Re: [PATCH v23 QEMU 0/5] virtio-balloon: add support for page poison reporting and free page reporting

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

I just wanted to follow up since it has been a little over a week
since I submitted this and I haven't heard anything back. It looks
like the linux-headers patches can be dropped since the headers appear
to have been synced. I was wondering if I should resubmit with just
the 3 patches that are adding the functionality, or if this patch-set
is good as-is?

Thanks.

- Alex

On Mon, Apr 27, 2020 at 5:53 PM Alexander Duyck
<alexander.duyck@gmail.com> wrote:
>
> This series provides an asynchronous means of reporting free guest pages
> to QEMU through virtio-balloon so that the memory associated with those
> pages can be dropped and reused by other processes and/or guests on the
> host. Using this it is possible to avoid unnecessary I/O to disk and
> greatly improve performance in the case of memory overcommit on the host.
>
> I originally submitted this patch series back on February 11th 2020[1],
> but at that time I was focused primarily on the kernel portion of this
> patch set. However as of April 7th those patches are now included in
> Linus's kernel tree[2] and so I am submitting the QEMU pieces for
> inclusion.
>
> [1]: https://lore.kernel.org/lkml/20200211224416.29318.44077.stgit@localhost.localdomain/
> [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b0c504f154718904ae49349147e3b7e6ae91ffdc
>
> Changes from v17:
> Fixed typo in patch 1 title
> Addressed white-space issues reported via checkpatch
> Added braces {} for two if statements to match expected coding style
>
> Changes from v18:
> Updated patches 2 and 3 based on input from dhildenb
> Added comment to patch 2 describing what keeps us from reporting a bad page
> Added patch to address issue with ROM devices being directly writable
>
> Changes from v19:
> Added std-headers change to match changes pushed for linux kernel headers
> Added patch to remove "report" from page hinting code paths
> Updated comment to better explain why we disable hints w/ page poisoning
> Removed code that was modifying config size for poison vs hinting
> Dropped x-page-poison property
> Added code to bounds check the reported region vs the RAM block
> Dropped patch for ROM devices as that was already pulled in by Paolo
>
> Changes from v20:
> Rearranged patches to push Linux header sync patches to front
> Removed association between free page hinting and VIRTIO_BALLOON_F_PAGE_POISON
> Added code to enable VIRTIO_BALLOON_F_PAGE_POISON if page reporting is enabled
> Fixed possible resource leak if poison or qemu_balloon_is_inhibited return true
>
> Changes from v21:
> Added ack for patch 3
> Rewrote patch description for page poison reporting feature
> Made page-poison independent property and set to enabled by default
> Added logic to migrate poison_val
> Added several comments in code to better explain features
> Switched free-page-reporting property to disabled by default
>
> Changes from v22:
> Added ack for patches 4 & 5
> Added additional comment fixes in patch 3 to remove "reporting" reference
> Renamed rvq in patch 5 to reporting_vq to improve readability
> Moved call adding reporting_vq to after free_page_vq to fix VQ ordering
>
> ---
>
> Alexander Duyck (5):
>       linux-headers: Update to allow renaming of free_page_report_cmd_id
>       linux-headers: update to contain virito-balloon free page reporting
>       virtio-balloon: Replace free page hinting references to 'report' with 'hint'
>       virtio-balloon: Implement support for page poison reporting feature
>       virtio-balloon: Provide an interface for free page reporting
>
>
>  hw/virtio/virtio-balloon.c                      |  176 ++++++++++++++++++-----
>  include/hw/virtio/virtio-balloon.h              |   23 ++-
>  include/standard-headers/linux/virtio_balloon.h |   12 +-
>  3 files changed, 159 insertions(+), 52 deletions(-)
>
> --