[PATCH] net/vmxnet3: disable RSS for single queue configuration for ESX8.0+ versions

[Amiya Ranjan Mohakud]

This fixes the issue of v4 RSS configuration failure in vmxnet3_v4_rss_configure
while writing to BAR register. It's very specific to single queue conifuguration.

Ref: https://mails.dpdk.org/archives/users/2025-April/008236.html

Bugzilla ID:1789
Cc: stable at dpdk.org

Signed-off-by: Amiya Ranjan Mohakud <amiyaranjan.mohakud at gmail.com>
---
 drivers/net/vmxnet3/vmxnet3_ethdev.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/vmxnet3/vmxnet3_ethdev.c b/drivers/net/vmxnet3/vmxnet3_ethdev.c
index f4cdb1bb31..fee4c23091 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethdev.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethdev.c
@@ -534,6 +534,12 @@ vmxnet3_dev_configure(struct rte_eth_dev *dev)
 
 	PMD_INIT_FUNC_TRACE();
 
+    /* Disabling RSS for single queue pair */
+    if (dev->data->nb_rx_queues == 1) {
+        dev->data->dev_conf.rxmode.mq_mode = ETH_MQ_RX_NONE;
+        PMD_INIT_LOG(ERR, "WARN: Disabling RSS for single Rx queue");
+    }
+
 	if (dev->data->dev_conf.rxmode.mq_mode & RTE_ETH_MQ_RX_RSS_FLAG)
 		dev->data->dev_conf.rxmode.offloads |= RTE_ETH_RX_OFFLOAD_RSS_HASH;
 
-- 
2.39.5 (Apple Git-154)