Re: [PATCH v4 6/6] virtio-balloon: Add support for providing unused page reports to host

[Alexander Duyck]

On Mon, Aug 12, 2019 at 8:50 AM David Hildenbrand <david@xxxxxxxxxx> wrote:
>
> On 12.08.19 17:20, Alexander Duyck wrote:
> > On Mon, Aug 12, 2019 at 2:53 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> >>
> >> On Wed, Aug 07, 2019 at 03:42:19PM -0700, Alexander Duyck wrote:
> >>> From: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> >
> > <snip>
> >
> >>> --- a/include/uapi/linux/virtio_balloon.h
> >>> +++ b/include/uapi/linux/virtio_balloon.h
> >>> @@ -36,6 +36,7 @@
> >>>  #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM      2 /* Deflate balloon on OOM */
> >>>  #define VIRTIO_BALLOON_F_FREE_PAGE_HINT      3 /* VQ to report free pages */
> >>>  #define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
> >>> +#define VIRTIO_BALLOON_F_REPORTING   5 /* Page reporting virtqueue */
> >>>
> >>>  /* Size of a PFN in the balloon interface. */
> >>>  #define VIRTIO_BALLOON_PFN_SHIFT 12
> >>
> >> Just a small comment: same as any feature bit,
> >> or indeed any host/guest interface changes, please
> >> CC virtio-dev on any changes to this UAPI file.
> >> We must maintain these in the central place in the spec,
> >> otherwise we run a risk of conflicts.
> >>
> >
> > Okay, other than that if I resubmit with the virtio-dev list added to
> > you thing this patch set is ready to be acked and pulled into either
> > the virtio or mm tree assuming there is no other significant feedback
> > that comes in?
> >
>
> I want to take a detailed look at the mm bits (might take a bit but I
> don't see a need to rush). I am fine with the page flag we are using.
> Hope some other mm people (cc'ing Michal and Oscar) can have a look.

Agreed. I just wanted to make sure we had the virtio bits locked in as
my concern was that some of the other MM maintainers might be waiting
on that.

I'll see about submitting a v5, hopefully before the end of today with
Michal, Oscar, and the virtio-dev mailing list also included.

Thanks.

- Alex