could be interesting to other people. Also, I'm CCing hotplug UIO > developer, Tetsuya Mukawa, since there is no a specific maintainer for this > functionality. > > I think the main problem for supporting VFIO hotplug is to deal with what > VFIO does, this is IOMMU mappings. > There is no code for doing so, and although the implementation would use > most of the code already there for UIO hotplug, which is basically related > to unmapping PCI resources, and the interrupt part will be likely quite > similar, the IOMMU unmapping requires more work. > > I dare to say this is the main reason for not having VFIO hotplug support > right now. Maybe Tetsuya can confirm this or give us other reasons. > > >> >> Eelco >> >> >> >> On 07/02/17 10:29, Alejandro Lucero wrote: >> >> It seems none is working on this VFIO support. >> >> I will work on this if there is no reply to this thread saying the >> opposite the next days. >> >> On Thu, Feb 2, 2017 at 12:58 PM, Eelco Chaudron >> wrote: >> >>> On 02/02/17 13:05, Burakov, Anatoly wrote: >>> >>>> Hi Eelco, >>>> >>>> Please forgive me my ignorance on this matter, but doesn't it work at >>>> the moment? I would assume that if regular PCI hotplug works (with >>>> igb_uio), then so would hotplug with VFIO, as it basically utilizes the >>>> same PCI infrastructure igb_uio does. That said, I'm not aware of any >>>> patches submitted that had to do with VFIO and hotplug, so I guess the >>>> answer is, not at the moment. >>>> >>>> Thanks, >>>> Anatoly >>>> >>> I was asking as the documentation explicitly mentions its not supported. >>> http://dpdk.org/doc/guides/prog_guide/port_hotplug_framework >>> .html#hotplug >>> >>> - "To detach a port, the port should be backed by a device that igb_uio >>> manages. VFIO is not supported." >>> >>> I could not find any specific reason why it's not supported, so if some >>> one can explain this it would help also... >>> >>> Cheers, >>> >>> Eelco >>> >>> >>> >> >> >