From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932215AbdJXW3E convert rfc822-to-8bit (ORCPT ); Tue, 24 Oct 2017 18:29:04 -0400 Received: from mga06.intel.com ([134.134.136.31]:40210 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751407AbdJXW3C (ORCPT ); Tue, 24 Oct 2017 18:29:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,430,1503385200"; d="scan'208";a="1028955953" From: "Wang, Liang-min" To: Alex Williamson CC: "Kirsher, Jeffrey T" , "kvm@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "bhelgaas@google.com" , "Duyck, Alexander H" Subject: RE: [PATCH] Enable SR-IOV instantiation through /sys file Thread-Topic: [PATCH] Enable SR-IOV instantiation through /sys file Thread-Index: AQHTTQNc3Jvwy6Ow/U2KUKrBywbFv6Lz/a6A//+LFZCAAHtcAP//i8Ug Date: Tue, 24 Oct 2017 22:29:00 +0000 Message-ID: References: <20171024200426.62811-1-jeffrey.t.kirsher@intel.com> <20171024234351.0af0ff4a@t450s.home> <20171025000654.7621b84e@t450s.home> In-Reply-To: <20171025000654.7621b84e@t450s.home> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.1.200.108] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Alex Williamson [mailto:alex.williamson@redhat.com] > Sent: Tuesday, October 24, 2017 6:07 PM > To: Wang, Liang-min > Cc: Kirsher, Jeffrey T ; kvm@vger.kernel.org; > linux-pci@vger.kernel.org; linux-kernel@vger.kernel.org; > bhelgaas@google.com; Duyck, Alexander H > Subject: Re: [PATCH] Enable SR-IOV instantiation through /sys file > > On Tue, 24 Oct 2017 21:49:15 +0000 > "Wang, Liang-min" wrote: > > > Just like any PCIe devices that supports SR-IOV. There are restrictions set for > VF. Also, there is a concept of trust VF now available for PF to manage certain > features that only selected VF could exercise. Are you saying all the devices > supporting SR-IOV all have security issue? > > Here's a simple example, most SR-IOV capable NICs, including those from > Intel, require the PF interface to be up in order to route traffic from > the VF. If the user controls the PF interface and VFs are used > elsewhere in the host, the PF driver in userspace can induce a denial > of service on the VFs. That doesn't even take into account that VFs > might be in separate IOMMU groups from the PF and therefore not > isolated from the host like the PF and that the PF driver can > potentially manipulate the VF, possibly performing DMA on behalf of the > PF. VFs are only considered secure today because the PF is managed by > a driver in the host kernel. Allowing simple enablement of VFs for a > user owned PF seems inherently insecure to me. Thanks, > > Alex So, I assume over PF+SR-IOV usage model, you would agree that PF is trusted, and not VF. So, the "potential" insecure issue occurs on both native device kernel driver and vfio-pci. The interface that is used to create SR-IOV is also considered trusted, either it's a script run by a network manager or manually done by network manager. So, it's up to the trusted network manager to give privileges to each individual VF according to respective policy. BTW, there is a separate effort on a similar support (https://lkml.org/lkml/2017/9/27/348). Do you have the same concern for uio_pci_generic? Liang-Min