From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50926) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TsJ5v-0006f1-Nw for qemu-devel@nongnu.org; Mon, 07 Jan 2013 15:14:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TsJ5u-0007Uo-IH for qemu-devel@nongnu.org; Mon, 07 Jan 2013 15:14:51 -0500 Received: from e9.ny.us.ibm.com ([32.97.182.139]:56816) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TsJ5u-0007UJ-ER for qemu-devel@nongnu.org; Mon, 07 Jan 2013 15:14:50 -0500 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 7 Jan 2013 15:14:50 -0500 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 933F4C9003C for ; Mon, 7 Jan 2013 15:14:46 -0500 (EST) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r07KEk4h347020 for ; Mon, 7 Jan 2013 15:14:46 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r07KEjkC003256 for ; Mon, 7 Jan 2013 15:14:46 -0500 From: Anthony Liguori In-Reply-To: <20130107195843.GC8679@redhat.com> References: <1354887155-32281-1-git-send-email-fred.konrad@greensocs.com> <20121217154508.GA28712@redhat.com> <20121218110153.GC22586@redhat.com> <50D053CC.9040203@greensocs.com> <20130107195843.GC8679@redhat.com> Date: Mon, 07 Jan 2013 14:14:36 -0600 Message-ID: <87sj6cg382.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [RFC PATCH v6 0/6] Virtio refactoring. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , KONRAD =?utf-8?B?RnLDqWTDqXJp?= =?utf-8?B?Yw==?= Cc: Peter Maydell , e.voevodin@samsung.com, mark.burton@greensocs.com, qemu-devel@nongnu.org, stefanha@redhat.com, cornelia.huck@de.ibm.com, afaerber@suse.de "Michael S. Tsirkin" writes: > On Tue, Dec 18, 2012 at 12:30:20PM +0100, KONRAD Fr=C3=A9d=C3=A9ric wrote: >> On 18/12/2012 12:01, Michael S. Tsirkin wrote: >> >On Tue, Dec 18, 2012 at 10:33:37AM +0000, Peter Maydell wrote: >> >>On 17 December 2012 15:45, Michael S. Tsirkin wrote: >> >>>Is the point to allow virtio-mmio? Why can't virtio-mmio be just >> >>>another bus, like a pci bus, and another binding, like the virtio-pci >> >>>binding? >> >>(a) the current code is really not very nice because it's not >> >>actually a proper set of QOM/qdev devices >> >>(b) unlike PCI, you can't create sysbus devices on the >> >>command line, because they don't correspond to a user >> >>pluggable bit of hardware. We don't want users to have to know >> >>an address and IRQ number for each virtio-mmio device (especially >> >>since these are board specific); instead the board can create >> >>and wire up transport devices wherever is suitable, and the >> >>user just creates the backend (which is plugged into the virtio bus). >> >> >> >>-- PMM >> >This is what I am saying: create your own bus and put >> >your devices there. Allocate resources when you init >> >a device. >> > >> >Instead you seem to want to expose a virtio device as two devices to >> >user - if true this is not reasonable. >> > >> The modifications will be transparent to the user, as we will keep >> virtio-x-pci devices. > > Then what's the point of all this? > > -device virtio-pci,id=3Dtransport1 -device virtio-net,bus=3Dtransport1 > > or > > -device virtio-mmio,id=3Dtransport1 -device virtio-net,bus=3Dtransport1 > > Is simply an insane way to create a network device. virtio-pci is pluggable into a bus, virtio-mmio is not. There is a fixed number of them for a specific board and you have the option to add virtio devices to the ones that already exist. virtio is a mess in its current state. Large swaths are not qdev'ified and we jump through hoops to try to set properties. I can't imagine how you can look at this cleanup and not understand why it's nicer... Regards, Anthony Liguori > > --=20 > MST