Patch "ibmveth: Add a proper check for the availability of the checksum features" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

ibmveth: Add a proper check for the availability of the checksum features

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ibmveth-add-a-proper-check-for-the-availability-of-the-checksum-features.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Thomas Huth <[email protected]>
Date: Tue, 24 Jan 2017 07:28:41 +0100
Subject: ibmveth: Add a proper check for the availability of the checksum features

From: Thomas Huth <[email protected]>

[ Upstream commit 23d28a859fb847fd7fcfbd31acb3b160abb5d6ae ]

When using the ibmveth driver in a KVM/QEMU based VM, it currently always prints out a scary error message like this when it is started:

ibmveth 71000003 (unregistered net_device): unable to change checksum offload settings. 1 rc=-2 ret_attr=71000003

This happens because the driver always tries to enable the checksum offloading without checking for the availability of this feature first. QEMU does not support checksum offloading for the spapr-vlan device, thus we always get the error message here.
According to the LoPAPR specification, the "ibm,illan-options" property of the corresponding device tree node should be checked first to see whether the H_ILLAN_ATTRIUBTES hypercall and thus the checksum offloading feature is available. Thus let's do this in the ibmveth driver, too, so that the error message is really only limited to cases where something goes wrong, and does not occur if the feature is just missing.

---
 drivers/net/ethernet/ibm/ibmveth.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

@@ -1604,8 +1604,11 @@ static int ibmveth_probe(struct vio_dev
 	netdev->netdev_ops = &ibmveth_netdev_ops;
 	netdev->ethtool_ops = &netdev_ethtool_ops;
 	SET_NETDEV_DEV(netdev, &dev->dev);
-	netdev->hw_features = NETIF_F_SG | NETIF_F_RXCSUM |
-		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+	netdev->hw_features = NETIF_F_SG;
+	if (vio_get_attribute(dev, "ibm,illan-options", NULL) != NULL) {
+		netdev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+				       NETIF_F_RXCSUM;
+	}
 
 	netdev->features |= netdev->hw_features;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/ibmveth-add-a-proper-check-for-the-availability-of-the-checksum-features.patch