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/net/xen-netfront.c b/drivers/net/xen-netfront.c
index e9b960f..13f5e7f 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1486,6 +1486,7 @@
{
struct xen_netif_tx_sring *txs;
struct xen_netif_rx_sring *rxs;
+ grant_ref_t gref;
int err;
queue->tx_ring_ref = GRANT_INVALID_REF;
@@ -1502,10 +1503,10 @@
SHARED_RING_INIT(txs);
FRONT_RING_INIT(&queue->tx, txs, PAGE_SIZE);
- err = xenbus_grant_ring(dev, virt_to_mfn(txs));
+ err = xenbus_grant_ring(dev, txs, 1, &gref);
if (err < 0)
goto grant_tx_ring_fail;
- queue->tx_ring_ref = err;
+ queue->tx_ring_ref = gref;
rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | __GFP_HIGH);
if (!rxs) {
@@ -1516,10 +1517,10 @@
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&queue->rx, rxs, PAGE_SIZE);
- err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
+ err = xenbus_grant_ring(dev, rxs, 1, &gref);
if (err < 0)
goto grant_rx_ring_fail;
- queue->rx_ring_ref = err;
+ queue->rx_ring_ref = gref;
if (feature_split_evtchn)
err = setup_netfront_split(queue);