Re: [Qemu-devel] [PATCH v12 5/8] virtio-balloon: VIRTIO_BALLOON_F_SG

[Wei Wang]

On 07/31/2017 12:20 AM, Michael S. Tsirkin wrote:
> On Sun, Jul 30, 2017 at 07:18:33PM +0300, Michael S. Tsirkin wrote:
> > On Sun, Jul 30, 2017 at 05:59:17AM +0000, Wang, Wei W wrote:
> > That's a hypervisor implementation detail. From guest point of view,
> > discarding contents can not be distinguished from writing old contents.
> Besides, ignoring the free page tricks, consider regular ballooning.
> We map page with DONTNEED then back with WILLNEED. Result is
> getting a zero page. So at least one of deflate/inflate should be input.
> I'd say both for symmetry.

OK, I see the point. Thanks.

Best,
Wei