virtio — archive

[Michael S. Tsirkin <mst@redhat.com>]

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" <mst@redhat.com> wrote: > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > --- > > 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: > > egin{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 <cohuck@redhat.com>