xenbus_client: Extend interface to support multi-page ring
Originally Xen PV drivers only use single-page ring to pass along
information. This might limit the throughput between frontend and
backend.
The patch extends Xenbus driver to support multi-page ring, which in
general should improve throughput if ring is the bottleneck. Changes to
various frontend / backend to adapt to the new interface are also
included.
Affected Xen drivers:
* blkfront/back
* netfront/back
* pcifront/back
* scsifront/back
* vtpmfront
The interface is documented, as before, in xenbus_client.c.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 2eab758..db42b59 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -809,7 +809,7 @@
if (info->irq)
return -1;
- err = xenbus_map_ring_valloc(info->dev, ring_ref, &area);
+ err = xenbus_map_ring_valloc(info->dev, &ring_ref, 1, &area);
if (err)
return err;