Re: [PATCH v2 resubmit] virtio-balloon: Disable free page reporting if page poison reporting is not enabled

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

Do I need to resubmit this patch? It has been over two weeks now since
it was originally submitted, and a week and a half since I last sent
out an email following up. I'm just wondering if there is some list I
missed as I am assuming the maintainers and lists I contacted here are
correct? It looks like we are at RC7 now so I am worried this won't
make it in before LInus releases 5.7.

Thanks.

- Alex

On Fri, May 15, 2020 at 10:02 AM Alexander Duyck
<alexander.duyck@gmail.com> wrote:
>
> Just following up. It has been a week since I submitted this. I was
> hoping we could get it in for 5.7 since this affects free page
> reporting which will be introduced with that kernel release.
>
> Thanks.
>
> - Alex
>
> On Fri, May 8, 2020 at 10:40 AM Alexander Duyck
> <alexander.duyck@gmail.com> wrote:
> >
> > From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> >
> > We should disable free page reporting if page poisoning is enabled but we
> > cannot report it via the balloon interface. This way we can avoid the
> > possibility of corrupting guest memory. Normally the page poisoning feature
> > should always be present when free page reporting is enabled on the
> > hypervisor, however this allows us to correctly handle a case of the
> > virtio-balloon device being possibly misconfigured.
> >
> > Fixes: 5d757c8d518d ("virtio-balloon: add support for providing free page reports to host")
> > Acked-by: David Hildenbrand <david@redhat.com>
> > Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> > ---
> >
> > Changes since v1:
> > Originally this patch also modified free page hinting, that has been removed.
> > Updated patch title and description.
> > Added a comment explaining reasoning for disabling free page reporting.
> >
> > Resbumitting v2 w/ Ack from David Hildebrand.
> >
> >  drivers/virtio/virtio_balloon.c |    9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> > index 51086a5afdd4..1f157d2f4952 100644
> > --- a/drivers/virtio/virtio_balloon.c
> > +++ b/drivers/virtio/virtio_balloon.c
> > @@ -1107,11 +1107,18 @@ static int virtballoon_restore(struct virtio_device *vdev)
> >
> >  static int virtballoon_validate(struct virtio_device *vdev)
> >  {
> > -       /* Tell the host whether we care about poisoned pages. */
> > +       /*
> > +        * Inform the hypervisor that our pages are poisoned or
> > +        * initialized. If we cannot do that then we should disable
> > +        * page reporting as it could potentially change the contents
> > +        * of our free pages.
> > +        */
> >         if (!want_init_on_free() &&
> >             (IS_ENABLED(CONFIG_PAGE_POISONING_NO_SANITY) ||
> >              !page_poisoning_enabled()))
> >                 __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
> > +       else if (!virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON))
> > +               __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_REPORTING);
> >
> >         __virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
> >         return 0;
> >