Re: [Qemu-devel] [RFC v2 04/12] hw/qdev-properties.c: Add "transport" property.

[Evgeny Voevodin]

On 09/17/2012 04:42 PM, Paolo Bonzini wrote:
> Il 17/09/2012 12:00, Evgeny Voevodin ha scritto:
> > Virtio back-end devices can be plugged into both transports:
> > VIRTIO_PCI and VIRTIO_MMIO. In order to choose the desired
> > transport we have a property "transport" in every back-end
> > state struct. By specifying -device virtio-blk-pci user chooses
> > VIRTIO_PCI transport and "transport" property is set automatically.
> > But in order to provide full control to user we need to have
> > "transport" property available to be set through command line:
> >
> > -device virtio-pci,id=virtio-pci.0
> > -device virtio-blk,transport=virtio-pci.0,...
> What's the difference between this and "bus"? i.e.
>
>    -device virtio-pci,id=virtio-pci-0
>    -device virtio-blk,bus=virtio-pci-0.0,...
>
> Paolo

The difference is that with "transport" I used a linked list like, say, 
bdrv_states in block.c.
It's much simpler then use buses. Also I was planning to use a <link>.
In this approach buses are used only to reflect hierarchy of devices in 
emulator manager.
And yes, cover letter contains quite misleading information because 
attach to transport
is based on a list of links, not on buses. Sorry, I forgot that when 
wrote the cover.

--
Kind regards,
Evgeny Voevodin,
Technical Leader,
Mobile Group,
Samsung Moscow Research Center,
e-mail: address@hidden