From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH] uio_pci_generic does not export memory resources Date: Sun, 10 Jun 2012 17:18:00 +0300 Message-ID: <20120610141759.GB8922@redhat.com> References: <1339156616.3870.9.camel@blech> <20120608130351.GB1964@redhat.com> <4FD1FB49.3020905@siemens.com> <1339165009.26976.60.camel@ul30vt> <1339166867.3870.29.camel@blech> <4FD22552.6090609@01019freenet.de> <20120608164426.GE9705@local> <1339175476.26976.102.camel@ul30vt> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Hans J. Koch" , Andreas Hartmann , Dominic Eschweiler , Jan Kiszka , Greg Kroah-Hartman , kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Alex Williamson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37421 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754421Ab2FJORn (ORCPT ); Sun, 10 Jun 2012 10:17:43 -0400 Content-Disposition: inline In-Reply-To: <1339175476.26976.102.camel@ul30vt> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Jun 08, 2012 at 11:11:16AM -0600, Alex Williamson wrote: > On Fri, 2012-06-08 at 18:44 +0200, Hans J. Koch wrote: > > On Fri, Jun 08, 2012 at 06:16:18PM +0200, Andreas Hartmann wrote: > > > Hi Dominic, > > > > > > Dominic Eschweiler wrote: > > > > Am Freitag, den 08.06.2012, 08:16 -0600 schrieb Alex Williamson: > > > >> Yes, thanks Jan. This is exactly what VFIO does. VFIO provides > > > >> secure config space access, resource access, DMA mapping services, and > > > >> full interrupt support to userspace. > > > > VFIO is not a "better UIO". It *requires* an IOMMU. Dominic didn't say on > > what CPU he's working, so it's not clear if he can use VFIO at all. > > > > UIO is intended for general use with devices that have mappable registers > > and don't fit into any other subsystem. No more, no less. > > VFIO is a secure UIO. A secure UIO *for VFs*. I think that's why it's called VFIO :). Other stuff sometimes also works but no real guarantees, though VFIO tries to make sure you don't burn yourself too badly if it breaks. -- MST