patch 'net/gve: update max Rx packet length to be based on MTU' has been queued to stable release 22.11.4

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 22.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 12/13/23. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://git.dpdk.org/dpdk-stable/log/?h=22.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=22.11-staging&id=8f4eb6095105663603e436adab910acfec485aed

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 8f4eb6095105663603e436adab910acfec485aed Mon Sep 17 00:00:00 2001
From: Joshua Washington <joshwash at google.com>
Date: Mon, 16 Oct 2023 13:59:48 -0700
Subject: [PATCH] net/gve: update max Rx packet length to be based on MTU
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit 3b7896cd4963933140e1621cc421ec744a3ca247 ]

Before this patch, max_rx_pktlen was always set to UINT16_MAX. This, in
conjunction with the MTU fix, causes problems with testpmd, as setting
the packet length with the --max-pkt-len flag causes the MTU to be set
higher than possible due to underflow.

As an example, setting --max-pkt-len=1460 (the default MTU on Google
Cloud VMs) causes testpmd to set the following:
    mtu = 1460 - eth_overhead,

where eth_overhead = dev->max_rx_pktlen - dev->max_mtu = 65535 - 1460.

Thus, mtu = 1460 - 65535 + 1460 = 2921 due to underflow.

Fixes: 030025b74202 ("net/gve: fix max MTU limit")

Signed-off-by: Joshua Washington <joshwash at google.com>
---
 drivers/net/gve/gve_ethdev.c | 2 +-
 drivers/net/gve/gve_ethdev.h | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/gve/gve_ethdev.c b/drivers/net/gve/gve_ethdev.c
index 806f45b0a7..7872b4e476 100644
--- a/drivers/net/gve/gve_ethdev.c
+++ b/drivers/net/gve/gve_ethdev.c
@@ -276,7 +276,7 @@ gve_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 	dev_info->max_rx_queues = priv->max_nb_rxq;
 	dev_info->max_tx_queues = priv->max_nb_txq;
 	dev_info->min_rx_bufsize = GVE_MIN_BUF_SIZE;
-	dev_info->max_rx_pktlen = GVE_MAX_RX_PKTLEN;
+	dev_info->max_rx_pktlen = priv->max_mtu + RTE_ETHER_HDR_LEN;
 	dev_info->max_mtu = priv->max_mtu;
 	dev_info->min_mtu = RTE_ETHER_MIN_MTU;
 
diff --git a/drivers/net/gve/gve_ethdev.h b/drivers/net/gve/gve_ethdev.h
index 975318938d..4123685b34 100644
--- a/drivers/net/gve/gve_ethdev.h
+++ b/drivers/net/gve/gve_ethdev.h
@@ -29,7 +29,6 @@
 #define GVE_TX_MAX_FREE_SZ          512
 
 #define GVE_MIN_BUF_SIZE	    1024
-#define GVE_MAX_RX_PKTLEN	    65535
 
 /* A list of pages registered with the device during setup and used by a queue
  * as buffers
-- 
2.25.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-12-11 17:56:23.750701000 +0800
+++ 0017-net-gve-update-max-Rx-packet-length-to-be-based-on-M.patch	2023-12-11 17:56:22.897652300 +0800
@@ -1 +1 @@
-From 3b7896cd4963933140e1621cc421ec744a3ca247 Mon Sep 17 00:00:00 2001
+From 8f4eb6095105663603e436adab910acfec485aed Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit 3b7896cd4963933140e1621cc421ec744a3ca247 ]
@@ -20 +22,0 @@
-Cc: stable at dpdk.org
@@ -29 +31 @@
-index b441f96623..eb3bc7e151 100644
+index 806f45b0a7..7872b4e476 100644
@@ -32 +34 @@
-@@ -297,7 +297,7 @@ gve_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
+@@ -276,7 +276,7 @@ gve_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
@@ -42 +44 @@
-index 1cba282128..755ee8ad15 100644
+index 975318938d..4123685b34 100644
@@ -45 +47 @@
-@@ -21,7 +21,6 @@
+@@ -29,7 +29,6 @@
@@ -51,2 +53,2 @@
- #define GVE_TX_CKSUM_OFFLOAD_MASK (		\
- 		RTE_MBUF_F_TX_L4_MASK  |	\
+ /* A list of pages registered with the device during setup and used by a queue
+  * as buffers