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 ` 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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).