On Wed, May 4, 2011 at 9:51 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > With the new used_event and avail_event and features, both > host and guest need similar logic to check whether events are > enabled, so it helps to put the common code in the header. > > Note that Xen has similar logic for notification hold-off > in include/xen/interface/io/ring.h with req_event and req_prod > corresponding to event_idx + 1 and new_idx respectively. > +1 comes from the fact that req_event and req_prod in Xen start at 1, > while event index in virtio starts at 0. > > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > --- > include/linux/virtio_ring.h | 14 ++++++++++++++ > 1 files changed, 14 insertions(+), 0 deletions(-) > > diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h > index f791772..2a3b0ea 100644 > --- a/include/linux/virtio_ring.h > +++ b/include/linux/virtio_ring.h > @@ -124,6 +124,20 @@ static inline unsigned vring_size(unsigned int num, unsigned long align) > + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num; > } > > +/* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */ > +/* Assuming a given event_idx value from the other size, if s/other size/other side/ ? Stefan _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
