Re: Balloon driver?

Jun Koi
2007-06-06T10:53:17Z

On 6/6/07, Dor Laor <dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org> wrote:
> >> >I want to try the balloon driver. Do we have it in any git tree?
> >> >
> >> >The git tree I am having now only has master branch, and nothing
> else.
> >> >
> >> >(Maybe the balloon driver is not working yet, but I am curious when
> >> >see the userspace code in user/)
> >> >
> >> >Thanks,
> >> >Jun
> >>
> >> You're welcome to test it, it is under
> >> git://kvm.qumranet.com/home/dor/src/linux-2.6
> >> Checkout the build-trunk branch.
> >>
> >> I don't have the time to merge it currently. Note that there are also
> >> some more balloon drivers for other architecture (s390).
> >>
> >> The Linux guest driver change the balloon size using a simple char
> >> device.
> >
> >Now I see the userspace tool again, and it seems it must be used from
> >inside the guest??
>
> That's right. That's the Linux guest side implementation.
> For windows we use the vmchannel option in qemu (qemu/hw/hypercall)
> interface. It is a qemu device from the host side that can be connected
> to tcp/unix socket. The guest sees it as a pci device.
> Both ends can define any protocol over the channel.
>
> So our windows guest passes balloon inflate/deflate commands/acks.
>
> What's your motivation of ballooning? If it's important I can add the
> pci interface + push it upstream.

I looked at the current balloon driver of Linux, and really I dont
like it. Why we have a different solution from Windows'? It is better
we have the same way of implementing it on different OS.

So the PCI interface is definetely better IMO. Please put it online,
so we can test it.

Thanks,
Jun