From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH/RFC 7/9] Virtual network guest device driver Date: Mon, 21 May 2007 19:29:06 -0500 Message-ID: <46523952.7070405@codemonkey.ws> References: <200705211328.04565.arnd@arndb.de> <4651E8D1.4010208@us.ibm.com> <13426df10705211609j613032c6j373d9a4660f8ec6c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jimi Xenidis , "jmk-zzFmDc4TPjtKvsKVC3L/VUEOCMrvLtNR@public.gmane.org" , kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, mschwid2-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, Christian Borntraeger , Suzanne McIntosh To: ron minnich Return-path: In-Reply-To: <13426df10705211609j613032c6j373d9a4660f8ec6c-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org ron minnich wrote: > OK, so what are we doing here? We're using a PCI abstraction, as a > common abstraction,which is not common really, because we don't have a > common abstraction? So we describe all these non-pci resources with a > pci abstraction? > No. You're confusing PV device discovery with the actual paravirtual transport. In a fully virtual environment like KVM, a PCI bus is present. You need some way for the guest to detect that a PV device is present. The most natural way to do this IMHO is to have an entry for the PV device in the PCI bus. That will make a lot of existing code happy. Once you've identified that the device exists, you're free to do whatever you want with it. Regards, Anthony Liguori > I don't get it at all. I really think the resource interface idea I > mentioned, which is borrowed from Plan 9, makes a whole lot more > sense. IBM Austin has already shown it in practice in the papers I > referenced. It can work. A memory channel at the bottom, with a > resource sharing protocol (9p) above it, and then you describe your > resources via names and a simple file-directory model. Note that PCI > sort of tries to do this tree model, but it's all binary, and, as > noted, it's hardly universal. > > All of this is trivially exported over a network, so the use of shared > memory channels in no way rules out network access. Plan 9 exports > devices over the network routinely. > > If you're using a PCI abstraction, something has gone badly wrong I think. > > thanks > > ron > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > kvm-devel mailing list > kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org > https://lists.sourceforge.net/lists/listinfo/kvm-devel > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/