From: Joshua Washington <joshwash@google.com>
To: Junfeng Guo <junfeng.guo@intel.com>,
Jeroen de Borst <jeroendb@google.com>,
Rushil Gupta <rushilg@google.com>,
Joshua Washington <joshwash@google.com>
Cc: dev@dpdk.org, Ferruh Yigit <ferruh.yigit@amd.com>
Subject: [PATCH] net/gve: Update max_rx_pktlen to be based on MTU
Date: Mon, 16 Oct 2023 13:59:48 -0700 [thread overview]
Message-ID: <20231016205948.2252342-1-joshwash@google.com> (raw)
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 <joshwash@google.com>
Fixes: 030025b74202 ("net/gve: fix max MTU limit")
Cc: joshwash@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
next reply other threads:[~2023-10-16 20:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-16 20:59 Joshua Washington [this message]
2023-10-16 21:20 ` [PATCH] net/gve: Update max_rx_pktlen to be based on MTU Stephen Hemminger
2023-10-16 22:58 ` Stephen Hemminger
2023-10-26 17:38 ` Ferruh Yigit
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231016205948.2252342-1-joshwash@google.com \
--to=joshwash@google.com \
--cc=dev@dpdk.org \
--cc=ferruh.yigit@amd.com \
--cc=jeroendb@google.com \
--cc=junfeng.guo@intel.com \
--cc=rushilg@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.