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.
Signed-off-by: Joshua Washington <joshw...@google.com>
Fixes: 030025b74202 ("net/gve: fix max MTU limit")
Cc: joshw...@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 b441f96623..eb3bc7e151 100644
--- a/drivers/net/gve/gve_ethdev.c
+++ b/drivers/net/gve/gve_ethdev.c
@@ -297,7 +297,7 @@ 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 1cba282128..755ee8ad15 100644
--- a/drivers/net/gve/gve_ethdev.h
+++ b/drivers/net/gve/gve_ethdev.h
@@ -21,7 +21,6 @@
#define GVE_TX_MAX_FREE_SZ 512
#define GVE_MIN_BUF_SIZE 1024
-#define GVE_MAX_RX_PKTLEN 65535
#define GVE_TX_CKSUM_OFFLOAD_MASK ( \
RTE_MBUF_F_TX_L4_MASK | \
--
2.42.0.655.g421f12c284-goog
