On Thu, 7 Mar 2013 20:02:21 +0200 "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > virtio-s390 on kvm can use a cookie value passed to guest s/virtio-s390/virtio-ccw/ (to avoid confusion with s390-virtio, which was never specced) > to optimize channel/VQ lookups. > Document this. > > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Otherwise: Reviewed-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx> Rusty, could you please apply? > > --- > diff --git a/virtio-spec.lyx b/virtio-spec.lyx > index 72d956c..91aed06 100644 > --- a/virtio-spec.lyx > +++ b/virtio-spec.lyx > @@ -10627,7 +10626,252 @@ Guest->Host Notification > For notifying the host of virtqueue buffers, the guest unfortunately can't > use a channel command (the asynchronous characteristics of channel I/O > interact badly with the host block I/O backend). > - Instead, it uses a diagnose 0x500 call with subcode 3 specifying the queue. > + Instead, it uses a diagnose 0x500 call with subcode 3 specifying the queue > +\change_inserted 1986246365 1362677938 > +, as follows: > +\end_layout > + > +\begin_layout Standard > + > +\change_inserted 1986246365 1362677973 > +\begin_inset Tabular > +<lyxtabular version="3" rows="5" columns="3"> > +<features tabularvalignment="middle"> > +<column alignment="center" valignment="top" width="0"> > +<column alignment="center" valignment="top" width="0"> > +<column alignment="center" valignment="top" width="0"> > +<row> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362677978 > +GPR > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678629 > +Input Value > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" rightline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678627 > +Output Value > +\end_layout > + > +\end_inset > +</cell> > +</row> > +<row> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362677991 > +1 > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678208 > +0x3 > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678620 > + > +\end_layout > + > +\end_inset > +</cell> > +</row> > +<row> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678226 > +2 > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678498 > +Subchannel ID > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678642 > +Host Cookie > +\end_layout > + > +\end_inset > +</cell> > +</row> > +<row> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678500 > +3 > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678540 > +Virtqueue number > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" leftline="true" rightline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678620 > + > +\end_layout > + > +\end_inset > +</cell> > +</row> > +<row> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678529 > +4 > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678644 > +Host Cookie > +\change_unchanged > + > +\end_layout > + > +\end_inset > +</cell> > +<cell alignment="center" valignment="top" topline="true" bottomline="true" leftline="true" rightline="true" usebox="none"> > +\begin_inset Text > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362678620 > + > +\end_layout > + > +\end_inset > +</cell> > +</row> > +</lyxtabular> > + > +\end_inset > + > + > +\change_deleted 1986246365 1362677938 > +. > +\change_inserted 1986246365 1362678646 > + > +\end_layout > + > +\begin_layout Standard > + > +\change_inserted 1986246365 1362679010 > +Host cookie is an optional per-virtqueue 64 bit value that can be used by > + the hypervisor to speed up the notification execution. > + For each notification, the output value is returned in GPR2 and should > + be passed in GPR4 for the next notification: > +\end_layout > + > +\begin_layout LyX-Code > + > +\change_inserted 1986246365 1362679011 > +\begin_inset listings > +inline false > +status open > + > +\begin_layout Plain Layout > + > +\change_inserted 1986246365 1362679033 > + > +info->cookie = do_notify(schid, virtqueue_get_queue_index(vq), info->cookie); > +\end_layout > + > +\end_inset > + > + > \end_layout > > \begin_layout Subsubsection* > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
