uhd-dpdk: Cover all paths to request TX offloads

Some NICs were not enabling TX IP checksum offloads. This fixes that
issue.

3 files changed, 61 insertions, 11 deletions

diff --git a/host/lib/transport/uhd-dpdk/uhd_dpdk.c b/host/lib/transport/uhd-dpdk/uhd_dpdk.c
index 09897eb11..dd09525f1 100644
--- a/host/lib/transport/uhd-dpdk/uhd_dpdk.c
+++ b/host/lib/transport/uhd-dpdk/uhd_dpdk.c
@@ -13,7 +13,7 @@
 #include <rte_malloc.h>
 #include <rte_log.h>
 
-/* FIXME: Replace with configurable values */
+/* FIXME: Descriptor ring size: Replace with configurable values */
 #define DEFAULT_RING_SIZE 512
 
 /* FIXME: This needs to be protected */
@@ -111,25 +111,58 @@ static inline int uhd_dpdk_port_init(struct uhd_dpdk_port *port,
         RTE_LOG(WARNING, EAL, "Current mtu=%d\n", actual_mtu);
         mtu = actual_mtu;
     }
-    /* FIXME: Check if hw_ip_checksum is possible */
+
+    // Require checksum offloads
+    struct rte_eth_dev_info dev_info;
+    rte_eth_dev_info_get(port->id, &dev_info);
+    uint64_t rx_offloads = DEV_RX_OFFLOAD_IPV4_CKSUM;
+    uint64_t tx_offloads = DEV_TX_OFFLOAD_IPV4_CKSUM;
+    if ((dev_info.rx_offload_capa & rx_offloads) != rx_offloads) {
+        RTE_LOG(WARNING, EAL, "%d: Only supports RX offloads 0x%0llx\n", port->id, dev_info.rx_offload_capa);
+        rte_exit(EXIT_FAILURE, "Missing required RX offloads\n");
+    }
+    if ((dev_info.tx_offload_capa & tx_offloads) != tx_offloads) {
+        RTE_LOG(WARNING, EAL, "%d: Only supports TX offloads 0x%0llx\n", port->id, dev_info.tx_offload_capa);
+        rte_exit(EXIT_FAILURE, "Missing required TX offloads\n");
+    }
+
     struct rte_eth_conf port_conf = {
         .rxmode = {
+            .offloads = rx_offloads | DEV_RX_OFFLOAD_JUMBO_FRAME,
             .max_rx_pkt_len = mtu,
             .jumbo_frame = 1,
             .hw_ip_checksum = 1,
+            .ignore_offload_bitfield = 0,
+        },
+        .txmode = {
+            .offloads = tx_offloads,
         }
     };
     retval = rte_eth_dev_configure(port->id, 1, 1, &port_conf);
     if (retval != 0)
         return retval;
 
-    retval = rte_eth_rx_queue_setup(port->id, 0, DEFAULT_RING_SIZE,
+    uint16_t rx_desc = DEFAULT_RING_SIZE;
+    uint16_t tx_desc = DEFAULT_RING_SIZE;
+    retval = rte_eth_dev_adjust_nb_rx_tx_desc(port->id, &rx_desc, &tx_desc);
+    if (retval != 0)
+        return retval;
+
+    if (rx_desc != DEFAULT_RING_SIZE)
+        RTE_LOG(WARNING, EAL, "RX descriptors changed to %d\n", rx_desc);
+    if (tx_desc != DEFAULT_RING_SIZE)
+        RTE_LOG(WARNING, EAL, "TX descriptors changed to %d\n", tx_desc);
+
+    retval = rte_eth_rx_queue_setup(port->id, 0, rx_desc,
                  rte_eth_dev_socket_id(port->id), NULL, rx_mbuf_pool);
     if (retval < 0)
         return retval;
 
-    retval = rte_eth_tx_queue_setup(port->id, 0, DEFAULT_RING_SIZE,
-                 rte_eth_dev_socket_id(port->id), NULL);
+    struct rte_eth_txconf txconf = {
+        .offloads = DEV_TX_OFFLOAD_IPV4_CKSUM
+    };
+    retval = rte_eth_tx_queue_setup(port->id, 0, tx_desc,
+                 rte_eth_dev_socket_id(port->id), &txconf);
     if (retval < 0)
         goto port_init_fail;
 
diff --git a/host/lib/transport/uhd-dpdk/uhd_dpdk_driver.c b/host/lib/transport/uhd-dpdk/uhd_dpdk_driver.c
index 61ed836df..7b4cf8df5 100644
--- a/host/lib/transport/uhd-dpdk/uhd_dpdk_driver.c
+++ b/host/lib/transport/uhd-dpdk/uhd_dpdk_driver.c
@@ -233,13 +233,25 @@ static int _uhd_dpdk_send(struct uhd_dpdk_port *port,
             }
         }
 
+        status = rte_eth_tx_prepare(port->id, 0, &buf, 1);
+        if (status != 1) {
+            status = rte_ring_enqueue(txq->retry_queue, buf);
+            if (status) {
+                RTE_LOG(WARNING, USER1, "%s: Could not re-enqueue pkt %d\n", __func__, i);
+                rte_pktmbuf_free(buf);
+            }
+            num_tx = i;
+            break;
+        }
+
         status = rte_eth_tx_burst(port->id, 0, &buf, 1); /* Automatically frees mbuf */
         if (status != 1) {
             status = rte_ring_enqueue(txq->retry_queue, buf);
-            if (status)
+            if (status) {
                 RTE_LOG(WARNING, USER1, "%s: Could not re-enqueue pkt %d\n", __func__, i);
+                rte_pktmbuf_free(buf);
+            }
             num_tx = i;
-            rte_pktmbuf_free(buf);
             break;
         }
     }
@@ -422,8 +434,10 @@ static inline void _uhd_dpdk_rx_burst(struct uhd_dpdk_port *port)
             rte_pktmbuf_free(bufs[buf]);
             break;
         case ETHER_TYPE_IPv4:
-            if (ol_flags & PKT_RX_IP_CKSUM_BAD) {
+            if ((ol_flags & PKT_RX_IP_CKSUM_MASK) == PKT_RX_IP_CKSUM_BAD) {
                 RTE_LOG(WARNING, RING, "Buf %d: Bad IP cksum\n", buf);
+            } else if ((ol_flags & PKT_RX_IP_CKSUM_MASK) == PKT_RX_IP_CKSUM_NONE) {
+                RTE_LOG(WARNING, RING, "Buf %d: Missing IP cksum\n", buf);
             } else {
                 _uhd_dpdk_process_ipv4(port, bufs[buf], (struct ipv4_hdr *) l2_data);
             }
@@ -510,7 +524,7 @@ static inline void _uhd_dpdk_process_tx_buf_wait(struct uhd_dpdk_thread *t,
     // Attempt to restore bufs only if failed before
     unsigned int num_bufs = sock->tx_buf_count + rte_ring_count(q->queue) +
                             rte_ring_count(q->retry_queue);
-    unsigned int max_bufs = rte_ring_get_size(q->freebufs);
+    unsigned int max_bufs = rte_ring_get_capacity(q->freebufs);
     if (num_bufs < max_bufs) {
         _uhd_dpdk_restore_bufs(sock->port, q, max_bufs - num_bufs);
     }
diff --git a/host/lib/transport/uhd-dpdk/uhd_dpdk_udp.c b/host/lib/transport/uhd-dpdk/uhd_dpdk_udp.c
index 4fc375b77..9429cd6cb 100644
--- a/host/lib/transport/uhd-dpdk/uhd_dpdk_udp.c
+++ b/host/lib/transport/uhd-dpdk/uhd_dpdk_udp.c
@@ -457,11 +457,13 @@ static void uhd_dpdk_ipv4_prep(struct uhd_dpdk_port *port,
     ip_hdr->fragment_offset = rte_cpu_to_be_16(IPV4_HDR_DF_FLAG);
     ip_hdr->time_to_live = 64;
     ip_hdr->next_proto_id = proto_id;
-    ip_hdr->hdr_checksum = 0; /* FIXME: Assuming hardware can offload */
-    mbuf->ol_flags |= PKT_TX_IP_CKSUM;
+    ip_hdr->hdr_checksum = 0; // Require HW offload
     ip_hdr->src_addr = port->ipv4_addr;
     ip_hdr->dst_addr = dst_ipv4_addr;
 
+    mbuf->ol_flags = PKT_TX_IP_CKSUM | PKT_TX_IPV4;
+    mbuf->l2_len = sizeof(struct ether_hdr);
+    mbuf->l3_len = sizeof(struct ipv4_hdr);
     mbuf->pkt_len = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + payload_len;
     mbuf->data_len = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + payload_len;
 }
@@ -493,6 +495,7 @@ int uhd_dpdk_udp_prep(struct uhd_dpdk_socket *sock,
     tx_hdr->dst_port = pdata->dst_port;
     tx_hdr->dgram_len = rte_cpu_to_be_16(8 + udp_data_len);
     tx_hdr->dgram_cksum = 0;
+    mbuf->l4_len = sizeof(struct udp_hdr);
 
     return 0;
 }