> Sent: Wednesday, January 18, 2017 3:11 AM
> To: Li, Liang Z
> Cc: k...@vger.kernel.org; virtio-...@lists.oasis-open.org; qemu-
> de...@nongnu.org; linux...@kvack.org; linux-ker...@vger.kernel.org;
> virtualizat...@lists.linux-foundation.org; amit.s...@redhat.com; Hansen,
> Dave; cornelia.h...@de.ibm.com; pbonz...@redhat.com;
> da...@redhat.com; aarca...@redhat.com; dgilb...@redhat.com;
> quint...@redhat.com
> Subject: Re: [virtio-dev] Re: [PATCH v6 kernel 2/5] virtio-balloon: define new
> feature bit and head struct
>
> 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...@intel.com>
> > > > Cc: Michael S. Tsirkin <m...@redhat.com>
> > > > Cc: Paolo Bonzini <pbonz...@redhat.com>
> > > > Cc: Cornelia Huck <cornelia.h...@de.ibm.com>
> > > > Cc: Amit Shah <amit.s...@redhat.com>
> > > > Cc: Dave Hansen <dave.han...@intel.com>
> > > > Cc: Andrea Arcangeli <aarca...@redhat.com>
> > > > Cc: David Hildenbrand <da...@redhat.com>
> > > > ---
> > > > 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
It's not true, all of the field will be referenced in the following patches
except
the 'reserved' filed.
> 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.
OK. I will post the header part separately.
Thanks!
Liang
>
> --
> MST
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org
> For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
