[ovs-dev] [PATCH 3/4] ofpbuf: Add ofpbuf_rss()

[Daniele Di Proietto]

ofpbuf_rss() is introduced to get the RSS hash from the NIC. It works only for
packets received by DPDK (otherwise it returns 0, which tells the caller to
compute the hash in another way)

This commit also configure DPDK devices to compute RSS hash for UDP packets

Signed-off-by: Daniele Di Proietto <ddiproietto at vmware.com>
---
 lib/netdev-dpdk.c |  3 ++-
 lib/ofpbuf.h      | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 62c9a0c..44d2dc0 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -96,7 +96,8 @@ static const struct rte_eth_conf port_conf = {
     .rx_adv_conf = {
         .rss_conf = {
             .rss_key = NULL,
-            .rss_hf = ETH_RSS_IPV4_TCP | ETH_RSS_IPV4 | ETH_RSS_IPV6,
+            .rss_hf = ETH_RSS_IPV4_TCP | ETH_RSS_IPV4 | ETH_RSS_IPV6
+                      | ETH_RSS_IPV4_UDP,
         },
     },
     .txmode = {
diff --git a/lib/ofpbuf.h b/lib/ofpbuf.h
index adaf526..9254c98 100644
--- a/lib/ofpbuf.h
+++ b/lib/ofpbuf.h
@@ -159,6 +159,7 @@ char *ofpbuf_to_string(const struct ofpbuf *, size_t maxbytes);
 static inline struct ofpbuf *ofpbuf_from_list(const struct list *);
 void ofpbuf_list_delete(struct list *);
 static inline bool ofpbuf_equal(const struct ofpbuf *, const struct ofpbuf *);
+static inline uint32_t ofpbuf_rss(const struct ofpbuf *);
 
 
 /* Returns a pointer that may be passed to free() to accomplish the same thing
@@ -389,6 +390,13 @@ static inline void ofpbuf_set_size(struct ofpbuf *b, uint32_t v)
     b->mbuf.pkt.pkt_len = v;     /* Total length of all segments linked to
                                   * this segment. */
 }
+static inline uint32_t ofpbuf_rss(const struct ofpbuf * b)
+{
+    if (OVS_LIKELY(b->source == OFPBUF_DPDK)) {
+        return (b)->mbuf.pkt.hash.rss;
+    }
+    return 0;
+}
 
 #else
 static inline void * ofpbuf_data(const struct ofpbuf *b)
@@ -420,6 +428,11 @@ static inline void ofpbuf_set_size(struct ofpbuf *b, uint32_t v)
 {
     b->size_ = v;
 }
+
+static inline uint32_t ofpbuf_rss(const struct ofpbuf *b OVS_UNUSED)
+{
+    return 0;
+}
 #endif
 
 #ifdef  __cplusplus
-- 
2.0.0