From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] VFIO driver: Non-privileged user level PCI drivers Date: Tue, 01 Jun 2010 11:10:45 +0300 Message-ID: <4C04C085.1030107@redhat.com> References: <4c004cba.Z/2Hpd7reetFaFC5%pugs@cisco.com> <20100530121944.GH27611@redhat.com> <4C025999.7080706@redhat.com> <20100530124949.GI27611@redhat.com> <4C0261C1.9090204@redhat.com> <20100530130332.GM27611@redhat.com> <4C026497.8070901@redhat.com> <20100530145309.GO27611@redhat.com> <4C03A285.7060902@redhat.com> <20100531171007.GA6516@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Tom Lyon , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, chrisw@sous-sol.org, joro@8bytes.org, hjk@linutronix.de, gregkh@suse.de, aafabbri@cisco.com, scofeldm@cisco.com To: "Michael S. Tsirkin" Return-path: In-Reply-To: <20100531171007.GA6516@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 05/31/2010 08:10 PM, Michael S. Tsirkin wrote: > On Mon, May 31, 2010 at 02:50:29PM +0300, Avi Kivity wrote: > >> On 05/30/2010 05:53 PM, Michael S. Tsirkin wrote: >> >>> So what I suggested is failing any kind of access until iommu >>> is assigned. >>> >>> >> So, the kernel driver must be aware of the iommu. In which case it may >> as well program it. >> > It's a kernel driver anyway. Point is that > the *device* driver is better off not programming iommu, > this way we do not need to reprogram it for each device. > The device driver is in userspace. It can't program the iommu. What the patch proposes is that userspace tells vfio about the needed mappings, and vfio programs the iommu. -- error compiling committee.c: too many arguments to function