xen-netback: use default TX queue size for vifs

[ Upstream commit 66cf7435a26917c0c4d6245ad9137e7606e84fdf ]

Do not set netback interfaces (vifs) default TX queue size to the ring size.
The TX queue size is not related to the ring size, and using the ring size (32)
as the queue size can lead to packet drops.  Note the TX side of the vif
interface in the netback domain is the one receiving packets to be injected
to the guest.

Do not explicitly set the TX queue length to any value when creating the
interface, and instead use the system default.  Note that the queue length can
also be adjusted at runtime.

Fixes: f942dc2552b8 ('xen network backend driver')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index f3f2c07423a6ac34f7266d68c65b52c38c961727..fc3bb63b9ac3e5f916811c819dd4ca3a03b9bce0 100644 (file)
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -41,8 +41,6 @@
 #include <asm/xen/hypercall.h>
 #include <xen/balloon.h>
 
-#define XENVIF_QUEUE_LENGTH 32
-
 /* Number of bytes allowed on the internal guest Rx queue. */
 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
 
@@ -530,8 +528,6 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
        dev->features = dev->hw_features | NETIF_F_RXCSUM;
        dev->ethtool_ops = &xenvif_ethtool_ops;
 
-       dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
-
        dev->min_mtu = ETH_MIN_MTU;
        dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN;