xen-netfront: always set num queues if possible
If netfront connects with two (or more) queues and then reconnects with
only one queue it fails to delete or rewrite the multi-queue-num-queues
key and netback will try to use the wrong number of queues.
Always write the num-queues field if the backend has multi-queue support.
Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index f821a97..9bf63c2 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1819,19 +1819,22 @@
goto destroy_ring;
}
+ if (xenbus_exists(XBT_NIL,
+ info->xbdev->otherend, "multi-queue-max-queues")) {
+ /* Write the number of queues */
+ err = xenbus_printf(xbt, dev->nodename,
+ "multi-queue-num-queues", "%u", num_queues);
+ if (err) {
+ message = "writing multi-queue-num-queues";
+ goto abort_transaction_no_dev_fatal;
+ }
+ }
+
if (num_queues == 1) {
err = write_queue_xenstore_keys(&info->queues[0], &xbt, 0); /* flat */
if (err)
goto abort_transaction_no_dev_fatal;
} else {
- /* Write the number of queues */
- err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues",
- "%u", num_queues);
- if (err) {
- message = "writing multi-queue-num-queues";
- goto abort_transaction_no_dev_fatal;
- }
-
/* Write the keys for each queue */
for (i = 0; i < num_queues; ++i) {
queue = &info->queues[i];