netfront: Introduce TX statistics interface

include/netfront.h

@@ -54,3 +54,8 @@ void networking_set_addr(struct ip_addr *ipaddr, struct ip_addr *netmask, struct
 #ifdef CONFIG_SELECT_POLL
 int netfront_get_fd(struct netfront_dev *dev);
 #endif
+
+#ifdef CONFIG_NETFRONT_STATS
+void netfront_reset_txcounters(struct netfront_dev *dev);
+void netfront_get_txcounters(struct netfront_dev *dev, uint64_t *out_txpkts, uint64_t *out_txbytes);
+#endif

netfront.c

@@ -168,6 +168,11 @@ struct netfront_dev {
 #endif
 	void (*netif_rx)(unsigned char* data, int len, void *arg);
 	void *netif_rx_arg;
+
+#ifdef CONFIG_NETFRONT_STATS
+	uint64_t txpkts;
+	uint64_t txbytes;
+#endif
 };
 
 struct netfront_dev_list {
@@ -934,6 +939,10 @@ void netfront_xmit(struct netfront_dev *dev, unsigned char *data, int len)
 	tx->flags |= (NETTXF_data_validated);
 	tx->size = len;
 
+#ifdef CONFIG_NETFRONT_STATS
+	++dev->txpkts;
+	dev->txbytes += len;
+#endif
 	netfront_xmit_notify(dev);
 	dprintk("tx: raw %d\n", len);
 
@@ -1207,6 +1216,10 @@ err_t netfront_xmit_pbuf(struct netfront_dev *dev, struct pbuf *p, int co_type,
 	if (push)
 		netfront_xmit_push(dev);
 
+#ifdef CONFIG_NETFRONT_STATS
+	++dev->txpkts;
+	dev->txbytes += p->tot_len;
+#endif
 	dprintk("tx: %c%c%c %u bytes (%u slots)\n", sego ? 'S' : '-', co_type ? 'C' : '-', push ? 'P' : '-', p->tot_len, slots);
 	return ERR_OK;
 }
@@ -1688,6 +1701,9 @@ static struct netfront_dev *_init_netfront(struct netfront_dev *dev,
 #ifdef CONFIG_SELECT_POLL
 	dev->fd = alloc_fd(FTYPE_TAP);
 	files[dev->fd].read = 0;
+#endif
+#ifdef CONFIG_NETFRONT_STATS
+	netfront_reset_txcounters(dev);
 #endif
 	return dev;
 error:
@@ -1859,3 +1875,19 @@ int netfront_get_fd(struct netfront_dev *dev)
     return dev->fd;
 }
 #endif
+
+#ifdef CONFIG_NETFRONT_STATS
+void netfront_reset_txcounters(struct netfront_dev *dev)
+{
+	dev->txpkts  = 0;
+	dev->txbytes = 0;
+}
+
+void netfront_get_txcounters(struct netfront_dev *dev, uint64_t *out_txpkts, uint64_t *out_txbytes)
+{
+	if (likely(out_txpkts))
+		*out_txpkts = dev->txpkts;
+	if (likely(out_txbytes))
+		*out_txbytes = dev->txbytes;
+}
+#endif

stub.mk

@@ -126,6 +126,7 @@ CONFIG_TPMBACK			?= n
 CONFIG_NETMAP			?= n
 CONFIG_NETMAP_API		?= 10
 CONFIG_NETFRONT			?= y
+CONFIG_NETFRONT_STATS		?= n
 CONFIG_NETFRONT_POLL		?= n
 CONFIG_NETFRONT_POLLTIMEOUT	?= 10000 # usecs
 CONFIG_SELECT_POLL		?= n
@@ -193,6 +194,7 @@ MINIOS_OPT_FLAGS-$(CONFIG_SPARSE_BSS)		+= -DCONFIG_SPARSE_BSS
 MINIOS_OPT_FLAGS-$(CONFIG_QEMU_XS_ARGS)		+= -DCONFIG_QEMU_XS_ARGS
 MINIOS_OPT_FLAGS-$(CONFIG_PCIFRONT)			+= -DCONFIG_PCIFRONT
 MINIOS_OPT_FLAGS-$(CONFIG_NETFRONT)			+= -DCONFIG_NETFRONT
+MINIOS_OPT_FLAGS-$(CONFIG_NETFRONT_STATS)		+= -DCONFIG_NETFRONT_STATS
 MINIOS_OPT_FLAGS-$(CONFIG_NETFRONT_GSO) 		+= -DCONFIG_NETFRONT_GSO
 MINIOS_OPT_FLAGS-$(CONFIG_NETFRONT_PERSISTENT_GRANTS) 	+= -DCONFIG_NETFRONT_PERSISTENT_GRANTS
 MINIOS_OPT_FLAGS-$(CONFIG_NETFRONT_WAITFORTX)		+= -DCONFIG_NETFRONT_WAITFORTX