Re: [PATCH v18 QEMU 2/3] virtio-balloon: Add support for providing free page reports to host

[Alexander Duyck <alexander.duyck@gmail.com>]

On Thu, Apr 9, 2020 at 12:36 AM David Hildenbrand <david@redhat.com> wrote:
>
> On 09.04.20 00:55, Alexander Duyck wrote:
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > Add support for the page reporting feature provided by virtio-balloon.
> > Reporting differs from the regular balloon functionality in that is is
> > much less durable than a standard memory balloon. Instead of creating a
> > list of pages that cannot be accessed the pages are only inaccessible
> > while they are being indicated to the virtio interface. Once the
> > interface has acknowledged them they are placed back into their respective
> > free lists and are once again accessible by the guest system.
> >
> > Unlike a standard balloon we don't inflate and deflate the pages. Instead
> > we perform the reporting, and once the reporting is completed it is
> > assumed that the page has been dropped from the guest and will be faulted
> > back in the next time the page is accessed.
> >
> > This patch is a subset of the UAPI patch that was submitted for the Linux
> > kernel. The original patch can be found at:
> > https://lore.kernel.org/lkml/20200211224657.29318.68624.stgit@localhost.localdomain/
>
> You don't need all these comments.

Sorry about that. Those are basically the same comments from the
original upstream patch. I just wasn't aware of the process so I just
copied that over and added the comment/link to the original patch.

> Usually we do
>
> "linux-headers: update to contain virito-balloon free page reporting
>
> Let's sync the latest upstream changes for free page reporting. To be
> replaced by a full linux header sync.
>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> "
>
> mst will replace this by a full header sync (if necessary) when sending
> it upstream

I will update the patch description.

Thanks.

- Alex