Patch "ibmveth: Remove condition to recompute TCP header checksum." has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    ibmveth: Remove condition to recompute TCP header checksum.

to the 5.15-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-remove-condition-to-recompute-tcp-header-che.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit c339a535c13b3f91801301ebbf7026e0a642017e
Author: David Wilder <dwilder@xxxxxxxxxx>
Date:   Tue Sep 26 16:42:51 2023 -0500

    ibmveth: Remove condition to recompute TCP header checksum.
    
    [ Upstream commit 51e7a66666e0ca9642c59464ef8359f0ac604d41 ]
    
    In some OVS environments the TCP pseudo header checksum may need to be
    recomputed. Currently this is only done when the interface instance is
    configured for "Trunk Mode". We found the issue also occurs in some
    Kubernetes environments, these environments do not use "Trunk Mode",
    therefor the condition is removed.
    
    Performance tests with this change show only a fractional decrease in
    throughput (< 0.2%).
    
    Fixes: 7525de2516fb ("ibmveth: Set CHECKSUM_PARTIAL if NULL TCP CSUM.")
    Signed-off-by: David Wilder <dwilder@xxxxxxxxxx>
    Reviewed-by: Nick Child <nnac123@xxxxxxxxxxxxx>
    Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 05759f690e1fd..67ea2cb21e849 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1297,24 +1297,23 @@ static void ibmveth_rx_csum_helper(struct sk_buff *skb,
 	 * the user space for finding a flow. During this process, OVS computes
 	 * checksum on the first packet when CHECKSUM_PARTIAL flag is set.
 	 *
-	 * So, re-compute TCP pseudo header checksum when configured for
-	 * trunk mode.
+	 * So, re-compute TCP pseudo header checksum.
 	 */
+
 	if (iph_proto == IPPROTO_TCP) {
 		struct tcphdr *tcph = (struct tcphdr *)(skb->data + iphlen);
+
 		if (tcph->check == 0x0000) {
 			/* Recompute TCP pseudo header checksum  */
-			if (adapter->is_active_trunk) {
-				tcphdrlen = skb->len - iphlen;
-				if (skb_proto == ETH_P_IP)
-					tcph->check =
-					 ~csum_tcpudp_magic(iph->saddr,
-					iph->daddr, tcphdrlen, iph_proto, 0);
-				else if (skb_proto == ETH_P_IPV6)
-					tcph->check =
-					 ~csum_ipv6_magic(&iph6->saddr,
-					&iph6->daddr, tcphdrlen, iph_proto, 0);
-			}
+			tcphdrlen = skb->len - iphlen;
+			if (skb_proto == ETH_P_IP)
+				tcph->check =
+				 ~csum_tcpudp_magic(iph->saddr,
+				iph->daddr, tcphdrlen, iph_proto, 0);
+			else if (skb_proto == ETH_P_IPV6)
+				tcph->check =
+				 ~csum_ipv6_magic(&iph6->saddr,
+				&iph6->daddr, tcphdrlen, iph_proto, 0);
 			/* Setup SKB fields for checksum offload */
 			skb_partial_csum_set(skb, iphlen,
 					     offsetof(struct tcphdr, check));