On Tue, Jan 30, 2018 at 11:31:18AM +0100, Cornelia Huck wrote:
> On Tue, 23 Jan 2018 02:01:05 +0200
> "Michael S. Tsirkin" <[email protected]> wrote:
>
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > ---
> > content.tex | 14 ++++++--------
> > 1 file changed, 6 insertions(+), 8 deletions(-)
> >
> > diff --git a/content.tex b/content.tex
> > index 9fc9673..5634c7d 100644
> > --- a/content.tex
> > +++ b/content.tex
> > @@ -1467,8 +1467,7 @@ All register values are organized as Little Endian.
> > }
> > \hline
> > \mmioreg{QueueNum}{Virtual queue size}{0x038}{W}{%
> > - Queue size is the number of elements in the queue, therefore in each
> > - of the Descriptor Table, the Available Ring and the Used Ring.
> > + Queue size is the number of elements in the queue.
> > Writing to this register notifies the device what size of the
> > queue the driver will use. This applies to the queue selected by
> > writing to \field{QueueSel}.
> > @@ -1491,9 +1490,9 @@ All register values are organized as Little Endian.
> > caused the device interrupt to be asserted.
> > The following events are possible:
> > \begin{description}
> > - \item[Used Ring Update] - bit 0 - the interrupt was asserted
> > - because the device has updated the Used
> > - Ring in at least one of the active virtual queues.
> > + \item[Used Buffer Update] - bit 0 - the interrupt was asserted
> > + because the device has used a buffer
> > + in at least one of the active virtual queues.
> > \item [Configuration Change] - bit 1 - the interrupt was
> > asserted because the configuration of the device has changed.
> > \end{description}
> > @@ -1642,9 +1641,8 @@ The driver will typically initialize the virtual
> > queue in the following way:
> > \field{QueueNumMax}. If the returned value is zero (0x0) the
> > queue is not available.
> >
> > -\item Allocate and zero the queue pages, making sure the memory
> > - is physically contiguous. It is recommended to align the
> > - Used Ring to an optimal boundary (usually the page size).
> > +\item Allocate and zero the queue memory, making sure the memory
> > + is physically contiguous.
>
> What about recommendations of that type? Will we want some kind of
> "best practice" suggestions (layout and/or transport specific?)
I don't really know what was this in aid of. When is page size an
optimal boundary? I suspect it never is. I suspect cache line alignment
is a good idea generally but I'm not sure. Want to write something up?
It's also unlikely to be transport specific.
> >
> > \item Notify the device about the queue size by writing the size to
> > \field{QueueNum}.
>
> Reviewed-by: Cornelia Huck <[email protected]>
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