From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 483B2C3B186 for ; Tue, 11 Feb 2020 13:57:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B29F2086A for ; Tue, 11 Feb 2020 13:57:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=monjalon.net header.i=@monjalon.net header.b="hEAdjWRE"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="y5Paqyy4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730000AbgBKN5t (ORCPT ); Tue, 11 Feb 2020 08:57:49 -0500 Received: from wnew1-smtp.messagingengine.com ([64.147.123.26]:41711 "EHLO wnew1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729509AbgBKN5t (ORCPT ); Tue, 11 Feb 2020 08:57:49 -0500 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailnew.west.internal (Postfix) with ESMTP id 3E42970F; Tue, 11 Feb 2020 08:57:47 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Tue, 11 Feb 2020 08:57:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=mesmtp; bh=noAzCHI04Ek8RDpgVHZPtuU30mmVFLmEki2n2dFXUfk=; b=hEAdjWREXeec UBe4OGm3aAkBhgEuC6s/I22PkSk8Qp5WD9sZd2YG3U1I9YFFI1jI2JPfe7CE8kua a9cwQ8EDSb1wXlcDnnJxxz05qpS73YVTsL1jk9BUPMwYuZQo55VetRWR4jgubvkw VE0SEnS5aHX6ey2GRCcfRVDcGKBgVuY= 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-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=noAzCHI04Ek8RDpgVHZPtuU30mmVFLmEki2n2dFXU fk=; b=y5Paqyy4NiV6O7SNz07Qb80FTYAjxZH4YjIhM2t1gTxOdGMvkqxirSsjJ Q6fSwKqri9dK8G3gtNgxo1R640+6+xgzBlaGD1ayurch2P6wA5yLj8n78rvxaiGI Yd544n7+BS/0xChp4rzcHA5C4jkZDNiP2D4jcv+yyhWPyakBFyKM+hF5ezz0B+Tv wVJpwUb4yM7QOHA7St4ivDthMER/Mxt+eMyQio8kRsUURkvHDRfHa5hZOTeTu77r M0V9DbaHQcHuuWh7yYn1Tou9rsdsc1u3gZLL/OpXADtsIVOv9fN1fTxIelwXcRg2 zRedtOWfwsJyFjmaVOP8u1ziPH/5g== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrieefgdehlecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucfkph epjeejrddufeegrddvtdefrddukeegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghr rghmpehmrghilhhfrhhomhepthhhohhmrghssehmohhnjhgrlhhonhdrnhgvth X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 4AB833060840; Tue, 11 Feb 2020 08:57:45 -0500 (EST) From: Thomas Monjalon To: Alex Williamson Cc: dev@dpdk.org, kvm@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dev@dpdk.org, mtosatti@redhat.com, Luca Boccassi , "Richardson, Bruce" , cohuck@redhat.com, Vamsi Attunuru , Jerin Jacob Subject: Re: [dpdk-dev] [RFC PATCH 0/7] vfio/pci: SR-IOV support Date: Tue, 11 Feb 2020 14:57:44 +0100 Message-ID: <2203508.9fHWaBTJ5E@xps> In-Reply-To: References: <158085337582.9445.17682266437583505502.stgit@gimli.home> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 11/02/2020 12:18, Jerin Jacob: > On Wed, Feb 5, 2020 at 4:35 AM Alex Williamson wrote: > > > > There seems to be an ongoing desire to use userspace, vfio-based > > drivers for both SR-IOV PF and VF devices. The fundamental issue > > with this concept is that the VF is not fully independent of the PF > > driver. Minimally the PF driver might be able to deny service to the > > VF, VF data paths might be dependent on the state of the PF device, > > or the PF my have some degree of ability to inspect or manipulate the > > VF data. It therefore would seem irresponsible to unleash VFs onto > > the system, managed by a user owned PF. > > > > We address this in a few ways in this series. First, we can use a bus > > notifier and the driver_override facility to make sure VFs are bound > > to the vfio-pci driver by default. This should eliminate the chance > > that a VF is accidentally bound and used by host drivers. We don't > > however remove the ability for a host admin to change this override. > > > > The next issue we need to address is how we let userspace drivers > > opt-in to this participation with the PF driver. We do not want an > > admin to be able to unwittingly assign one of these VFs to a tenant > > that isn't working in collaboration with the PF driver. We could use > > IOMMU grouping, but this seems to push too far towards tightly coupled > > PF and VF drivers. This series introduces a "VF token", implemented > > as a UUID, as a shared secret between PF and VF drivers. The token > > needs to be set by the PF driver and used as part of the device > > matching by the VF driver. Provisions in the code also account for > > restarting the PF driver with active VF drivers, requiring the PF to > > use the current token to re-gain access to the PF. > > Thanks Alex for the series. DPDK realizes this use-case through, an out of > tree igb_uio module, for non VFIO devices. Supporting this use case, with > VFIO, will be a great enhancement for DPDK as we are planning to > get rid of out of tree modules any focus only on userspace aspects. [..] > Regarding the use case where PF bound to DPDK/VFIO and > VF bound to DPDK/VFIO are _two different_ processes then sharing the UUID > will be a little tricky thing in terms of usage. But if that is the > purpose of bringing UUID to the equation then it fine. > > Overall this series looks good to me. We can test the next non-RFC > series and give > Tested-by by after testing with DPDK. [..] > > Please comment. In particular, does this approach meet the DPDK needs > > for userspace PF and VF drivers, with the hopefully minor hurdle of > > sharing a token between drivers. The token is of course left to > > userspace how to manage, and might be static (and not very secret) for > > a given set of drivers. Thanks, Thanks Alex, it looks to be a great improvement. In the meantime, DPDK is going to move igb_uio (an out-of-tree Linux kernel module) from the main DPDK repository to a side-repo. This move and this patchset will hopefully encourage using VFIO. As Jerin said, DPDK prefers relying on upstream Linux modules.