dpdk: fix RSS configuration

Previously, RSS was set to RTE_ETH_RSS_IP, which is not supported by all NICs.
This update allows configuring RSS to a subset of RTE_ETH_RSS_IP, ensuring better compatibility.

Author: SiskaPavel

input/dpdk/dpdkDevice.cpp

@@ -93,7 +93,11 @@ void DpdkDevice::recognizeDriver()
 	std::cerr << "\tflow type RSS offloads: " << rteDevInfo.flow_type_rss_offloads << std::endl;
 
 	/* Check if RSS hashing is supported in NIC */
+#if RTE_VERSION >= RTE_VERSION_NUM(21, 11, 0, 0)
 	m_supportedRSS = (rteDevInfo.flow_type_rss_offloads & RTE_ETH_RSS_IP) != 0;
+#else
+	m_supportedRSS = (rteDevInfo.flow_type_rss_offloads & ETH_RSS_IP) != 0;
+#endif
 	std::cerr << "\tDetected RSS offload capability: " << (m_supportedRSS ? "yes" : "no")
 			  << std::endl;
 
@@ -219,25 +223,41 @@ void DpdkDevice::configureRSS()
 		return;
 	}
 
-	constexpr size_t RSS_KEY_LEN = 40;
-	// biflow hash key
-	static uint8_t rssKey[RSS_KEY_LEN]
-		= {0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
-		   0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A,
-		   0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A, 0x6D, 0x5A};
+	rte_eth_dev_info rteDevInfo;
+	if (rte_eth_dev_info_get(m_portID, &rteDevInfo)) {
+		throw PluginError("DpdkDevice::configureRSS() has failed. Unable to get rte dev info");
+	}
+
+	const uint8_t rssHashKeySize = rteDevInfo.hash_key_size;
+
+	m_hashKey.resize(rssHashKeySize);
+	std::generate(
+		m_hashKey.begin(),
+		m_hashKey.end(),
+		[idx = static_cast<std::size_t>(0)]() mutable {
+			static const std::array<uint8_t, 2> hashKey = {0x6D, 0x5A};
+			return hashKey[idx++ % sizeof(hashKey)];
+		});
 
-	struct rte_eth_rss_conf rssConfig
-		= {.rss_key = rssKey,
-		   .rss_key_len = RSS_KEY_LEN,
 #if RTE_VERSION >= RTE_VERSION_NUM(21, 11, 0, 0)
-		   .rss_hf = RTE_ETH_RSS_IP,
+	const uint64_t rssOffloads = rteDevInfo.flow_type_rss_offloads & RTE_ETH_RSS_IP;
+	if (rssOffloads != RTE_ETH_RSS_IP) {
+		std::cerr << "RTE_ETH_RSS_IP is not supported by the card. Used subset: " << rssOffloads << std::endl;
+	}
 #else
-		   .rss_hf = ETH_RSS_IP,
+	const uint64_t rssOffloads = rteDevInfo.flow_type_rss_offloads & ETH_RSS_IP;
+	if (rssOffloads != ETH_RSS_IP) {
+		std::cerr << "ETH_RSS_IP is not supported by the card. Used subset: " << rssOffloads << std::endl;
+	}
 #endif
-		  };
+
+	struct rte_eth_rss_conf rssConfig = {};
+	rssConfig.rss_key = m_hashKey.data();
+	rssConfig.rss_key_len = rssHashKeySize;
+	rssConfig.rss_hf = rssOffloads;
 
 	if (rte_eth_dev_rss_hash_update(m_portID, &rssConfig)) {
-		std::cerr << "Setting RSS hash for port " << m_portID << "." << std::endl;
+		std::cerr << "Setting RSS {" << rssOffloads << "} for port " << m_portID << "." << std::endl;
 	}
 }
 

input/dpdk/dpdkDevice.hpp

@@ -84,7 +84,8 @@ class DpdkDevice {
 	void registerRxTimestamp();
 
 	std::vector<rte_mempool*> m_memPools;
-    uint16_t m_portID;
+	std::vector<uint8_t> m_hashKey;
+	uint16_t m_portID;
 	uint16_t m_rxQueueCount;
 	uint16_t m_txQueueCount;
 	uint16_t m_mBufsCount;