From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54357) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tkx4S-0007Ya-Sb for qemu-devel@nongnu.org; Tue, 18 Dec 2012 08:19:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tkx4L-0001nL-TC for qemu-devel@nongnu.org; Tue, 18 Dec 2012 08:18:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48747) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tkx4L-0001nA-Kt for qemu-devel@nongnu.org; Tue, 18 Dec 2012 08:18:49 -0500 Date: Tue, 18 Dec 2012 15:21:53 +0200 From: "Michael S. Tsirkin" Message-ID: <20121218132152.GB26110@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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <50D053CC.9040203@greensocs.com> 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: KONRAD =?iso-8859-1?Q?Fr=E9d=E9ric?= Cc: Peter Maydell , aliguori@us.ibm.com, e.voevodin@samsung.com, mark.burton@greensocs.com, qemu-devel@nongnu.org, stefanha@redhat.com, cornelia.huck@de.ibm.com, afaerber@suse.de On Tue, Dec 18, 2012 at 12:30:20PM +0100, KONRAD Fr=E9d=E9ric 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-pc= i > >>>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. So there are three ways to add virtio pci devices now. Legacy -device virtio-net-pci, legacy legacy -net nic.model=3Dvirtio and the new one with two devices. If yes it's not transparent, it's user visible. Or did I misunderstand? Look we can have a virtio network device on a PCI bus. A very similar device can be created on XXX bus, and we can and do share a lot of code. This makes it two devices? Why not 4? One for TX one for RX one for control one for PCI. I hope I'm not giving anyone ideas ... --=20 MST