RE: [RFC qemu 2/4] virtio-balloon: Add a new feature to balloon device

From: Li, Liang Z
Date: Thu Mar 03 2016 - 21:29:27 EST


> Subject: Re: [RFC qemu 2/4] virtio-balloon: Add a new feature to balloon
> device
>
> On Thu, Mar 03, 2016 at 06:44:26PM +0800, Liang Li wrote:
> > Extend the virtio balloon device to support a new feature, this new
> > feature can help to get guest's free pages information, which can be
> > used for live migration optimzation.
> >
> > Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx>
>
> I don't understand why we need a new interface.
> Balloon already sends free pages to host.
> Just teach host to skip these pages.
>

I just make use the current virtio-balloon implementation, it's more complicated to
invent a new virtio-io device...
Actually, there is no need to inflate the balloon before live migration, so the host has
no information about the guest's free pages, that's why I add a new one.

> Maybe instead of starting with code, you should send a high level description
> to the virtio tc for consideration?
>
> You can do it through the mailing list or using the web form:
> http://www.oasis-
> open.org/committees/comments/form.php?wg_abbrev=virtio
>

Thanks for your information and suggestion.

Liang