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/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c
index c3b4f5a..3111f27 100644
--- a/drivers/char/tpm/xen-tpmfront.c
+++ b/drivers/char/tpm/xen-tpmfront.c
@@ -193,6 +193,7 @@
struct xenbus_transaction xbt;
const char *message = NULL;
int rv;
+ grant_ref_t gref;
priv->shr = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
if (!priv->shr) {
@@ -200,11 +201,11 @@
return -ENOMEM;
}
- rv = xenbus_grant_ring(dev, virt_to_mfn(priv->shr));
+ rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref);
if (rv < 0)
return rv;
- priv->ring_ref = rv;
+ priv->ring_ref = gref;
rv = xenbus_alloc_evtchn(dev, &priv->evtchn);
if (rv)