virtio — archive

[Cornelia Huck <mst@redhat.com>]

On Mon, 24 Feb 2014 01:10:18 +0200 "Michael S. Tsirkin" <mst@redhat.com> wrote: > --- > content.tex | 15 ++++++++++ ----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/content.tex b/content.tex > index 2de0644..58402f3 100644 > --- a/content.tex > +++ b/content.tex > @@ -4352,20 +4352,25 @@ and should not be used. > > \section{Legacy Interface: Reserved Feature Bits}\label{sec:Reserved Feature Bits / Legacy Interface: Reserved Feature Bits} > > -Legacy or transitional devices may offer the following: > - > +Transitional devices MAY offer the following: > \begin{description} > -\item[VIRTIO_F_NOTIFY_ON_EMPTY (24)] Negotiating this feature > - indicates that the driver wants an interrupt if the device runs > +\item[VIRTIO_F_NOTIFY_ON_EMPTY (24)] If this feature > + has been negotiated by driver, the device MUST issue > + an interrupt if the device runs > out of available descriptors on a virtqueue, even though > interrupts are suppressed using the VRING_AVAIL_F_NO_INTERRUPT > - flag or the \field{used_event} field. An example of this is the > + flag or the \field{used_event} field. An example of a driver > + using this feature is the legacy > networking driver: it doesn't need to know every time a packet > is transmitted, but it does need to free the transmitted > packets a finite time after they are transmitted. It can avoid > using a timer if the device interrupts it when all the packets > are transmitted. > +\end{description} > > +Transitional devices MUST offer, and if offered by the device > +traditional drivers MUST negotiate the following: s/traditional/transitional/ > +\begin{description} > \item[VIRTIO_F_ANY_LAYOUT (27)] This feature indicates that the device > accepts arbitrary descriptor layouts, as described in Section > \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Message Framing / Legacy Interface: Message Framing}~\nameref{sec:Basic Facilities of a Virtio Device / Virtqueues / Message Framing / Legacy Interface: Message Framing}.