# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID 23c37bc942da6cffaa9936784af7913a0a091675
# Parent 2e91ad1a89ce35c522e8989593cd2d4e83f04755
[NET] front: Added feature-rx-notify
This patch adds support to the frontend for notifying the backend whenever
the rx ring is refilled. This is required in order for the backend to
get a tx queue.
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Modified to only send notification if req_event index is set
appropriately.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c | 12 ++++++++++--
xen/include/public/io/netif.h | 7 ++++---
2 files changed, 14 insertions(+), 5 deletions(-)
diff -r 2e91ad1a89ce -r 23c37bc942da
linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c Fri Jul 28
17:04:55 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c Fri Jul 28
17:13:08 2006 +0100
@@ -326,6 +326,12 @@ again:
goto abort_transaction;
}
+ err = xenbus_printf(xbt, dev->nodename, "feature-rx-notify", "%d", 1);
+ if (err) {
+ message = "writing feature-rx-notify";
+ goto abort_transaction;
+ }
+
err = xenbus_transaction_end(xbt, 0);
if (err) {
if (err == -EAGAIN)
@@ -569,7 +575,7 @@ static void network_alloc_rx_buffers(str
unsigned short id;
struct netfront_info *np = netdev_priv(dev);
struct sk_buff *skb;
- int i, batch_target;
+ int i, batch_target, notify;
RING_IDX req_prod = np->rx.req_prod_pvt;
struct xen_memory_reservation reservation;
grant_ref_t ref;
@@ -682,7 +688,9 @@ static void network_alloc_rx_buffers(str
/* Above is a suitable barrier to ensure backend will see requests. */
np->rx.req_prod_pvt = req_prod + i;
push:
- RING_PUSH_REQUESTS(&np->rx);
+ RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
+ if (notify)
+ notify_remote_via_irq(np->irq);
}
static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev,
diff -r 2e91ad1a89ce -r 23c37bc942da xen/include/public/io/netif.h
--- a/xen/include/public/io/netif.h Fri Jul 28 17:04:55 2006 +0100
+++ b/xen/include/public/io/netif.h Fri Jul 28 17:13:08 2006 +0100
@@ -13,10 +13,11 @@
#include "../grant_table.h"
/*
- * Note that there is *never* any need to notify the backend when
- * enqueuing receive requests (struct netif_rx_request). Notifications
- * after enqueuing any other type of message should be conditional on
+ * Notifications after enqueuing any type of message should be conditional on
* the appropriate req_event or rsp_event field in the shared ring.
+ * If the client sends notification for rx requests then it should specify
+ * feature 'feature-rx-notify' via xenbus. Otherwise the backend will assume
+ * that it cannot safely queue packets (as it may not be kicked to send them).
*/
/*
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