On Fri, Jan 13, 2017 at 09:24:22AM +0000, Li, Liang Z wrote:
> > On Wed, Dec 21, 2016 at 02:52:25PM +0800, Liang Li wrote:
> > > Add a new feature which supports sending the page information with
> > > range array. The current implementation uses PFNs array, which is not
> > > very efficient. Using ranges can improve the performance of
> > > inflating/deflating significantly.
> > >
> > > Signed-off-by: Liang Li <liang.z.li@xxxxxxxxx>
> > > Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> > > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> > > Cc: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
> > > Cc: Amit Shah <amit.shah@xxxxxxxxxx>
> > > Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
> > > Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> > > Cc: David Hildenbrand <david@xxxxxxxxxx>
> > > ---
> > > include/uapi/linux/virtio_balloon.h | 12 ++++++++++++
> > > 1 file changed, 12 insertions(+)
> > >
> > > diff --git a/include/uapi/linux/virtio_balloon.h
> > > b/include/uapi/linux/virtio_balloon.h
> > > index 343d7dd..2f850bf 100644
> > > --- a/include/uapi/linux/virtio_balloon.h
> > > +++ b/include/uapi/linux/virtio_balloon.h
> > > @@ -34,10 +34,14 @@
> > > #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before
> > reclaiming pages */
> > > #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue
> > */
> > > #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon
> > on OOM */
> > > +#define VIRTIO_BALLOON_F_PAGE_RANGE 3 /* Send page info
> > with ranges */
> > >
> > > /* Size of a PFN in the balloon interface. */ #define
> > > VIRTIO_BALLOON_PFN_SHIFT 12
> > >
> > > +/* Bits width for the length of the pfn range */
> >
> > What does this mean? Couldn't figure it out.
> >
> > > +#define VIRTIO_BALLOON_NR_PFN_BITS 12
> > > +
> > > struct virtio_balloon_config {
> > > /* Number of pages host wants Guest to give up. */
> > > __u32 num_pages;
> > > @@ -82,4 +86,12 @@ struct virtio_balloon_stat {
> > > __virtio64 val;
> > > } __attribute__((packed));
> > >
> > > +/* Response header structure */
> > > +struct virtio_balloon_resp_hdr {
> > > + __le64 cmd : 8; /* Distinguish different requests type */
> > > + __le64 flag: 8; /* Mark status for a specific request type */
> > > + __le64 id : 16; /* Distinguish requests of a specific type */
> > > + __le64 data_len: 32; /* Length of the following data, in bytes */
> >
> > This use of __le64 makes no sense. Just use u8/le16/le32 pls.
> >
>
> Got it, will change in the next version.
>
> And could help take a look at other parts? as well as the QEMU part.
>
> Thanks!
> Liang
Yes but first I would like to understand how come no fields
in this new structure come up if I search for them in the
following patch. I don't see why should I waste time on
reviewing the implementation if the interface isn't
reasonable. You don't have to waste it too - just send RFC
patches with the header until we can agree on it.
--
MST
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