Re: [PATCH v26 2/2 RESEND] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT

[Wei Wang]

On 02/07/2018 12:34 PM, Michael S. Tsirkin wrote:
> On Wed, Feb 07, 2018 at 11:01:06AM +0800, Wei Wang wrote:
> > Negotiation of the VIRTIO_BALLOON_F_FREE_PAGE_HINT feature indicates the
> > support of reporting hints of guest free pages to host via virtio-balloon.
> >
> > Host requests the guest to report free page hints by sending a new cmd
> > id to the guest via the free_page_report_cmd_id configuration register.
> >
> > When the guest starts to report, the first element added to the free page
> > vq is the cmd id given by host. When the guest finishes the reporting
> > of all the free pages, VIRTIO_BALLOON_FREE_PAGE_REPORT_STOP_ID is added
> > to the vq to tell host that the reporting is done. Host polls the free
> > page vq after sending the starting cmd id, so the guest doesn't need to
> > kick after filling an element to the vq.
> >
> > Host may also requests the guest to stop the reporting in advance by
> > sending the stop cmd id to the guest via the configuration register.
> >
> > Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
> > Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx>
> > Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> > Cc: Michal Hocko <mhocko@xxxxxxxxxx>
> > ---
> >   drivers/virtio/virtio_balloon.c     | 255 +++++++++++++++++++++++++++++++-----
> >   include/uapi/linux/virtio_balloon.h |   7 +
> >   mm/page_poison.c                    |   6 +
> >   3 files changed, 232 insertions(+), 36 deletions(-)
> >
> > Resend Change:
> > 	- Expose page_poisoning_enabled to kernel modules
> RESEND tag is for reposting unchanged patches.
> you want to post a v27, and you want the mm patch
> as a separate one, so you can get an ack on it from
> someone on linux-mm.
>
> In fact, I would probably add reporting the poison value as
> a separate feature/couple of patches.

OK. I have made them separate patches in v27. Thanks a lot for reviewing 
so many versions, I learned a lot from the comments and discussion.

Best,
Wei