From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominic Eschweiler Subject: Re: UIO: missing resource mapping Date: Fri, 13 Jul 2012 10:09:15 +0200 Message-ID: <1342166955.6607.5.camel@blech> References: <4FFE7C1F.7080702@gmx.net> <20120712194432.GA2592@local> <20120712231632.GC9317@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Hans J. Koch" , Andreas Schallenberg , "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman , kvm@vger.kernel.org To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20120712231632.GC9317@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Am Freitag, den 13.07.2012, 02:16 +0300 schrieb Michael S. Tsirkin: > My concern was people will ask for more and more stuff that pci > sysfs already has. > If we do add these is there a way to not duplicate code from pci?=20 I have some concerns about the placing for the BAR mapping code inside the kernel. The point is, that sysfs currently makes it possible to map BARs of all card which are handled by any driver. This is fine in case of UIO, because it is intended that a user-space program maps BARs, but it is also possible to map BARs that are already handle by a kernel driver. It i therefore possible to jam the system by confusing sysfs entries. I don't know which implications this has, but I would move the BAR mapping capabilities completely to UIO. This should ensure that only BARs can be mapped, which are handled by UIO and no other kernel-space driver. --=20 Gru=C3=9F Dominic =46rankfurt Institute for Advanced Studies (FIAS) Ruth-Moufang-Stra=C3=9Fe 1 D-60438 Frankfurt am Main Germany Phone: +49 69 79844114