Add startup conf options to set per-interface descriptor ring size

This patch introduces following 2 startup options:

  num-rx-desc
  num-tx-desc

Which can be specified under the dpdk { dev PCI_ADDR {...} } or
dpdk { dev default {...} } .

"show hardware" output is extended to display what is set:

TenGigabitEthernet2/0/0            5    down  TenGigabitEthernet2/0/0
  Ethernet address 90:e2:ba:96:d0:54
  Intel 82599
    carrier up full duplex speed 10000 mtu 9216
    rx queues 2, rx desc 512, tx queues 2, tx desc 1024
    cpu socket 0

Change-Id: Ia832885c8e5cf0eb0575367e97581e7065934753
Signed-off-by: Damjan Marion <damarion@cisco.com>

3 files changed, 21 insertions, 7 deletions

diff --git a/vnet/vnet/devices/dpdk/dpdk.h b/vnet/vnet/devices/dpdk/dpdk.h
index 5ebb067e981..4123cc9cbef 100644
--- a/vnet/vnet/devices/dpdk/dpdk.h
+++ b/vnet/vnet/devices/dpdk/dpdk.h
@@ -311,7 +311,9 @@ typedef struct dpdk_efd_t {
 
 #define foreach_dpdk_device_config_item \
   _ (num_rx_queues) \
-  _ (num_tx_queues)
+  _ (num_tx_queues) \
+  _ (num_rx_desc) \
+  _ (num_tx_desc)
 
 typedef struct {
     vlib_pci_addr_t pci_addr;
diff --git a/vnet/vnet/devices/dpdk/format.c b/vnet/vnet/devices/dpdk/format.c
index b093a99e203..3aee0d9275f 100644
--- a/vnet/vnet/devices/dpdk/format.c
+++ b/vnet/vnet/devices/dpdk/format.c
@@ -486,6 +486,8 @@ u8 * format_dpdk_device (u8 * s, va_list * args)
                    pci->addr.devid, pci->addr.function);
       s = format(s, "%Umax rx packet len: %d\n",
                  format_white_space, indent + 2, di.max_rx_pktlen);
+      s = format(s, "%Umax num of queues: rx %d tx %d\n",
+                 format_white_space, indent + 2, di.max_rx_queues, di.max_tx_queues);
       s = format(s, "%Upromiscuous:       unicast %s all-multicast %s\n",
                  format_white_space, indent + 2,
                  rte_eth_promiscuous_get(xd->device_index) ? "on" : "off",
@@ -517,12 +519,14 @@ u8 * format_dpdk_device (u8 * s, va_list * args)
                  xd->tx_q_used, xd->tx_q_used);
     }
 
+  s = format (s, "%Urx queues %d, rx desc %d, tx queues %d, tx desc %d\n",
+              format_white_space, indent + 2,
+              xd->rx_q_used, xd->nb_rx_desc,
+              xd->tx_q_used, xd->nb_tx_desc);
+
   if (xd->cpu_socket > -1)
-    s = format (s, "%Ucpu socket %d\n%Uqueues rx %d (%d) tx %d (%d)",
-                format_white_space, indent + 2, xd->cpu_socket,
-                format_white_space, indent + 2,
-                xd->rx_q_used, di.max_rx_queues,
-                xd->tx_q_used, di.max_tx_queues);
+    s = format (s, "%Ucpu socket %d\n",
+                format_white_space, indent + 2, xd->cpu_socket);
 
   /* $$$ MIB counters  */
 
diff --git a/vnet/vnet/devices/dpdk/init.c b/vnet/vnet/devices/dpdk/init.c
index 58e16ee71e0..b49c405504c 100644
--- a/vnet/vnet/devices/dpdk/init.c
+++ b/vnet/vnet/devices/dpdk/init.c
@@ -504,7 +504,11 @@ dpdk_lib_init (dpdk_main_t * dm)
             xd->port_type = VNET_DPDK_PORT_TYPE_NETMAP;
           }
   #endif
+	if (devconf->num_rx_desc)
+	  xd->nb_rx_desc = devconf->num_rx_desc;
 
+	if (devconf->num_tx_desc)
+	  xd->nb_tx_desc = devconf->num_tx_desc;
       }
 
       /*
@@ -871,7 +875,11 @@ dpdk_device_config (dpdk_config_main_t * conf, vlib_pci_addr_t pci_addr, unforma
     {
       if (unformat (input, "num-rx-queues %u", &devconf->num_rx_queues))
 	;
-      if (unformat (input, "num-tx-queues %u", &devconf->num_tx_queues))
+      else if (unformat (input, "num-tx-queues %u", &devconf->num_tx_queues))
+	;
+      else if (unformat (input, "num-rx-desc %u", &devconf->num_rx_desc))
+	;
+      else if (unformat (input, "num-tx-desc %u", &devconf->num_tx_desc))
 	;
       else
 	{