On Mon, Jan 07, 2013 at 02:12:23PM -0600, Anthony Liguori wrote: > "Michael S. Tsirkin" <m...@redhat.com> writes: > > > On Tue, Dec 18, 2012 at 12:30:20PM +0100, KONRAD Frédéric 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 <m...@redhat.com> 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. > > > > So there are three ways to add virtio pci devices now. > > Legacy -device virtio-net-pci, legacy legacy -net nic.model=virtio > > 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 ... > > Devices != things users need to worry about. > > The documented way to create network devices is completely different > than any possible syntax you can conjure up with -device. > > Really, -device is not something users should have to deal with--ever. > It's a low level API, not a UI. > > Regards, > > Anthony Liguori
Interesting. Let's assume I want to put a device behind a pci bridge (for example I want more than 32 of these). It's impossible without -device, isn't it? > > > > -- > > MST