Re: Balloon driver?

Carsten Otte
2007-06-06T16:46:12Z

Arnd Bergmann wrote:
> On Wednesday 06 June 2007, Carsten Otte wrote:
>> We do have something basic, our vdev bus. The bad thing is, it is
>> platform specific. I really prefer to aim for an idea that Arnd came
>> up with when discussing this issue:
>> We could define a virtual device bus.
>
> I guess, more specifically, you mean a bus_type in Linux terminology.
Indeed, sorry for the confusion.

> So you suggest having a PCI driver that exports a virtio device for
> each PCI device it matches? Sounds fine to me, though it goes beyond
> what I think Rusty had in mind with his latest set of virtio
> patches.
We don't need a PCI device per virtio device. We can have a PCI device
that is a virtio bus driver.

> Note that contrary to what I may have said previously, I think that
> such a virtio device on top of a PCI device need not use any PCI
> specific APIs (readl/writel, pci_map_*, ioremap_, pci_dev->irq, ...)
> but could do all of that by means of a hypercall interface. The
> only real point we want to use PCI for is to find out about the
> existence of a device and to get an identifier that gets passed
> to the hypercalls.
True. We need to abstract how things get passed. Simple primitives,
but good enough to provide all functionality needed by the exploiters.
See Avis Lego box.

so long,
Carsten