MFC 270063: update of netmap code

(vtnet and cxgbe not merged yet because we need some other mfc first)

21 files changed, 3320 insertions, 797 deletions

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index cc8b34e..20321d0 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -3389,10 +3389,10 @@ em_setup_transmit_ring(struct tx_ring *txr)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + si, &paddr);
+			addr = PNMB(na, slot + si, &paddr);
 			txr->tx_base[i].buffer_addr = htole64(paddr);
 			/* reload the map for netmap mode */
-			netmap_load_map(txr->txtag, txbuf->map, addr);
+			netmap_load_map(na, txr->txtag, txbuf->map, addr);
 		}
 #endif /* DEV_NETMAP */
 
@@ -4131,8 +4131,8 @@ em_setup_receive_ring(struct rx_ring *rxr)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + si, &paddr);
-			netmap_load_map(rxr->rxtag, rxbuf->map, addr);
+			addr = PNMB(na, slot + si, &paddr);
+			netmap_load_map(na, rxr->rxtag, rxbuf->map, addr);
 			/* Update descriptor */
 			rxr->rx_base[j].buffer_addr = htole64(paddr);
 			continue;
diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index 15d71ce..484cba1 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -3531,7 +3531,7 @@ igb_setup_transmit_ring(struct tx_ring *txr)
 		if (slot) {
 			int si = netmap_idx_n2k(&na->tx_rings[txr->me], i);
 			/* no need to set the address */
-			netmap_load_map(txr->txtag, txbuf->map, NMB(slot + si));
+			netmap_load_map(na, txr->txtag, txbuf->map, NMB(na, slot + si));
 		}
 #endif /* DEV_NETMAP */
 		/* clear the watch index */
@@ -4335,8 +4335,8 @@ igb_setup_receive_ring(struct rx_ring *rxr)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + sj, &paddr);
-			netmap_load_map(rxr->ptag, rxbuf->pmap, addr);
+			addr = PNMB(na, slot + sj, &paddr);
+			netmap_load_map(na, rxr->ptag, rxbuf->pmap, addr);
 			/* Update descriptor */
 			rxr->rx_base[j].read.pkt_addr = htole64(paddr);
 			continue;
diff --git a/sys/dev/e1000/if_lem.c b/sys/dev/e1000/if_lem.c
index bc25e18..04a984b 100644
--- a/sys/dev/e1000/if_lem.c
+++ b/sys/dev/e1000/if_lem.c
@@ -32,6 +32,15 @@
 ******************************************************************************/
 /*$FreeBSD$*/
 
+/*
+ * Uncomment the following extensions for better performance in a VM,
+ * especially if you have support in the hypervisor.
+ * See http://info.iet.unipi.it/~luigi/netmap/
+ */
+// #define BATCH_DISPATCH
+// #define NIC_SEND_COMBINING
+// #define NIC_PARAVIRT	/* enable virtio-like synchronization */
+
 #include "opt_inet.h"
 #include "opt_inet6.h"
 
@@ -289,6 +298,10 @@ static int lem_tx_int_delay_dflt = EM_TICKS_TO_USECS(EM_TIDV);
 static int lem_rx_int_delay_dflt = EM_TICKS_TO_USECS(EM_RDTR);
 static int lem_tx_abs_int_delay_dflt = EM_TICKS_TO_USECS(EM_TADV);
 static int lem_rx_abs_int_delay_dflt = EM_TICKS_TO_USECS(EM_RADV);
+/*
+ * increase lem_rxd and lem_txd to at least 2048 in netmap mode
+ * for better performance.
+ */
 static int lem_rxd = EM_DEFAULT_RXD;
 static int lem_txd = EM_DEFAULT_TXD;
 static int lem_smart_pwr_down = FALSE;
@@ -458,6 +471,20 @@ lem_attach(device_t dev)
 	    "max number of rx packets to process", &adapter->rx_process_limit,
 	    lem_rx_process_limit);
 
+#ifdef NIC_SEND_COMBINING
+	/* Sysctls to control mitigation */
+	lem_add_rx_process_limit(adapter, "sc_enable",
+	    "driver TDT mitigation", &adapter->sc_enable, 0);
+#endif /* NIC_SEND_COMBINING */
+#ifdef BATCH_DISPATCH
+	lem_add_rx_process_limit(adapter, "batch_enable",
+	    "driver rx batch", &adapter->batch_enable, 0);
+#endif /* BATCH_DISPATCH */
+#ifdef NIC_PARAVIRT
+	lem_add_rx_process_limit(adapter, "rx_retries",
+	    "driver rx retries", &adapter->rx_retries, 0);
+#endif /* NIC_PARAVIRT */
+
         /* Sysctl for setting the interface flow control */
 	lem_set_flow_cntrl(adapter, "flow_control",
 	    "flow control setting",
@@ -515,6 +542,49 @@ lem_attach(device_t dev)
 	 */
 	adapter->hw.mac.report_tx_early = 1;
 
+#ifdef NIC_PARAVIRT
+	device_printf(dev, "driver supports paravirt, subdev 0x%x\n",
+		adapter->hw.subsystem_device_id);
+	if (adapter->hw.subsystem_device_id == E1000_PARA_SUBDEV) {
+		uint64_t bus_addr;
+
+		device_printf(dev, "paravirt support on dev %p\n", adapter);
+		tsize = 4096; // XXX one page for the csb
+		if (lem_dma_malloc(adapter, tsize, &adapter->csb_mem, BUS_DMA_NOWAIT)) {
+			device_printf(dev, "Unable to allocate csb memory\n");
+			error = ENOMEM;
+			goto err_csb;
+		}
+		/* Setup the Base of the CSB */
+		adapter->csb = (struct paravirt_csb *)adapter->csb_mem.dma_vaddr;
+		/* force the first kick */
+		adapter->csb->host_need_txkick = 1; /* txring empty */
+		adapter->csb->guest_need_rxkick = 1; /* no rx packets */
+		bus_addr = adapter->csb_mem.dma_paddr;
+		lem_add_rx_process_limit(adapter, "csb_on",
+		    "enable paravirt.", &adapter->csb->guest_csb_on, 0);
+		lem_add_rx_process_limit(adapter, "txc_lim",
+		    "txc_lim", &adapter->csb->host_txcycles_lim, 1);
+
+		/* some stats */
+#define PA_SC(name, var, val)		\
+	lem_add_rx_process_limit(adapter, name, name, var, val)
+		PA_SC("host_need_txkick",&adapter->csb->host_need_txkick, 1);
+		PA_SC("host_rxkick_at",&adapter->csb->host_rxkick_at, ~0);
+		PA_SC("guest_need_txkick",&adapter->csb->guest_need_txkick, 0);
+		PA_SC("guest_need_rxkick",&adapter->csb->guest_need_rxkick, 1);
+		PA_SC("tdt_reg_count",&adapter->tdt_reg_count, 0);
+		PA_SC("tdt_csb_count",&adapter->tdt_csb_count, 0);
+		PA_SC("tdt_int_count",&adapter->tdt_int_count, 0);
+		PA_SC("guest_need_kick_count",&adapter->guest_need_kick_count, 0);
+		/* tell the host where the block is */
+		E1000_WRITE_REG(&adapter->hw, E1000_CSBAH,
+			(u32)(bus_addr >> 32));
+		E1000_WRITE_REG(&adapter->hw, E1000_CSBAL,
+			(u32)bus_addr);
+	}
+#endif /* NIC_PARAVIRT */
+
 	tsize = roundup2(adapter->num_tx_desc * sizeof(struct e1000_tx_desc),
 	    EM_DBA_ALIGN);
 
@@ -673,6 +743,11 @@ err_hw_init:
 err_rx_desc:
 	lem_dma_free(adapter, &adapter->txdma);
 err_tx_desc:
+#ifdef NIC_PARAVIRT
+	lem_dma_free(adapter, &adapter->csb_mem);
+err_csb:
+#endif /* NIC_PARAVIRT */
+
 err_pci:
 	if (adapter->ifp != NULL)
 		if_free(adapter->ifp);
@@ -760,6 +835,12 @@ lem_detach(device_t dev)
 		adapter->rx_desc_base = NULL;
 	}
 
+#ifdef NIC_PARAVIRT
+	if (adapter->csb) {
+		lem_dma_free(adapter, &adapter->csb_mem);
+		adapter->csb = NULL;
+	}
+#endif /* NIC_PARAVIRT */
 	lem_release_hw_control(adapter);
 	free(adapter->mta, M_DEVBUF);
 	EM_TX_LOCK_DESTROY(adapter);
@@ -869,6 +950,16 @@ lem_start_locked(struct ifnet *ifp)
 	}
 	if (adapter->num_tx_desc_avail <= EM_TX_OP_THRESHOLD)
 		ifp->if_drv_flags |= IFF_DRV_OACTIVE;
+#ifdef NIC_PARAVIRT
+	if (if_getdrvflags(ifp) & IFF_DRV_OACTIVE && adapter->csb &&
+	    adapter->csb->guest_csb_on &&
+	    !(adapter->csb->guest_need_txkick & 1))  {
+		adapter->csb->guest_need_txkick = 1;
+		adapter->guest_need_kick_count++;
+		// XXX memory barrier
+		lem_txeof(adapter); // XXX possibly clear IFF_DRV_OACTIVE
+	}
+#endif /* NIC_PARAVIRT */
 
 	return;
 }
@@ -1715,6 +1806,37 @@ lem_xmit(struct adapter *adapter, struct mbuf **m_headp)
 	 */
 	bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 	    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+
+#ifdef NIC_PARAVIRT
+	if (adapter->csb) {
+		adapter->csb->guest_tdt = i;
+		/* XXX memory barrier ? */
+ 		if (adapter->csb->guest_csb_on &&
+		    !(adapter->csb->host_need_txkick & 1)) {
+			/* XXX maybe useless
+			 * clean the ring. maybe do it before ?
+			 * maybe a little bit of histeresys ?
+			 */
+			if (adapter->num_tx_desc_avail <= 64) {// XXX
+				lem_txeof(adapter);
+			}
+			return (0);
+		}
+	}
+#endif /* NIC_PARAVIRT */
+
+#ifdef NIC_SEND_COMBINING
+	if (adapter->sc_enable) {
+		if (adapter->shadow_tdt & MIT_PENDING_INT) {
+			/* signal intr and data pending */
+			adapter->shadow_tdt = MIT_PENDING_TDT | (i & 0xffff);
+			return (0);
+		} else {
+			adapter->shadow_tdt = MIT_PENDING_INT;
+		}
+	}
+#endif /* NIC_SEND_COMBINING */
+
 	if (adapter->hw.mac.type == e1000_82547 &&
 	    adapter->link_duplex == HALF_DUPLEX)
 		lem_82547_move_tail(adapter);
@@ -1995,6 +2117,20 @@ lem_local_timer(void *arg)
 
 	lem_smartspeed(adapter);
 
+#ifdef NIC_PARAVIRT
+	/* recover space if needed */
+	if (adapter->csb && adapter->csb->guest_csb_on &&
+	    (adapter->watchdog_check == TRUE) &&
+	    (ticks - adapter->watchdog_time > EM_WATCHDOG) &&
+	    (adapter->num_tx_desc_avail != adapter->num_tx_desc) ) {
+		lem_txeof(adapter);
+		/*
+		 * lem_txeof() normally (except when space in the queue
+		 * runs low XXX) cleans watchdog_check so that
+		 * we do not hung.
+		 */
+	}
+#endif /* NIC_PARAVIRT */
 	/*
 	 * We check the watchdog: the time since
 	 * the last TX descriptor was cleaned.
@@ -2677,10 +2813,10 @@ lem_setup_transmit_structures(struct adapter *adapter)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + si, &paddr);
+			addr = PNMB(na, slot + si, &paddr);
 			adapter->tx_desc_base[i].buffer_addr = htole64(paddr);
 			/* reload the map for netmap mode */
-			netmap_load_map(adapter->txtag, tx_buffer->map, addr);
+			netmap_load_map(na, adapter->txtag, tx_buffer->map, addr);
 		}
 #endif /* DEV_NETMAP */
 		tx_buffer->next_eop = -1;
@@ -3055,6 +3191,16 @@ lem_txeof(struct adapter *adapter)
         adapter->next_tx_to_clean = first;
         adapter->num_tx_desc_avail = num_avail;
 
+#ifdef NIC_SEND_COMBINING
+	if ((adapter->shadow_tdt & MIT_PENDING_TDT) == MIT_PENDING_TDT) {
+		/* a tdt write is pending, do it */
+		E1000_WRITE_REG(&adapter->hw, E1000_TDT(0),
+			0xffff & adapter->shadow_tdt);
+		adapter->shadow_tdt = MIT_PENDING_INT;
+	} else {
+		adapter->shadow_tdt = 0; // disable
+	}
+#endif /* NIC_SEND_COMBINING */
         /*
          * If we have enough room, clear IFF_DRV_OACTIVE to
          * tell the stack that it is OK to send packets.
@@ -3062,6 +3208,12 @@ lem_txeof(struct adapter *adapter)
          */
         if (adapter->num_tx_desc_avail > EM_TX_CLEANUP_THRESHOLD) {                
                 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
+#ifdef NIC_PARAVIRT
+		if (adapter->csb) { // XXX also csb_on ?
+			adapter->csb->guest_need_txkick = 2; /* acked */
+			// XXX memory barrier
+		}
+#endif /* NIC_PARAVIRT */
                 if (adapter->num_tx_desc_avail == adapter->num_tx_desc) {
 			adapter->watchdog_check = FALSE;
 			return;
@@ -3247,8 +3399,8 @@ lem_setup_receive_structures(struct adapter *adapter)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + si, &paddr);
-			netmap_load_map(adapter->rxtag, rx_buffer->map, addr);
+			addr = PNMB(na, slot + si, &paddr);
+			netmap_load_map(na, adapter->rxtag, rx_buffer->map, addr);
 			/* Update descriptor */
 			adapter->rx_desc_base[i].buffer_addr = htole64(paddr);
 			continue;
@@ -3445,7 +3597,23 @@ lem_rxeof(struct adapter *adapter, int count, int *done)
 	int		i, rx_sent = 0;
 	struct e1000_rx_desc   *current_desc;
 
+#ifdef BATCH_DISPATCH
+	struct mbuf *mh = NULL, *mt = NULL;
+#endif /* BATCH_DISPATCH */
+#ifdef NIC_PARAVIRT
+	int retries = 0;
+	struct paravirt_csb* csb = adapter->csb;
+	int csb_mode = csb && csb->guest_csb_on;
+
+	//ND("clear guest_rxkick at %d", adapter->next_rx_desc_to_check);
+	if (csb_mode && csb->guest_need_rxkick)
+		csb->guest_need_rxkick = 0;
+#endif /* NIC_PARAVIRT */
 	EM_RX_LOCK(adapter);
+
+#ifdef BATCH_DISPATCH
+    batch_again:
+#endif /* BATCH_DISPATCH */
 	i = adapter->next_rx_desc_to_check;
 	current_desc = &adapter->rx_desc_base[i];
 	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
@@ -3458,19 +3626,45 @@ lem_rxeof(struct adapter *adapter, int count, int *done)
 	}
 #endif /* DEV_NETMAP */
 
+#if 1 // XXX optimization ?
 	if (!((current_desc->status) & E1000_RXD_STAT_DD)) {
 		if (done != NULL)
 			*done = rx_sent;
 		EM_RX_UNLOCK(adapter);
 		return (FALSE);
 	}
+#endif /* 0 */
 
 	while (count != 0 && ifp->if_drv_flags & IFF_DRV_RUNNING) {
 		struct mbuf *m = NULL;
 
 		status = current_desc->status;
-		if ((status & E1000_RXD_STAT_DD) == 0)
+		if ((status & E1000_RXD_STAT_DD) == 0) {
+#ifdef NIC_PARAVIRT
+		    if (csb_mode) {
+			/* buffer not ready yet. Retry a few times before giving up */
+			if (++retries <= adapter->rx_retries) {
+				continue;
+			}
+			if (csb->guest_need_rxkick == 0) {
+				// ND("set guest_rxkick at %d", adapter->next_rx_desc_to_check);
+				csb->guest_need_rxkick = 1;
+				// XXX memory barrier, status volatile ?
+				continue; /* double check */
+			}
+		    }
+		    /* no buffer ready, give up */
+#endif /* NIC_PARAVIRT */
 			break;
+		}
+#ifdef NIC_PARAVIRT
+		if (csb_mode) {
+			if (csb->guest_need_rxkick)
+				// ND("clear again guest_rxkick at %d", adapter->next_rx_desc_to_check);
+			csb->guest_need_rxkick = 0;
+			retries = 0;
+		}
+#endif /* NIC_PARAVIRT */
 
 		mp = adapter->rx_buffer_area[i].m_head;
 		/*
@@ -3595,11 +3789,36 @@ discard:
 		bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
 		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
+#ifdef NIC_PARAVIRT
+		if (csb_mode) {
+			/* the buffer at i has been already replaced by lem_get_buf()
+			 * so it is safe to set guest_rdt = i and possibly send a kick.
+			 * XXX see if we can optimize it later.
+			 */
+			csb->guest_rdt = i;
+			// XXX memory barrier
+			if (i == csb->host_rxkick_at)
+				E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), i);
+		}
+#endif /* NIC_PARAVIRT */
 		/* Advance our pointers to the next descriptor. */
 		if (++i == adapter->num_rx_desc)
 			i = 0;
 		/* Call into the stack */
 		if (m != NULL) {
+#ifdef BATCH_DISPATCH
+		    if (adapter->batch_enable) {
+			if (mh == NULL)
+				mh = mt = m;
+			else
+				mt->m_nextpkt = m;
+			mt = m;
+			m->m_nextpkt = NULL;
+			rx_sent++;
+			current_desc = &adapter->rx_desc_base[i];
+			continue;
+		    }
+#endif /* BATCH_DISPATCH */
 			adapter->next_rx_desc_to_check = i;
 			EM_RX_UNLOCK(adapter);
 			(*ifp->if_input)(ifp, m);
@@ -3610,10 +3829,27 @@ discard:
 		current_desc = &adapter->rx_desc_base[i];
 	}
 	adapter->next_rx_desc_to_check = i;
+#ifdef BATCH_DISPATCH
+	if (mh) {
+		EM_RX_UNLOCK(adapter);
+		while ( (mt = mh) != NULL) {
+			mh = mh->m_nextpkt;
+			mt->m_nextpkt = NULL;
+			if_input(ifp, mt);
+		}
+		EM_RX_LOCK(adapter);
+		i = adapter->next_rx_desc_to_check; /* in case of interrupts */
+		if (count > 0)
+			goto batch_again;
+	}
+#endif /* BATCH_DISPATCH */
 
 	/* Advance the E1000's Receive Queue #0  "Tail Pointer". */
 	if (--i < 0)
 		i = adapter->num_rx_desc - 1;
+#ifdef NIC_PARAVIRT
+	if (!csb_mode) /* filter out writes */
+#endif /* NIC_PARAVIRT */
 	E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), i);
 	if (done != NULL)
 		*done = rx_sent;
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index c27440a..75ab2eb 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -3079,7 +3079,7 @@ ixgbe_setup_transmit_ring(struct tx_ring *txr)
 		 */
 		if (slot) {
 			int si = netmap_idx_n2k(&na->tx_rings[txr->me], i);
-			netmap_load_map(txr->txtag, txbuf->map, NMB(slot + si));
+			netmap_load_map(na, txr->txtag, txbuf->map, NMB(na, slot + si));
 		}
 #endif /* DEV_NETMAP */
 		/* Clear the EOP descriptor pointer */
@@ -4025,8 +4025,8 @@ ixgbe_setup_receive_ring(struct rx_ring *rxr)
 			uint64_t paddr;
 			void *addr;
 
-			addr = PNMB(slot + sj, &paddr);
-			netmap_load_map(rxr->ptag, rxbuf->pmap, addr);
+			addr = PNMB(na, slot + sj, &paddr);
+			netmap_load_map(na, rxr->ptag, rxbuf->pmap, addr);
 			/* Update descriptor and the cached value */
 			rxr->rx_base[j].read.pkt_addr = htole64(paddr);
 			rxbuf->addr = htole64(paddr);
diff --git a/sys/dev/netmap/if_em_netmap.h b/sys/dev/netmap/if_em_netmap.h
index 17b4c4f..15e9be5 100644
--- a/sys/dev/netmap/if_em_netmap.h
+++ b/sys/dev/netmap/if_em_netmap.h
@@ -113,10 +113,10 @@ em_netmap_reg(struct netmap_adapter *na, int onoff)
  * Reconcile kernel and user view of the transmit ring.
  */
 static int
-em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+em_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -128,7 +128,7 @@ em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct tx_ring *txr = &adapter->tx_rings[ring_nr];
+	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
 
 	bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
 			BUS_DMASYNC_POSTREAD);
@@ -144,7 +144,7 @@ em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			/* device-specific */
 			struct e1000_tx_desc *curr = &txr->tx_base[nic_i];
@@ -153,12 +153,12 @@ em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 				nic_i == 0 || nic_i == report_frequency) ?
 				E1000_TXD_CMD_RS : 0;
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				curr->buffer_addr = htole64(paddr);
 				/* buffer has changed, reload map */
-				netmap_reload_map(txr->txtag, txbuf->map, addr);
+				netmap_reload_map(na, txr->txtag, txbuf->map, addr);
 			}
 			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
 
@@ -187,7 +187,7 @@ em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 	 */
 	if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
 		/* record completed transmissions using TDH */
-		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(ring_nr));
+		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(kring->ring_id));
 		if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
 			D("TDH wrap %d", nic_i);
 			nic_i -= kring->nkr_num_slots;
@@ -208,10 +208,10 @@ em_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
  * Reconcile kernel and user view of the receive ring.
  */
 static int
-em_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+em_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -222,7 +222,7 @@ em_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
+	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];
 
 	if (head > lim)
 		return netmap_ring_reinit(kring);
@@ -271,18 +271,18 @@ em_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		for (n = 0; nm_i != head; n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			struct e1000_rx_desc *curr = &rxr->rx_base[nic_i];
 			struct em_buffer *rxbuf = &rxr->rx_buffers[nic_i];
 
-			if (addr == netmap_buffer_base) /* bad buf */
+			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
 				curr->buffer_addr = htole64(paddr);
-				netmap_reload_map(rxr->rxtag, rxbuf->map, addr);
+				netmap_reload_map(na, rxr->rxtag, rxbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			curr->status = 0;
diff --git a/sys/dev/netmap/if_igb_netmap.h b/sys/dev/netmap/if_igb_netmap.h
index e1929f0..c738460 100644
--- a/sys/dev/netmap/if_igb_netmap.h
+++ b/sys/dev/netmap/if_igb_netmap.h
@@ -81,10 +81,10 @@ igb_netmap_reg(struct netmap_adapter *na, int onoff)
  * Reconcile kernel and user view of the transmit ring.
  */
 static int
-igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+igb_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -96,7 +96,7 @@ igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct tx_ring *txr = &adapter->tx_rings[ring_nr];
+	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
 	/* 82575 needs the queue index added */
 	u32 olinfo_status =
 	    (adapter->hw.mac.type == e1000_82575) ? (txr->me << 4) : 0;
@@ -115,7 +115,7 @@ igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			/* device-specific */
 			union e1000_adv_tx_desc *curr =
@@ -125,11 +125,11 @@ igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 				nic_i == 0 || nic_i == report_frequency) ?
 				E1000_ADVTXD_DCMD_RS : 0;
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				netmap_reload_map(txr->txtag, txbuf->map, addr);
+				netmap_reload_map(na, txr->txtag, txbuf->map, addr);
 			}
 			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
 
@@ -171,7 +171,7 @@ igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 	 */
 	if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
 		/* record completed transmissions using TDH */
-		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(ring_nr));
+		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(kring->ring_id));
 		if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
 			D("TDH wrap %d", nic_i);
 			nic_i -= kring->nkr_num_slots;
@@ -190,10 +190,10 @@ igb_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
  * Reconcile kernel and user view of the receive ring.
  */
 static int
-igb_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+igb_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -204,7 +204,7 @@ igb_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
+	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];
 
 	if (head > lim)
 		return netmap_ring_reinit(kring);
@@ -251,17 +251,17 @@ igb_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		for (n = 0; nm_i != head; n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			union e1000_adv_rx_desc *curr = &rxr->rx_base[nic_i];
 			struct igb_rx_buf *rxbuf = &rxr->rx_buffers[nic_i];
 
-			if (addr == netmap_buffer_base) /* bad buf */
+			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				netmap_reload_map(rxr->ptag, rxbuf->pmap, addr);
+				netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			curr->wb.upper.status_error = 0;
diff --git a/sys/dev/netmap/if_lem_netmap.h b/sys/dev/netmap/if_lem_netmap.h
index 4fce5c9..272f02c 100644
--- a/sys/dev/netmap/if_lem_netmap.h
+++ b/sys/dev/netmap/if_lem_netmap.h
@@ -39,6 +39,7 @@
 #include <vm/pmap.h>    /* vtophys ? */
 #include <dev/netmap/netmap_kern.h>
 
+extern int netmap_adaptive_io;
 
 /*
  * Register/unregister. We are already under netmap lock.
@@ -84,10 +85,10 @@ lem_netmap_reg(struct netmap_adapter *na, int onoff)
  * Reconcile kernel and user view of the transmit ring.
  */
 static int
-lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+lem_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -98,6 +99,10 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
+#ifdef NIC_PARAVIRT
+	struct paravirt_csb *csb = adapter->csb;
+	uint64_t *csbd = (uint64_t *)(csb + 1);
+#endif /* NIC_PARAVIRT */
 
 	bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 			BUS_DMASYNC_POSTREAD);
@@ -108,12 +113,25 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	nm_i = kring->nr_hwcur;
 	if (nm_i != head) {	/* we have new packets to send */
+#ifdef NIC_PARAVIRT
+		int do_kick = 0;
+		uint64_t t = 0; // timestamp
+		int n = head - nm_i;
+		if (n < 0)
+			n += lim + 1;
+		if (csb) {
+			t = rdtsc(); /* last timestamp */
+			csbd[16] += t - csbd[0]; /* total Wg */
+			csbd[17] += n;		/* Wg count */
+			csbd[0] = t;
+		}
+#endif /* NIC_PARAVIRT */
 		nic_i = netmap_idx_k2n(kring, nm_i);
 		while (nm_i != head) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			/* device-specific */
 			struct e1000_tx_desc *curr = &adapter->tx_desc_base[nic_i];
@@ -122,12 +140,12 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 				nic_i == 0 || nic_i == report_frequency) ?
 				E1000_TXD_CMD_RS : 0;
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
 				curr->buffer_addr = htole64(paddr);
-				netmap_reload_map(adapter->txtag, txbuf->map, addr);
+				netmap_reload_map(na, adapter->txtag, txbuf->map, addr);
 			}
 			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
 
@@ -140,6 +158,7 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 			nm_i = nm_next(nm_i, lim);
 			nic_i = nm_next(nic_i, lim);
+			// XXX might try an early kick
 		}
 		kring->nr_hwcur = head;
 
@@ -147,8 +166,38 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
 			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
+#ifdef NIC_PARAVIRT
+		/* set unconditionally, then also kick if needed */
+		if (csb) {
+			t = rdtsc();
+			if (csb->host_need_txkick == 2) {
+				/* can compute an update of delta */
+				int64_t delta = t - csbd[3];
+				if (delta < 0)
+					delta = -delta;
+				if (csbd[8] == 0 || delta < csbd[8]) {
+					csbd[8] = delta;
+					csbd[9]++;
+				}
+				csbd[10]++;
+			}
+			csb->guest_tdt = nic_i;
+			csbd[18] += t - csbd[0]; // total wp
+			csbd[19] += n;
+		}
+		if (!csb || !csb->guest_csb_on || (csb->host_need_txkick & 1))
+			do_kick = 1;
+		if (do_kick)
+#endif /* NIC_PARAVIRT */
 		/* (re)start the tx unit up to slot nic_i (excluded) */
 		E1000_WRITE_REG(&adapter->hw, E1000_TDT(0), nic_i);
+#ifdef NIC_PARAVIRT
+		if (do_kick) {
+			uint64_t t1 = rdtsc();
+			csbd[20] += t1 - t; // total Np
+			csbd[21]++;
+		}
+#endif /* NIC_PARAVIRT */
 	}
 
 	/*
@@ -157,6 +206,93 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 	if (ticks != kring->last_reclaim || flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
 		kring->last_reclaim = ticks;
 		/* record completed transmissions using TDH */
+#ifdef NIC_PARAVIRT
+		/* host updates tdh unconditionally, and we have
+		 * no side effects on reads, so we can read from there
+		 * instead of exiting.
+		 */
+		if (csb) {
+		    static int drain = 0, nodrain=0, good = 0, bad = 0, fail = 0;
+		    u_int x = adapter->next_tx_to_clean;
+		    csbd[19]++; // XXX count reclaims
+		    nic_i = csb->host_tdh;
+		    if (csb->guest_csb_on) {
+			if (nic_i == x) {
+			    bad++;
+		    	    csbd[24]++; // failed reclaims
+			    /* no progress, request kick and retry */
+			    csb->guest_need_txkick = 1;
+			    mb(); // XXX barrier
+		    	    nic_i = csb->host_tdh;
+			} else {
+			    good++;
+			}
+			if (nic_i != x) {
+			    csb->guest_need_txkick = 2;
+			    if (nic_i == csb->guest_tdt)
+				drain++;
+			    else
+				nodrain++;
+#if 1
+			if (netmap_adaptive_io) {
+			    /* new mechanism: last half ring (or so)
+			     * released one slot at a time.
+			     * This effectively makes the system spin.
+			     *
+			     * Take next_to_clean + 1 as a reference.
+			     * tdh must be ahead or equal
+			     * On entry, the logical order is
+			     *		x < tdh = nic_i
+			     * We first push tdh up to avoid wraps.
+			     * The limit is tdh-ll (half ring).
+			     * if tdh-256 < x we report x;
+			     * else we report tdh-256
+			     */
+			    u_int tdh = nic_i;
+			    u_int ll = csbd[15];
+			    u_int delta = lim/8;
+			    if (netmap_adaptive_io == 2 || ll > delta)
+				csbd[15] = ll = delta;
+			    else if (netmap_adaptive_io == 1 && ll > 1) {
+				csbd[15]--;
+			    }
+
+			    if (nic_i >= kring->nkr_num_slots) {
+				RD(5, "bad nic_i %d on input", nic_i);
+			    }
+			    x = nm_next(x, lim);
+			    if (tdh < x)
+				tdh += lim + 1;
+			    if (tdh <= x + ll) {
+				nic_i = x;
+				csbd[25]++; //report n + 1;
+			    } else {
+				tdh = nic_i;
+				if (tdh < ll)
+				    tdh += lim + 1;
+				nic_i = tdh - ll;
+				csbd[26]++; // report tdh - ll
+			    }
+			}
+#endif
+			} else {
+			    /* we stop, count whether we are idle or not */
+			    int bh_active = csb->host_need_txkick & 2 ? 4 : 0;
+			    csbd[27+ csb->host_need_txkick]++;
+			    if (netmap_adaptive_io == 1) {
+				if (bh_active && csbd[15] > 1)
+				    csbd[15]--;
+				else if (!bh_active && csbd[15] < lim/2)
+				    csbd[15]++;
+			    }
+			    bad--;
+			    fail++;
+			}
+		    }
+		    RD(1, "drain %d nodrain %d good %d retry %d fail %d",
+			drain, nodrain, good, bad, fail);
+		} else
+#endif /* !NIC_PARAVIRT */
 		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(0));
 		if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
 			D("TDH wrap %d", nic_i);
@@ -176,10 +312,10 @@ lem_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
  * Reconcile kernel and user view of the receive ring.
  */
 static int
-lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+lem_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -190,10 +326,21 @@ lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
+#ifdef NIC_PARAVIRT
+	struct paravirt_csb *csb = adapter->csb;
+	uint32_t csb_mode = csb && csb->guest_csb_on;
+	uint32_t do_host_rxkick = 0;
+#endif /* NIC_PARAVIRT */
 
 	if (head > lim)
 		return netmap_ring_reinit(kring);
 
+#ifdef NIC_PARAVIRT
+	if (csb_mode) {
+		force_update = 1;
+		csb->guest_need_rxkick = 0;
+	}
+#endif /* NIC_PARAVIRT */
 	/* XXX check sync modes */
 	bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
 			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
@@ -212,11 +359,28 @@ lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			uint32_t staterr = le32toh(curr->status);
 			int len;
 
+#ifdef NIC_PARAVIRT
+			if (csb_mode) {
+			    if ((staterr & E1000_RXD_STAT_DD) == 0) {
+				/* don't bother to retry if more than 1 pkt */
+				if (n > 1)
+				    break;
+				csb->guest_need_rxkick = 1;
+				wmb();
+				staterr = le32toh(curr->status);
+				if ((staterr & E1000_RXD_STAT_DD) == 0) {
+				    break;
+				} else { /* we are good */
+				   csb->guest_need_rxkick = 0;
+				}
+			    }
+			} else
+#endif /* NIC_PARAVIRT */
 			if ((staterr & E1000_RXD_STAT_DD) == 0)
 				break;
 			len = le16toh(curr->length) - 4; // CRC
 			if (len < 0) {
-				D("bogus pkt size %d nic idx %d", len, nic_i);
+				RD(5, "bogus pkt (%d) size %d nic idx %d", n, len, nic_i);
 				len = 0;
 			}
 			ring->slot[nm_i].len = len;
@@ -228,6 +392,18 @@ lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			nic_i = nm_next(nic_i, lim);
 		}
 		if (n) { /* update the state variables */
+#ifdef NIC_PARAVIRT
+			if (csb_mode) {
+			    if (n > 1) {
+				/* leave one spare buffer so we avoid rxkicks */
+				nm_i = nm_prev(nm_i, lim);
+				nic_i = nm_prev(nic_i, lim);
+				n--;
+			    } else {
+				csb->guest_need_rxkick = 1;
+			    }
+			}
+#endif /* NIC_PARAVIRT */
 			ND("%d new packets at nic %d nm %d tail %d",
 				n,
 				adapter->next_rx_desc_to_check,
@@ -249,23 +425,27 @@ lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		for (n = 0; nm_i != head; n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			struct e1000_rx_desc *curr = &adapter->rx_desc_base[nic_i];
 			struct em_buffer *rxbuf = &adapter->rx_buffer_area[nic_i];
 
-			if (addr == netmap_buffer_base) /* bad buf */
+			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
 				curr->buffer_addr = htole64(paddr);
-				netmap_reload_map(adapter->rxtag, rxbuf->map, addr);
+				netmap_reload_map(na, adapter->rxtag, rxbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			curr->status = 0;
 			bus_dmamap_sync(adapter->rxtag, rxbuf->map,
 			    BUS_DMASYNC_PREREAD);
+#ifdef NIC_PARAVIRT
+			if (csb_mode && csb->host_rxkick_at == nic_i)
+				do_host_rxkick = 1;
+#endif /* NIC_PARAVIRT */
 			nm_i = nm_next(nm_i, lim);
 			nic_i = nm_next(nic_i, lim);
 		}
@@ -277,6 +457,12 @@ lem_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		 * so move nic_i back by one unit
 		 */
 		nic_i = nm_prev(nic_i, lim);
+#ifdef NIC_PARAVIRT
+		/* set unconditionally, then also kick if needed */
+		if (csb)
+			csb->guest_rdt = nic_i;
+		if (!csb_mode || do_host_rxkick)
+#endif /* NIC_PARAVIRT */
 		E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), nic_i);
 	}
 
diff --git a/sys/dev/netmap/if_re_netmap.h b/sys/dev/netmap/if_re_netmap.h
index 10abe4f..98f6143 100644
--- a/sys/dev/netmap/if_re_netmap.h
+++ b/sys/dev/netmap/if_re_netmap.h
@@ -65,10 +65,10 @@ re_netmap_reg(struct netmap_adapter *na, int onoff)
  * Reconcile kernel and user view of the transmit ring.
  */
 static int
-re_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+re_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -96,14 +96,14 @@ re_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			/* device-specific */
 			struct rl_desc *desc = &sc->rl_ldata.rl_tx_list[nic_i];
 			int cmd = slot->len | RL_TDESC_CMD_EOF |
 				RL_TDESC_CMD_OWN | RL_TDESC_CMD_SOF ;
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			if (nic_i == lim)	/* mark end of ring */
 				cmd |= RL_TDESC_CMD_EOR;
@@ -112,7 +112,7 @@ re_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 				/* buffer has changed, reload map */
 				desc->rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 				desc->rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
-				netmap_reload_map(sc->rl_ldata.rl_tx_mtag,
+				netmap_reload_map(na, sc->rl_ldata.rl_tx_mtag,
 					txd[nic_i].tx_dmamap, addr);
 			}
 			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
@@ -169,10 +169,10 @@ re_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
  * Reconcile kernel and user view of the receive ring.
  */
 static int
-re_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+re_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -240,12 +240,12 @@ re_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		for (n = 0; nm_i != head; n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			struct rl_desc *desc = &sc->rl_ldata.rl_rx_list[nic_i];
-			int cmd = NETMAP_BUF_SIZE | RL_RDESC_CMD_OWN;
+			int cmd = NETMAP_BUF_SIZE(na) | RL_RDESC_CMD_OWN;
 
-			if (addr == netmap_buffer_base) /* bad buf */
+			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
 			if (nic_i == lim)	/* mark end of ring */
@@ -255,7 +255,7 @@ re_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 				/* buffer has changed, reload map */
 				desc->rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 				desc->rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
-				netmap_reload_map(sc->rl_ldata.rl_rx_mtag,
+				netmap_reload_map(na, sc->rl_ldata.rl_rx_mtag,
 					rxd[nic_i].rx_dmamap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
@@ -296,14 +296,10 @@ re_netmap_tx_init(struct rl_softc *sc)
 	struct netmap_adapter *na = NA(sc->rl_ifp);
 	struct netmap_slot *slot;
 
-	if (!na || !(na->na_flags & NAF_NATIVE_ON)) {
-		return;
-	}
-
 	slot = netmap_reset(na, NR_TX, 0, 0);
-	/* slot is NULL if we are not in netmap mode */
+	/* slot is NULL if we are not in native netmap mode */
 	if (!slot)
-		return;  // XXX cannot happen
+		return;
 	/* in netmap mode, overwrite addresses and maps */
 	txd = sc->rl_ldata.rl_tx_desc;
 	desc = sc->rl_ldata.rl_tx_list;
@@ -313,11 +309,11 @@ re_netmap_tx_init(struct rl_softc *sc)
 	for (i = 0; i < n; i++) {
 		uint64_t paddr;
 		int l = netmap_idx_n2k(&na->tx_rings[0], i);
-		void *addr = PNMB(slot + l, &paddr);
+		void *addr = PNMB(na, slot + l, &paddr);
 
 		desc[i].rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 		desc[i].rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
-		netmap_load_map(sc->rl_ldata.rl_tx_mtag,
+		netmap_load_map(na, sc->rl_ldata.rl_tx_mtag,
 			txd[i].tx_dmamap, addr);
 	}
 }
@@ -344,15 +340,15 @@ re_netmap_rx_init(struct rl_softc *sc)
 		uint64_t paddr;
 		uint32_t nm_i = netmap_idx_n2k(&na->rx_rings[0], nic_i);
 
-		addr = PNMB(slot + nm_i, &paddr);
+		addr = PNMB(na, slot + nm_i, &paddr);
 
-		netmap_reload_map(sc->rl_ldata.rl_rx_mtag,
+		netmap_reload_map(na, sc->rl_ldata.rl_rx_mtag,
 		    sc->rl_ldata.rl_rx_desc[nic_i].rx_dmamap, addr);
 		bus_dmamap_sync(sc->rl_ldata.rl_rx_mtag,
 		    sc->rl_ldata.rl_rx_desc[nic_i].rx_dmamap, BUS_DMASYNC_PREREAD);
 		desc[nic_i].rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 		desc[nic_i].rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
-		cmdstat = NETMAP_BUF_SIZE;
+		cmdstat = NETMAP_BUF_SIZE(na);
 		if (nic_i == n - 1) /* mark the end of ring */
 			cmdstat |= RL_RDESC_CMD_EOR;
 		if (nic_i < max_avail)
diff --git a/sys/dev/netmap/if_vtnet_netmap.h b/sys/dev/netmap/if_vtnet_netmap.h
new file mode 100644
index 0000000..63f4fa9
--- /dev/null
+++ b/sys/dev/netmap/if_vtnet_netmap.h
@@ -0,0 +1,434 @@
+/*
+ * Copyright (C) 2014 Vincenzo Maffione, Luigi Rizzo. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * $FreeBSD$
+ */
+
+#include <net/netmap.h>
+#include <sys/selinfo.h>
+#include <vm/vm.h>
+#include <vm/pmap.h>    /* vtophys ? */
+#include <dev/netmap/netmap_kern.h>
+
+
+#define SOFTC_T	vtnet_softc
+
+/* Free all the unused buffer in all the RX virtqueues.
+ * This function is called when entering and exiting netmap mode.
+ * - buffers queued by the virtio driver return skbuf/mbuf pointer
+ *   and need to be freed;
+ * - buffers queued by netmap return the txq/rxq, and do not need work
+ */
+static void
+vtnet_netmap_free_bufs(struct SOFTC_T* sc)
+{
+	int i, nmb = 0, n = 0, last;
+
+	for (i = 0; i < sc->vtnet_max_vq_pairs; i++) {
+		struct vtnet_rxq *rxq = &sc->vtnet_rxqs[i];
+		struct virtqueue *vq;
+		struct mbuf *m;
+		struct vtnet_txq *txq = &sc->vtnet_txqs[i];
+                struct vtnet_tx_header *txhdr;
+
+		last = 0;
+		vq = rxq->vtnrx_vq;
+		while ((m = virtqueue_drain(vq, &last)) != NULL) {
+			n++;
+			if (m != (void *)rxq)
+				m_freem(m);
+			else
+				nmb++;
+		}
+
+		last = 0;
+		vq = txq->vtntx_vq;
+		while ((txhdr = virtqueue_drain(vq, &last)) != NULL) {
+			n++;
+			if (txhdr != (void *)txq) {
+				m_freem(txhdr->vth_mbuf);
+				uma_zfree(vtnet_tx_header_zone, txhdr);
+			} else
+				nmb++;
+		}
+	}
+	D("freed %d mbufs, %d netmap bufs on %d queues",
+		n - nmb, nmb, i);
+}
+
+/* Register and unregister. */
+static int
+vtnet_netmap_reg(struct netmap_adapter *na, int onoff)
+{
+        struct ifnet *ifp = na->ifp;
+	struct SOFTC_T *sc = ifp->if_softc;
+
+	VTNET_CORE_LOCK(sc);
+	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
+	/* enable or disable flags and callbacks in na and ifp */
+	if (onoff) {
+		nm_set_native_flags(na);
+	} else {
+		nm_clear_native_flags(na);
+	}
+	/* drain queues so netmap and native drivers
+	 * do not interfere with each other
+	 */
+	vtnet_netmap_free_bufs(sc);
+        vtnet_init_locked(sc);       /* also enable intr */
+        VTNET_CORE_UNLOCK(sc);
+        return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
+}
+
+
+/* Reconcile kernel and user view of the transmit ring. */
+static int
+vtnet_netmap_txsync(struct netmap_kring *kring, int flags)
+{
+	struct netmap_adapter *na = kring->na;
+        struct ifnet *ifp = na->ifp;
+	struct netmap_ring *ring = kring->ring;
+	u_int ring_nr = kring->ring_id;
+	u_int nm_i;	/* index into the netmap ring */
+	u_int nic_i;	/* index into the NIC ring */
+	u_int n;
+	u_int const lim = kring->nkr_num_slots - 1;
+	u_int const head = kring->rhead;
+
+	/* device-specific */
+	struct SOFTC_T *sc = ifp->if_softc;
+	struct vtnet_txq *txq = &sc->vtnet_txqs[ring_nr];
+	struct virtqueue *vq = txq->vtntx_vq;
+
+	/*
+	 * First part: process new packets to send.
+	 */
+	rmb();
+	
+	nm_i = kring->nr_hwcur;
+	if (nm_i != head) {	/* we have new packets to send */
+		struct sglist *sg = txq->vtntx_sg;
+
+		nic_i = netmap_idx_k2n(kring, nm_i);
+		for (n = 0; nm_i != head; n++) {
+			/* we use an empty header here */
+			static struct virtio_net_hdr_mrg_rxbuf hdr;
+			struct netmap_slot *slot = &ring->slot[nm_i];
+			u_int len = slot->len;
+			uint64_t paddr;
+			void *addr = PNMB(na, slot, &paddr);
+                        int err;
+
+			NM_CHECK_ADDR_LEN(na, addr, len);
+
+			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
+			/* Initialize the scatterlist, expose it to the hypervisor,
+			 * and kick the hypervisor (if necessary).
+			 */
+			sglist_reset(sg); // cheap
+			// if vtnet_hdr_size > 0 ...
+			err = sglist_append(sg, &hdr, sc->vtnet_hdr_size);
+			// XXX later, support multi segment
+			err = sglist_append_phys(sg, paddr, len);
+			/* use na as the cookie */
+                        err = virtqueue_enqueue(vq, txq, sg, sg->sg_nseg, 0);
+                        if (unlikely(err < 0)) {
+                                D("virtqueue_enqueue failed");
+                                break;
+                        }
+
+			nm_i = nm_next(nm_i, lim);
+			nic_i = nm_next(nic_i, lim);
+		}
+		/* Update hwcur depending on where we stopped. */
+		kring->nr_hwcur = nm_i; /* note we migth break early */
+
+		/* No more free TX slots? Ask the hypervisor for notifications,
+		 * possibly only when a considerable amount of work has been
+		 * done.
+		 */
+		ND(3,"sent %d packets, hwcur %d", n, nm_i);
+		virtqueue_disable_intr(vq);
+		virtqueue_notify(vq);
+	} else {
+		if (ring->head != ring->tail)
+		    ND(5, "pure notify ? head %d tail %d nused %d %d",
+			ring->head, ring->tail, virtqueue_nused(vq),
+			(virtqueue_dump(vq), 1));
+		virtqueue_notify(vq);
+		virtqueue_enable_intr(vq); // like postpone with 0
+	}
+
+	
+        /* Free used slots. We only consider our own used buffers, recognized
+	 * by the token we passed to virtqueue_add_outbuf.
+	 */
+        n = 0;
+        for (;;) {
+                struct vtnet_tx_header *txhdr = virtqueue_dequeue(vq, NULL);
+                if (txhdr == NULL)
+                        break;
+                if (likely(txhdr == (void *)txq)) {
+                        n++;
+			if (virtqueue_nused(vq) < 32) { // XXX slow release
+				break;
+			}
+		} else { /* leftover from previous transmission */
+			m_freem(txhdr->vth_mbuf);
+			uma_zfree(vtnet_tx_header_zone, txhdr);
+		}
+        }
+	if (n) {
+		kring->nr_hwtail += n;
+		if (kring->nr_hwtail > lim)
+			kring->nr_hwtail -= lim + 1;
+	}
+	if (nm_i != kring->nr_hwtail /* && vtnet_txq_below_threshold(txq) == 0*/) {
+		ND(3, "disable intr, hwcur %d", nm_i);
+		virtqueue_disable_intr(vq);
+	} else {
+		ND(3, "enable intr, hwcur %d", nm_i);
+		virtqueue_postpone_intr(vq, VQ_POSTPONE_SHORT);
+	}
+
+//out:
+	nm_txsync_finalize(kring);
+
+        return 0;
+}
+
+static int
+vtnet_refill_rxq(struct netmap_kring *kring, u_int nm_i, u_int head)
+{
+	struct netmap_adapter *na = kring->na;
+        struct ifnet *ifp = na->ifp;
+	struct netmap_ring *ring = kring->ring;
+	u_int ring_nr = kring->ring_id;
+	u_int const lim = kring->nkr_num_slots - 1;
+	u_int n;
+
+	/* device-specific */
+	struct SOFTC_T *sc = ifp->if_softc;
+	struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
+	struct virtqueue *vq = rxq->vtnrx_vq;
+
+	/* use a local sglist, default might be short */
+	struct sglist_seg ss[2];
+	struct sglist sg = { ss, 0, 0, 2 };
+
+	for (n = 0; nm_i != head; n++) {
+		static struct virtio_net_hdr_mrg_rxbuf hdr;
+		struct netmap_slot *slot = &ring->slot[nm_i];
+		uint64_t paddr;
+		void *addr = PNMB(na, slot, &paddr);
+		int err = 0;
+
+		if (addr == NETMAP_BUF_BASE(na)) { /* bad buf */
+			if (netmap_ring_reinit(kring))
+				return -1;
+		}
+
+		slot->flags &= ~NS_BUF_CHANGED;
+		sglist_reset(&sg); // cheap
+		err = sglist_append(&sg, &hdr, sc->vtnet_hdr_size);
+		err = sglist_append_phys(&sg, paddr, NETMAP_BUF_SIZE(na));
+		/* writable for the host */
+		err = virtqueue_enqueue(vq, rxq, &sg, 0, sg.sg_nseg);
+		if (err < 0) {
+			D("virtqueue_enqueue failed");
+			break;
+		}
+		nm_i = nm_next(nm_i, lim);
+	}
+	return nm_i;
+}
+
+/* Reconcile kernel and user view of the receive ring. */
+static int
+vtnet_netmap_rxsync(struct netmap_kring *kring, int flags)
+{
+	struct netmap_adapter *na = kring->na;
+        struct ifnet *ifp = na->ifp;
+	struct netmap_ring *ring = kring->ring;
+	u_int ring_nr = kring->ring_id;
+	u_int nm_i;	/* index into the netmap ring */
+	// u_int nic_i;	/* index into the NIC ring */
+	u_int n;
+	u_int const lim = kring->nkr_num_slots - 1;
+	u_int const head = nm_rxsync_prologue(kring);
+	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
+
+	/* device-specific */
+	struct SOFTC_T *sc = ifp->if_softc;
+	struct vtnet_rxq *rxq = &sc->vtnet_rxqs[ring_nr];
+	struct virtqueue *vq = rxq->vtnrx_vq;
+
+	/* XXX netif_carrier_ok ? */
+
+	if (head > lim)
+		return netmap_ring_reinit(kring);
+
+	rmb();
+	/*
+	 * First part: import newly received packets.
+	 * Only accept our
+	 * own buffers (matching the token). We should only get
+	 * matching buffers, because of vtnet_netmap_free_rx_unused_bufs()
+	 * and vtnet_netmap_init_buffers().
+	 */
+	if (netmap_no_pendintr || force_update) {
+		uint16_t slot_flags = kring->nkr_slot_flags;
+                struct netmap_adapter *token;
+
+                nm_i = kring->nr_hwtail;
+                n = 0;
+		for (;;) {
+			int len;
+                        token = virtqueue_dequeue(vq, &len);
+                        if (token == NULL)
+                                break;
+                        if (likely(token == (void *)rxq)) {
+                            ring->slot[nm_i].len = len;
+                            ring->slot[nm_i].flags = slot_flags;
+                            nm_i = nm_next(nm_i, lim);
+                            n++;
+                        } else {
+			    D("This should not happen");
+                        }
+		}
+		kring->nr_hwtail = nm_i;
+		kring->nr_kflags &= ~NKR_PENDINTR;
+	}
+        ND("[B] h %d c %d hwcur %d hwtail %d",
+		ring->head, ring->cur, kring->nr_hwcur,
+			      kring->nr_hwtail);
+
+	/*
+	 * Second part: skip past packets that userspace has released.
+	 */
+	nm_i = kring->nr_hwcur; /* netmap ring index */
+	if (nm_i != head) {
+		int err = vtnet_refill_rxq(kring, nm_i, head);
+		if (err < 0)
+			return 1;
+		kring->nr_hwcur = err;
+		virtqueue_notify(vq);
+		/* After draining the queue may need an intr from the hypervisor */
+        	vtnet_rxq_enable_intr(rxq);
+	}
+
+	/* tell userspace that there might be new packets. */
+	nm_rxsync_finalize(kring);
+
+        ND("[C] h %d c %d t %d hwcur %d hwtail %d",
+		ring->head, ring->cur, ring->tail,
+		kring->nr_hwcur, kring->nr_hwtail);
+
+	return 0;
+}
+
+
+/* Make RX virtqueues buffers pointing to netmap buffers. */
+static int
+vtnet_netmap_init_rx_buffers(struct SOFTC_T *sc)
+{
+	struct ifnet *ifp = sc->vtnet_ifp;
+	struct netmap_adapter* na = NA(ifp);
+	unsigned int r;
+
+	if (!nm_native_on(na))
+		return 0;
+	for (r = 0; r < na->num_rx_rings; r++) {
+                struct netmap_kring *kring = &na->rx_rings[r];
+		struct vtnet_rxq *rxq = &sc->vtnet_rxqs[r];
+		struct virtqueue *vq = rxq->vtnrx_vq;
+	        struct netmap_slot* slot;
+		int err = 0;
+
+		slot = netmap_reset(na, NR_RX, r, 0);
+		if (!slot) {
+			D("strange, null netmap ring %d", r);
+			return 0;
+		}
+		/* Add up to na>-num_rx_desc-1 buffers to this RX virtqueue.
+		 * It's important to leave one virtqueue slot free, otherwise
+		 * we can run into ring->cur/ring->tail wraparounds.
+		 */
+		err = vtnet_refill_rxq(kring, 0, na->num_rx_desc-1);
+		if (err < 0)
+			return 0;
+		virtqueue_notify(vq);
+	}
+
+	return 1;
+}
+
+/* Update the virtio-net device configurations. Number of queues can
+ * change dinamically, by 'ethtool --set-channels $IFNAME combined $N'.
+ * This is actually the only way virtio-net can currently enable
+ * the multiqueue mode.
+ * XXX note that we seem to lose packets if the netmap ring has more
+ * slots than the queue
+ */
+static int
+vtnet_netmap_config(struct netmap_adapter *na, u_int *txr, u_int *txd,
+						u_int *rxr, u_int *rxd)
+{
+	struct ifnet *ifp = na->ifp;
+	struct SOFTC_T *sc = ifp->if_softc;
+
+	*txr = *rxr = sc->vtnet_max_vq_pairs;
+	*rxd = 512; // sc->vtnet_rx_nmbufs;
+	*txd = *rxd; // XXX
+        D("vtnet config txq=%d, txd=%d rxq=%d, rxd=%d",
+					*txr, *txd, *rxr, *rxd);
+
+	return 0;
+}
+
+static void
+vtnet_netmap_attach(struct SOFTC_T *sc)
+{
+	struct netmap_adapter na;
+
+	bzero(&na, sizeof(na));
+
+	na.ifp = sc->vtnet_ifp;
+	na.num_tx_desc =  1024;// sc->vtnet_rx_nmbufs;
+	na.num_rx_desc =  1024; // sc->vtnet_rx_nmbufs;
+	na.nm_register = vtnet_netmap_reg;
+	na.nm_txsync = vtnet_netmap_txsync;
+	na.nm_rxsync = vtnet_netmap_rxsync;
+	na.nm_config = vtnet_netmap_config;
+	na.num_tx_rings = na.num_rx_rings = sc->vtnet_max_vq_pairs;
+	D("max rings %d", sc->vtnet_max_vq_pairs);
+	netmap_attach(&na);
+
+        D("virtio attached txq=%d, txd=%d rxq=%d, rxd=%d",
+			na.num_tx_rings, na.num_tx_desc,
+			na.num_tx_rings, na.num_rx_desc);
+}
+/* end of file */
diff --git a/sys/dev/netmap/ixgbe_netmap.h b/sys/dev/netmap/ixgbe_netmap.h
index a617cc4..3dc628a 100644
--- a/sys/dev/netmap/ixgbe_netmap.h
+++ b/sys/dev/netmap/ixgbe_netmap.h
@@ -153,10 +153,10 @@ ixgbe_netmap_reg(struct netmap_adapter *na, int onoff)
  * methods should be handled by the individual drivers.
  */
 static int
-ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+ixgbe_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -171,7 +171,7 @@ ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct tx_ring *txr = &adapter->tx_rings[ring_nr];
+	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
 	int reclaim_tx;
 
 	bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
@@ -223,7 +223,7 @@ ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			/* device-specific */
 			union ixgbe_adv_tx_desc *curr = &txr->tx_base[nic_i];
@@ -236,11 +236,11 @@ ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			__builtin_prefetch(&ring->slot[nm_i + 1]);
 			__builtin_prefetch(&txr->tx_buffers[nic_i + 1]);
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				netmap_reload_map(txr->txtag, txbuf->map, addr);
+				netmap_reload_map(na, txr->txtag, txbuf->map, addr);
 			}
 			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
 
@@ -309,7 +309,7 @@ ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		 * REPORT_STATUS in a few slots so TDH is the only
 		 * good way.
 		 */
-		nic_i = IXGBE_READ_REG(&adapter->hw, IXGBE_TDH(ring_nr));
+		nic_i = IXGBE_READ_REG(&adapter->hw, IXGBE_TDH(kring->ring_id));
 		if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
 			D("TDH wrap %d", nic_i);
 			nic_i -= kring->nkr_num_slots;
@@ -341,10 +341,10 @@ ixgbe_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
  * of whether or not we received an interrupt.
  */
 static int
-ixgbe_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+ixgbe_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */
 	u_int nic_i;	/* index into the NIC ring */
@@ -355,7 +355,7 @@ ixgbe_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 
 	/* device-specific */
 	struct adapter *adapter = ifp->if_softc;
-	struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
+	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];
 
 	if (head > lim)
 		return netmap_ring_reinit(kring);
@@ -425,17 +425,17 @@ ixgbe_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		for (n = 0; nm_i != head; n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			uint64_t paddr;
-			void *addr = PNMB(slot, &paddr);
+			void *addr = PNMB(na, slot, &paddr);
 
 			union ixgbe_adv_rx_desc *curr = &rxr->rx_base[nic_i];
 			struct ixgbe_rx_buf *rxbuf = &rxr->rx_buffers[nic_i];
 
-			if (addr == netmap_buffer_base) /* bad buf */
+			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
 				goto ring_reset;
 
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				netmap_reload_map(rxr->ptag, rxbuf->pmap, addr);
+				netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			curr->wb.upper.status_error = 0;
diff --git a/sys/dev/netmap/netmap.c b/sys/dev/netmap/netmap.c
index e8b6c5a..0fd362f 100644
--- a/sys/dev/netmap/netmap.c
+++ b/sys/dev/netmap/netmap.c
@@ -124,6 +124,223 @@ ports attached to the switch)
 
  */
 
+
+/* --- internals ----
+ *
+ * Roadmap to the code that implements the above.
+ *
+ * > 1. a process/thread issues one or more open() on /dev/netmap, to create
+ * >    select()able file descriptor on which events are reported.
+ *
+ *  	Internally, we allocate a netmap_priv_d structure, that will be
+ *  	initialized on ioctl(NIOCREGIF).
+ *
+ *      os-specific:
+ *  	    FreeBSD: netmap_open (netmap_freebsd.c). The priv is
+ *  		     per-thread.
+ *  	    linux:   linux_netmap_open (netmap_linux.c). The priv is
+ *  		     per-open.
+ *
+ * > 2. on each descriptor, the process issues an ioctl() to identify
+ * >    the interface that should report events to the file descriptor.
+ *
+ * 	Implemented by netmap_ioctl(), NIOCREGIF case, with nmr->nr_cmd==0.
+ * 	Most important things happen in netmap_get_na() and
+ * 	netmap_do_regif(), called from there. Additional details can be
+ * 	found in the comments above those functions.
+ *
+ * 	In all cases, this action creates/takes-a-reference-to a
+ * 	netmap_*_adapter describing the port, and allocates a netmap_if
+ * 	and all necessary netmap rings, filling them with netmap buffers.
+ *
+ *      In this phase, the sync callbacks for each ring are set (these are used
+ *      in steps 5 and 6 below).  The callbacks depend on the type of adapter.
+ *      The adapter creation/initialization code puts them in the
+ * 	netmap_adapter (fields na->nm_txsync and na->nm_rxsync).  Then, they
+ * 	are copied from there to the netmap_kring's during netmap_do_regif(), by
+ * 	the nm_krings_create() callback.  All the nm_krings_create callbacks
+ * 	actually call netmap_krings_create() to perform this and the other
+ * 	common stuff. netmap_krings_create() also takes care of the host rings,
+ * 	if needed, by setting their sync callbacks appropriately.
+ *
+ * 	Additional actions depend on the kind of netmap_adapter that has been
+ * 	registered:
+ *
+ * 	- netmap_hw_adapter:  	     [netmap.c]
+ * 	     This is a system netdev/ifp with native netmap support.
+ * 	     The ifp is detached from the host stack by redirecting:
+ * 	       - transmissions (from the network stack) to netmap_transmit()
+ * 	       - receive notifications to the nm_notify() callback for
+ * 	         this adapter. The callback is normally netmap_notify(), unless
+ * 	         the ifp is attached to a bridge using bwrap, in which case it
+ * 	         is netmap_bwrap_intr_notify().
+ *
+ * 	- netmap_generic_adapter:      [netmap_generic.c]
+ * 	      A system netdev/ifp without native netmap support.
+ *
+ * 	(the decision about native/non native support is taken in
+ * 	 netmap_get_hw_na(), called by netmap_get_na())
+ *
+ * 	- netmap_vp_adapter 		[netmap_vale.c]
+ * 	      Returned by netmap_get_bdg_na().
+ * 	      This is a persistent or ephemeral VALE port. Ephemeral ports
+ * 	      are created on the fly if they don't already exist, and are
+ * 	      always attached to a bridge.
+ * 	      Persistent VALE ports must must be created seperately, and i
+ * 	      then attached like normal NICs. The NIOCREGIF we are examining
+ * 	      will find them only if they had previosly been created and
+ * 	      attached (see VALE_CTL below).
+ *
+ * 	- netmap_pipe_adapter 	      [netmap_pipe.c]
+ * 	      Returned by netmap_get_pipe_na().
+ * 	      Both pipe ends are created, if they didn't already exist.
+ *
+ * 	- netmap_monitor_adapter      [netmap_monitor.c]
+ * 	      Returned by netmap_get_monitor_na().
+ * 	      If successful, the nm_sync callbacks of the monitored adapter
+ * 	      will be intercepted by the returned monitor.
+ *
+ * 	- netmap_bwrap_adapter	      [netmap_vale.c]
+ * 	      Cannot be obtained in this way, see VALE_CTL below
+ *
+ *
+ * 	os-specific:
+ * 	    linux: we first go through linux_netmap_ioctl() to
+ * 	           adapt the FreeBSD interface to the linux one.
+ *
+ *
+ * > 3. on each descriptor, the process issues an mmap() request to
+ * >    map the shared memory region within the process' address space.
+ * >    The list of interesting queues is indicated by a location in
+ * >    the shared memory region.
+ *
+ *      os-specific:
+ *  	    FreeBSD: netmap_mmap_single (netmap_freebsd.c).
+ *  	    linux:   linux_netmap_mmap (netmap_linux.c).
+ *
+ * > 4. using the functions in the netmap(4) userspace API, a process
+ * >    can look up the occupation state of a queue, access memory buffers,
+ * >    and retrieve received packets or enqueue packets to transmit.
+ *
+ * 	these actions do not involve the kernel.
+ *
+ * > 5. using some ioctl()s the process can synchronize the userspace view
+ * >    of the queue with the actual status in the kernel. This includes both
+ * >    receiving the notification of new packets, and transmitting new
+ * >    packets on the output interface.
+ *
+ * 	These are implemented in netmap_ioctl(), NIOCTXSYNC and NIOCRXSYNC
+ * 	cases. They invoke the nm_sync callbacks on the netmap_kring
+ * 	structures, as initialized in step 2 and maybe later modified
+ * 	by a monitor. Monitors, however, will always call the original
+ * 	callback before doing anything else.
+ *
+ *
+ * > 6. select() or poll() can be used to wait for events on individual
+ * >    transmit or receive queues (or all queues for a given interface).
+ *
+ * 	Implemented in netmap_poll(). This will call the same nm_sync()
+ * 	callbacks as in step 5 above.
+ *
+ * 	os-specific:
+ * 		linux: we first go through linux_netmap_poll() to adapt
+ * 		       the FreeBSD interface to the linux one.
+ *
+ *
+ *  ----  VALE_CTL -----
+ *
+ *  VALE switches are controlled by issuing a NIOCREGIF with a non-null
+ *  nr_cmd in the nmreq structure. These subcommands are handled by
+ *  netmap_bdg_ctl() in netmap_vale.c. Persistent VALE ports are created
+ *  and destroyed by issuing the NETMAP_BDG_NEWIF and NETMAP_BDG_DELIF
+ *  subcommands, respectively.
+ *
+ *  Any network interface known to the system (including a persistent VALE
+ *  port) can be attached to a VALE switch by issuing the
+ *  NETMAP_BDG_ATTACH subcommand. After the attachment, persistent VALE ports
+ *  look exactly like ephemeral VALE ports (as created in step 2 above).  The
+ *  attachment of other interfaces, instead, requires the creation of a
+ *  netmap_bwrap_adapter.  Moreover, the attached interface must be put in
+ *  netmap mode. This may require the creation of a netmap_generic_adapter if
+ *  we have no native support for the interface, or if generic adapters have
+ *  been forced by sysctl.
+ *
+ *  Both persistent VALE ports and bwraps are handled by netmap_get_bdg_na(),
+ *  called by nm_bdg_ctl_attach(), and discriminated by the nm_bdg_attach()
+ *  callback.  In the case of the bwrap, the callback creates the
+ *  netmap_bwrap_adapter.  The initialization of the bwrap is then
+ *  completed by calling netmap_do_regif() on it, in the nm_bdg_ctl()
+ *  callback (netmap_bwrap_bdg_ctl in netmap_vale.c).
+ *  A generic adapter for the wrapped ifp will be created if needed, when
+ *  netmap_get_bdg_na() calls netmap_get_hw_na().
+ *
+ *
+ *  ---- DATAPATHS -----
+ *
+ *              -= SYSTEM DEVICE WITH NATIVE SUPPORT =-
+ *
+ *    na == NA(ifp) == netmap_hw_adapter created in DEVICE_netmap_attach()
+ *
+ *    - tx from netmap userspace:
+ *	 concurrently:
+ *           1) ioctl(NIOCTXSYNC)/netmap_poll() in process context
+ *                kring->nm_sync() == DEVICE_netmap_txsync()
+ *           2) device interrupt handler
+ *                na->nm_notify()  == netmap_notify()
+ *    - rx from netmap userspace:
+ *       concurrently:
+ *           1) ioctl(NIOCRXSYNC)/netmap_poll() in process context
+ *                kring->nm_sync() == DEVICE_netmap_rxsync()
+ *           2) device interrupt handler
+ *                na->nm_notify()  == netmap_notify()
+ *    - tx from host stack
+ *       concurrently:
+ *           1) host stack
+ *                netmap_transmit()
+ *                  na->nm_notify  == netmap_notify()
+ *           2) ioctl(NIOCRXSYNC)/netmap_poll() in process context
+ *                kring->nm_sync() == netmap_rxsync_from_host_compat
+ *                  netmap_rxsync_from_host(na, NULL, NULL)
+ *    - tx to host stack
+ *           ioctl(NIOCTXSYNC)/netmap_poll() in process context
+ *             kring->nm_sync() == netmap_txsync_to_host_compat
+ *               netmap_txsync_to_host(na)
+ *                 NM_SEND_UP()
+ *                   FreeBSD: na->if_input() == ?? XXX
+ *                   linux: netif_rx() with NM_MAGIC_PRIORITY_RX
+ *
+ *
+ *
+ *               -= SYSTEM DEVICE WITH GENERIC SUPPORT =-
+ *
+ *
+ *
+ *                           -= VALE PORT =-
+ *
+ *
+ *
+ *                           -= NETMAP PIPE =-
+ *
+ *
+ *
+ *  -= SYSTEM DEVICE WITH NATIVE SUPPORT, CONNECTED TO VALE, NO HOST RINGS =-
+ *
+ *
+ *
+ *  -= SYSTEM DEVICE WITH NATIVE SUPPORT, CONNECTED TO VALE, WITH HOST RINGS =-
+ *
+ *
+ *
+ *  -= SYSTEM DEVICE WITH GENERIC SUPPORT, CONNECTED TO VALE, NO HOST RINGS =-
+ *
+ *
+ *
+ *  -= SYSTEM DEVICE WITH GENERIC SUPPORT, CONNECTED TO VALE, WITH HOST RINGS =-
+ *
+ *
+ *
+ */
+
 /*
  * OS-specific code that is used only within this file.
  * Other OS-specific code that must be accessed by drivers
@@ -218,6 +435,10 @@ int netmap_txsync_retry = 2;
 SYSCTL_INT(_dev_netmap, OID_AUTO, txsync_retry, CTLFLAG_RW,
     &netmap_txsync_retry, 0 , "Number of txsync loops in bridge's flush.");
 
+int netmap_adaptive_io = 0;
+SYSCTL_INT(_dev_netmap, OID_AUTO, adaptive_io, CTLFLAG_RW,
+    &netmap_adaptive_io, 0 , "Adaptive I/O on paravirt");
+
 int netmap_flags = 0;	/* debug flags */
 int netmap_fwd = 0;	/* force transparent mode */
 int netmap_mmap_unreg = 0; /* allow mmap of unregistered fds */
@@ -259,7 +480,7 @@ nm_kr_get(struct netmap_kring *kr)
  * mark the ring as stopped, and run through the locks
  * to make sure other users get to see it.
  */
-void
+static void
 netmap_disable_ring(struct netmap_kring *kr)
 {
 	kr->nkr_stopped = 1;
@@ -269,41 +490,59 @@ netmap_disable_ring(struct netmap_kring *kr)
 	nm_kr_put(kr);
 }
 
+/* stop or enable a single tx ring */
+void
+netmap_set_txring(struct netmap_adapter *na, u_int ring_id, int stopped)
+{
+	if (stopped)
+		netmap_disable_ring(na->tx_rings + ring_id);
+	else
+		na->tx_rings[ring_id].nkr_stopped = 0;
+	/* nofify that the stopped state has changed. This is currently
+	 *only used by bwrap to propagate the state to its own krings.
+	 * (see netmap_bwrap_intr_notify).
+	 */
+	na->nm_notify(na, ring_id, NR_TX, NAF_DISABLE_NOTIFY);
+}
+
+/* stop or enable a single rx ring */
+void
+netmap_set_rxring(struct netmap_adapter *na, u_int ring_id, int stopped)
+{
+	if (stopped)
+		netmap_disable_ring(na->rx_rings + ring_id);
+	else
+		na->rx_rings[ring_id].nkr_stopped = 0;
+	/* nofify that the stopped state has changed. This is currently
+	 *only used by bwrap to propagate the state to its own krings.
+	 * (see netmap_bwrap_intr_notify).
+	 */
+	na->nm_notify(na, ring_id, NR_RX, NAF_DISABLE_NOTIFY);
+}
+
 
 /* stop or enable all the rings of na */
-static void
-netmap_set_all_rings(struct ifnet *ifp, int stopped)
+void
+netmap_set_all_rings(struct netmap_adapter *na, int stopped)
 {
-	struct netmap_adapter *na;
 	int i;
 	u_int ntx, nrx;
 
-	if (!(ifp->if_capenable & IFCAP_NETMAP))
+	if (!nm_netmap_on(na))
 		return;
 
-	na = NA(ifp);
-
 	ntx = netmap_real_tx_rings(na);
 	nrx = netmap_real_rx_rings(na);
 
 	for (i = 0; i < ntx; i++) {
-		if (stopped)
-			netmap_disable_ring(na->tx_rings + i);
-		else
-			na->tx_rings[i].nkr_stopped = 0;
-		na->nm_notify(na, i, NR_TX, NAF_DISABLE_NOTIFY);
+		netmap_set_txring(na, i, stopped);
 	}
 
 	for (i = 0; i < nrx; i++) {
-		if (stopped)
-			netmap_disable_ring(na->rx_rings + i);
-		else
-			na->rx_rings[i].nkr_stopped = 0;
-		na->nm_notify(na, i, NR_RX, NAF_DISABLE_NOTIFY);
+		netmap_set_rxring(na, i, stopped);
 	}
 }
 
-
 /*
  * Convenience function used in drivers.  Waits for current txsync()s/rxsync()s
  * to finish and prevents any new one from starting.  Call this before turning
@@ -314,10 +553,9 @@ netmap_set_all_rings(struct ifnet *ifp, int stopped)
 void
 netmap_disable_all_rings(struct ifnet *ifp)
 {
-	netmap_set_all_rings(ifp, 1 /* stopped */);
+	netmap_set_all_rings(NA(ifp), 1 /* stopped */);
 }
 
-
 /*
  * Convenience function used in drivers.  Re-enables rxsync and txsync on the
  * adapter's rings In linux drivers, this should be placed near each
@@ -326,7 +564,7 @@ netmap_disable_all_rings(struct ifnet *ifp)
 void
 netmap_enable_all_rings(struct ifnet *ifp)
 {
-	netmap_set_all_rings(ifp, 0 /* enabled */);
+	netmap_set_all_rings(NA(ifp), 0 /* enabled */);
 }
 
 
@@ -410,7 +648,6 @@ nm_dump_buf(char *p, int len, int lim, char *dst)
 int
 netmap_update_config(struct netmap_adapter *na)
 {
-	struct ifnet *ifp = na->ifp;
 	u_int txr, txd, rxr, rxd;
 
 	txr = txd = rxr = rxd = 0;
@@ -429,11 +666,11 @@ netmap_update_config(struct netmap_adapter *na)
 		return 0; /* nothing changed */
 	if (netmap_verbose || na->active_fds > 0) {
 		D("stored config %s: txring %d x %d, rxring %d x %d",
-			NM_IFPNAME(ifp),
+			na->name,
 			na->num_tx_rings, na->num_tx_desc,
 			na->num_rx_rings, na->num_rx_desc);
 		D("new config %s: txring %d x %d, rxring %d x %d",
-			NM_IFPNAME(ifp), txr, txd, rxr, rxd);
+			na->name, txr, txd, rxr, rxd);
 	}
 	if (na->active_fds == 0) {
 		D("configuration changed (but fine)");
@@ -447,20 +684,6 @@ netmap_update_config(struct netmap_adapter *na)
 	return 1;
 }
 
-static int
-netmap_txsync_compat(struct netmap_kring *kring, int flags)
-{
-	struct netmap_adapter *na = kring->na;
-	return na->nm_txsync(na, kring->ring_id, flags);
-}
-
-static int
-netmap_rxsync_compat(struct netmap_kring *kring, int flags)
-{
-	struct netmap_adapter *na = kring->na;
-	return na->nm_rxsync(na, kring->ring_id, flags);
-}
-
 /* kring->nm_sync callback for the host tx ring */
 static int
 netmap_txsync_to_host_compat(struct netmap_kring *kring, int flags)
@@ -538,7 +761,7 @@ netmap_krings_create(struct netmap_adapter *na, u_int tailroom)
 		kring->ring_id = i;
 		kring->nkr_num_slots = ndesc;
 		if (i < na->num_tx_rings) {
-			kring->nm_sync = netmap_txsync_compat; // XXX
+			kring->nm_sync = na->nm_txsync;
 		} else if (i == na->num_tx_rings) {
 			kring->nm_sync = netmap_txsync_to_host_compat;
 		}
@@ -547,7 +770,7 @@ netmap_krings_create(struct netmap_adapter *na, u_int tailroom)
 		 */
 		kring->rhead = kring->rcur = kring->nr_hwcur = 0;
 		kring->rtail = kring->nr_hwtail = ndesc - 1;
-		snprintf(kring->name, sizeof(kring->name) - 1, "%s TX%d", NM_IFPNAME(na->ifp), i);
+		snprintf(kring->name, sizeof(kring->name) - 1, "%s TX%d", na->name, i);
 		ND("ktx %s h %d c %d t %d",
 			kring->name, kring->rhead, kring->rcur, kring->rtail);
 		mtx_init(&kring->q_lock, "nm_txq_lock", NULL, MTX_DEF);
@@ -562,13 +785,13 @@ netmap_krings_create(struct netmap_adapter *na, u_int tailroom)
 		kring->ring_id = i;
 		kring->nkr_num_slots = ndesc;
 		if (i < na->num_rx_rings) {
-			kring->nm_sync = netmap_rxsync_compat; // XXX
+			kring->nm_sync = na->nm_rxsync;
 		} else if (i == na->num_rx_rings) {
 			kring->nm_sync = netmap_rxsync_from_host_compat;
 		}
 		kring->rhead = kring->rcur = kring->nr_hwcur = 0;
 		kring->rtail = kring->nr_hwtail = 0;
-		snprintf(kring->name, sizeof(kring->name) - 1, "%s RX%d", NM_IFPNAME(na->ifp), i);
+		snprintf(kring->name, sizeof(kring->name) - 1, "%s RX%d", na->name, i);
 		ND("krx %s h %d c %d t %d",
 			kring->name, kring->rhead, kring->rcur, kring->rtail);
 		mtx_init(&kring->q_lock, "nm_rxq_lock", NULL, MTX_DEF);
@@ -624,7 +847,7 @@ netmap_hw_krings_delete(struct netmap_adapter *na)
  */
 /* call with NMG_LOCK held */
 static struct netmap_if*
-netmap_if_new(const char *ifname, struct netmap_adapter *na)
+netmap_if_new(struct netmap_adapter *na)
 {
 	struct netmap_if *nifp;
 
@@ -641,7 +864,7 @@ netmap_if_new(const char *ifname, struct netmap_adapter *na)
 	 * the netmap rings themselves
 	 */
 	if (na->nm_krings_create(na))
-		goto cleanup;
+		return NULL;
 
 	/* create all missing netmap rings */
 	if (netmap_mem_rings_create(na))
@@ -650,7 +873,7 @@ netmap_if_new(const char *ifname, struct netmap_adapter *na)
 final:
 
 	/* in all cases, create a new netmap if */
-	nifp = netmap_mem_if_new(ifname, na);
+	nifp = netmap_mem_if_new(na);
 	if (nifp == NULL)
 		goto cleanup;
 
@@ -689,7 +912,7 @@ netmap_get_memory_locked(struct netmap_priv_d* p)
 		nmd = p->np_na->nm_mem;
 	}
 	if (p->np_mref == NULL) {
-		error = netmap_mem_finalize(nmd);
+		error = netmap_mem_finalize(nmd, p->np_na);
 		if (!error)
 			p->np_mref = nmd;
 	} else if (p->np_mref != nmd) {
@@ -728,17 +951,15 @@ static void
 netmap_drop_memory_locked(struct netmap_priv_d* p)
 {
 	if (p->np_mref) {
-		netmap_mem_deref(p->np_mref);
+		netmap_mem_deref(p->np_mref, p->np_na);
 		p->np_mref = NULL;
 	}
 }
 
 
 /*
- * File descriptor's private data destructor.
- *
  * Call nm_register(ifp,0) to stop netmap mode on the interface and
- * revert to normal operation. We expect that np_na->ifp has not gone.
+ * revert to normal operation.
  * The second argument is the nifp to work on. In some cases it is
  * not attached yet to the netmap_priv_d so we need to pass it as
  * a separate argument.
@@ -748,14 +969,13 @@ static void
 netmap_do_unregif(struct netmap_priv_d *priv, struct netmap_if *nifp)
 {
 	struct netmap_adapter *na = priv->np_na;
-	struct ifnet *ifp = na->ifp;
 
 	NMG_LOCK_ASSERT();
 	na->active_fds--;
 	if (na->active_fds <= 0) {	/* last instance */
 
 		if (netmap_verbose)
-			D("deleting last instance for %s", NM_IFPNAME(ifp));
+			D("deleting last instance for %s", na->name);
 		/*
 		 * (TO CHECK) This function is only called
 		 * when the last reference to this file descriptor goes
@@ -770,8 +990,7 @@ netmap_do_unregif(struct netmap_priv_d *priv, struct netmap_if *nifp)
 		 * happens if the close() occurs while a concurrent
 		 * syscall is running.
 		 */
-		if (ifp)
-			na->nm_register(na, 0); /* off, clear flags */
+		na->nm_register(na, 0); /* off, clear flags */
 		/* Wake up any sleeping threads. netmap_poll will
 		 * then return POLLERR
 		 * XXX The wake up now must happen during *_down(), when
@@ -922,13 +1141,13 @@ netmap_grab_packets(struct netmap_kring *kring, struct mbq *q, int force)
 
 		if ((slot->flags & NS_FORWARD) == 0 && !force)
 			continue;
-		if (slot->len < 14 || slot->len > NETMAP_BDG_BUF_SIZE(na->nm_mem)) {
+		if (slot->len < 14 || slot->len > NETMAP_BUF_SIZE(na)) {
 			RD(5, "bad pkt at %d len %d", n, slot->len);
 			continue;
 		}
 		slot->flags &= ~NS_FORWARD; // XXX needed ?
 		/* XXX TODO: adapt to the case of a multisegment packet */
-		m = m_devget(BDG_NMB(na, slot), slot->len, 0, na->ifp, NULL);
+		m = m_devget(NMB(na, slot), slot->len, 0, na->ifp, NULL);
 
 		if (m == NULL)
 			break;
@@ -981,7 +1200,7 @@ netmap_sw_to_nic(struct netmap_adapter *na)
 			dst->len = tmp.len;
 			dst->flags = NS_BUF_CHANGED;
 
-			rdst->head = rdst->cur = nm_next(dst_cur, dst_lim);
+			rdst->cur = nm_next(dst_cur, dst_lim);
 		}
 		/* if (sent) XXX txsync ? */
 	}
@@ -1028,6 +1247,11 @@ netmap_txsync_to_host(struct netmap_adapter *na)
  * They have been put in kring->rx_queue by netmap_transmit().
  * We protect access to the kring using kring->rx_queue.lock
  *
+ * This routine also does the selrecord if called from the poll handler
+ * (we know because td != NULL).
+ *
+ * NOTE: on linux, selrecord() is defined as a macro and uses pwait
+ *     as an additional hidden argument.
  * returns the number of packets delivered to tx queues in
  * transparent mode, or a negative value if error
  */
@@ -1059,14 +1283,15 @@ netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwai
 			int len = MBUF_LEN(m);
 			struct netmap_slot *slot = &ring->slot[nm_i];
 
-			m_copydata(m, 0, len, BDG_NMB(na, slot));
+			m_copydata(m, 0, len, NMB(na, slot));
 			ND("nm %d len %d", nm_i, len);
 			if (netmap_verbose)
-                                D("%s", nm_dump_buf(BDG_NMB(na, slot),len, 128, NULL));
+                                D("%s", nm_dump_buf(NMB(na, slot),len, 128, NULL));
 
 			slot->len = len;
 			slot->flags = kring->nkr_slot_flags;
 			nm_i = nm_next(nm_i, lim);
+			m_freem(m);
 		}
 		kring->nr_hwtail = nm_i;
 	}
@@ -1083,6 +1308,10 @@ netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwai
 
 	nm_rxsync_finalize(kring);
 
+	/* access copies of cur,tail in the kring */
+	if (kring->rcur == kring->rtail && td) /* no bufs available */
+		selrecord(td, &kring->si);
+
 	mbq_unlock(q);
 	return ret;
 }
@@ -1128,21 +1357,23 @@ netmap_get_hw_na(struct ifnet *ifp, struct netmap_adapter **na)
 		i = netmap_admode = NETMAP_ADMODE_BEST;
 
 	if (NETMAP_CAPABLE(ifp)) {
-		/* If an adapter already exists, but is
-		 * attached to a vale port, we report that the
-		 * port is busy.
-		 */
-		if (NETMAP_OWNED_BY_KERN(NA(ifp)))
-			return EBUSY;
-
+		prev_na = NA(ifp);
 		/* If an adapter already exists, return it if
 		 * there are active file descriptors or if
 		 * netmap is not forced to use generic
 		 * adapters.
 		 */
-		if (NA(ifp)->active_fds > 0 ||
-				i != NETMAP_ADMODE_GENERIC) {
-			*na = NA(ifp);
+		if (NETMAP_OWNED_BY_ANY(prev_na)
+			|| i != NETMAP_ADMODE_GENERIC
+			|| prev_na->na_flags & NAF_FORCE_NATIVE
+#ifdef WITH_PIPES
+			/* ugly, but we cannot allow an adapter switch
+			 * if some pipe is referring to this one
+			 */
+			|| prev_na->na_next_pipe > 0
+#endif
+		) {
+			*na = prev_na;
 			return 0;
 		}
 	}
@@ -1212,13 +1443,30 @@ netmap_get_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 
 	*na = NULL;     /* default return value */
 
-	/* first try to see if this is a bridge port. */
 	NMG_LOCK_ASSERT();
 
+	/* we cascade through all possibile types of netmap adapter.
+	 * All netmap_get_*_na() functions return an error and an na,
+	 * with the following combinations:
+	 *
+	 * error    na
+	 *   0	   NULL		type doesn't match
+	 *  !0	   NULL		type matches, but na creation/lookup failed
+	 *   0	  !NULL		type matches and na created/found
+	 *  !0    !NULL		impossible
+	 */
+
+	/* try to see if this is a monitor port */
+	error = netmap_get_monitor_na(nmr, na, create);
+	if (error || *na != NULL)
+		return error;
+
+	/* try to see if this is a pipe port */
 	error = netmap_get_pipe_na(nmr, na, create);
 	if (error || *na != NULL)
 		return error;
 
+	/* try to see if this is a bridge port */
 	error = netmap_get_bdg_na(nmr, na, create);
 	if (error)
 		return error;
@@ -1241,11 +1489,6 @@ netmap_get_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 	if (error)
 		goto out;
 
-	/* Users cannot use the NIC attached to a bridge directly */
-	if (NETMAP_OWNED_BY_KERN(ret)) {
-		error = EBUSY;
-		goto out;
-	}
 	*na = ret;
 	netmap_adapter_get(ret);
 
@@ -1444,7 +1687,7 @@ netmap_ring_reinit(struct netmap_kring *kring)
 	int errors = 0;
 
 	// XXX KASSERT nm_kr_tryget
-	RD(10, "called for %s", NM_IFPNAME(kring->na->ifp));
+	RD(10, "called for %s", kring->name);
 	// XXX probably wrong to trust userspace
 	kring->rhead = ring->head;
 	kring->rcur  = ring->cur;
@@ -1463,7 +1706,7 @@ netmap_ring_reinit(struct netmap_kring *kring)
 			RD(5, "bad index at slot %d idx %d len %d ", i, idx, len);
 			ring->slot[i].buf_idx = 0;
 			ring->slot[i].len = 0;
-		} else if (len > NETMAP_BDG_BUF_SIZE(kring->na->nm_mem)) {
+		} else if (len > NETMAP_BUF_SIZE(kring->na)) {
 			ring->slot[i].len = 0;
 			RD(5, "bad len at slot %d idx %d len %d", i, idx, len);
 		}
@@ -1481,13 +1724,15 @@ netmap_ring_reinit(struct netmap_kring *kring)
 	return (errors ? 1 : 0);
 }
 
-
-/*
- * Set the ring ID. For devices with a single queue, a request
- * for all rings is the same as a single ring.
+/* interpret the ringid and flags fields of an nmreq, by translating them
+ * into a pair of intervals of ring indices:
+ *
+ * [priv->np_txqfirst, priv->np_txqlast) and
+ * [priv->np_rxqfirst, priv->np_rxqlast)
+ *
  */
-static int
-netmap_set_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags)
+int
+netmap_interp_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags)
 {
 	struct netmap_adapter *na = priv->np_na;
 	u_int j, i = ringid & NETMAP_RING_MASK;
@@ -1551,15 +1796,11 @@ netmap_set_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags)
 		D("invalid regif type %d", reg);
 		return EINVAL;
 	}
-	priv->np_txpoll = (ringid & NETMAP_NO_TX_POLL) ? 0 : 1;
 	priv->np_flags = (flags & ~NR_REG_MASK) | reg;
-	if (nm_tx_si_user(priv))
-		na->tx_si_users++;
-	if (nm_rx_si_user(priv))
-		na->rx_si_users++;
+
 	if (netmap_verbose) {
 		D("%s: tx [%d,%d) rx [%d,%d) id %d",
-			NM_IFPNAME(na->ifp),
+			na->name,
 			priv->np_txqfirst,
 			priv->np_txqlast,
 			priv->np_rxqfirst,
@@ -1569,16 +1810,113 @@ netmap_set_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags)
 	return 0;
 }
 
+
+/*
+ * Set the ring ID. For devices with a single queue, a request
+ * for all rings is the same as a single ring.
+ */
+static int
+netmap_set_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags)
+{
+	struct netmap_adapter *na = priv->np_na;
+	int error;
+
+	error = netmap_interp_ringid(priv, ringid, flags);
+	if (error) {
+		return error;
+	}
+
+	priv->np_txpoll = (ringid & NETMAP_NO_TX_POLL) ? 0 : 1;
+
+	/* optimization: count the users registered for more than
+	 * one ring, which are the ones sleeping on the global queue.
+	 * The default netmap_notify() callback will then
+	 * avoid signaling the global queue if nobody is using it
+	 */
+	if (nm_tx_si_user(priv))
+		na->tx_si_users++;
+	if (nm_rx_si_user(priv))
+		na->rx_si_users++;
+	return 0;
+}
+
 /*
  * possibly move the interface to netmap-mode.
  * If success it returns a pointer to netmap_if, otherwise NULL.
  * This must be called with NMG_LOCK held.
+ *
+ * The following na callbacks are called in the process:
+ *
+ * na->nm_config()			[by netmap_update_config]
+ * (get current number and size of rings)
+ *
+ *  	We have a generic one for linux (netmap_linux_config).
+ *  	The bwrap has to override this, since it has to forward
+ *  	the request to the wrapped adapter (netmap_bwrap_config).
+ *
+ *    	XXX netmap_if_new calls this again (2014-03-15)
+ *
+ * na->nm_krings_create()		[by netmap_if_new]
+ * (create and init the krings array)
+ *
+ * 	One of the following:
+ *
+ *	* netmap_hw_krings_create, 			(hw ports)
+ *		creates the standard layout for the krings
+ * 		and adds the mbq (used for the host rings).
+ *
+ * 	* netmap_vp_krings_create			(VALE ports)
+ * 		add leases and scratchpads
+ *
+ * 	* netmap_pipe_krings_create			(pipes)
+ * 		create the krings and rings of both ends and
+ * 		cross-link them
+ *
+ *      * netmap_monitor_krings_create 			(monitors)
+ *      	avoid allocating the mbq
+ *
+ *      * netmap_bwrap_krings_create			(bwraps)
+ *      	create both the brap krings array,
+ *      	the krings array of the wrapped adapter, and
+ *      	(if needed) the fake array for the host adapter
+ *
+ * na->nm_register(, 1)
+ * (put the adapter in netmap mode)
+ *
+ * 	This may be one of the following:
+ * 	(XXX these should be either all *_register or all *_reg 2014-03-15)
+ *
+ * 	* netmap_hw_register				(hw ports)
+ * 		checks that the ifp is still there, then calls
+ * 		the hardware specific callback;
+ *
+ * 	* netmap_vp_reg					(VALE ports)
+ *		If the port is connected to a bridge,
+ *		set the NAF_NETMAP_ON flag under the
+ *		bridge write lock.
+ *
+ *	* netmap_pipe_reg				(pipes)
+ *		inform the other pipe end that it is no
+ *		longer responsibile for the lifetime of this
+ *		pipe end
+ *
+ *	* netmap_monitor_reg				(monitors)
+ *		intercept the sync callbacks of the monitored
+ *		rings
+ *
+ *	* netmap_bwrap_register				(bwraps)
+ *		cross-link the bwrap and hwna rings,
+ *		forward the request to the hwna, override
+ *		the hwna notify callback (to get the frames
+ *		coming from outside go through the bridge).
+ *
+ * XXX maybe netmap_if_new() should be merged with this (2014-03-15).
+ *
  */
 struct netmap_if *
 netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
 	uint16_t ringid, uint32_t flags, int *err)
 {
-	struct ifnet *ifp = na->ifp;
 	struct netmap_if *nifp = NULL;
 	int error, need_mem = 0;
 
@@ -1597,24 +1935,22 @@ netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
 		if (error)
 			goto out;
 	}
-	nifp = netmap_if_new(NM_IFPNAME(ifp), na);
-
 	/* Allocate a netmap_if and, if necessary, all the netmap_ring's */
+	nifp = netmap_if_new(na);
 	if (nifp == NULL) { /* allocation failed */
 		error = ENOMEM;
 		goto out;
 	}
 	na->active_fds++;
-	if (ifp->if_capenable & IFCAP_NETMAP) {
-		/* was already set */
-	} else {
-		/* Otherwise set the card in netmap mode
+	if (!nm_netmap_on(na)) {
+		/* Netmap not active, set the card in netmap mode
 		 * and make it use the shared buffers.
 		 */
 		/* cache the allocator info in the na */
-		na->na_lut = na->nm_mem->pools[NETMAP_BUF_POOL].lut;
+		na->na_lut = netmap_mem_get_lut(na->nm_mem);
 		ND("%p->na_lut == %p", na, na->na_lut);
-		na->na_lut_objtotal = na->nm_mem->pools[NETMAP_BUF_POOL].objtotal;
+		na->na_lut_objtotal = netmap_mem_get_buftotal(na->nm_mem);
+		na->na_lut_objsize = netmap_mem_get_bufsize(na->nm_mem);
 		error = na->nm_register(na, 1); /* mode on */
 		if (error) {
 			netmap_do_unregif(priv, nifp);
@@ -1624,12 +1960,12 @@ netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
 out:
 	*err = error;
 	if (error) {
-		priv->np_na = NULL;
 		/* we should drop the allocator, but only
 		 * if we were the ones who grabbed it
 		 */
 		if (need_mem)
 			netmap_drop_memory_locked(priv);
+		priv->np_na = NULL;
 	}
 	if (nifp != NULL) {
 		/*
@@ -1662,7 +1998,6 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 	int fflag, struct thread *td)
 {
 	struct netmap_priv_d *priv = NULL;
-	struct ifnet *ifp = NULL;
 	struct nmreq *nmr = (struct nmreq *) data;
 	struct netmap_adapter *na = NULL;
 	int error;
@@ -1740,7 +2075,9 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 		/* possibly attach/detach NIC and VALE switch */
 		i = nmr->nr_cmd;
 		if (i == NETMAP_BDG_ATTACH || i == NETMAP_BDG_DETACH
-				|| i == NETMAP_BDG_VNET_HDR) {
+				|| i == NETMAP_BDG_VNET_HDR
+				|| i == NETMAP_BDG_NEWIF
+				|| i == NETMAP_BDG_DELIF) {
 			error = netmap_bdg_ctl(nmr, NULL);
 			break;
 		} else if (i != 0) {
@@ -1762,7 +2099,6 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 			error = netmap_get_na(nmr, &na, 1 /* create */); /* keep reference */
 			if (error)
 				break;
-			ifp = na->ifp;
 			if (NETMAP_OWNED_BY_KERN(na)) {
 				netmap_adapter_put(na);
 				error = EBUSY;
@@ -1824,9 +2160,7 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 			break;
 		}
 
-		ifp = na->ifp;
-		if (ifp == NULL) {
-			RD(1, "the ifp is gone");
+		if (!nm_netmap_on(na)) {
 			error = ENXIO;
 			break;
 		}
@@ -1870,6 +2204,9 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 
 		break;
 
+	case NIOCCONFIG:
+		error = netmap_bdg_config(nmr);
+		break;
 #ifdef __FreeBSD__
 	case FIONBIO:
 	case FIOASYNC:
@@ -1886,6 +2223,7 @@ netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
 	default:	/* allow device-specific ioctls */
 	    {
 		struct socket so;
+		struct ifnet *ifp;
 
 		bzero(&so, sizeof(so));
 		NMG_LOCK();
@@ -1935,7 +2273,6 @@ netmap_poll(struct cdev *dev, int events, struct thread *td)
 {
 	struct netmap_priv_d *priv = NULL;
 	struct netmap_adapter *na;
-	struct ifnet *ifp;
 	struct netmap_kring *kring;
 	u_int i, check_all_tx, check_all_rx, want_tx, want_rx, revents = 0;
 	struct mbq q;		/* packets from hw queues to host stack */
@@ -1974,18 +2311,12 @@ netmap_poll(struct cdev *dev, int events, struct thread *td)
 	rmb(); /* make sure following reads are not from cache */
 
 	na = priv->np_na;
-	ifp = na->ifp;
-	// check for deleted
-	if (ifp == NULL) {
-		RD(1, "the ifp is gone");
-		return POLLERR;
-	}
 
-	if ( (ifp->if_capenable & IFCAP_NETMAP) == 0)
+	if (!nm_netmap_on(na))
 		return POLLERR;
 
 	if (netmap_verbose & 0x8000)
-		D("device %s events 0x%x", NM_IFPNAME(ifp), events);
+		D("device %s events 0x%x", na->name, events);
 	want_tx = events & (POLLOUT | POLLWRNORM);
 	want_rx = events & (POLLIN | POLLRDNORM);
 
@@ -2056,7 +2387,6 @@ flush_tx:
 				 * be better. In current code, however, we only
 				 * stop the rings for brief intervals (2014-03-14)
 				 */
-
 				if (netmap_verbose)
 					RD(2, "%p lost race on txring %d, ok",
 					    priv, i);
@@ -2115,6 +2445,8 @@ do_retry_rx:
 			/*
 			 * transparent mode support: collect packets
 			 * from the rxring(s).
+			 * XXX NR_FORWARD should only be read on
+			 * physical or NIC ports
 			 */
 			if (netmap_fwd ||kring->ring->flags & NR_FORWARD) {
 				ND(10, "forwarding some buffers up %d to %d",
@@ -2141,12 +2473,13 @@ do_retry_rx:
 		/* transparent mode XXX only during first pass ? */
 		if (na->na_flags & NAF_HOST_RINGS) {
 			kring = &na->rx_rings[na->num_rx_rings];
-			if (netmap_fwd || kring->ring->flags & NR_FORWARD) {
-				send_down = netmap_rxsync_from_host(na, td, dev);
-				if (send_down && (netmap_no_timestamp == 0 ||
-				    kring->ring->flags & NR_TIMESTAMP)) {
-					microtime(&kring->ring->ts);
-				}
+			if (check_all_rx
+			    && (netmap_fwd || kring->ring->flags & NR_FORWARD)) {
+				/* XXX fix to use kring fields */
+				if (nm_ring_empty(kring->ring))
+					send_down = netmap_rxsync_from_host(na, td, dev);
+				if (!nm_ring_empty(kring->ring))
+					revents |= want_rx;
 			}
 		}
 
@@ -2174,7 +2507,7 @@ do_retry_rx:
  	 * rings to a single file descriptor.
 	 */
 
-	if (q.head)
+	if (q.head && na->ifp != NULL)
 		netmap_send_up(na->ifp, &q);
 
 	return (revents);
@@ -2224,19 +2557,27 @@ netmap_attach_common(struct netmap_adapter *na)
 
 	if (na->num_tx_rings == 0 || na->num_rx_rings == 0) {
 		D("%s: invalid rings tx %d rx %d",
-			ifp->if_xname, na->num_tx_rings, na->num_rx_rings);
+			na->name, na->num_tx_rings, na->num_rx_rings);
 		return EINVAL;
 	}
-	WNA(ifp) = na;
+	/* ifp is NULL for virtual adapters (bwrap, non-persistent VALE ports,
+	 * pipes, monitors). For bwrap we actually have a non-null ifp for
+	 * use by the external modules, but that is set after this
+	 * function has been called.
+	 * XXX this is ugly, maybe split this function in two (2014-03-14)
+	 */
+	if (ifp != NULL) {
+		WNA(ifp) = na;
 
 	/* the following is only needed for na that use the host port.
 	 * XXX do we have something similar for linux ?
 	 */
 #ifdef __FreeBSD__
-	na->if_input = ifp->if_input; /* for netmap_send_up */
+		na->if_input = ifp->if_input; /* for netmap_send_up */
 #endif /* __FreeBSD__ */
 
-	NETMAP_SET_CAPABLE(ifp);
+		NETMAP_SET_CAPABLE(ifp);
+	}
 	if (na->nm_krings_create == NULL) {
 		/* we assume that we have been called by a driver,
 		 * since other port types all provide their own
@@ -2250,7 +2591,13 @@ netmap_attach_common(struct netmap_adapter *na)
 	na->active_fds = 0;
 
 	if (na->nm_mem == NULL)
+		/* use the global allocator */
 		na->nm_mem = &nm_mem;
+	if (na->nm_bdg_attach == NULL)
+		/* no special nm_bdg_attach callback. On VALE
+		 * attach, we need to interpose a bwrap
+		 */
+		na->nm_bdg_attach = netmap_bwrap_attach;
 	return 0;
 }
 
@@ -2273,6 +2620,28 @@ netmap_detach_common(struct netmap_adapter *na)
 	free(na, M_DEVBUF);
 }
 
+/* Wrapper for the register callback provided hardware drivers.
+ * na->ifp == NULL means the the driver module has been
+ * unloaded, so we cannot call into it.
+ * Note that module unloading, in our patched linux drivers,
+ * happens under NMG_LOCK and after having stopped all the
+ * nic rings (see netmap_detach). This provides sufficient
+ * protection for the other driver-provied callbacks
+ * (i.e., nm_config and nm_*xsync), that therefore don't need
+ * to wrapped.
+ */
+static int
+netmap_hw_register(struct netmap_adapter *na, int onoff)
+{
+	struct netmap_hw_adapter *hwna =
+		(struct netmap_hw_adapter*)na;
+
+	if (na->ifp == NULL)
+		return onoff ? ENXIO : 0;
+
+	return hwna->nm_hw_register(na, onoff);
+}
+
 
 /*
  * Initialize a ``netmap_adapter`` object created by driver on attach.
@@ -2298,6 +2667,9 @@ netmap_attach(struct netmap_adapter *arg)
 		goto fail;
 	hwna->up = *arg;
 	hwna->up.na_flags |= NAF_HOST_RINGS;
+	strncpy(hwna->up.name, ifp->if_xname, sizeof(hwna->up.name));
+	hwna->nm_hw_register = hwna->up.nm_register;
+	hwna->up.nm_register = netmap_hw_register;
 	if (netmap_attach_common(&hwna->up)) {
 		free(hwna, M_DEVBUF);
 		goto fail;
@@ -2314,10 +2686,20 @@ netmap_attach(struct netmap_adapter *arg)
 #endif
 	}
 	hwna->nm_ndo.ndo_start_xmit = linux_netmap_start_xmit;
+	if (ifp->ethtool_ops) {
+		hwna->nm_eto = *ifp->ethtool_ops;
+	}
+	hwna->nm_eto.set_ringparam = linux_netmap_set_ringparam;
+#ifdef ETHTOOL_SCHANNELS
+	hwna->nm_eto.set_channels = linux_netmap_set_channels;
+#endif
+	if (arg->nm_config == NULL) {
+		hwna->up.nm_config = netmap_linux_config;
+	}
 #endif /* linux */
 
 	D("success for %s tx %d/%d rx %d/%d queues/slots",
-		NM_IFPNAME(ifp),
+		hwna->up.name,
 		hwna->up.num_tx_rings, hwna->up.num_tx_desc,
 		hwna->up.num_rx_rings, hwna->up.num_rx_desc
 		);
@@ -2393,6 +2775,8 @@ netmap_detach(struct ifnet *ifp)
 		 * tell them that the interface is gone
 		 */
 		na->ifp = NULL;
+		// XXX also clear NAF_NATIVE_ON ?
+		na->na_flags &= ~NAF_NETMAP_ON;
 		/* give them a chance to notice */
 		netmap_enable_all_rings(ifp);
 	}
@@ -2426,8 +2810,8 @@ netmap_transmit(struct ifnet *ifp, struct mbuf *m)
 	// if we follow the down/configure/up protocol -gl
 	// mtx_lock(&na->core_lock);
 
-	if ( (ifp->if_capenable & IFCAP_NETMAP) == 0) {
-		D("%s not in netmap mode anymore", NM_IFPNAME(ifp));
+	if (!nm_netmap_on(na)) {
+		D("%s not in netmap mode anymore", na->name);
 		error = ENXIO;
 		goto done;
 	}
@@ -2436,9 +2820,9 @@ netmap_transmit(struct ifnet *ifp, struct mbuf *m)
 	q = &kring->rx_queue;
 
 	// XXX reconsider long packets if we handle fragments
-	if (len > NETMAP_BDG_BUF_SIZE(na->nm_mem)) { /* too long for us */
-		D("%s from_host, drop packet size %d > %d", NM_IFPNAME(ifp),
-			len, NETMAP_BDG_BUF_SIZE(na->nm_mem));
+	if (len > NETMAP_BUF_SIZE(na)) { /* too long for us */
+		D("%s from_host, drop packet size %d > %d", na->name,
+			len, NETMAP_BUF_SIZE(na));
 		goto done;
 	}
 
@@ -2454,12 +2838,12 @@ netmap_transmit(struct ifnet *ifp, struct mbuf *m)
                 space += kring->nkr_num_slots;
 	if (space + mbq_len(q) >= kring->nkr_num_slots - 1) { // XXX
 		RD(10, "%s full hwcur %d hwtail %d qlen %d len %d m %p",
-			 NM_IFPNAME(ifp), kring->nr_hwcur, kring->nr_hwtail, mbq_len(q),
+			na->name, kring->nr_hwcur, kring->nr_hwtail, mbq_len(q),
 			len, m);
 	} else {
 		mbq_enqueue(q, m);
 		ND(10, "%s %d bufs in queue len %d m %p",
-			NM_IFPNAME(ifp), mbq_len(q), len, m);
+			na->name, mbq_len(q), len, m);
 		/* notify outside the lock */
 		m = NULL;
 		error = 0;
@@ -2492,12 +2876,8 @@ netmap_reset(struct netmap_adapter *na, enum txrx tx, u_int n,
 	struct netmap_kring *kring;
 	int new_hwofs, lim;
 
-	if (na == NULL) {
-		D("NULL na, should not happen");
-		return NULL;	/* no netmap support here */
-	}
-	if (!(na->ifp->if_capenable & IFCAP_NETMAP)) {
-		ND("interface not in netmap mode");
+	if (!nm_native_on(na)) {
+		ND("interface not in native netmap mode");
 		return NULL;	/* nothing to reinitialize */
 	}
 
@@ -2528,7 +2908,7 @@ netmap_reset(struct netmap_adapter *na, enum txrx tx, u_int n,
 	/* Always set the new offset value and realign the ring. */
 	if (netmap_verbose)
 	    D("%s %s%d hwofs %d -> %d, hwtail %d -> %d",
-		NM_IFPNAME(na->ifp),
+		na->name,
 		tx == NR_TX ? "TX" : "RX", n,
 		kring->nkr_hwofs, new_hwofs,
 		kring->nr_hwtail,
@@ -2570,8 +2950,9 @@ netmap_reset(struct netmap_adapter *na, enum txrx tx, u_int n,
  * The 'notify' routine depends on what the ring is attached to.
  * - for a netmap file descriptor, do a selwakeup on the individual
  *   waitqueue, plus one on the global one if needed
- * - for a switch, call the proper forwarding routine
- * - XXX more ?
+ *   (see netmap_notify)
+ * - for a nic connected to a switch, call the proper forwarding routine
+ *   (see netmap_bwrap_intr_notify)
  */
 void
 netmap_common_irq(struct ifnet *ifp, u_int q, u_int *work_done)
@@ -2620,11 +3001,18 @@ netmap_common_irq(struct ifnet *ifp, u_int q, u_int *work_done)
 int
 netmap_rx_irq(struct ifnet *ifp, u_int q, u_int *work_done)
 {
-	// XXX could we check NAF_NATIVE_ON ?
-	if (!(ifp->if_capenable & IFCAP_NETMAP))
+	struct netmap_adapter *na = NA(ifp);
+
+	/*
+	 * XXX emulated netmap mode sets NAF_SKIP_INTR so
+	 * we still use the regular driver even though the previous
+	 * check fails. It is unclear whether we should use
+	 * nm_native_on() here.
+	 */
+	if (!nm_netmap_on(na))
 		return 0;
 
-	if (NA(ifp)->na_flags & NAF_SKIP_INTR) {
+	if (na->na_flags & NAF_SKIP_INTR) {
 		ND("use regular interrupt");
 		return 0;
 	}
@@ -2677,6 +3065,9 @@ netmap_init(void)
 		goto fail;
 
 	netmap_init_bridges();
+#ifdef __FreeBSD__
+	nm_vi_init_index();
+#endif
 	printf("netmap: loaded module\n");
 	return (0);
 fail:
diff --git a/sys/dev/netmap/netmap_freebsd.c b/sys/dev/netmap/netmap_freebsd.c
index e43d669..160b7c0 100644
--- a/sys/dev/netmap/netmap_freebsd.c
+++ b/sys/dev/netmap/netmap_freebsd.c
@@ -50,6 +50,9 @@
 #include <sys/selinfo.h>
 #include <net/if.h>
 #include <net/if_var.h>
+#include <net/if_types.h> /* IFT_ETHER */
+#include <net/ethernet.h> /* ether_ifdetach */
+#include <net/if_dl.h> /* LLADDR */
 #include <machine/bus.h>        /* bus_dmamap_* */
 #include <netinet/in.h>		/* in6_cksum_pseudo() */
 #include <machine/in_cksum.h>  /* in_pseudo(), in_cksum_hdr() */
@@ -91,8 +94,7 @@ nm_csum_fold(rawsum_t cur_sum)
 	return htobe16((~cur_sum) & 0xFFFF);
 }
 
-uint16_t
-nm_csum_ipv4(struct nm_iphdr *iph)
+uint16_t nm_csum_ipv4(struct nm_iphdr *iph)
 {
 #if 0
 	return in_cksum_hdr((void *)iph);
@@ -148,8 +150,7 @@ nm_csum_tcpudp_ipv6(struct nm_ipv6hdr *ip6h, void *data,
 int
 netmap_catch_rx(struct netmap_adapter *na, int intercept)
 {
-	struct netmap_generic_adapter *gna =
-		(struct netmap_generic_adapter *)na;
+	struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na;
 	struct ifnet *ifp = na->ifp;
 
 	if (intercept) {
@@ -221,9 +222,9 @@ generic_xmit_frame(struct ifnet *ifp, struct mbuf *m,
 	 * (and eventually, just reference the netmap buffer)
 	 */
 
-	if (*m->m_ext.ref_cnt != 1) {
+	if (GET_MBUF_REFCNT(m) != 1) {
 		D("invalid refcnt %d for %p",
-			*m->m_ext.ref_cnt, m);
+			GET_MBUF_REFCNT(m), m);
 		panic("in generic_xmit_frame");
 	}
 	// XXX the ext_size check is unnecessary if we link the netmap buf
@@ -231,14 +232,14 @@ generic_xmit_frame(struct ifnet *ifp, struct mbuf *m,
 		RD(5, "size %d < len %d", m->m_ext.ext_size, len);
 		len = m->m_ext.ext_size;
 	}
-	if (1) { /* XXX seems to have negligible benefits */
+	if (0) { /* XXX seems to have negligible benefits */
 		m->m_ext.ext_buf = m->m_data = addr;
 	} else {
 		bcopy(addr, m->m_data, len);
 	}
 	m->m_len = m->m_pkthdr.len = len;
 	// inc refcount. All ours, we could skip the atomic
-	atomic_fetchadd_int(m->m_ext.ref_cnt, 1);
+	atomic_fetchadd_int(PNT_MBUF_REFCNT(m), 1);
 	m->m_flags |= M_FLOWID;
 	m->m_pkthdr.flowid = ring_nr;
 	m->m_pkthdr.rcvif = ifp; /* used for tx notification */
@@ -277,10 +278,11 @@ generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq)
 
 
 void
-netmap_mitigation_init(struct nm_generic_mit *mit, struct netmap_adapter *na)
+netmap_mitigation_init(struct nm_generic_mit *mit, int idx, struct netmap_adapter *na)
 {
 	ND("called");
 	mit->mit_pending = 0;
+	mit->mit_ring_idx = idx;
 	mit->mit_na = na;
 }
 
@@ -313,6 +315,135 @@ netmap_mitigation_cleanup(struct nm_generic_mit *mit)
 	ND("called");
 }
 
+static int
+nm_vi_dummy(struct ifnet *ifp, u_long cmd, caddr_t addr)
+{
+	return EINVAL;
+}
+
+static void
+nm_vi_start(struct ifnet *ifp)
+{
+	panic("nm_vi_start() must not be called");
+}
+
+/*
+ * Index manager of persistent virtual interfaces.
+ * It is used to decide the lowest byte of the MAC address.
+ * We use the same algorithm with management of bridge port index.
+ */
+#define NM_VI_MAX	255
+static struct {
+	uint8_t index[NM_VI_MAX]; /* XXX just for a reasonable number */
+	uint8_t active;
+	struct mtx lock;
+} nm_vi_indices;
+
+void
+nm_vi_init_index(void)
+{
+	int i;
+	for (i = 0; i < NM_VI_MAX; i++)
+		nm_vi_indices.index[i] = i;
+	nm_vi_indices.active = 0;
+	mtx_init(&nm_vi_indices.lock, "nm_vi_indices_lock", NULL, MTX_DEF);
+}
+
+/* return -1 if no index available */
+static int
+nm_vi_get_index(void)
+{
+	int ret;
+
+	mtx_lock(&nm_vi_indices.lock);
+	ret = nm_vi_indices.active == NM_VI_MAX ? -1 :
+		nm_vi_indices.index[nm_vi_indices.active++];
+	mtx_unlock(&nm_vi_indices.lock);
+	return ret;
+}
+
+static void
+nm_vi_free_index(uint8_t val)
+{
+	int i, lim;
+
+	mtx_lock(&nm_vi_indices.lock);
+	lim = nm_vi_indices.active;
+	for (i = 0; i < lim; i++) {
+		if (nm_vi_indices.index[i] == val) {
+			/* swap index[lim-1] and j */
+			int tmp = nm_vi_indices.index[lim-1];
+			nm_vi_indices.index[lim-1] = val;
+			nm_vi_indices.index[i] = tmp;
+			nm_vi_indices.active--;
+			break;
+		}
+	}
+	if (lim == nm_vi_indices.active)
+		D("funny, index %u didn't found", val);
+	mtx_unlock(&nm_vi_indices.lock);
+}
+#undef NM_VI_MAX
+
+/*
+ * Implementation of a netmap-capable virtual interface that
+ * registered to the system.
+ * It is based on if_tap.c and ip_fw_log.c in FreeBSD 9.
+ *
+ * Note: Linux sets refcount to 0 on allocation of net_device,
+ * then increments it on registration to the system.
+ * FreeBSD sets refcount to 1 on if_alloc(), and does not
+ * increment this refcount on if_attach().
+ */
+int
+nm_vi_persist(const char *name, struct ifnet **ret)
+{
+	struct ifnet *ifp;
+	u_short macaddr_hi;
+	uint32_t macaddr_mid;
+	u_char eaddr[6];
+	int unit = nm_vi_get_index(); /* just to decide MAC address */
+
+	if (unit < 0)
+		return EBUSY;
+	/*
+	 * We use the same MAC address generation method with tap
+	 * except for the highest octet is 00:be instead of 00:bd
+	 */
+	macaddr_hi = htons(0x00be); /* XXX tap + 1 */
+	macaddr_mid = (uint32_t) ticks;
+	bcopy(&macaddr_hi, eaddr, sizeof(short));
+	bcopy(&macaddr_mid, &eaddr[2], sizeof(uint32_t));
+	eaddr[5] = (uint8_t)unit;
+
+	ifp = if_alloc(IFT_ETHER);
+	if (ifp == NULL) {
+		D("if_alloc failed");
+		return ENOMEM;
+	}
+	if_initname(ifp, name, IF_DUNIT_NONE);
+	ifp->if_mtu = 65536;
+	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
+	ifp->if_init = (void *)nm_vi_dummy;
+	ifp->if_ioctl = nm_vi_dummy;
+	ifp->if_start = nm_vi_start;
+	ifp->if_mtu = ETHERMTU;
+	IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
+	ifp->if_capabilities |= IFCAP_LINKSTATE;
+	ifp->if_capenable |= IFCAP_LINKSTATE;
+
+	ether_ifattach(ifp, eaddr);
+	*ret = ifp;
+	return 0;
+}
+/* unregister from the system and drop the final refcount */
+void
+nm_vi_detach(struct ifnet *ifp)
+{
+	nm_vi_free_index(((char *)IF_LLADDR(ifp))[5]);
+	ether_ifdetach(ifp);
+	if_free(ifp);
+}
 
 /*
  * In order to track whether pages are still mapped, we hook into
diff --git a/sys/dev/netmap/netmap_generic.c b/sys/dev/netmap/netmap_generic.c
index a14dbc2..7740382 100644
--- a/sys/dev/netmap/netmap_generic.c
+++ b/sys/dev/netmap/netmap_generic.c
@@ -102,51 +102,42 @@ __FBSDID("$FreeBSD$");
  * mbuf wrappers
  */
 
-/*
- * mbuf destructor, also need to change the type to EXT_EXTREF,
+/* mbuf destructor, also need to change the type to EXT_EXTREF,
  * add an M_NOFREE flag, and then clear the flag and
  * chain into uma_zfree(zone_pack, mf)
  * (or reinstall the buffer ?)
- *
- * On FreeBSD 9 the destructor is called as ext_free(ext_arg1, ext_arg2)
- * whereas newer version have ext_free(m, ext_arg1, ext_arg2)
- * For compatibility we set ext_arg1 = m on allocation so we have
- * the same code on both.
  */
 #define SET_MBUF_DESTRUCTOR(m, fn)	do {		\
-		(m)->m_ext.ext_free = (void *)fn;	\
-		(m)->m_ext.ext_type = EXT_EXTREF;	\
-	} while (0)
+	(m)->m_ext.ext_free = (void *)fn;	\
+	(m)->m_ext.ext_type = EXT_EXTREF;	\
+} while (0)
 
-static void 
+static void
 netmap_default_mbuf_destructor(struct mbuf *m)
-{ 
-	/* restore original data pointer and type */
-	m->m_ext.ext_buf = m->m_data = m->m_ext.ext_arg2;
+{
+	/* restore original mbuf */
+	m->m_ext.ext_buf = m->m_data = m->m_ext.ext_arg1;
+	m->m_ext.ext_arg1 = NULL;
 	m->m_ext.ext_type = EXT_PACKET;
 	m->m_ext.ext_free = NULL;
-	m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
-	if (*(m->m_ext.ref_cnt) == 0)
-		*(m->m_ext.ref_cnt) = 1;
+	if (GET_MBUF_REFCNT(m) == 0)
+		SET_MBUF_REFCNT(m, 1);
 	uma_zfree(zone_pack, m);
-} 
+}
 
-static inline struct mbuf * 
-netmap_get_mbuf(int len) 
-{ 
+static inline struct mbuf *
+netmap_get_mbuf(int len)
+{
 	struct mbuf *m;
 	m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR | M_NOFREE);
 	if (m) {
-		m->m_ext.ext_arg1 = m; /* FreeBSD 9 compat */
-		m->m_ext.ext_arg2 = m->m_ext.ext_buf; /* save original */
+		m->m_ext.ext_arg1 = m->m_ext.ext_buf; // XXX save
 		m->m_ext.ext_free = (void *)netmap_default_mbuf_destructor;
 		m->m_ext.ext_type = EXT_EXTREF;
-		ND(5, "create m %p refcnt %d", m, *m->m_ext.ref_cnt);
+		ND(5, "create m %p refcnt %d", m, GET_MBUF_REFCNT(m));
 	}
 	return m;
-} 
-
-#define GET_MBUF_REFCNT(m)	((m)->m_ext.ref_cnt ? *(m)->m_ext.ref_cnt : -1)
+}
 
 
 
@@ -158,8 +149,6 @@ netmap_get_mbuf(int len)
 #include <linux/ethtool.h>      /* struct ethtool_ops, get_ringparam */
 #include <linux/hrtimer.h>
 
-//#define RATE  /* Enables communication statistics. */
-
 //#define REG_RESET
 
 #endif /* linux */
@@ -174,7 +163,7 @@ netmap_get_mbuf(int len)
 
 /* ======================== usage stats =========================== */
 
-#ifdef RATE
+#ifdef RATE_GENERIC
 #define IFRATE(x) x
 struct rate_stats {
 	unsigned long txpkt;
@@ -218,23 +207,33 @@ static void rate_callback(unsigned long arg)
 
 static struct rate_context rate_ctx;
 
+void generic_rate(int txp, int txs, int txi, int rxp, int rxs, int rxi)
+{
+    if (txp) rate_ctx.new.txpkt++;
+    if (txs) rate_ctx.new.txsync++;
+    if (txi) rate_ctx.new.txirq++;
+    if (rxp) rate_ctx.new.rxpkt++;
+    if (rxs) rate_ctx.new.rxsync++;
+    if (rxi) rate_ctx.new.rxirq++;
+}
+
 #else /* !RATE */
 #define IFRATE(x)
 #endif /* !RATE */
 
 
 /* =============== GENERIC NETMAP ADAPTER SUPPORT ================= */
-#define GENERIC_BUF_SIZE        netmap_buf_size    /* Size of the mbufs in the Tx pool. */
 
 /*
  * Wrapper used by the generic adapter layer to notify
  * the poller threads. Differently from netmap_rx_irq(), we check
- * only IFCAP_NETMAP instead of NAF_NATIVE_ON to enable the irq.
+ * only NAF_NETMAP_ON instead of NAF_NATIVE_ON to enable the irq.
  */
 static void
 netmap_generic_irq(struct ifnet *ifp, u_int q, u_int *work_done)
 {
-	if (unlikely(!(ifp->if_capenable & IFCAP_NETMAP)))
+	struct netmap_adapter *na = NA(ifp);
+	if (unlikely(!nm_netmap_on(na)))
 		return;
 
 	netmap_common_irq(ifp, q, work_done);
@@ -245,7 +244,6 @@ netmap_generic_irq(struct ifnet *ifp, u_int q, u_int *work_done)
 static int
 generic_netmap_register(struct netmap_adapter *na, int enable)
 {
-	struct ifnet *ifp = na->ifp;
 	struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na;
 	struct mbuf *m;
 	int error;
@@ -271,7 +269,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 			goto out;
 		}
 		for (r=0; r<na->num_rx_rings; r++)
-			netmap_mitigation_init(&gna->mit[r], na);
+			netmap_mitigation_init(&gna->mit[r], r, na);
 
 		/* Initialize the rx queue, as generic_rx_handler() can
 		 * be called as soon as netmap_catch_rx() returns.
@@ -296,7 +294,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 			for (i=0; i<na->num_tx_desc; i++)
 				na->tx_rings[r].tx_pool[i] = NULL;
 			for (i=0; i<na->num_tx_desc; i++) {
-				m = netmap_get_mbuf(GENERIC_BUF_SIZE);
+				m = netmap_get_mbuf(NETMAP_BUF_SIZE(na));
 				if (!m) {
 					D("tx_pool[%d] allocation failed", i);
 					error = ENOMEM;
@@ -312,14 +310,14 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 			D("netdev_rx_handler_register() failed (%d)", error);
 			goto register_handler;
 		}
-		ifp->if_capenable |= IFCAP_NETMAP;
+		na->na_flags |= NAF_NETMAP_ON;
 
 		/* Make netmap control the packet steering. */
 		netmap_catch_tx(gna, 1);
 
 		rtnl_unlock();
 
-#ifdef RATE
+#ifdef RATE_GENERIC
 		if (rate_ctx.refcount == 0) {
 			D("setup_timer()");
 			memset(&rate_ctx, 0, sizeof(rate_ctx));
@@ -338,7 +336,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 		   error handling code below. */
 		rtnl_lock();
 
-		ifp->if_capenable &= ~IFCAP_NETMAP;
+		na->na_flags &= ~NAF_NETMAP_ON;
 
 		/* Release packet steering control. */
 		netmap_catch_tx(gna, 0);
@@ -365,7 +363,7 @@ generic_netmap_register(struct netmap_adapter *na, int enable)
 			free(na->tx_rings[r].tx_pool, M_DEVBUF);
 		}
 
-#ifdef RATE
+#ifdef RATE_GENERIC
 		if (--rate_ctx.refcount == 0) {
 			D("del_timer()");
 			del_timer(&rate_ctx.timer);
@@ -421,6 +419,8 @@ generic_mbuf_destructor(struct mbuf *m)
 	IFRATE(rate_ctx.new.txirq++);
 }
 
+extern int netmap_adaptive_io;
+
 /* Record completed transmissions and update hwtail.
  *
  * The oldest tx buffer not yet completed is at nr_hwtail + 1,
@@ -440,7 +440,7 @@ generic_netmap_tx_clean(struct netmap_kring *kring)
 
 		if (unlikely(m == NULL)) {
 			/* this is done, try to replenish the entry */
-			tx_pool[nm_i] = m = netmap_get_mbuf(GENERIC_BUF_SIZE);
+			tx_pool[nm_i] = m = netmap_get_mbuf(NETMAP_BUF_SIZE(kring->na));
 			if (unlikely(m == NULL)) {
 				D("mbuf allocation failed, XXX error");
 				// XXX how do we proceed ? break ?
@@ -451,6 +451,23 @@ generic_netmap_tx_clean(struct netmap_kring *kring)
 		}
 		n++;
 		nm_i = nm_next(nm_i, lim);
+#if 0 /* rate adaptation */
+		if (netmap_adaptive_io > 1) {
+			if (n >= netmap_adaptive_io)
+				break;
+		} else if (netmap_adaptive_io) {
+			/* if hwcur - nm_i < lim/8 do an early break
+			 * so we prevent the sender from stalling. See CVT.
+			 */
+			if (hwcur >= nm_i) {
+				if (hwcur - nm_i < lim/2)
+					break;
+			} else {
+				if (hwcur + lim + 1 - nm_i < lim/2)
+					break;
+			}
+		}
+#endif
 	}
 	kring->nr_hwtail = nm_prev(nm_i, lim);
 	ND("tx completed [%d] -> hwtail %d", n, kring->nr_hwtail);
@@ -530,14 +547,15 @@ generic_set_tx_event(struct netmap_kring *kring, u_int hwcur)
  * since it implements the TX flow control (and takes some locks).
  */
 static int
-generic_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+generic_netmap_txsync(struct netmap_kring *kring, int flags)
 {
+	struct netmap_adapter *na = kring->na;
 	struct ifnet *ifp = na->ifp;
-	struct netmap_kring *kring = &na->tx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i;	/* index into the netmap ring */ // j
 	u_int const lim = kring->nkr_num_slots - 1;
 	u_int const head = kring->rhead;
+	u_int ring_nr = kring->ring_id;
 
 	IFRATE(rate_ctx.new.txsync++);
 
@@ -553,19 +571,19 @@ generic_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		while (nm_i != head) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
 			u_int len = slot->len;
-			void *addr = NMB(slot);
+			void *addr = NMB(na, slot);
 
 			/* device-specific */
 			struct mbuf *m;
 			int tx_ret;
 
-			NM_CHECK_ADDR_LEN(addr, len);
+			NM_CHECK_ADDR_LEN(na, addr, len);
 
 			/* Tale a mbuf from the tx pool and copy in the user packet. */
 			m = kring->tx_pool[nm_i];
 			if (unlikely(!m)) {
 				RD(5, "This should never happen");
-				kring->tx_pool[nm_i] = m = netmap_get_mbuf(GENERIC_BUF_SIZE);
+				kring->tx_pool[nm_i] = m = netmap_get_mbuf(NETMAP_BUF_SIZE(na));
 				if (unlikely(m == NULL)) {
 					D("mbuf allocation failed");
 					break;
@@ -580,7 +598,7 @@ generic_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 			 */
 			tx_ret = generic_xmit_frame(ifp, m, addr, len, ring_nr);
 			if (unlikely(tx_ret)) {
-				RD(5, "start_xmit failed: err %d [nm_i %u, head %u, hwtail %u]",
+				ND(5, "start_xmit failed: err %d [nm_i %u, head %u, hwtail %u]",
 						tx_ret, nm_i, head, kring->nr_hwtail);
 				/*
 				 * No room for this mbuf in the device driver.
@@ -686,10 +704,10 @@ generic_rx_handler(struct ifnet *ifp, struct mbuf *m)
  * Access must be protected because the rx handler is asynchronous,
  */
 static int
-generic_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+generic_netmap_rxsync(struct netmap_kring *kring, int flags)
 {
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	struct netmap_ring *ring = kring->ring;
+	struct netmap_adapter *na = kring->na;
 	u_int nm_i;	/* index into the netmap ring */ //j,
 	u_int n;
 	u_int const lim = kring->nkr_num_slots - 1;
@@ -712,11 +730,11 @@ generic_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		nm_i = kring->nr_hwtail; /* first empty slot in the receive ring */
 		for (n = 0; nm_i != stop_i; n++) {
 			int len;
-			void *addr = NMB(&ring->slot[nm_i]);
+			void *addr = NMB(na, &ring->slot[nm_i]);
 			struct mbuf *m;
 
 			/* we only check the address here on generic rx rings */
-			if (addr == netmap_buffer_base) { /* Bad buffer */
+			if (addr == NETMAP_BUF_BASE(na)) { /* Bad buffer */
 				return netmap_ring_reinit(kring);
 			}
 			/*
@@ -823,7 +841,7 @@ generic_netmap_attach(struct ifnet *ifp)
 	na->nm_txsync = &generic_netmap_txsync;
 	na->nm_rxsync = &generic_netmap_rxsync;
 	na->nm_dtor = &generic_netmap_dtor;
-	/* when using generic, IFCAP_NETMAP is set so we force
+	/* when using generic, NAF_NETMAP_ON is set so we force
 	 * NAF_SKIP_INTR to use the regular interrupt handler
 	 */
 	na->na_flags = NAF_SKIP_INTR | NAF_HOST_RINGS;
diff --git a/sys/dev/netmap/netmap_kern.h b/sys/dev/netmap/netmap_kern.h
index 087564c..dc6afd8 100644
--- a/sys/dev/netmap/netmap_kern.h
+++ b/sys/dev/netmap/netmap_kern.h
@@ -36,6 +36,7 @@
 
 #define WITH_VALE	// comment out to disable VALE support
 #define WITH_PIPES
+#define WITH_MONITOR
 
 #if defined(__FreeBSD__)
 
@@ -66,11 +67,23 @@
 struct netmap_adapter *netmap_getna(if_t ifp);
 #endif
 
+#if __FreeBSD_version >= 1100027
+#define GET_MBUF_REFCNT(m)      ((m)->m_ext.ext_cnt ? *((m)->m_ext.ext_cnt) : -1)
+#define SET_MBUF_REFCNT(m, x)   *((m)->m_ext.ext_cnt) = x
+#define PNT_MBUF_REFCNT(m)      ((m)->m_ext.ext_cnt)
+#else
+#define GET_MBUF_REFCNT(m)      ((m)->m_ext.ref_cnt ? *((m)->m_ext.ref_cnt) : -1)
+#define SET_MBUF_REFCNT(m, x)   *((m)->m_ext.ref_cnt) = x
+#define PNT_MBUF_REFCNT(m)      ((m)->m_ext.ref_cnt)
+#endif
+
 MALLOC_DECLARE(M_NETMAP);
 
 // XXX linux struct, not used in FreeBSD
 struct net_device_ops {
 };
+struct ethtool_ops {
+};
 struct hrtimer {
 };
 
@@ -82,7 +95,7 @@ struct hrtimer {
 #define	MBUF_IFP(m)	((m)->dev)
 #define	NM_SEND_UP(ifp, m)  \
                         do { \
-                            m->priority = NM_MAGIC_PRIORITY; \
+                            m->priority = NM_MAGIC_PRIORITY_RX; \
                             netif_rx(m); \
                         } while (0)
 
@@ -100,18 +113,6 @@ struct hrtimer {
 #define DEV_NETMAP
 #endif /* DEV_NETMAP */
 
-/*
- * IFCAP_NETMAP goes into net_device's priv_flags (if_capenable).
- * This was 16 bits up to linux 2.6.36, so we need a 16 bit value on older
- * platforms and tolerate the clash with IFF_DYNAMIC and IFF_BRIDGE_PORT.
- * For the 32-bit value, 0x100000 has no clashes until at least 3.5.1
- */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,37)
-#define IFCAP_NETMAP	0x8000
-#else
-#define IFCAP_NETMAP	0x200000
-#endif
-
 #elif defined (__APPLE__)
 
 #warning apple support is incomplete.
@@ -215,7 +216,7 @@ extern NMG_LOCK_T	netmap_global_lock;
  * rxsync_from_host() and netmap_transmit(). The mbq is protected
  * by its internal lock.
  *
- * RX rings attached to the VALE switch are accessed by both sender
+ * RX rings attached to the VALE switch are accessed by both senders
  * and receiver. They are protected through the q_lock on the RX ring.
  */
 struct netmap_kring {
@@ -266,7 +267,13 @@ struct netmap_kring {
 	uint32_t	nkr_hwlease;
 	uint32_t	nkr_lease_idx;
 
-	volatile int nkr_stopped;	// XXX what for ?
+	/* while nkr_stopped is set, no new [tr]xsync operations can
+	 * be started on this kring.
+	 * This is used by netmap_disable_all_rings()
+	 * to find a synchronization point where critical data
+	 * structures pointed to by the kring can be added or removed
+	 */
+	volatile int nkr_stopped;
 
 	/* Support for adapters without native netmap support.
 	 * On tx rings we preallocate an array of tx buffers
@@ -281,13 +288,40 @@ struct netmap_kring {
 	uint32_t	ring_id;	/* debugging */
 	char name[64];			/* diagnostic */
 
+	/* [tx]sync callback for this kring.
+	 * The default nm_kring_create callback (netmap_krings_create)
+	 * sets the nm_sync callback of each hardware tx(rx) kring to
+	 * the corresponding nm_txsync(nm_rxsync) taken from the
+	 * netmap_adapter; moreover, it sets the sync callback
+	 * of the host tx(rx) ring to netmap_txsync_to_host
+	 * (netmap_rxsync_from_host).
+	 *
+	 * Overrides: the above configuration is not changed by
+	 * any of the nm_krings_create callbacks.
+	 */
 	int (*nm_sync)(struct netmap_kring *kring, int flags);
 
 #ifdef WITH_PIPES
-	struct netmap_kring *pipe;
-	struct netmap_ring *save_ring;
+	struct netmap_kring *pipe;	/* if this is a pipe ring,
+					 * pointer to the other end
+					 */
+	struct netmap_ring *save_ring;	/* pointer to hidden rings
+       					 * (see netmap_pipe.c for details)
+					 */
 #endif /* WITH_PIPES */
 
+#ifdef WITH_MONITOR
+	/* pointer to the adapter that is monitoring this kring (if any)
+	 */
+	struct netmap_monitor_adapter *monitor;
+	/*
+	 * Monitors work by intercepting the txsync and/or rxsync of the
+	 * monitored krings. This is implemented by replacing
+	 * the nm_sync pointer above and saving the previous
+	 * one in save_sync below.
+	 */
+	int (*save_sync)(struct netmap_kring *kring, int flags);
+#endif
 } __attribute__((__aligned__(64)));
 
 
@@ -360,6 +394,8 @@ tail->|                 |<-hwtail    |                 |<-hwlease
 
 enum txrx { NR_RX = 0, NR_TX = 1 };
 
+struct netmap_vp_adapter; // forward
+
 /*
  * The "struct netmap_adapter" extends the "struct adapter"
  * (or equivalent) device descriptor.
@@ -390,13 +426,19 @@ struct netmap_adapter {
 				 * deallocation of the memory allocator
 				 */
 #define NAF_NATIVE_ON   16      /* the adapter is native and the attached
-				 * interface is in netmap mode
+				 * interface is in netmap mode.
+				 * Virtual ports (vale, pipe, monitor...)
+				 * should never use this flag.
 				 */
 #define	NAF_NETMAP_ON	32	/* netmap is active (either native or
-				 * emulated. Where possible (e.g. FreeBSD)
+				 * emulated). Where possible (e.g. FreeBSD)
 				 * IFCAP_NETMAP also mirrors this flag.
 				 */
 #define NAF_HOST_RINGS  64	/* the adapter supports the host rings */
+#define NAF_FORCE_NATIVE 128	/* the adapter is always NATIVE */
+#define	NAF_BUSY	(1U<<31) /* the adapter is used internally and
+				  * cannot be registered from userspace
+				  */
 	int active_fds; /* number of user-space descriptors using this
 			 interface, which is equal to the number of
 			 struct netmap_if objs in the mapped region. */
@@ -423,6 +465,8 @@ struct netmap_adapter {
 	/* count users of the global wait queues */
 	int tx_si_users, rx_si_users;
 
+	void *pdev; /* used to store pci device */
+
 	/* copy of if_qflush and if_transmit pointers, to intercept
 	 * packets from the network stack when netmap is active.
 	 */
@@ -444,7 +488,7 @@ struct netmap_adapter {
 	 *
 	 * nm_register() is called on NIOCREGIF and close() to enter
 	 *	or exit netmap mode on the NIC
-	 *	Called with NMG_LOCK held.
+	 *	Called with NNG_LOCK held.
 	 *
 	 * nm_txsync() pushes packets to the underlying hw/switch
 	 *
@@ -453,14 +497,20 @@ struct netmap_adapter {
 	 * nm_config() returns configuration information from the OS
 	 *	Called with NMG_LOCK held.
 	 *
-	 * nm_krings_create() create and init the krings array
-	 * 	(the array layout must conform to the description
-	 * 	found above the definition of netmap_krings_create)
+	 * nm_krings_create() create and init the tx_rings and
+	 * 	rx_rings arrays of kring structures. In particular,
+	 * 	set the nm_sync callbacks for each ring.
+	 * 	There is no need to also allocate the corresponding
+	 * 	netmap_rings, since netmap_mem_rings_create() will always
+	 * 	be called to provide the missing ones.
+	 *	Called with NNG_LOCK held.
 	 *
-	 * nm_krings_delete() cleanup and delete the kring array
+	 * nm_krings_delete() cleanup and delete the tx_rings and rx_rings
+	 * 	arrays
+	 *	Called with NMG_LOCK held.
 	 *
 	 * nm_notify() is used to act after data have become available
-	 *	(or the stopped state of the ring has changed)
+	 * 	(or the stopped state of the ring has changed)
 	 *	For hw devices this is typically a selwakeup(),
 	 *	but for NIC/host ports attached to a switch (or vice-versa)
 	 *	we also need to invoke the 'txsync' code downstream.
@@ -469,8 +519,8 @@ struct netmap_adapter {
 
 	int (*nm_register)(struct netmap_adapter *, int onoff);
 
-	int (*nm_txsync)(struct netmap_adapter *, u_int ring, int flags);
-	int (*nm_rxsync)(struct netmap_adapter *, u_int ring, int flags);
+	int (*nm_txsync)(struct netmap_kring *kring, int flags);
+	int (*nm_rxsync)(struct netmap_kring *kring, int flags);
 #define NAF_FORCE_READ    1
 #define NAF_FORCE_RECLAIM 2
 	/* return configuration information */
@@ -480,7 +530,35 @@ struct netmap_adapter {
 	void (*nm_krings_delete)(struct netmap_adapter *);
 	int (*nm_notify)(struct netmap_adapter *,
 		u_int ring, enum txrx, int flags);
-#define NAF_DISABLE_NOTIFY 8
+#define NAF_DISABLE_NOTIFY 8	/* notify that the stopped state of the
+				 * ring has changed (kring->nkr_stopped)
+				 */
+
+#ifdef WITH_VALE
+	/*
+	 * nm_bdg_attach() initializes the na_vp field to point
+	 *      to an adapter that can be attached to a VALE switch. If the
+	 *      current adapter is already a VALE port, na_vp is simply a cast;
+	 *      otherwise, na_vp points to a netmap_bwrap_adapter.
+	 *      If applicable, this callback also initializes na_hostvp,
+	 *      that can be used to connect the adapter host rings to the
+	 *      switch.
+	 *      Called with NMG_LOCK held.
+	 *
+	 * nm_bdg_ctl() is called on the actual attach/detach to/from
+	 *      to/from the switch, to perform adapter-specific
+	 *      initializations
+	 *      Called with NMG_LOCK held.
+	 */
+	int (*nm_bdg_attach)(const char *bdg_name, struct netmap_adapter *);
+	int (*nm_bdg_ctl)(struct netmap_adapter *, struct nmreq *, int);
+
+	/* adapter used to attach this adapter to a VALE switch (if any) */
+	struct netmap_vp_adapter *na_vp;
+	/* adapter used to attach the host rings of this adapter
+	 * to a VALE switch (if any) */
+	struct netmap_vp_adapter *na_hostvp;
+#endif
 
 	/* standard refcount to control the lifetime of the adapter
 	 * (it should be equal to the lifetime of the corresponding ifp)
@@ -494,17 +572,22 @@ struct netmap_adapter {
  	struct netmap_mem_d *nm_mem;
 	struct lut_entry *na_lut;
 	uint32_t na_lut_objtotal;	/* max buffer index */
+	uint32_t na_lut_objsize;	/* buffer size */
 
-	/* used internally. If non-null, the interface cannot be bound
-	 * from userspace
+	/* additional information attached to this adapter
+	 * by other netmap subsystems. Currently used by
+	 * bwrap and LINUX/v1000.
 	 */
 	void *na_private;
 
 #ifdef WITH_PIPES
+	/* array of pipes that have this adapter as a parent */
 	struct netmap_pipe_adapter **na_pipes;
-	int na_next_pipe;
-	int na_max_pipes;
+	int na_next_pipe;	/* next free slot in the array */
+	int na_max_pipes;	/* size of the array */
 #endif /* WITH_PIPES */
+
+	char name[64];
 };
 
 
@@ -514,9 +597,9 @@ struct netmap_adapter {
  * if the NIC is owned by a user, only users can share it.
  * Evaluation must be done under NMG_LOCK().
  */
-#define NETMAP_OWNED_BY_KERN(na)	(na->na_private)
+#define NETMAP_OWNED_BY_KERN(na)	((na)->na_flags & NAF_BUSY)
 #define NETMAP_OWNED_BY_ANY(na) \
-	(NETMAP_OWNED_BY_KERN(na) || (na->active_fds > 0))
+	(NETMAP_OWNED_BY_KERN(na) || ((na)->active_fds > 0))
 
 
 /*
@@ -546,12 +629,17 @@ struct netmap_hw_adapter {	/* physical device */
 	struct netmap_adapter up;
 
 	struct net_device_ops nm_ndo;	// XXX linux only
+	struct ethtool_ops    nm_eto;	// XXX linux only
+	const struct ethtool_ops*   save_ethtool;
+
+	int (*nm_hw_register)(struct netmap_adapter *, int onoff);
 };
 
 /* Mitigation support. */
 struct nm_generic_mit {
 	struct hrtimer mit_timer;
 	int mit_pending;
+	int mit_ring_idx;  /* index of the ring being mitigated */
 	struct netmap_adapter *mit_na;  /* backpointer */
 };
 
@@ -641,16 +729,19 @@ struct netmap_bwrap_adapter {
 	/* backup of the hwna notify callback */
 	int (*save_notify)(struct netmap_adapter *,
 			u_int ring, enum txrx, int flags);
+	/* backup of the hwna memory allocator */
+	struct netmap_mem_d *save_nmd;
 
 	/*
 	 * When we attach a physical interface to the bridge, we
 	 * allow the controlling process to terminate, so we need
-	 * a place to store the netmap_priv_d data structure.
+	 * a place to store the n_detmap_priv_d data structure.
 	 * This is only done when physical interfaces
 	 * are attached to a bridge.
 	 */
 	struct netmap_priv_d *na_kpriv;
 };
+int netmap_bwrap_attach(const char *name, struct netmap_adapter *);
 
 
 #endif /* WITH_VALE */
@@ -747,12 +838,11 @@ static __inline int nm_kr_tryget(struct netmap_kring *kr)
  * netmap_load_map/netmap_reload_map are helper routines to set/reset
  *	the dmamap for a packet buffer
  *
- * netmap_reset() is a helper routine to be called in the driver
- *	when reinitializing a ring.
+ * netmap_reset() is a helper routine to be called in the hw driver
+ *	when reinitializing a ring. It should not be called by
+ *	virtual ports (vale, pipes, monitor)
  */
 int netmap_attach(struct netmap_adapter *);
-int netmap_attach_common(struct netmap_adapter *);
-void netmap_detach_common(struct netmap_adapter *na);
 void netmap_detach(struct ifnet *);
 int netmap_transmit(struct ifnet *, struct mbuf *);
 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
@@ -764,10 +854,33 @@ int netmap_rx_irq(struct ifnet *, u_int, u_int *);
 #define netmap_tx_irq(_n, _q) netmap_rx_irq(_n, _q, NULL)
 void netmap_common_irq(struct ifnet *, u_int, u_int *work_done);
 
-void netmap_disable_all_rings(struct ifnet *);
-void netmap_enable_all_rings(struct ifnet *);
-void netmap_disable_ring(struct netmap_kring *kr);
 
+#ifdef WITH_VALE
+/* functions used by external modules to interface with VALE */
+#define netmap_vp_to_ifp(_vp)	((_vp)->up.ifp)
+#define netmap_ifp_to_vp(_ifp)	(NA(_ifp)->na_vp)
+#define netmap_ifp_to_host_vp(_ifp) (NA(_ifp)->na_hostvp)
+#define netmap_bdg_idx(_vp)	((_vp)->bdg_port)
+const char *netmap_bdg_name(struct netmap_vp_adapter *);
+#else /* !WITH_VALE */
+#define netmap_vp_to_ifp(_vp)	NULL
+#define netmap_ifp_to_vp(_ifp)	NULL
+#define netmap_ifp_to_host_vp(_ifp) NULL
+#define netmap_bdg_idx(_vp)	-1
+#define netmap_bdg_name(_vp)	NULL
+#endif /* WITH_VALE */
+
+static inline int
+nm_native_on(struct netmap_adapter *na)
+{
+	return na && na->na_flags & NAF_NATIVE_ON;
+}
+
+static inline int
+nm_netmap_on(struct netmap_adapter *na)
+{
+	return na && na->na_flags & NAF_NETMAP_ON;
+}
 
 /* set/clear native flags and if_transmit/netdev_ops */
 static inline void
@@ -785,6 +898,8 @@ nm_set_native_flags(struct netmap_adapter *na)
 #else
 	na->if_transmit = (void *)ifp->netdev_ops;
 	ifp->netdev_ops = &((struct netmap_hw_adapter *)na)->nm_ndo;
+	((struct netmap_hw_adapter *)na)->save_ethtool = ifp->ethtool_ops;
+	ifp->ethtool_ops = &((struct netmap_hw_adapter*)na)->nm_eto;
 #endif
 }
 
@@ -798,6 +913,7 @@ nm_clear_native_flags(struct netmap_adapter *na)
 	ifp->if_transmit = na->if_transmit;
 #else
 	ifp->netdev_ops = (void *)na->if_transmit;
+	ifp->ethtool_ops = ((struct netmap_hw_adapter*)na)->save_ethtool;
 #endif
 	na->na_flags &= ~(NAF_NATIVE_ON | NAF_NETMAP_ON);
 #ifdef IFCAP_NETMAP /* or FreeBSD ? */
@@ -858,30 +974,72 @@ nm_rxsync_finalize(struct netmap_kring *kring)
 
 /* check/fix address and len in tx rings */
 #if 1 /* debug version */
-#define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
-	if (_a == netmap_buffer_base || _l > NETMAP_BUF_SIZE) {		\
+#define	NM_CHECK_ADDR_LEN(_na, _a, _l)	do {				\
+	if (_a == NETMAP_BUF_BASE(_na) || _l > NETMAP_BUF_SIZE(_na)) {	\
 		RD(5, "bad addr/len ring %d slot %d idx %d len %d",	\
-			ring_nr, nm_i, slot->buf_idx, len);		\
-		if (_l > NETMAP_BUF_SIZE)				\
-			_l = NETMAP_BUF_SIZE;				\
+			kring->ring_id, nm_i, slot->buf_idx, len);	\
+		if (_l > NETMAP_BUF_SIZE(_na))				\
+			_l = NETMAP_BUF_SIZE(_na);			\
 	} } while (0)
 #else /* no debug version */
-#define	NM_CHECK_ADDR_LEN(_a, _l)	do {				\
-		if (_l > NETMAP_BUF_SIZE)				\
-			_l = NETMAP_BUF_SIZE;				\
+#define	NM_CHECK_ADDR_LEN(_na, _a, _l)	do {				\
+		if (_l > NETMAP_BUF_SIZE(_na))				\
+			_l = NETMAP_BUF_SIZE(_na);			\
 	} while (0)
 #endif
 
 
 /*---------------------------------------------------------------*/
 /*
- * Support routines to be used with the VALE switch
+ * Support routines used by netmap subsystems
+ * (native drivers, VALE, generic, pipes, monitors, ...)
+ */
+
+
+/* common routine for all functions that create a netmap adapter. It performs
+ * two main tasks:
+ * - if the na points to an ifp, mark the ifp as netmap capable
+ *   using na as its native adapter;
+ * - provide defaults for the setup callbacks and the memory allocator
+ */
+int netmap_attach_common(struct netmap_adapter *);
+/* common actions to be performed on netmap adapter destruction */
+void netmap_detach_common(struct netmap_adapter *);
+/* fill priv->np_[tr]xq{first,last} using the ringid and flags information
+ * coming from a struct nmreq
+ */
+int netmap_interp_ringid(struct netmap_priv_d *priv, uint16_t ringid, uint32_t flags);
+/* update the ring parameters (number and size of tx and rx rings).
+ * It calls the nm_config callback, if available.
  */
 int netmap_update_config(struct netmap_adapter *na);
+/* create and initialize the common fields of the krings array.
+ * using the information that must be already available in the na.
+ * tailroom can be used to request the allocation of additional
+ * tailroom bytes after the krings array. This is used by
+ * netmap_vp_adapter's (i.e., VALE ports) to make room for
+ * leasing-related data structures
+ */
 int netmap_krings_create(struct netmap_adapter *na, u_int tailroom);
+/* deletes the kring array of the adapter. The array must have
+ * been created using netmap_krings_create
+ */
 void netmap_krings_delete(struct netmap_adapter *na);
-int netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwait);
 
+/* set the stopped/enabled status of ring
+ * When stopping, they also wait for all current activity on the ring to
+ * terminate. The status change is then notified using the na nm_notify
+ * callback.
+ */
+void netmap_set_txring(struct netmap_adapter *, u_int ring_id, int stopped);
+void netmap_set_rxring(struct netmap_adapter *, u_int ring_id, int stopped);
+/* set the stopped/enabled status of all rings of the adapter. */
+void netmap_set_all_rings(struct netmap_adapter *, int stopped);
+/* convenience wrappers for netmap_set_all_rings, used in drivers */
+void netmap_disable_all_rings(struct ifnet *);
+void netmap_enable_all_rings(struct ifnet *);
+
+int netmap_rxsync_from_host(struct netmap_adapter *na, struct thread *td, void *pwait);
 
 struct netmap_if *
 netmap_do_regif(struct netmap_priv_d *priv, struct netmap_adapter *na,
@@ -904,10 +1062,18 @@ int netmap_get_hw_na(struct ifnet *ifp, struct netmap_adapter **na);
  * NM_BDG_MAXPORTS for broadcast, NM_BDG_MAXPORTS+1 for unknown.
  * XXX in practice "unknown" might be handled same as broadcast.
  */
-typedef u_int (*bdg_lookup_fn_t)(char *buf, u_int len,
-		uint8_t *ring_nr, struct netmap_vp_adapter *);
-u_int netmap_bdg_learning(char *, u_int, uint8_t *,
-		struct netmap_vp_adapter *);
+typedef u_int (*bdg_lookup_fn_t)(struct nm_bdg_fwd *ft, uint8_t *ring_nr,
+		const struct netmap_vp_adapter *);
+typedef int (*bdg_config_fn_t)(struct nm_ifreq *);
+typedef void (*bdg_dtor_fn_t)(const struct netmap_vp_adapter *);
+struct netmap_bdg_ops {
+	bdg_lookup_fn_t lookup;
+	bdg_config_fn_t config;
+	bdg_dtor_fn_t	dtor;
+};
+
+u_int netmap_bdg_learning(struct nm_bdg_fwd *ft, uint8_t *dst_ring,
+		const struct netmap_vp_adapter *);
 
 #define	NM_BDG_MAXPORTS		254	/* up to 254 */
 #define	NM_BDG_BROADCAST	NM_BDG_MAXPORTS
@@ -915,11 +1081,11 @@ u_int netmap_bdg_learning(char *, u_int, uint8_t *,
 
 #define	NM_NAME			"vale"	/* prefix for bridge port name */
 
-
 /* these are redefined in case of no VALE support */
 int netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
 void netmap_init_bridges(void);
-int netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func);
+int netmap_bdg_ctl(struct nmreq *nmr, struct netmap_bdg_ops *bdg_ops);
+int netmap_bdg_config(struct nmreq *nmr);
 
 #else /* !WITH_VALE */
 #define	netmap_get_bdg_na(_1, _2, _3)	0
@@ -941,6 +1107,12 @@ int netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create
 #define netmap_get_pipe_na(_1, _2, _3)	0
 #endif
 
+#ifdef WITH_MONITOR
+int netmap_get_monitor_na(struct nmreq *nmr, struct netmap_adapter **na, int create);
+#else
+#define netmap_get_monitor_na(_1, _2, _3) 0
+#endif
+
 /* Various prototypes */
 int netmap_poll(struct cdev *dev, int events, struct thread *td);
 int netmap_init(void);
@@ -952,7 +1124,6 @@ int netmap_dtor_locked(struct netmap_priv_d *priv);
 int netmap_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td);
 
 /* netmap_adapter creation/destruction */
-#define NM_IFPNAME(ifp) ((ifp) ? (ifp)->if_xname : "zombie")
 
 // #define NM_DEBUG_PUTGET 1
 
@@ -965,7 +1136,7 @@ void __netmap_adapter_get(struct netmap_adapter *na);
 #define netmap_adapter_get(na) 				\
 	do {						\
 		struct netmap_adapter *__na = na;	\
-		D("getting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
+		D("getting %p:%s (%d)", __na, (__na)->name, (__na)->na_refcount);	\
 		__netmap_adapter_get(__na);		\
 	} while (0)
 
@@ -974,7 +1145,7 @@ int __netmap_adapter_put(struct netmap_adapter *na);
 #define netmap_adapter_put(na)				\
 	({						\
 		struct netmap_adapter *__na = na;	\
-		D("putting %p:%s (%d)", __na, NM_IFPNAME(__na->ifp), __na->na_refcount);	\
+		D("putting %p:%s (%d)", __na, (__na)->name, (__na)->na_refcount);	\
 		__netmap_adapter_put(__na);		\
 	})
 
@@ -990,12 +1161,10 @@ int netmap_adapter_put(struct netmap_adapter *na);
 /*
  * module variables
  */
-extern u_int netmap_buf_size;
-#define NETMAP_BUF_SIZE	netmap_buf_size	// XXX remove
+#define NETMAP_BUF_BASE(na)	((na)->na_lut[0].vaddr)
+#define NETMAP_BUF_SIZE(na)	((na)->na_lut_objsize)
 extern int netmap_mitigate;	// XXX not really used
 extern int netmap_no_pendintr;
-extern u_int netmap_total_buffers;	// global allocator
-extern char *netmap_buffer_base;	// global allocator
 extern int netmap_verbose;	// XXX debugging
 enum {                                  /* verbose flags */
 	NM_VERB_ON = 1,                 /* generic verbose */
@@ -1055,6 +1224,10 @@ extern int netmap_generic_rings;
 
 #ifdef __FreeBSD__
 
+/* Assigns the device IOMMU domain to an allocator.
+ * Returns -ENOMEM in case the domain is different */
+#define nm_iommu_group_id(dev) (0)
+
 /* Callback invoked by the dma machinery after a successful dmamap_load */
 static void netmap_dmamap_cb(__unused void *arg,
     __unused bus_dma_segment_t * segs, __unused int nseg, __unused int error)
@@ -1065,26 +1238,77 @@ static void netmap_dmamap_cb(__unused void *arg,
  * XXX can we do it without a callback ?
  */
 static inline void
-netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
+netmap_load_map(struct netmap_adapter *na,
+	bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
 {
 	if (map)
-		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
+		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE(na),
 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
 }
 
+static inline void
+netmap_unload_map(struct netmap_adapter *na,
+        bus_dma_tag_t tag, bus_dmamap_t map)
+{
+	if (map)
+		bus_dmamap_unload(tag, map);
+}
+
 /* update the map when a buffer changes. */
 static inline void
-netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
+netmap_reload_map(struct netmap_adapter *na,
+	bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
 {
 	if (map) {
 		bus_dmamap_unload(tag, map);
-		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE,
+		bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE(na),
 		    netmap_dmamap_cb, NULL, BUS_DMA_NOWAIT);
 	}
 }
 
 #else /* linux */
 
+int nm_iommu_group_id(bus_dma_tag_t dev);
+extern size_t     netmap_mem_get_bufsize(struct netmap_mem_d *);
+#include <linux/dma-mapping.h>
+
+static inline void
+netmap_load_map(struct netmap_adapter *na,
+	bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
+{
+	if (map) {
+		*map = dma_map_single(na->pdev, buf, netmap_mem_get_bufsize(na->nm_mem),
+				DMA_BIDIRECTIONAL);
+	}
+}
+
+static inline void
+netmap_unload_map(struct netmap_adapter *na,
+	bus_dma_tag_t tag, bus_dmamap_t map)
+{
+	u_int sz = netmap_mem_get_bufsize(na->nm_mem);
+
+	if (*map) {
+		dma_unmap_single(na->pdev, *map, sz,
+				DMA_BIDIRECTIONAL);
+	}
+}
+
+static inline void
+netmap_reload_map(struct netmap_adapter *na,
+	bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
+{
+	u_int sz = netmap_mem_get_bufsize(na->nm_mem);
+
+	if (*map) {
+		dma_unmap_single(na->pdev, *map, sz,
+				DMA_BIDIRECTIONAL);
+	}
+
+	*map = dma_map_single(na->pdev, buf, sz,
+				DMA_BIDIRECTIONAL);
+}
+
 /*
  * XXX How do we redefine these functions:
  *
@@ -1095,8 +1319,7 @@ netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
  * unfortunately the direction is not, so we need to change
  * something to have a cross API
  */
-#define netmap_load_map(_t, _m, _b)
-#define netmap_reload_map(_t, _m, _b)
+
 #if 0
 	struct e1000_buffer *buffer_info =  &tx_ring->buffer_info[l];
 	/* set time_stamp *before* dma to help avoid a possible race */
@@ -1165,40 +1388,32 @@ struct lut_entry {
 };
 
 struct netmap_obj_pool;
-extern struct lut_entry *netmap_buffer_lut;
-#define NMB_VA(i)	(netmap_buffer_lut[i].vaddr)
-#define NMB_PA(i)	(netmap_buffer_lut[i].paddr)
 
 /*
  * NMB return the virtual address of a buffer (buffer 0 on bad index)
  * PNMB also fills the physical address
  */
 static inline void *
-NMB(struct netmap_slot *slot)
+NMB(struct netmap_adapter *na, struct netmap_slot *slot)
 {
+	struct lut_entry *lut = na->na_lut;
 	uint32_t i = slot->buf_idx;
-	return (unlikely(i >= netmap_total_buffers)) ?  NMB_VA(0) : NMB_VA(i);
+	return (unlikely(i >= na->na_lut_objtotal)) ?
+		lut[0].vaddr : lut[i].vaddr;
 }
 
 static inline void *
-PNMB(struct netmap_slot *slot, uint64_t *pp)
+PNMB(struct netmap_adapter *na, struct netmap_slot *slot, uint64_t *pp)
 {
 	uint32_t i = slot->buf_idx;
-	void *ret = (i >= netmap_total_buffers) ? NMB_VA(0) : NMB_VA(i);
+	struct lut_entry *lut = na->na_lut;
+	void *ret = (i >= na->na_lut_objtotal) ? lut[0].vaddr : lut[i].vaddr;
 
-	*pp = (i >= netmap_total_buffers) ? NMB_PA(0) : NMB_PA(i);
+	*pp = (i >= na->na_lut_objtotal) ? lut[0].paddr : lut[i].paddr;
 	return ret;
 }
 
 /* Generic version of NMB, which uses device-specific memory. */
-static inline void *
-BDG_NMB(struct netmap_adapter *na, struct netmap_slot *slot)
-{
-	struct lut_entry *lut = na->na_lut;
-	uint32_t i = slot->buf_idx;
-	return (unlikely(i >= na->na_lut_objtotal)) ?
-		lut[0].vaddr : lut[i].vaddr;
-}
 
 
 
@@ -1251,6 +1466,17 @@ struct netmap_priv_d {
 	struct thread	*np_td;		/* kqueue, just debugging */
 };
 
+#ifdef WITH_MONITOR
+
+struct netmap_monitor_adapter {
+	struct netmap_adapter up;
+
+	struct netmap_priv_d priv;
+	uint32_t flags;
+};
+
+#endif /* WITH_MONITOR */
+
 
 /*
  * generic netmap emulation for devices that do not have
@@ -1265,12 +1491,20 @@ int generic_xmit_frame(struct ifnet *ifp, struct mbuf *m, void *addr, u_int len,
 int generic_find_num_desc(struct ifnet *ifp, u_int *tx, u_int *rx);
 void generic_find_num_queues(struct ifnet *ifp, u_int *txq, u_int *rxq);
 
+//#define RATE_GENERIC  /* Enables communication statistics for generic. */
+#ifdef RATE_GENERIC
+void generic_rate(int txp, int txs, int txi, int rxp, int rxs, int rxi);
+#else
+#define generic_rate(txp, txs, txi, rxp, rxs, rxi)
+#endif
+
 /*
  * netmap_mitigation API. This is used by the generic adapter
  * to reduce the number of interrupt requests/selwakeup
  * to clients on incoming packets.
  */
-void netmap_mitigation_init(struct nm_generic_mit *mit, struct netmap_adapter *na);
+void netmap_mitigation_init(struct nm_generic_mit *mit, int idx,
+                                struct netmap_adapter *na);
 void netmap_mitigation_start(struct nm_generic_mit *mit);
 void netmap_mitigation_restart(struct nm_generic_mit *mit);
 int netmap_mitigation_active(struct nm_generic_mit *mit);
@@ -1378,4 +1612,10 @@ void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
 			   struct netmap_vp_adapter *dst_na,
 			   struct nm_bdg_fwd *ft_p, struct netmap_ring *ring,
 			   u_int *j, u_int lim, u_int *howmany);
+
+/* persistent virtual port routines */
+int nm_vi_persist(const char *, struct ifnet **);
+void nm_vi_detach(struct ifnet *);
+void nm_vi_init_index(void);
+
 #endif /* _NET_NETMAP_KERN_H_ */
diff --git a/sys/dev/netmap/netmap_mbq.h b/sys/dev/netmap/netmap_mbq.h
index a011c4c..455ca8a 100644
--- a/sys/dev/netmap/netmap_mbq.h
+++ b/sys/dev/netmap/netmap_mbq.h
@@ -74,6 +74,7 @@ mbq_unlock(struct mbq *q)
 	mtx_unlock_spin(&q->lock);
 }
 
+
 void mbq_safe_init(struct mbq *q);
 void mbq_safe_destroy(struct mbq *q);
 void mbq_safe_enqueue(struct mbq *q, struct mbuf *m);
diff --git a/sys/dev/netmap/netmap_mem2.c b/sys/dev/netmap/netmap_mem2.c
index d237794..fa891ec 100644
--- a/sys/dev/netmap/netmap_mem2.c
+++ b/sys/dev/netmap/netmap_mem2.c
@@ -54,6 +54,112 @@ __FBSDID("$FreeBSD$");
 #include <dev/netmap/netmap_kern.h>
 #include "netmap_mem2.h"
 
+#define NETMAP_BUF_MAX_NUM	20*4096*2	/* large machine */
+
+#define NETMAP_POOL_MAX_NAMSZ	32
+
+
+enum {
+	NETMAP_IF_POOL   = 0,
+	NETMAP_RING_POOL,
+	NETMAP_BUF_POOL,
+	NETMAP_POOLS_NR
+};
+
+
+struct netmap_obj_params {
+	u_int size;
+	u_int num;
+};
+struct netmap_obj_pool {
+	char name[NETMAP_POOL_MAX_NAMSZ];	/* name of the allocator */
+
+	/* ---------------------------------------------------*/
+	/* these are only meaningful if the pool is finalized */
+	/* (see 'finalized' field in netmap_mem_d)            */
+	u_int objtotal;         /* actual total number of objects. */
+	u_int memtotal;		/* actual total memory space */
+	u_int numclusters;	/* actual number of clusters */
+
+	u_int objfree;          /* number of free objects. */
+
+	struct lut_entry *lut;  /* virt,phys addresses, objtotal entries */
+	uint32_t *bitmap;       /* one bit per buffer, 1 means free */
+	uint32_t bitmap_slots;	/* number of uint32 entries in bitmap */
+	/* ---------------------------------------------------*/
+
+	/* limits */
+	u_int objminsize;	/* minimum object size */
+	u_int objmaxsize;	/* maximum object size */
+	u_int nummin;		/* minimum number of objects */
+	u_int nummax;		/* maximum number of objects */
+
+	/* these are changed only by config */
+	u_int _objtotal;	/* total number of objects */
+	u_int _objsize;		/* object size */
+	u_int _clustsize;       /* cluster size */
+	u_int _clustentries;    /* objects per cluster */
+	u_int _numclusters;	/* number of clusters */
+
+	/* requested values */
+	u_int r_objtotal;
+	u_int r_objsize;
+};
+
+#ifdef linux
+// XXX a mtx would suffice here 20130415 lr
+#define NMA_LOCK_T		struct semaphore
+#else /* !linux */
+#define NMA_LOCK_T		struct mtx
+#endif /* linux */
+
+typedef int (*netmap_mem_config_t)(struct netmap_mem_d*);
+typedef int (*netmap_mem_finalize_t)(struct netmap_mem_d*);
+typedef void (*netmap_mem_deref_t)(struct netmap_mem_d*);
+
+typedef uint16_t nm_memid_t;
+
+struct netmap_mem_d {
+	NMA_LOCK_T nm_mtx;  /* protect the allocator */
+	u_int nm_totalsize; /* shorthand */
+
+	u_int flags;
+#define NETMAP_MEM_FINALIZED	0x1	/* preallocation done */
+	int lasterr;		/* last error for curr config */
+	int refcount;		/* existing priv structures */
+	/* the three allocators */
+	struct netmap_obj_pool pools[NETMAP_POOLS_NR];
+
+	netmap_mem_config_t   config;
+	netmap_mem_finalize_t finalize;
+	netmap_mem_deref_t    deref;
+
+	nm_memid_t nm_id;	/* allocator identifier */
+	int nm_grp;	/* iommu groupd id */
+
+	/* list of all existing allocators, sorted by nm_id */
+	struct netmap_mem_d *prev, *next;
+};
+
+/* accessor functions */
+struct lut_entry*
+netmap_mem_get_lut(struct netmap_mem_d *nmd)
+{
+	return nmd->pools[NETMAP_BUF_POOL].lut;
+}
+
+u_int
+netmap_mem_get_buftotal(struct netmap_mem_d *nmd)
+{
+	return nmd->pools[NETMAP_BUF_POOL].objtotal;
+}
+
+size_t
+netmap_mem_get_bufsize(struct netmap_mem_d *nmd)
+{
+	return nmd->pools[NETMAP_BUF_POOL]._objsize;
+}
+
 #ifdef linux
 #define NMA_LOCK_INIT(n)	sema_init(&(n)->nm_mtx, 1)
 #define NMA_LOCK_DESTROY(n)
@@ -135,6 +241,7 @@ struct netmap_mem_d nm_mem = {	/* Our memory allocator. */
 	.deref    = netmap_mem_global_deref,
 
 	.nm_id = 1,
+	.nm_grp = -1,
 
 	.prev = &nm_mem,
 	.next = &nm_mem,
@@ -143,9 +250,6 @@ struct netmap_mem_d nm_mem = {	/* Our memory allocator. */
 
 struct netmap_mem_d *netmap_last_mem_d = &nm_mem;
 
-// XXX logically belongs to nm_mem
-struct lut_entry *netmap_buffer_lut;	/* exported */
-
 /* blueprint for the private memory allocators */
 static int netmap_mem_private_config(struct netmap_mem_d *nmd);
 static int netmap_mem_private_finalize(struct netmap_mem_d *nmd);
@@ -254,6 +358,25 @@ nm_mem_release_id(struct netmap_mem_d *nmd)
 	NMA_UNLOCK(&nm_mem);
 }
 
+static int
+nm_mem_assign_group(struct netmap_mem_d *nmd, struct device *dev)
+{
+	int err = 0, id;
+	id = nm_iommu_group_id(dev);
+	if (netmap_verbose)
+		D("iommu_group %d", id);
+
+	NMA_LOCK(nmd);
+
+	if (nmd->nm_grp < 0)
+		nmd->nm_grp = id;
+
+	if (nmd->nm_grp != id)
+		nmd->lasterr = err = ENOMEM;
+
+	NMA_UNLOCK(nmd);
+	return err;
+}
 
 /*
  * First, find the allocator that contains the requested offset,
@@ -274,7 +397,7 @@ netmap_mem_ofstophys(struct netmap_mem_d* nmd, vm_ooffset_t offset)
 		if (offset >= p[i].memtotal)
 			continue;
 		// now lookup the cluster's address
-		pa = p[i].lut[offset / p[i]._objsize].paddr +
+		pa = vtophys(p[i].lut[offset / p[i]._objsize].vaddr) +
 			offset % p[i]._objsize;
 		NMA_UNLOCK(nmd);
 		return pa;
@@ -300,18 +423,22 @@ netmap_mem_get_info(struct netmap_mem_d* nmd, u_int* size, u_int *memflags,
 	error = nmd->config(nmd);
 	if (error)
 		goto out;
-	if (nmd->flags & NETMAP_MEM_FINALIZED) {
-		*size = nmd->nm_totalsize;
-	} else {
-		int i;
-		*size = 0;
-		for (i = 0; i < NETMAP_POOLS_NR; i++) {
-			struct netmap_obj_pool *p = nmd->pools + i;
-			*size += (p->_numclusters * p->_clustsize);
+	if (size) {
+		if (nmd->flags & NETMAP_MEM_FINALIZED) {
+			*size = nmd->nm_totalsize;
+		} else {
+			int i;
+			*size = 0;
+			for (i = 0; i < NETMAP_POOLS_NR; i++) {
+				struct netmap_obj_pool *p = nmd->pools + i;
+				*size += (p->_numclusters * p->_clustsize);
+			}
 		}
 	}
-	*memflags = nmd->flags;
-	*id = nmd->nm_id;
+	if (memflags)
+		*memflags = nmd->flags;
+	if (id)
+		*id = nmd->nm_id;
 out:
 	NMA_UNLOCK(nmd);
 	return error;
@@ -471,12 +598,15 @@ netmap_obj_free_va(struct netmap_obj_pool *p, void *vaddr)
 	    vaddr, p->name);
 }
 
+#define netmap_mem_bufsize(n)	\
+	((n)->pools[NETMAP_BUF_POOL]._objsize)
+
 #define netmap_if_malloc(n, len)	netmap_obj_malloc(&(n)->pools[NETMAP_IF_POOL], len, NULL, NULL)
 #define netmap_if_free(n, v)		netmap_obj_free_va(&(n)->pools[NETMAP_IF_POOL], (v))
 #define netmap_ring_malloc(n, len)	netmap_obj_malloc(&(n)->pools[NETMAP_RING_POOL], len, NULL, NULL)
 #define netmap_ring_free(n, v)		netmap_obj_free_va(&(n)->pools[NETMAP_RING_POOL], (v))
 #define netmap_buf_malloc(n, _pos, _index)			\
-	netmap_obj_malloc(&(n)->pools[NETMAP_BUF_POOL], NETMAP_BDG_BUF_SIZE(n), _pos, _index)
+	netmap_obj_malloc(&(n)->pools[NETMAP_BUF_POOL], netmap_mem_bufsize(n), _pos, _index)
 
 
 #if 0 // XXX unused
@@ -675,7 +805,7 @@ netmap_config_obj_allocator(struct netmap_obj_pool *p, u_int objtotal, u_int obj
 	p->r_objtotal = objtotal;
 	p->r_objsize = objsize;
 
-#define MAX_CLUSTSIZE	(1<<17)
+#define MAX_CLUSTSIZE	(1<<22)		// 4 MB
 #define LINE_ROUND	NM_CACHE_ALIGN	// 64
 	if (objsize >= MAX_CLUSTSIZE) {
 		/* we could do it but there is no point */
@@ -713,15 +843,14 @@ netmap_config_obj_allocator(struct netmap_obj_pool *p, u_int objtotal, u_int obj
 			clustentries = i;
 			break;
 		}
-		if (delta > ( (clustentries*objsize) % PAGE_SIZE) )
-			clustentries = i;
 	}
-	// D("XXX --- ouch, delta %d (bad for buffers)", delta);
-	/* compute clustsize and round to the next page */
+	/* exact solution not found */
+	if (clustentries == 0) {
+		D("unsupported allocation for %d bytes", objsize);
+		return EINVAL;
+	}
+	/* compute clustsize */
 	clustsize = clustentries * objsize;
-	i =  (clustsize & (PAGE_SIZE - 1));
-	if (i)
-		clustsize += PAGE_SIZE - i;
 	if (netmap_verbose)
 		D("objsize %d clustsize %d objects %d",
 			objsize, clustsize, clustentries);
@@ -857,6 +986,47 @@ netmap_mem_reset_all(struct netmap_mem_d *nmd)
 }
 
 static int
+netmap_mem_unmap(struct netmap_obj_pool *p, struct netmap_adapter *na)
+{
+	int i, lim = p->_objtotal;
+
+	if (na->pdev == NULL)
+		return 0;
+
+#ifdef __FreeBSD__
+	(void)i;
+	(void)lim;
+	D("unsupported on FreeBSD");
+#else /* linux */
+	for (i = 2; i < lim; i++) {
+		netmap_unload_map(na, (bus_dma_tag_t) na->pdev, &p->lut[i].paddr);
+	}
+#endif /* linux */
+
+	return 0;
+}
+
+static int
+netmap_mem_map(struct netmap_obj_pool *p, struct netmap_adapter *na)
+{
+#ifdef __FreeBSD__
+	D("unsupported on FreeBSD");
+#else /* linux */
+	int i, lim = p->_objtotal;
+
+	if (na->pdev == NULL)
+		return 0;
+
+	for (i = 2; i < lim; i++) {
+		netmap_load_map(na, (bus_dma_tag_t) na->pdev, &p->lut[i].paddr,
+				p->lut[i].vaddr);
+	}
+#endif /* linux */
+
+	return 0;
+}
+
+static int
 netmap_mem_finalize_all(struct netmap_mem_d *nmd)
 {
 	int i;
@@ -1091,13 +1261,6 @@ netmap_mem_global_finalize(struct netmap_mem_d *nmd)
 	if (netmap_mem_finalize_all(nmd))
 		goto out;
 
-	/* backward compatibility */
-	netmap_buf_size = nmd->pools[NETMAP_BUF_POOL]._objsize;
-	netmap_total_buffers = nmd->pools[NETMAP_BUF_POOL].objtotal;
-
-	netmap_buffer_lut = nmd->pools[NETMAP_BUF_POOL].lut;
-	netmap_buffer_base = nmd->pools[NETMAP_BUF_POOL].lut[0].vaddr;
-
 	nmd->lasterr = 0;
 
 out:
@@ -1198,7 +1361,7 @@ netmap_mem_rings_create(struct netmap_adapter *na)
 		ring->cur = kring->rcur;
 		ring->tail = kring->rtail;
 		*(uint16_t *)(uintptr_t)&ring->nr_buf_size =
-			NETMAP_BDG_BUF_SIZE(na->nm_mem);
+			netmap_mem_bufsize(na->nm_mem);
 		ND("%s h %d c %d t %d", kring->name,
 			ring->head, ring->cur, ring->tail);
 		ND("initializing slots for txring");
@@ -1241,7 +1404,7 @@ netmap_mem_rings_create(struct netmap_adapter *na)
 		ring->cur = kring->rcur;
 		ring->tail = kring->rtail;
 		*(int *)(uintptr_t)&ring->nr_buf_size =
-			NETMAP_BDG_BUF_SIZE(na->nm_mem);
+			netmap_mem_bufsize(na->nm_mem);
 		ND("%s h %d c %d t %d", kring->name,
 			ring->head, ring->cur, ring->tail);
 		ND("initializing slots for rxring %p", ring);
@@ -1290,7 +1453,7 @@ netmap_mem_rings_delete(struct netmap_adapter *na)
  * the interface is in netmap mode.
  */
 struct netmap_if *
-netmap_mem_if_new(const char *ifname, struct netmap_adapter *na)
+netmap_mem_if_new(struct netmap_adapter *na)
 {
 	struct netmap_if *nifp;
 	ssize_t base; /* handy for relative offsets between rings and nifp */
@@ -1316,7 +1479,7 @@ netmap_mem_if_new(const char *ifname, struct netmap_adapter *na)
 	/* initialize base fields -- override const */
 	*(u_int *)(uintptr_t)&nifp->ni_tx_rings = na->num_tx_rings;
 	*(u_int *)(uintptr_t)&nifp->ni_rx_rings = na->num_rx_rings;
-	strncpy(nifp->ni_name, ifname, (size_t)IFNAMSIZ);
+	strncpy(nifp->ni_name, na->name, (size_t)IFNAMSIZ);
 
 	/*
 	 * fill the slots for the rx and tx rings. They contain the offset
@@ -1358,6 +1521,8 @@ netmap_mem_global_deref(struct netmap_mem_d *nmd)
 	NMA_LOCK(nmd);
 
 	nmd->refcount--;
+	if (!nmd->refcount)
+		nmd->nm_grp = -1;
 	if (netmap_verbose)
 		D("refcount = %d", nmd->refcount);
 
@@ -1365,13 +1530,25 @@ netmap_mem_global_deref(struct netmap_mem_d *nmd)
 }
 
 int
-netmap_mem_finalize(struct netmap_mem_d *nmd)
+netmap_mem_finalize(struct netmap_mem_d *nmd, struct netmap_adapter *na)
 {
-	return nmd->finalize(nmd);
+	if (nm_mem_assign_group(nmd, na->pdev) < 0) {
+		return ENOMEM;
+	} else {
+		nmd->finalize(nmd);
+	}
+
+	if (!nmd->lasterr && na->pdev)
+		netmap_mem_map(&nmd->pools[NETMAP_BUF_POOL], na);
+
+	return nmd->lasterr;
 }
 
 void
-netmap_mem_deref(struct netmap_mem_d *nmd)
+netmap_mem_deref(struct netmap_mem_d *nmd, struct netmap_adapter *na)
 {
+	NMA_LOCK(nmd);
+	netmap_mem_unmap(&nmd->pools[NETMAP_BUF_POOL], na);
+	NMA_UNLOCK(nmd);
 	return nmd->deref(nmd);
 }
diff --git a/sys/dev/netmap/netmap_mem2.h b/sys/dev/netmap/netmap_mem2.h
index e83616a..4c620bd 100644
--- a/sys/dev/netmap/netmap_mem2.h
+++ b/sys/dev/netmap/netmap_mem2.h
@@ -97,70 +97,6 @@
 #define _NET_NETMAP_MEM2_H_
 
 
-#define NETMAP_BUF_MAX_NUM	20*4096*2	/* large machine */
-
-#define NETMAP_POOL_MAX_NAMSZ	32
-
-
-enum {
-	NETMAP_IF_POOL   = 0,
-	NETMAP_RING_POOL,
-	NETMAP_BUF_POOL,
-	NETMAP_POOLS_NR
-};
-
-
-struct netmap_obj_params {
-	u_int size;
-	u_int num;
-};
-struct netmap_obj_pool {
-	char name[NETMAP_POOL_MAX_NAMSZ];	/* name of the allocator */
-
-	/* ---------------------------------------------------*/
-	/* these are only meaningful if the pool is finalized */
-	/* (see 'finalized' field in netmap_mem_d)            */
-	u_int objtotal;         /* actual total number of objects. */
-	u_int memtotal;		/* actual total memory space */
-	u_int numclusters;	/* actual number of clusters */
-
-	u_int objfree;          /* number of free objects. */
-
-	struct lut_entry *lut;  /* virt,phys addresses, objtotal entries */
-	uint32_t *bitmap;       /* one bit per buffer, 1 means free */
-	uint32_t bitmap_slots;	/* number of uint32 entries in bitmap */
-	/* ---------------------------------------------------*/
-
-	/* limits */
-	u_int objminsize;	/* minimum object size */
-	u_int objmaxsize;	/* maximum object size */
-	u_int nummin;		/* minimum number of objects */
-	u_int nummax;		/* maximum number of objects */
-
-	/* these are changed only by config */
-	u_int _objtotal;	/* total number of objects */
-	u_int _objsize;		/* object size */
-	u_int _clustsize;       /* cluster size */
-	u_int _clustentries;    /* objects per cluster */
-	u_int _numclusters;	/* number of clusters */
-
-	/* requested values */
-	u_int r_objtotal;
-	u_int r_objsize;
-};
-
-#ifdef linux
-// XXX a mtx would suffice here 20130415 lr
-#define NMA_LOCK_T		struct semaphore
-#else /* !linux */
-#define NMA_LOCK_T		struct mtx
-#endif /* linux */
-
-typedef int (*netmap_mem_config_t)(struct netmap_mem_d*);
-typedef int (*netmap_mem_finalize_t)(struct netmap_mem_d*);
-typedef void (*netmap_mem_deref_t)(struct netmap_mem_d*);
-
-typedef uint16_t nm_memid_t;
 
 /* We implement two kinds of netmap_mem_d structures:
  *
@@ -178,40 +114,21 @@ typedef uint16_t nm_memid_t;
  * are no active users.  By 'active user' we mean an existing netmap_priv
  * structure holding a reference to the allocator.
  */
-struct netmap_mem_d {
-	NMA_LOCK_T nm_mtx;  /* protect the allocator */
-	u_int nm_totalsize; /* shorthand */
-
-	u_int flags;
-#define NETMAP_MEM_FINALIZED	0x1	/* preallocation done */
-#define NETMAP_MEM_PRIVATE	0x2	/* uses private address space */
-	int lasterr;		/* last error for curr config */
-	int refcount;		/* existing priv structures */
-	/* the three allocators */
-	struct netmap_obj_pool pools[NETMAP_POOLS_NR];
-
-	netmap_mem_config_t   config;
-	netmap_mem_finalize_t finalize;
-	netmap_mem_deref_t    deref;
-
-	nm_memid_t nm_id;	/* allocator identifier */
-
-	/* list of all existing allocators, sorted by nm_id */
-	struct netmap_mem_d *prev, *next;
-};
 
 extern struct netmap_mem_d nm_mem;
 
+struct lut_entry* netmap_mem_get_lut(struct netmap_mem_d *);
+u_int      netmap_mem_get_buftotal(struct netmap_mem_d *);
+size_t     netmap_mem_get_bufsize(struct netmap_mem_d *);
 vm_paddr_t netmap_mem_ofstophys(struct netmap_mem_d *, vm_ooffset_t);
-int	   netmap_mem_finalize(struct netmap_mem_d *);
+int	   netmap_mem_finalize(struct netmap_mem_d *, struct netmap_adapter *);
 int 	   netmap_mem_init(void);
 void 	   netmap_mem_fini(void);
-struct netmap_if *
-	   netmap_mem_if_new(const char *, struct netmap_adapter *);
+struct netmap_if * netmap_mem_if_new(struct netmap_adapter *);
 void 	   netmap_mem_if_delete(struct netmap_adapter *, struct netmap_if *);
 int	   netmap_mem_rings_create(struct netmap_adapter *);
 void	   netmap_mem_rings_delete(struct netmap_adapter *);
-void 	   netmap_mem_deref(struct netmap_mem_d *);
+void 	   netmap_mem_deref(struct netmap_mem_d *, struct netmap_adapter *);
 int	   netmap_mem_get_info(struct netmap_mem_d *, u_int *size, u_int *memflags, uint16_t *id);
 ssize_t    netmap_mem_if_offset(struct netmap_mem_d *, const void *vaddr);
 struct netmap_mem_d* netmap_mem_private_new(const char *name,
@@ -219,7 +136,8 @@ struct netmap_mem_d* netmap_mem_private_new(const char *name,
 	int* error);
 void	   netmap_mem_private_delete(struct netmap_mem_d *);
 
-#define NETMAP_BDG_BUF_SIZE(n)	((n)->pools[NETMAP_BUF_POOL]._objsize)
+#define NETMAP_MEM_PRIVATE	0x2	/* allocator uses private address space */
+#define NETMAP_MEM_IO		0x4	/* the underlying memory is mmapped I/O */
 
 uint32_t netmap_extra_alloc(struct netmap_adapter *, uint32_t *, uint32_t n);
 
diff --git a/sys/dev/netmap/netmap_monitor.c b/sys/dev/netmap/netmap_monitor.c
new file mode 100644
index 0000000..485c370
--- /dev/null
+++ b/sys/dev/netmap/netmap_monitor.c
@@ -0,0 +1,498 @@
+/*
+ * Copyright (C) 2014 Giuseppe Lettieri. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * $FreeBSD$
+ *
+ * Monitors
+ *
+ * netmap monitors can be used to do zero-copy monitoring of network traffic
+ * on another adapter, when the latter adapter is working in netmap mode.
+ *
+ * Monitors offer to userspace the same interface as any other netmap port,
+ * with as many pairs of netmap rings as the monitored adapter.
+ * However, only the rx rings are actually used. Each monitor rx ring receives
+ * the traffic transiting on both the tx and rx corresponding rings in the
+ * monitored adapter. During registration, the user can choose if she wants
+ * to intercept tx only, rx only, or both tx and rx traffic.
+ *
+ * The monitor only sees the frames after they have been consumed in the
+ * monitored adapter:
+ *
+ *  - For tx traffic, this is after the slots containing the frames have been
+ *    marked as free. Note that this may happen at a considerably delay after
+ *    frame transmission, since freeing of slots is often done lazily.
+ *
+ *  - For rx traffic, this is after the consumer on the monitored adapter
+ *    has released them. In most cases, the consumer is a userspace
+ *    application which may have modified the frame contents.
+ *
+ * If the monitor is not able to cope with the stream of frames, excess traffic
+ * will be dropped.
+ *
+ * Each ring can be monitored by at most one monitor. This may change in the
+ * future, if we implement monitor chaining.
+ *
+ */
+
+
+#if defined(__FreeBSD__)
+#include <sys/cdefs.h> /* prerequisite */
+
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/param.h>	/* defines used in kernel.h */
+#include <sys/kernel.h>	/* types used in module initialization */
+#include <sys/malloc.h>
+#include <sys/poll.h>
+#include <sys/lock.h>
+#include <sys/rwlock.h>
+#include <sys/selinfo.h>
+#include <sys/sysctl.h>
+#include <sys/socket.h> /* sockaddrs */
+#include <net/if.h>
+#include <net/if_var.h>
+#include <machine/bus.h>	/* bus_dmamap_* */
+#include <sys/refcount.h>
+
+
+#elif defined(linux)
+
+#include "bsd_glue.h"
+
+#elif defined(__APPLE__)
+
+#warning OSX support is only partial
+#include "osx_glue.h"
+
+#else
+
+#error	Unsupported platform
+
+#endif /* unsupported */
+
+/*
+ * common headers
+ */
+
+#include <net/netmap.h>
+#include <dev/netmap/netmap_kern.h>
+#include <dev/netmap/netmap_mem2.h>
+
+#ifdef WITH_MONITOR
+
+#define NM_MONITOR_MAXSLOTS 4096
+
+/* monitor works by replacing the nm_sync callbacks in the monitored rings.
+ * The actions to be performed are the same on both tx and rx rings, so we
+ * have collected them here
+ */
+static int
+netmap_monitor_parent_sync(struct netmap_kring *kring, int flags, u_int* ringptr)
+{
+	struct netmap_monitor_adapter *mna = kring->monitor;
+	struct netmap_kring *mkring = &mna->up.rx_rings[kring->ring_id];
+	struct netmap_ring *ring = kring->ring, *mring = mkring->ring;
+	int error;
+	int rel_slots, free_slots, busy;
+	u_int beg, end, i;
+	u_int lim = kring->nkr_num_slots - 1,
+	      mlim = mkring->nkr_num_slots - 1;
+
+	/* get the relased slots (rel_slots) */
+	beg = *ringptr;
+	error = kring->save_sync(kring, flags);
+	if (error)
+		return error;
+	end = *ringptr;
+	rel_slots = end - beg;
+	if (rel_slots < 0)
+		rel_slots += kring->nkr_num_slots;
+
+	if (!rel_slots) {
+		return 0;
+	}
+
+	/* we need to lock the monitor receive ring, since it
+	 * is the target of bot tx and rx traffic from the monitored
+	 * adapter
+	 */
+	mtx_lock(&mkring->q_lock);
+	/* get the free slots available on the monitor ring */
+	i = mkring->nr_hwtail;
+	busy = i - mkring->nr_hwcur;
+	if (busy < 0)
+		busy += mkring->nkr_num_slots;
+	free_slots = mlim - busy;
+
+	if (!free_slots) {
+		mtx_unlock(&mkring->q_lock);
+		return 0;
+	}
+
+	/* swap min(free_slots, rel_slots) slots */
+	if (free_slots < rel_slots) {
+		beg += (rel_slots - free_slots);
+		if (beg > lim)
+			beg = 0;
+		rel_slots = free_slots;
+	}
+
+	for ( ; rel_slots; rel_slots--) {
+		struct netmap_slot *s = &ring->slot[beg];
+		struct netmap_slot *ms = &mring->slot[i];
+		uint32_t tmp;
+
+		tmp = ms->buf_idx;
+		ms->buf_idx = s->buf_idx;
+		s->buf_idx = tmp;
+
+		tmp = ms->len;
+		ms->len = s->len;
+		s->len = tmp;
+
+		s->flags |= NS_BUF_CHANGED;
+
+		beg = nm_next(beg, lim);
+		i = nm_next(i, mlim);
+
+	}
+	wmb();
+	mkring->nr_hwtail = i;
+
+	mtx_unlock(&mkring->q_lock);
+	/* notify the new frames to the monitor */
+	mna->up.nm_notify(&mna->up, mkring->ring_id, NR_RX, 0);
+	return 0;
+}
+
+/* callback used to replace the nm_sync callback in the monitored tx rings */
+static int
+netmap_monitor_parent_txsync(struct netmap_kring *kring, int flags)
+{
+        ND("%s %x", kring->name, flags);
+        return netmap_monitor_parent_sync(kring, flags, &kring->nr_hwtail);
+}
+
+/* callback used to replace the nm_sync callback in the monitored rx rings */
+static int
+netmap_monitor_parent_rxsync(struct netmap_kring *kring, int flags)
+{
+        ND("%s %x", kring->name, flags);
+        return netmap_monitor_parent_sync(kring, flags, &kring->rcur);
+}
+
+/* nm_sync callback for the monitor's own tx rings.
+ * This makes no sense and always returns error
+ */
+static int
+netmap_monitor_txsync(struct netmap_kring *kring, int flags)
+{
+        D("%s %x", kring->name, flags);
+	return EIO;
+}
+
+/* nm_sync callback for the monitor's own rx rings.
+ * Note that the lock in netmap_monitor_parent_sync only protects
+ * writers among themselves. Synchronization between writers
+ * (i.e., netmap_monitor_parent_txsync and netmap_monitor_parent_rxsync)
+ * and readers (i.e., netmap_monitor_rxsync) relies on memory barriers.
+ */
+static int
+netmap_monitor_rxsync(struct netmap_kring *kring, int flags)
+{
+        ND("%s %x", kring->name, flags);
+	kring->nr_hwcur = kring->rcur;
+	rmb();
+	nm_rxsync_finalize(kring);
+        return 0;
+}
+
+/* nm_krings_create callbacks for monitors.
+ * We could use the default netmap_hw_krings_monitor, but
+ * we don't need the mbq.
+ */
+static int
+netmap_monitor_krings_create(struct netmap_adapter *na)
+{
+	return netmap_krings_create(na, 0);
+}
+
+
+/* nm_register callback for monitors.
+ *
+ * On registration, replace the nm_sync callbacks in the monitored
+ * rings with our own, saving the previous ones in the monitored
+ * rings themselves, where they are used by netmap_monitor_parent_sync.
+ *
+ * On de-registration, restore the original callbacks. We need to
+ * stop traffic while we are doing this, since the monitored adapter may
+ * have already started executing a netmap_monitor_parent_sync
+ * and may not like the kring->save_sync pointer to become NULL.
+ */
+static int
+netmap_monitor_reg(struct netmap_adapter *na, int onoff)
+{
+	struct netmap_monitor_adapter *mna =
+		(struct netmap_monitor_adapter *)na;
+	struct netmap_priv_d *priv = &mna->priv;
+	struct netmap_adapter *pna = priv->np_na;
+	struct netmap_kring *kring;
+	int i;
+
+	ND("%p: onoff %d", na, onoff);
+	if (onoff) {
+		if (!nm_netmap_on(pna)) {
+			/* parent left netmap mode, fatal */
+			return ENXIO;
+		}
+		if (mna->flags & NR_MONITOR_TX) {
+			for (i = priv->np_txqfirst; i < priv->np_txqlast; i++) {
+				kring = &pna->tx_rings[i];
+				kring->save_sync = kring->nm_sync;
+				kring->nm_sync = netmap_monitor_parent_txsync;
+			}
+		}
+		if (mna->flags & NR_MONITOR_RX) {
+			for (i = priv->np_rxqfirst; i < priv->np_rxqlast; i++) {
+				kring = &pna->rx_rings[i];
+				kring->save_sync = kring->nm_sync;
+				kring->nm_sync = netmap_monitor_parent_rxsync;
+			}
+		}
+		na->na_flags |= NAF_NETMAP_ON;
+	} else {
+		if (!nm_netmap_on(pna)) {
+			/* parent left netmap mode, nothing to restore */
+			return 0;
+		}
+		na->na_flags &= ~NAF_NETMAP_ON;
+		if (mna->flags & NR_MONITOR_TX) {
+			for (i = priv->np_txqfirst; i < priv->np_txqlast; i++) {
+				netmap_set_txring(pna, i, 1 /* stopped */);
+				kring = &pna->tx_rings[i];
+				kring->nm_sync = kring->save_sync;
+				kring->save_sync = NULL;
+				netmap_set_txring(pna, i, 0 /* enabled */);
+			}
+		}
+		if (mna->flags & NR_MONITOR_RX) {
+			for (i = priv->np_rxqfirst; i < priv->np_rxqlast; i++) {
+				netmap_set_rxring(pna, i, 1 /* stopped */);
+				kring = &pna->rx_rings[i];
+				kring->nm_sync = kring->save_sync;
+				kring->save_sync = NULL;
+				netmap_set_rxring(pna, i, 0 /* enabled */);
+			}
+		}
+	}
+	return 0;
+}
+/* nm_krings_delete callback for monitors */
+static void
+netmap_monitor_krings_delete(struct netmap_adapter *na)
+{
+	netmap_krings_delete(na);
+}
+
+
+/* nm_dtor callback for monitors */
+static void
+netmap_monitor_dtor(struct netmap_adapter *na)
+{
+	struct netmap_monitor_adapter *mna =
+		(struct netmap_monitor_adapter *)na;
+	struct netmap_priv_d *priv = &mna->priv;
+	struct netmap_adapter *pna = priv->np_na;
+	int i;
+
+	ND("%p", na);
+	if (nm_netmap_on(pna)) {
+		/* parent still in netmap mode, mark its krings as free */
+		if (mna->flags & NR_MONITOR_TX) {
+			for (i = priv->np_txqfirst; i < priv->np_txqlast; i++) {
+				pna->tx_rings[i].monitor = NULL;
+			}
+		}
+		if (mna->flags & NR_MONITOR_RX) {
+			for (i = priv->np_rxqfirst; i < priv->np_rxqlast; i++) {
+				pna->rx_rings[i].monitor = NULL;
+			}
+		}
+	}
+	netmap_adapter_put(pna);
+}
+
+
+/* check if nmr is a request for a monitor adapter that we can satisfy */
+int
+netmap_get_monitor_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
+{
+	struct nmreq pnmr;
+	struct netmap_adapter *pna; /* parent adapter */
+	struct netmap_monitor_adapter *mna;
+	int i, error;
+
+	if ((nmr->nr_flags & (NR_MONITOR_TX | NR_MONITOR_RX)) == 0) {
+		ND("not a monitor");
+		return 0;
+	}
+	/* this is a request for a monitor adapter */
+
+	D("flags %x", nmr->nr_flags);
+
+	mna = malloc(sizeof(*mna), M_DEVBUF, M_NOWAIT | M_ZERO);
+	if (mna == NULL) {
+		D("memory error");
+		return ENOMEM;
+	}
+
+	/* first, try to find the adapter that we want to monitor
+	 * We use the same nmr, after we have turned off the monitor flags.
+	 * In this way we can potentially monitor everything netmap understands,
+	 * except other monitors.
+	 */
+	memcpy(&pnmr, nmr, sizeof(pnmr));
+	pnmr.nr_flags &= ~(NR_MONITOR_TX | NR_MONITOR_RX);
+	error = netmap_get_na(&pnmr, &pna, create);
+	if (error) {
+		D("parent lookup failed: %d", error);
+		return error;
+	}
+	D("found parent: %s", pna->name);
+
+	if (!nm_netmap_on(pna)) {
+		/* parent not in netmap mode */
+		/* XXX we can wait for the parent to enter netmap mode,
+		 * by intercepting its nm_register callback (2014-03-16)
+		 */
+		D("%s not in netmap mode", pna->name);
+		error = EINVAL;
+		goto put_out;
+	}
+
+	/* grab all the rings we need in the parent */
+	mna->priv.np_na = pna;
+	error = netmap_interp_ringid(&mna->priv, nmr->nr_ringid, nmr->nr_flags);
+	if (error) {
+		D("ringid error");
+		goto put_out;
+	}
+	if (nmr->nr_flags & NR_MONITOR_TX) {
+		for (i = mna->priv.np_txqfirst; i < mna->priv.np_txqlast; i++) {
+			struct netmap_kring *kring = &pna->tx_rings[i];
+			if (kring->monitor) {
+				error = EBUSY;
+				D("ring busy");
+				goto release_out;
+			}
+			kring->monitor = mna;
+		}
+	}
+	if (nmr->nr_flags & NR_MONITOR_RX) {
+		for (i = mna->priv.np_rxqfirst; i < mna->priv.np_rxqlast; i++) {
+			struct netmap_kring *kring = &pna->rx_rings[i];
+			if (kring->monitor) {
+				error = EBUSY;
+				D("ring busy");
+				goto release_out;
+			}
+			kring->monitor = mna;
+		}
+	}
+
+	snprintf(mna->up.name, sizeof(mna->up.name), "mon:%s", pna->name);
+
+	/* the monitor supports the host rings iff the parent does */
+	mna->up.na_flags = (pna->na_flags & NAF_HOST_RINGS);
+	mna->up.nm_txsync = netmap_monitor_txsync;
+	mna->up.nm_rxsync = netmap_monitor_rxsync;
+	mna->up.nm_register = netmap_monitor_reg;
+	mna->up.nm_dtor = netmap_monitor_dtor;
+	mna->up.nm_krings_create = netmap_monitor_krings_create;
+	mna->up.nm_krings_delete = netmap_monitor_krings_delete;
+	mna->up.nm_mem = pna->nm_mem;
+	mna->up.na_lut = pna->na_lut;
+	mna->up.na_lut_objtotal = pna->na_lut_objtotal;
+	mna->up.na_lut_objsize = pna->na_lut_objsize;
+
+	mna->up.num_tx_rings = 1; // XXX we don't need it, but field can't be zero
+	/* we set the number of our rx_rings to be max(num_rx_rings, num_rx_rings)
+	 * in the parent
+	 */
+	mna->up.num_rx_rings = pna->num_rx_rings;
+	if (pna->num_tx_rings > pna->num_rx_rings)
+		mna->up.num_rx_rings = pna->num_tx_rings;
+	/* by default, the number of slots is the same as in
+	 * the parent rings, but the user may ask for a different
+	 * number
+	 */
+	mna->up.num_tx_desc = nmr->nr_tx_slots;
+	nm_bound_var(&mna->up.num_tx_desc, pna->num_tx_desc,
+			1, NM_MONITOR_MAXSLOTS, NULL);
+	mna->up.num_rx_desc = nmr->nr_rx_slots;
+	nm_bound_var(&mna->up.num_rx_desc, pna->num_rx_desc,
+			1, NM_MONITOR_MAXSLOTS, NULL);
+	error = netmap_attach_common(&mna->up);
+	if (error) {
+		D("attach_common error");
+		goto release_out;
+	}
+
+	/* remember the traffic directions we have to monitor */
+	mna->flags = (nmr->nr_flags & (NR_MONITOR_TX | NR_MONITOR_RX));
+
+	*na = &mna->up;
+	netmap_adapter_get(*na);
+
+	/* write the configuration back */
+	nmr->nr_tx_rings = mna->up.num_tx_rings;
+	nmr->nr_rx_rings = mna->up.num_rx_rings;
+	nmr->nr_tx_slots = mna->up.num_tx_desc;
+	nmr->nr_rx_slots = mna->up.num_rx_desc;
+
+	/* keep the reference to the parent */
+	D("monitor ok");
+
+	return 0;
+
+release_out:
+	D("monitor error");
+	for (i = mna->priv.np_txqfirst; i < mna->priv.np_txqlast; i++) {
+		if (pna->tx_rings[i].monitor == mna)
+			pna->tx_rings[i].monitor = NULL;
+	}
+	for (i = mna->priv.np_rxqfirst; i < mna->priv.np_rxqlast; i++) {
+		if (pna->rx_rings[i].monitor == mna)
+			pna->rx_rings[i].monitor = NULL;
+	}
+put_out:
+	netmap_adapter_put(pna);
+	free(mna, M_DEVBUF);
+	return error;
+}
+
+
+#endif /* WITH_MONITOR */
diff --git a/sys/dev/netmap/netmap_offloadings.c b/sys/dev/netmap/netmap_offloadings.c
index a776a24..34eafab 100644
--- a/sys/dev/netmap/netmap_offloadings.c
+++ b/sys/dev/netmap/netmap_offloadings.c
@@ -159,7 +159,7 @@ void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
 	src = ft_p->ft_buf;
 	src_len = ft_p->ft_len;
 	slot = &ring->slot[*j];
-	dst = BDG_NMB(&dst_na->up, slot);
+	dst = NMB(&dst_na->up, slot);
 	dst_len = src_len;
 
 	/* We are processing the first input slot and there is a mismatch
@@ -303,7 +303,7 @@ void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
 				/* Next destination slot. */
 				*j = nm_next(*j, lim);
 				slot = &ring->slot[*j];
-				dst = BDG_NMB(&dst_na->up, slot);
+				dst = NMB(&dst_na->up, slot);
 
 				gso_bytes = 0;
 				gso_idx++;
@@ -365,7 +365,7 @@ void bdg_mismatch_datapath(struct netmap_vp_adapter *na,
 			/* Next destination slot. */
 			*j = nm_next(*j, lim);
 			slot = &ring->slot[*j];
-			dst = BDG_NMB(&dst_na->up, slot);
+			dst = NMB(&dst_na->up, slot);
 
 			/* Next source slot. */
 			ft_p++;
diff --git a/sys/dev/netmap/netmap_pipe.c b/sys/dev/netmap/netmap_pipe.c
index 9fcc4d2..bc998c0 100644
--- a/sys/dev/netmap/netmap_pipe.c
+++ b/sys/dev/netmap/netmap_pipe.c
@@ -126,7 +126,7 @@ void
 netmap_pipe_dealloc(struct netmap_adapter *na)
 {
 	if (na->na_pipes) {
-		ND("freeing pipes for %s", NM_IFPNAME(na->ifp));
+		ND("freeing pipes for %s", na->name);
 		free(na->na_pipes, M_DEVBUF);
 		na->na_pipes = NULL;
 		na->na_max_pipes = 0;
@@ -155,7 +155,7 @@ static int
 netmap_pipe_add(struct netmap_adapter *parent, struct netmap_pipe_adapter *na)
 {
 	if (parent->na_next_pipe >= parent->na_max_pipes) {
-		D("%s: no space left for pipes", NM_IFPNAME(parent->ifp));
+		D("%s: no space left for pipes", parent->name);
 		return ENOMEM;
 	}
 
@@ -179,10 +179,9 @@ netmap_pipe_remove(struct netmap_adapter *parent, struct netmap_pipe_adapter *na
 }
 
 static int
-netmap_pipe_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+netmap_pipe_txsync(struct netmap_kring *txkring, int flags)
 {
-        struct netmap_kring *txkring = na->tx_rings + ring_nr,
-		*rxkring = txkring->pipe;
+        struct netmap_kring *rxkring = txkring->pipe;
         u_int limit; /* slots to transfer */
         u_int j, k, lim_tx = txkring->nkr_num_slots - 1,
                 lim_rx = rxkring->nkr_num_slots - 1;
@@ -245,10 +244,9 @@ netmap_pipe_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 }
 
 static int
-netmap_pipe_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+netmap_pipe_rxsync(struct netmap_kring *rxkring, int flags)
 {
-        struct netmap_kring *rxkring = na->rx_rings + ring_nr,
-		*txkring = rxkring->pipe;
+        struct netmap_kring *txkring = rxkring->pipe;
 	uint32_t oldhwcur = rxkring->nr_hwcur;
 
         ND("%s %x <- %s", rxkring->name, flags, txkring->name);
@@ -425,12 +423,11 @@ netmap_pipe_reg(struct netmap_adapter *na, int onoff)
 {
 	struct netmap_pipe_adapter *pna =
 		(struct netmap_pipe_adapter *)na;
-	struct ifnet *ifp = na->ifp;
 	ND("%p: onoff %d", na, onoff);
 	if (onoff) {
-		ifp->if_capenable |= IFCAP_NETMAP;
+		na->na_flags |= NAF_NETMAP_ON;
 	} else {
-		ifp->if_capenable &= ~IFCAP_NETMAP;
+		na->na_flags &= ~NAF_NETMAP_ON;
 	}
 	if (pna->peer_ref) {
 		ND("%p: case 1.a or 2.a, nothing to do", na);
@@ -522,8 +519,6 @@ netmap_pipe_dtor(struct netmap_adapter *na)
 	if (pna->role == NR_REG_PIPE_MASTER)
 		netmap_pipe_remove(pna->parent, pna);
 	netmap_adapter_put(pna->parent);
-	free(na->ifp, M_DEVBUF);
-	na->ifp = NULL;
 	pna->parent = NULL;
 }
 
@@ -533,7 +528,6 @@ netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 	struct nmreq pnmr;
 	struct netmap_adapter *pna; /* parent adapter */
 	struct netmap_pipe_adapter *mna, *sna, *req;
-	struct ifnet *ifp, *ifp2;
 	u_int pipe_id;
 	int role = nmr->nr_flags & NR_REG_MASK;
 	int error;
@@ -556,7 +550,7 @@ netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 		ND("parent lookup failed: %d", error);
 		return error;
 	}
-	ND("found parent: %s", NM_IFPNAME(pna->ifp));
+	ND("found parent: %s", na->name);
 
 	if (NETMAP_OWNED_BY_KERN(pna)) {
 		ND("parent busy");
@@ -591,19 +585,12 @@ netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
          * The endpoint we were asked for holds a reference to
          * the other one.
          */
-	ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT | M_ZERO);
-	if (!ifp) {
-		error = ENOMEM;
-		goto put_out;
-	}
-	strcpy(ifp->if_xname, NM_IFPNAME(pna->ifp));
-
 	mna = malloc(sizeof(*mna), M_DEVBUF, M_NOWAIT | M_ZERO);
 	if (mna == NULL) {
 		error = ENOMEM;
-		goto free_ifp;
+		goto put_out;
 	}
-	mna->up.ifp = ifp;
+	snprintf(mna->up.name, sizeof(mna->up.name), "%s{%d", pna->name, pipe_id);
 
 	mna->id = pipe_id;
 	mna->role = NR_REG_PIPE_MASTER;
@@ -618,6 +605,7 @@ netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 	mna->up.nm_mem = pna->nm_mem;
 	mna->up.na_lut = pna->na_lut;
 	mna->up.na_lut_objtotal = pna->na_lut_objtotal;
+	mna->up.na_lut_objsize = pna->na_lut_objsize;
 
 	mna->up.num_tx_rings = 1;
 	mna->up.num_rx_rings = 1;
@@ -629,28 +617,21 @@ netmap_get_pipe_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 			1, NM_PIPE_MAXSLOTS, NULL);
 	error = netmap_attach_common(&mna->up);
 	if (error)
-		goto free_ifp;
+		goto free_mna;
 	/* register the master with the parent */
 	error = netmap_pipe_add(pna, mna);
 	if (error)
 		goto free_mna;
 
 	/* create the slave */
-	ifp2 = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT | M_ZERO);
-	if (!ifp) {
-		error = ENOMEM;
-		goto free_mna;
-	}
-	strcpy(ifp2->if_xname, NM_IFPNAME(pna->ifp));
-
 	sna = malloc(sizeof(*mna), M_DEVBUF, M_NOWAIT | M_ZERO);
 	if (sna == NULL) {
 		error = ENOMEM;
-		goto free_ifp2;
+		goto free_mna;
 	}
 	/* most fields are the same, copy from master and then fix */
 	*sna = *mna;
-	sna->up.ifp = ifp2;
+	snprintf(sna->up.name, sizeof(sna->up.name), "%s}%d", pna->name, pipe_id);
 	sna->role = NR_REG_PIPE_SLAVE;
 	error = netmap_attach_common(&sna->up);
 	if (error)
@@ -696,12 +677,8 @@ found:
 
 free_sna:
 	free(sna, M_DEVBUF);
-free_ifp2:
-	free(ifp2, M_DEVBUF);
 free_mna:
 	free(mna, M_DEVBUF);
-free_ifp:
-	free(ifp, M_DEVBUF);
 put_out:
 	netmap_adapter_put(pna);
 	return error;
diff --git a/sys/dev/netmap/netmap_vale.c b/sys/dev/netmap/netmap_vale.c
index 8e309e9..6b1fe1f 100644
--- a/sys/dev/netmap/netmap_vale.c
+++ b/sys/dev/netmap/netmap_vale.c
@@ -157,11 +157,9 @@ SYSCTL_DECL(_dev_netmap);
 SYSCTL_INT(_dev_netmap, OID_AUTO, bridge_batch, CTLFLAG_RW, &bridge_batch, 0 , "");
 
 
-static int bdg_netmap_attach(struct nmreq *nmr, struct ifnet *ifp);
-static int bdg_netmap_reg(struct netmap_adapter *na, int onoff);
-static int netmap_bwrap_attach(struct ifnet *, struct ifnet *);
+static int netmap_vp_create(struct nmreq *, struct ifnet *, struct netmap_vp_adapter **);
+static int netmap_vp_reg(struct netmap_adapter *na, int onoff);
 static int netmap_bwrap_register(struct netmap_adapter *, int onoff);
-int kern_netmap_regif(struct nmreq *nmr);
 
 /*
  * For each output interface, nm_bdg_q is used to construct a list.
@@ -217,7 +215,7 @@ struct nm_bridge {
 	 * different ring index.
 	 * This function must be set by netmap_bdgctl().
 	 */
-	bdg_lookup_fn_t nm_bdg_lookup;
+	struct netmap_bdg_ops bdg_ops;
 
 	/* the forwarding table, MAC+ports.
 	 * XXX should be changed to an argument to be passed to
@@ -226,6 +224,15 @@ struct nm_bridge {
 	struct nm_hash_ent ht[NM_BDG_HASH];
 };
 
+const char*
+netmap_bdg_name(struct netmap_vp_adapter *vp)
+{
+	struct nm_bridge *b = vp->na_bdg;
+	if (b == NULL)
+		return NULL;
+	return b->bdg_basename;
+}
+
 
 /*
  * XXX in principle nm_bridges could be created dynamically
@@ -321,7 +328,7 @@ nm_find_bridge(const char *name, int create)
 		for (i = 0; i < NM_BDG_MAXPORTS; i++)
 			b->bdg_port_index[i] = i;
 		/* set the default function */
-		b->nm_bdg_lookup = netmap_bdg_learning;
+		b->bdg_ops.lookup = netmap_bdg_learning;
 		/* reset the MAC address table */
 		bzero(b->ht, sizeof(struct nm_hash_ent) * NM_BDG_HASH);
 	}
@@ -389,6 +396,9 @@ nm_alloc_bdgfwd(struct netmap_adapter *na)
 }
 
 
+/* remove from bridge b the ports in slots hw and sw
+ * (sw can be -1 if not needed)
+ */
 static void
 netmap_bdg_detach_common(struct nm_bridge *b, int hw, int sw)
 {
@@ -434,6 +444,8 @@ netmap_bdg_detach_common(struct nm_bridge *b, int hw, int sw)
 	}
 
 	BDG_WLOCK(b);
+	if (b->bdg_ops.dtor)
+		b->bdg_ops.dtor(b->bdg_ports[s_hw]);
 	b->bdg_ports[s_hw] = NULL;
 	if (s_sw >= 0) {
 		b->bdg_ports[s_sw] = NULL;
@@ -445,29 +457,131 @@ netmap_bdg_detach_common(struct nm_bridge *b, int hw, int sw)
 	ND("now %d active ports", lim);
 	if (lim == 0) {
 		ND("marking bridge %s as free", b->bdg_basename);
-		b->nm_bdg_lookup = NULL;
+		bzero(&b->bdg_ops, sizeof(b->bdg_ops));
 	}
 }
 
+/* nm_bdg_ctl callback for VALE ports */
+static int
+netmap_vp_bdg_ctl(struct netmap_adapter *na, struct nmreq *nmr, int attach)
+{
+	struct netmap_vp_adapter *vpna = (struct netmap_vp_adapter *)na;
+	struct nm_bridge *b = vpna->na_bdg;
+
+	if (attach)
+		return 0; /* nothing to do */
+	if (b) {
+		netmap_set_all_rings(na, 0 /* disable */);
+		netmap_bdg_detach_common(b, vpna->bdg_port, -1);
+		vpna->na_bdg = NULL;
+		netmap_set_all_rings(na, 1 /* enable */);
+	}
+	/* I have took reference just for attach */
+	netmap_adapter_put(na);
+	return 0;
+}
 
+/* nm_dtor callback for ephemeral VALE ports */
 static void
-netmap_adapter_vp_dtor(struct netmap_adapter *na)
+netmap_vp_dtor(struct netmap_adapter *na)
 {
 	struct netmap_vp_adapter *vpna = (struct netmap_vp_adapter*)na;
 	struct nm_bridge *b = vpna->na_bdg;
-	struct ifnet *ifp = na->ifp;
 
-	ND("%s has %d references", NM_IFPNAME(ifp), na->na_refcount);
+	ND("%s has %d references", na->name, na->na_refcount);
 
 	if (b) {
 		netmap_bdg_detach_common(b, vpna->bdg_port, -1);
 	}
+}
 
-	bzero(ifp, sizeof(*ifp));
-	free(ifp, M_DEVBUF);
+/* nm_dtor callback for persistent VALE ports */
+static void
+netmap_persist_vp_dtor(struct netmap_adapter *na)
+{
+	struct ifnet *ifp = na->ifp;
+
+	netmap_vp_dtor(na);
 	na->ifp = NULL;
+	nm_vi_detach(ifp);
+}
+
+/* remove a persistent VALE port from the system */
+static int
+nm_vi_destroy(const char *name)
+{
+	struct ifnet *ifp;
+	int error;
+
+	ifp = ifunit_ref(name);
+	if (!ifp)
+		return ENXIO;
+	NMG_LOCK();
+	/* make sure this is actually a VALE port */
+	if (!NETMAP_CAPABLE(ifp) || NA(ifp)->nm_register != netmap_vp_reg) {
+		error = EINVAL;
+		goto err;
+	}
+
+	if (NA(ifp)->na_refcount > 1) {
+		error = EBUSY;
+		goto err;
+	}
+	NMG_UNLOCK();
+
+	D("destroying a persistent vale interface %s", ifp->if_xname);
+	/* Linux requires all the references are released
+	 * before unregister
+	 */
+	if_rele(ifp);
+	netmap_detach(ifp);
+	return 0;
+
+err:
+	NMG_UNLOCK();
+	if_rele(ifp);
+	return error;
 }
 
+/*
+ * Create a virtual interface registered to the system.
+ * The interface will be attached to a bridge later.
+ */
+static int
+nm_vi_create(struct nmreq *nmr)
+{
+	struct ifnet *ifp;
+	struct netmap_vp_adapter *vpna;
+	int error;
+
+	/* don't include VALE prefix */
+	if (!strncmp(nmr->nr_name, NM_NAME, strlen(NM_NAME)))
+		return EINVAL;
+	ifp = ifunit_ref(nmr->nr_name);
+	if (ifp) { /* already exist, cannot create new one */
+		if_rele(ifp);
+		return EEXIST;
+	}
+	error = nm_vi_persist(nmr->nr_name, &ifp);
+	if (error)
+		return error;
+
+	NMG_LOCK();
+	/* netmap_vp_create creates a struct netmap_vp_adapter */
+	error = netmap_vp_create(nmr, ifp, &vpna);
+	if (error) {
+		D("error %d", error);
+		nm_vi_detach(ifp);
+		return error;
+	}
+	/* persist-specific routines */
+	vpna->up.nm_bdg_ctl = netmap_vp_bdg_ctl;
+	vpna->up.nm_dtor = netmap_persist_vp_dtor;
+	netmap_adapter_get(&vpna->up);
+	NMG_UNLOCK();
+	D("created %s", ifp->if_xname);
+	return 0;
+}
 
 /* Try to get a reference to a netmap adapter attached to a VALE switch.
  * If the adapter is found (or is created), this function returns 0, a
@@ -481,11 +595,11 @@ netmap_adapter_vp_dtor(struct netmap_adapter *na)
 int
 netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 {
-	const char *name = nmr->nr_name;
+	char *nr_name = nmr->nr_name;
+	const char *ifname;
 	struct ifnet *ifp;
 	int error = 0;
-	struct netmap_adapter *ret;
-	struct netmap_vp_adapter *vpna;
+	struct netmap_vp_adapter *vpna, *hostna = NULL;
 	struct nm_bridge *b;
 	int i, j, cand = -1, cand2 = -1;
 	int needed;
@@ -494,15 +608,17 @@ netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 
 	/* first try to see if this is a bridge port. */
 	NMG_LOCK_ASSERT();
-	if (strncmp(name, NM_NAME, sizeof(NM_NAME) - 1)) {
+	if (strncmp(nr_name, NM_NAME, sizeof(NM_NAME) - 1)) {
 		return 0;  /* no error, but no VALE prefix */
 	}
 
-	b = nm_find_bridge(name, create);
+	b = nm_find_bridge(nr_name, create);
 	if (b == NULL) {
-		D("no bridges available for '%s'", name);
+		D("no bridges available for '%s'", nr_name);
 		return (create ? ENOMEM : ENXIO);
 	}
+	if (strlen(nr_name) < b->bdg_namelen) /* impossible */
+		panic("x");
 
 	/* Now we are sure that name starts with the bridge's name,
 	 * lookup the port in the bridge. We need to scan the entire
@@ -516,13 +632,11 @@ netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 		i = b->bdg_port_index[j];
 		vpna = b->bdg_ports[i];
 		// KASSERT(na != NULL);
-		ifp = vpna->up.ifp;
-		/* XXX make sure the name only contains one : */
-		if (!strcmp(NM_IFPNAME(ifp), name)) {
+		D("checking %s", vpna->up.name);
+		if (!strcmp(vpna->up.name, nr_name)) {
 			netmap_adapter_get(&vpna->up);
-			ND("found existing if %s refs %d", name,
-				vpna->na_bdg_refcount);
-			*na = (struct netmap_adapter *)vpna;
+			ND("found existing if %s refs %d", nr_name)
+			*na = &vpna->up;
 			return 0;
 		}
 	}
@@ -539,68 +653,50 @@ netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 	cand = b->bdg_port_index[b->bdg_active_ports];
 	cand2 = b->bdg_port_index[b->bdg_active_ports + 1];
 	ND("+++ bridge %s port %s used %d avail %d %d",
-		b->bdg_basename, name, b->bdg_active_ports, cand, cand2);
+		b->bdg_basename, ifname, b->bdg_active_ports, cand, cand2);
 
 	/*
 	 * try see if there is a matching NIC with this name
 	 * (after the bridge's name)
 	 */
-	ifp = ifunit_ref(name + b->bdg_namelen + 1);
-	if (!ifp) { /* this is a virtual port */
+	ifname = nr_name + b->bdg_namelen + 1;
+	ifp = ifunit_ref(ifname);
+	if (!ifp) {
+		/* Create an ephemeral virtual port
+		 * This block contains all the ephemeral-specific logics
+		 */
 		if (nmr->nr_cmd) {
 			/* nr_cmd must be 0 for a virtual port */
 			return EINVAL;
 		}
 
-	 	/* create a struct ifnet for the new port.
-		 * need M_NOWAIT as we are under nma_lock
-		 */
-		ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT | M_ZERO);
-		if (!ifp)
-			return ENOMEM;
-
-		strcpy(ifp->if_xname, name);
 		/* bdg_netmap_attach creates a struct netmap_adapter */
-		error = bdg_netmap_attach(nmr, ifp);
+		error = netmap_vp_create(nmr, NULL, &vpna);
 		if (error) {
 			D("error %d", error);
 			free(ifp, M_DEVBUF);
 			return error;
 		}
-		ret = NA(ifp);
-		cand2 = -1;	/* only need one port */
-	} else {  /* this is a NIC */
-		struct ifnet *fake_ifp;
+		/* shortcut - we can skip get_hw_na(),
+		 * ownership check and nm_bdg_attach()
+		 */
+	} else {
+		struct netmap_adapter *hw;
 
-		error = netmap_get_hw_na(ifp, &ret);
-		if (error || ret == NULL)
+		error = netmap_get_hw_na(ifp, &hw);
+		if (error || hw == NULL)
 			goto out;
 
-		/* make sure the NIC is not already in use */
-		if (NETMAP_OWNED_BY_ANY(ret)) {
-			D("NIC %s busy, cannot attach to bridge",
-				NM_IFPNAME(ifp));
-			error = EBUSY;
-			goto out;
-		}
-		/* create a fake interface */
-		fake_ifp = malloc(sizeof(*ifp), M_DEVBUF, M_NOWAIT | M_ZERO);
-		if (!fake_ifp) {
-			error = ENOMEM;
-			goto out;
-		}
-		strcpy(fake_ifp->if_xname, name);
-		error = netmap_bwrap_attach(fake_ifp, ifp);
-		if (error) {
-			free(fake_ifp, M_DEVBUF);
+		/* host adapter might not be created */
+		error = hw->nm_bdg_attach(nr_name, hw);
+		if (error)
 			goto out;
-		}
-		ret = NA(fake_ifp);
-		if (nmr->nr_arg1 != NETMAP_BDG_HOST)
-			cand2 = -1; /* only need one port */
+		vpna = hw->na_vp;
+		hostna = hw->na_hostvp;
 		if_rele(ifp);
+		if (nmr->nr_arg1 != NETMAP_BDG_HOST)
+			hostna = NULL;
 	}
-	vpna = (struct netmap_vp_adapter *)ret;
 
 	BDG_WLOCK(b);
 	vpna->bdg_port = cand;
@@ -609,8 +705,7 @@ netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 	b->bdg_ports[cand] = vpna;
 	vpna->na_bdg = b;
 	b->bdg_active_ports++;
-	if (cand2 >= 0) {
-		struct netmap_vp_adapter *hostna = vpna + 1;
+	if (hostna != NULL) {
 		/* also bind the host stack to the bridge */
 		b->bdg_ports[cand2] = hostna;
 		hostna->bdg_port = cand2;
@@ -618,10 +713,10 @@ netmap_get_bdg_na(struct nmreq *nmr, struct netmap_adapter **na, int create)
 		b->bdg_active_ports++;
 		ND("host %p to bridge port %d", hostna, cand2);
 	}
-	ND("if %s refs %d", name, vpna->up.na_refcount);
+	ND("if %s refs %d", ifname, vpna->up.na_refcount);
 	BDG_WUNLOCK(b);
-	*na = ret;
-	netmap_adapter_get(ret);
+	*na = &vpna->up;
+	netmap_adapter_get(*na);
 	return 0;
 
 out:
@@ -631,24 +726,17 @@ out:
 }
 
 
-/* Process NETMAP_BDG_ATTACH and NETMAP_BDG_DETACH */
+/* Process NETMAP_BDG_ATTACH */
 static int
-nm_bdg_attach(struct nmreq *nmr)
+nm_bdg_ctl_attach(struct nmreq *nmr)
 {
 	struct netmap_adapter *na;
-	struct netmap_if *nifp;
-	struct netmap_priv_d *npriv;
-	struct netmap_bwrap_adapter *bna;
 	int error;
 
-	npriv = malloc(sizeof(*npriv), M_DEVBUF, M_NOWAIT|M_ZERO);
-	if (npriv == NULL)
-		return ENOMEM;
-
 	NMG_LOCK();
 
 	error = netmap_get_bdg_na(nmr, &na, 1 /* create if not exists */);
-	if (error) /* no device, or another bridge or user owns the device */
+	if (error) /* no device */
 		goto unlock_exit;
 
 	if (na == NULL) { /* VALE prefix missing */
@@ -656,39 +744,37 @@ nm_bdg_attach(struct nmreq *nmr)
 		goto unlock_exit;
 	}
 
-	if (na->active_fds > 0) { /* already registered */
+	if (NETMAP_OWNED_BY_ANY(na)) {
 		error = EBUSY;
 		goto unref_exit;
 	}
 
-	nifp = netmap_do_regif(npriv, na, nmr->nr_ringid, nmr->nr_flags, &error);
-	if (!nifp) {
-		goto unref_exit;
+	if (na->nm_bdg_ctl) {
+		/* nop for VALE ports. The bwrap needs to put the hwna
+		 * in netmap mode (see netmap_bwrap_bdg_ctl)
+		 */
+		error = na->nm_bdg_ctl(na, nmr, 1);
+		if (error)
+			goto unref_exit;
+		ND("registered %s to netmap-mode", na->name);
 	}
-
-	bna = (struct netmap_bwrap_adapter*)na;
-	bna->na_kpriv = npriv;
 	NMG_UNLOCK();
-	ND("registered %s to netmap-mode", NM_IFPNAME(na->ifp));
 	return 0;
 
 unref_exit:
 	netmap_adapter_put(na);
 unlock_exit:
 	NMG_UNLOCK();
-	bzero(npriv, sizeof(*npriv));
-	free(npriv, M_DEVBUF);
 	return error;
 }
 
 
+/* process NETMAP_BDG_DETACH */
 static int
-nm_bdg_detach(struct nmreq *nmr)
+nm_bdg_ctl_detach(struct nmreq *nmr)
 {
 	struct netmap_adapter *na;
 	int error;
-	struct netmap_bwrap_adapter *bna;
-	int last_instance;
 
 	NMG_LOCK();
 	error = netmap_get_bdg_na(nmr, &na, 0 /* don't create */);
@@ -701,28 +787,13 @@ nm_bdg_detach(struct nmreq *nmr)
 		goto unlock_exit;
 	}
 
-	bna = (struct netmap_bwrap_adapter *)na;
-
-	if (na->active_fds == 0) { /* not registered */
-		error = EINVAL;
-		goto unref_exit;
-	}
-
-	last_instance = netmap_dtor_locked(bna->na_kpriv); /* unregister */
-	if (!last_instance) {
-		D("--- error, trying to detach an entry with active mmaps");
-		error = EINVAL;
-	} else {
-		struct netmap_priv_d *npriv = bna->na_kpriv;
-
-		bna->na_kpriv = NULL;
-		D("deleting priv");
-
-		bzero(npriv, sizeof(*npriv));
-		free(npriv, M_DEVBUF);
+	if (na->nm_bdg_ctl) {
+		/* remove the port from bridge. The bwrap
+		 * also needs to put the hwna in normal mode
+		 */
+		error = na->nm_bdg_ctl(na, nmr, 0);
 	}
 
-unref_exit:
 	netmap_adapter_put(na);
 unlock_exit:
 	NMG_UNLOCK();
@@ -731,28 +802,39 @@ unlock_exit:
 }
 
 
-/* exported to kernel callers, e.g. OVS ?
- * Entry point.
+/* Called by either user's context (netmap_ioctl())
+ * or external kernel modules (e.g., Openvswitch).
+ * Operation is indicated in nmr->nr_cmd.
+ * NETMAP_BDG_OPS that sets configure/lookup/dtor functions to the bridge
+ * requires bdg_ops argument; the other commands ignore this argument.
+ *
  * Called without NMG_LOCK.
  */
 int
-netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
+netmap_bdg_ctl(struct nmreq *nmr, struct netmap_bdg_ops *bdg_ops)
 {
 	struct nm_bridge *b;
 	struct netmap_adapter *na;
 	struct netmap_vp_adapter *vpna;
-	struct ifnet *iter;
 	char *name = nmr->nr_name;
 	int cmd = nmr->nr_cmd, namelen = strlen(name);
 	int error = 0, i, j;
 
 	switch (cmd) {
+	case NETMAP_BDG_NEWIF:
+		error = nm_vi_create(nmr);
+		break;
+
+	case NETMAP_BDG_DELIF:
+		error = nm_vi_destroy(nmr->nr_name);
+		break;
+
 	case NETMAP_BDG_ATTACH:
-		error = nm_bdg_attach(nmr);
+		error = nm_bdg_ctl_attach(nmr);
 		break;
 
 	case NETMAP_BDG_DETACH:
-		error = nm_bdg_detach(nmr);
+		error = nm_bdg_ctl_detach(nmr);
 		break;
 
 	case NETMAP_BDG_LIST:
@@ -770,6 +852,7 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 				break;
 			}
 
+			name = name + b->bdg_namelen + 1;
 			error = ENOENT;
 			for (j = 0; j < b->bdg_active_ports; j++) {
 				i = b->bdg_port_index[j];
@@ -778,11 +861,10 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 					D("---AAAAAAAAARGH-------");
 					continue;
 				}
-				iter = vpna->up.ifp;
 				/* the former and the latter identify a
 				 * virtual port and a NIC, respectively
 				 */
-				if (!strcmp(iter->if_xname, name)) {
+				if (!strcmp(vpna->up.name, name)) {
 					/* bridge index */
 					nmr->nr_arg1 = b - nm_bridges;
 					nmr->nr_arg2 = i; /* port index */
@@ -813,8 +895,7 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 				nmr->nr_arg2 = j;
 				j = b->bdg_port_index[j];
 				vpna = b->bdg_ports[j];
-				iter = vpna->up.ifp;
-				strncpy(name, iter->if_xname, (size_t)IFNAMSIZ);
+				strncpy(name, vpna->up.name, (size_t)IFNAMSIZ);
 				error = 0;
 				break;
 			}
@@ -822,12 +903,12 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 		}
 		break;
 
-	case NETMAP_BDG_LOOKUP_REG:
-		/* register a lookup function to the given bridge.
+	case NETMAP_BDG_REGOPS: /* XXX this should not be available from userspace */
+		/* register callbacks to the given bridge.
 		 * nmr->nr_name may be just bridge's name (including ':'
 		 * if it is not just NM_NAME).
 		 */
-		if (!func) {
+		if (!bdg_ops) {
 			error = EINVAL;
 			break;
 		}
@@ -836,7 +917,7 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 		if (!b) {
 			error = EINVAL;
 		} else {
-			b->nm_bdg_lookup = func;
+			b->bdg_ops = *bdg_ops;
 		}
 		NMG_UNLOCK();
 		break;
@@ -856,7 +937,7 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 			vpna = (struct netmap_vp_adapter *)na;
 			vpna->virt_hdr_len = nmr->nr_arg1;
 			if (vpna->virt_hdr_len)
-				vpna->mfs = NETMAP_BDG_BUF_SIZE(na->nm_mem);
+				vpna->mfs = NETMAP_BUF_SIZE(na);
 			D("Using vnet_hdr_len %d for %p", vpna->virt_hdr_len, vpna);
 			netmap_adapter_put(na);
 		}
@@ -871,6 +952,32 @@ netmap_bdg_ctl(struct nmreq *nmr, bdg_lookup_fn_t func)
 	return error;
 }
 
+int
+netmap_bdg_config(struct nmreq *nmr)
+{
+	struct nm_bridge *b;
+	int error = EINVAL;
+
+	NMG_LOCK();
+	b = nm_find_bridge(nmr->nr_name, 0);
+	if (!b) {
+		NMG_UNLOCK();
+		return error;
+	}
+	NMG_UNLOCK();
+	/* Don't call config() with NMG_LOCK() held */
+	BDG_RLOCK(b);
+	if (b->bdg_ops.config != NULL)
+		error = b->bdg_ops.config((struct nm_ifreq *)nmr);
+	BDG_RUNLOCK(b);
+	return error;
+}
+
+
+/* nm_krings_create callback for VALE ports.
+ * Calls the standard netmap_krings_create, then adds leases on rx
+ * rings and bdgfwd on tx rings.
+ */
 static int
 netmap_vp_krings_create(struct netmap_adapter *na)
 {
@@ -905,6 +1012,7 @@ netmap_vp_krings_create(struct netmap_adapter *na)
 }
 
 
+/* nm_krings_delete callback for VALE ports. */
 static void
 netmap_vp_krings_delete(struct netmap_adapter *na)
 {
@@ -919,17 +1027,20 @@ nm_bdg_flush(struct nm_bdg_fwd *ft, u_int n,
 
 
 /*
+ * main dispatch routine for the bridge.
  * Grab packets from a kring, move them into the ft structure
  * associated to the tx (input) port. Max one instance per port,
  * filtered on input (ioctl, poll or XXX).
  * Returns the next position in the ring.
  */
 static int
-nm_bdg_preflush(struct netmap_vp_adapter *na, u_int ring_nr,
-	struct netmap_kring *kring, u_int end)
+nm_bdg_preflush(struct netmap_kring *kring, u_int end)
 {
+	struct netmap_vp_adapter *na =
+		(struct netmap_vp_adapter*)kring->na;
 	struct netmap_ring *ring = kring->ring;
 	struct nm_bdg_fwd *ft;
+	u_int ring_nr = kring->ring_id;
 	u_int j = kring->nr_hwcur, lim = kring->nkr_num_slots - 1;
 	u_int ft_i = 0;	/* start from 0 */
 	u_int frags = 1; /* how many frags ? */
@@ -958,12 +1069,12 @@ nm_bdg_preflush(struct netmap_vp_adapter *na, u_int ring_nr,
 		/* this slot goes into a list so initialize the link field */
 		ft[ft_i].ft_next = NM_FT_NULL;
 		buf = ft[ft_i].ft_buf = (slot->flags & NS_INDIRECT) ?
-			(void *)(uintptr_t)slot->ptr : BDG_NMB(&na->up, slot);
+			(void *)(uintptr_t)slot->ptr : NMB(&na->up, slot);
 		if (unlikely(buf == NULL)) {
 			RD(5, "NULL %s buffer pointer from %s slot %d len %d",
 				(slot->flags & NS_INDIRECT) ? "INDIRECT" : "DIRECT",
 				kring->name, j, ft[ft_i].ft_len);
-			buf = ft[ft_i].ft_buf = NMB_VA(0); /* the 'null' buffer */
+			buf = ft[ft_i].ft_buf = NETMAP_BUF_BASE(&na->up);
 			ft[ft_i].ft_len = 0;
 			ft[ft_i].ft_flags = 0;
 		}
@@ -1035,23 +1146,28 @@ nm_bridge_rthash(const uint8_t *addr)
 #undef mix
 
 
+/* nm_register callback for VALE ports */
 static int
-bdg_netmap_reg(struct netmap_adapter *na, int onoff)
+netmap_vp_reg(struct netmap_adapter *na, int onoff)
 {
 	struct netmap_vp_adapter *vpna =
 		(struct netmap_vp_adapter*)na;
-	struct ifnet *ifp = na->ifp;
 
-	/* the interface is already attached to the bridge,
-	 * so we only need to toggle IFCAP_NETMAP.
+	/* persistent ports may be put in netmap mode
+	 * before being attached to a bridge
 	 */
-	BDG_WLOCK(vpna->na_bdg);
+	if (vpna->na_bdg)
+		BDG_WLOCK(vpna->na_bdg);
 	if (onoff) {
-		ifp->if_capenable |= IFCAP_NETMAP;
+		na->na_flags |= NAF_NETMAP_ON;
+		 /* XXX on FreeBSD, persistent VALE ports should also
+		 * toggle IFCAP_NETMAP in na->ifp (2014-03-16)
+		 */
 	} else {
-		ifp->if_capenable &= ~IFCAP_NETMAP;
+		na->na_flags &= ~NAF_NETMAP_ON;
 	}
-	BDG_WUNLOCK(vpna->na_bdg);
+	if (vpna->na_bdg)
+		BDG_WUNLOCK(vpna->na_bdg);
 	return 0;
 }
 
@@ -1063,16 +1179,28 @@ bdg_netmap_reg(struct netmap_adapter *na, int onoff)
  * ring in *dst_ring (at the moment, always use ring 0)
  */
 u_int
-netmap_bdg_learning(char *buf, u_int buf_len, uint8_t *dst_ring,
-		struct netmap_vp_adapter *na)
+netmap_bdg_learning(struct nm_bdg_fwd *ft, uint8_t *dst_ring,
+		const struct netmap_vp_adapter *na)
 {
+	uint8_t *buf = ft->ft_buf;
+	u_int buf_len = ft->ft_len;
 	struct nm_hash_ent *ht = na->na_bdg->ht;
 	uint32_t sh, dh;
 	u_int dst, mysrc = na->bdg_port;
 	uint64_t smac, dmac;
 
-	if (buf_len < 14) {
-		RD(5, "invalid buf length %d", buf_len);
+	/* safety check, unfortunately we have many cases */
+	if (buf_len >= 14 + na->virt_hdr_len) {
+		/* virthdr + mac_hdr in the same slot */
+		buf += na->virt_hdr_len;
+		buf_len -= na->virt_hdr_len;
+	} else if (buf_len == na->virt_hdr_len && ft->ft_flags & NS_MOREFRAG) {
+		/* only header in first fragment */
+		ft++;
+		buf = ft->ft_buf;
+		buf_len = ft->ft_len;
+	} else {
+		RD(5, "invalid buf format, length %d", buf_len);
 		return NM_BDG_NOPORT;
 	}
 	dmac = le64toh(*(uint64_t *)(buf)) & 0xffffffffffff;
@@ -1170,7 +1298,7 @@ nm_kr_lease(struct netmap_kring *k, u_int n, int is_rx)
 		k->nr_hwtail >= k->nkr_num_slots ||
 		k->nkr_lease_idx >= k->nkr_num_slots) {
 		D("invalid kring %s, cur %d tail %d lease %d lease_idx %d lim %d",
-			k->na->ifp->if_xname,
+			k->na->name,
 			k->nr_hwcur, k->nr_hwtail, k->nkr_hwlease,
 			k->nkr_lease_idx, k->nkr_num_slots);
 	}
@@ -1178,6 +1306,7 @@ nm_kr_lease(struct netmap_kring *k, u_int n, int is_rx)
 }
 
 /*
+ *
  * This flush routine supports only unicast and broadcast but a large
  * number of ports, and lets us replace the learn and dispatch functions.
  */
@@ -1204,22 +1333,13 @@ nm_bdg_flush(struct nm_bdg_fwd *ft, u_int n, struct netmap_vp_adapter *na,
 		uint8_t dst_ring = ring_nr; /* default, same ring as origin */
 		uint16_t dst_port, d_i;
 		struct nm_bdg_q *d;
-		uint8_t *buf = ft[i].ft_buf;
-		u_int len = ft[i].ft_len;
 
 		ND("slot %d frags %d", i, ft[i].ft_frags);
 		/* Drop the packet if the virtio-net header is not into the first
 		   fragment nor at the very beginning of the second. */
-		if (unlikely(na->virt_hdr_len > len))
+		if (unlikely(na->virt_hdr_len > ft[i].ft_len))
 			continue;
-		if (len == na->virt_hdr_len) {
-			buf = ft[i+1].ft_buf;
-			len = ft[i+1].ft_len;
-		} else {
-			buf += na->virt_hdr_len;
-			len -= na->virt_hdr_len;
-		}
-		dst_port = b->nm_bdg_lookup(buf, len, &dst_ring, na);
+		dst_port = b->bdg_ops.lookup(&ft[i], &dst_ring, na);
 		if (netmap_verbose > 255)
 			RD(5, "slot %d port %d -> %d", i, me, dst_port);
 		if (dst_port == NM_BDG_NOPORT)
@@ -1270,9 +1390,8 @@ nm_bdg_flush(struct nm_bdg_fwd *ft, u_int n, struct netmap_vp_adapter *na,
 	}
 
 	ND(5, "pass 1 done %d pkts %d dsts", n, num_dsts);
-	/* second pass: scan destinations (XXX will be modular somehow) */
+	/* second pass: scan destinations */
 	for (i = 0; i < num_dsts; i++) {
-		struct ifnet *dst_ifp;
 		struct netmap_vp_adapter *dst_na;
 		struct netmap_kring *kring;
 		struct netmap_ring *ring;
@@ -1296,13 +1415,12 @@ nm_bdg_flush(struct nm_bdg_fwd *ft, u_int n, struct netmap_vp_adapter *na,
 			goto cleanup;
 		if (dst_na->up.na_flags & NAF_SW_ONLY)
 			goto cleanup;
-		dst_ifp = dst_na->up.ifp;
 		/*
 		 * The interface may be in !netmap mode in two cases:
 		 * - when na is attached but not activated yet;
 		 * - when na is being deactivated but is still attached.
 		 */
-		if (unlikely(!(dst_ifp->if_capenable & IFCAP_NETMAP))) {
+		if (unlikely(!nm_netmap_on(&dst_na->up))) {
 			ND("not in netmap mode!");
 			goto cleanup;
 		}
@@ -1320,7 +1438,7 @@ nm_bdg_flush(struct nm_bdg_fwd *ft, u_int n, struct netmap_vp_adapter *na,
 		needed = d->bq_len + brddst->bq_len;
 
 		if (unlikely(dst_na->virt_hdr_len != na->virt_hdr_len)) {
-			RD(3, "virt_hdr_mismatch, src %d len %d", na->virt_hdr_len, dst_na->virt_hdr_len);
+			RD(3, "virt_hdr_mismatch, src %d dst %d", na->virt_hdr_len, dst_na->virt_hdr_len);
 			/* There is a virtio-net header/offloadings mismatch between
 			 * source and destination. The slower mismatch datapath will
 			 * be used to cope with all the mismatches.
@@ -1358,6 +1476,10 @@ retry:
 		if (dst_na->retry && retry) {
 			/* try to get some free slot from the previous run */
 			dst_na->up.nm_notify(&dst_na->up, dst_nr, NR_RX, 0);
+			/* actually useful only for bwraps, since there
+			 * the notify will trigger a txsync on the hwna. VALE ports
+			 * have dst_na->retry == 0
+			 */
 		}
 		/* reserve the buffers in the queue and an entry
 		 * to report completion, and drop lock.
@@ -1413,7 +1535,7 @@ retry:
 					size_t copy_len = ft_p->ft_len, dst_len = copy_len;
 
 					slot = &ring->slot[j];
-					dst = BDG_NMB(&dst_na->up, slot);
+					dst = NMB(&dst_na->up, slot);
 
 					ND("send [%d] %d(%d) bytes at %s:%d",
 							i, (int)copy_len, (int)dst_len,
@@ -1421,8 +1543,8 @@ retry:
 					/* round to a multiple of 64 */
 					copy_len = (copy_len + 63) & ~63;
 
-					if (unlikely(copy_len > NETMAP_BUF_SIZE ||
-							copy_len > NETMAP_BUF_SIZE)) {
+					if (unlikely(copy_len > NETMAP_BUF_SIZE(&dst_na->up) ||
+						     copy_len > NETMAP_BUF_SIZE(&na->up))) {
 						RD(5, "invalid len %d, down to 64", (int)copy_len);
 						copy_len = dst_len = 64; // XXX
 					}
@@ -1495,8 +1617,16 @@ retry:
 				still_locked = 0;
 				mtx_unlock(&kring->q_lock);
 				dst_na->up.nm_notify(&dst_na->up, dst_nr, NR_RX, 0);
-				if (dst_na->retry && retry--)
+				/* this is netmap_notify for VALE ports and
+				 * netmap_bwrap_notify for bwrap. The latter will
+				 * trigger a txsync on the underlying hwna
+				 */
+				if (dst_na->retry && retry--) {
+					/* XXX this is going to call nm_notify again.
+					 * Only useful for bwrap in virtual machines
+					 */
 					goto retry;
+				}
 			}
 		    }
 		    if (still_locked)
@@ -1511,11 +1641,12 @@ cleanup:
 	return 0;
 }
 
-
+/* nm_txsync callback for VALE ports */
 static int
-netmap_vp_txsync(struct netmap_vp_adapter *na, u_int ring_nr, int flags)
+netmap_vp_txsync(struct netmap_kring *kring, int flags)
 {
-	struct netmap_kring *kring = &na->up.tx_rings[ring_nr];
+	struct netmap_vp_adapter *na =
+		(struct netmap_vp_adapter *)kring->na;
 	u_int done;
 	u_int const lim = kring->nkr_num_slots - 1;
 	u_int const cur = kring->rcur;
@@ -1524,10 +1655,14 @@ netmap_vp_txsync(struct netmap_vp_adapter *na, u_int ring_nr, int flags)
 		done = cur; // used all
 		goto done;
 	}
+	if (!na->na_bdg) {
+		done = cur;
+		goto done;
+	}
 	if (bridge_batch > NM_BDG_BATCH)
 		bridge_batch = NM_BDG_BATCH;
 
-	done = nm_bdg_preflush(na, ring_nr, kring, cur);
+	done = nm_bdg_preflush(kring, cur);
 done:
 	if (done != cur)
 		D("early break at %d/ %d, tail %d", done, cur, kring->nr_hwtail);
@@ -1538,27 +1673,18 @@ done:
 	kring->nr_hwtail = nm_prev(done, lim);
 	nm_txsync_finalize(kring);
 	if (netmap_verbose)
-		D("%s ring %d flags %d", NM_IFPNAME(na->up.ifp), ring_nr, flags);
+		D("%s ring %d flags %d", na->up.name, kring->ring_id, flags);
 	return 0;
 }
 
 
-/*
- * main dispatch routine for the bridge.
- * We already know that only one thread is running this.
- * we must run nm_bdg_preflush without lock.
+/* rxsync code used by VALE ports nm_rxsync callback and also
+ * internally by the brwap
  */
 static int
-bdg_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+netmap_vp_rxsync_locked(struct netmap_kring *kring, int flags)
 {
-	struct netmap_vp_adapter *vpna = (struct netmap_vp_adapter*)na;
-	return netmap_vp_txsync(vpna, ring_nr, flags);
-}
-
-static int
-netmap_vp_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
-{
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
+	struct netmap_adapter *na = kring->na;
 	struct netmap_ring *ring = kring->ring;
 	u_int nm_i, lim = kring->nkr_num_slots - 1;
 	u_int head = nm_rxsync_prologue(kring);
@@ -1579,9 +1705,9 @@ netmap_vp_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
 		/* consistency check, but nothing really important here */
 		for (n = 0; likely(nm_i != head); n++) {
 			struct netmap_slot *slot = &ring->slot[nm_i];
-			void *addr = BDG_NMB(na, slot);
+			void *addr = NMB(na, slot);
 
-			if (addr == netmap_buffer_base) { /* bad buf */
+			if (addr == NETMAP_BUF_BASE(kring->na)) { /* bad buf */
 				D("bad buffer index %d, ignore ?",
 					slot->buf_idx);
 			}
@@ -1599,26 +1725,45 @@ done:
 }
 
 /*
+ * nm_rxsync callback for VALE ports
  * user process reading from a VALE switch.
  * Already protected against concurrent calls from userspace,
  * but we must acquire the queue's lock to protect against
  * writers on the same queue.
  */
 static int
-bdg_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
+netmap_vp_rxsync(struct netmap_kring *kring, int flags)
 {
-	struct netmap_kring *kring = &na->rx_rings[ring_nr];
 	int n;
 
 	mtx_lock(&kring->q_lock);
-	n = netmap_vp_rxsync(na, ring_nr, flags);
+	n = netmap_vp_rxsync_locked(kring, flags);
 	mtx_unlock(&kring->q_lock);
 	return n;
 }
 
 
+/* nm_bdg_attach callback for VALE ports
+ * The na_vp port is this same netmap_adapter. There is no host port.
+ */
+static int
+netmap_vp_bdg_attach(const char *name, struct netmap_adapter *na)
+{
+	struct netmap_vp_adapter *vpna = (struct netmap_vp_adapter *)na;
+
+	if (vpna->na_bdg)
+		return EBUSY;
+	na->na_vp = vpna;
+	strncpy(na->name, name, sizeof(na->name));
+	na->na_hostvp = NULL;
+	return 0;
+}
+
+/* create a netmap_vp_adapter that describes a VALE port.
+ * Only persistent VALE ports have a non-null ifp.
+ */
 static int
-bdg_netmap_attach(struct nmreq *nmr, struct ifnet *ifp)
+netmap_vp_create(struct nmreq *nmr, struct ifnet *ifp, struct netmap_vp_adapter **ret)
 {
 	struct netmap_vp_adapter *vpna;
 	struct netmap_adapter *na;
@@ -1632,6 +1777,7 @@ bdg_netmap_attach(struct nmreq *nmr, struct ifnet *ifp)
  	na = &vpna->up;
 
 	na->ifp = ifp;
+	strncpy(na->name, nmr->nr_name, sizeof(na->name));
 
 	/* bound checking */
 	na->num_tx_rings = nmr->nr_tx_rings;
@@ -1664,22 +1810,24 @@ bdg_netmap_attach(struct nmreq *nmr, struct ifnet *ifp)
 		D("max frame size %u", vpna->mfs);
 
 	na->na_flags |= NAF_BDG_MAYSLEEP | NAF_MEM_OWNER;
-	na->nm_txsync = bdg_netmap_txsync;
-	na->nm_rxsync = bdg_netmap_rxsync;
-	na->nm_register = bdg_netmap_reg;
-	na->nm_dtor = netmap_adapter_vp_dtor;
+	na->nm_txsync = netmap_vp_txsync;
+	na->nm_rxsync = netmap_vp_rxsync;
+	na->nm_register = netmap_vp_reg;
 	na->nm_krings_create = netmap_vp_krings_create;
 	na->nm_krings_delete = netmap_vp_krings_delete;
-	na->nm_mem = netmap_mem_private_new(NM_IFPNAME(na->ifp),
+	na->nm_dtor = netmap_vp_dtor;
+	na->nm_mem = netmap_mem_private_new(na->name,
 			na->num_tx_rings, na->num_tx_desc,
 			na->num_rx_rings, na->num_rx_desc,
 			nmr->nr_arg3, npipes, &error);
 	if (na->nm_mem == NULL)
 		goto err;
+	na->nm_bdg_attach = netmap_vp_bdg_attach;
 	/* other nmd fields are set in the common routine */
 	error = netmap_attach_common(na);
 	if (error)
 		goto err;
+	*ret = vpna;
 	return 0;
 
 err:
@@ -1689,30 +1837,60 @@ err:
 	return error;
 }
 
+/* Bridge wrapper code (bwrap).
+ * This is used to connect a non-VALE-port netmap_adapter (hwna) to a
+ * VALE switch.
+ * The main task is to swap the meaning of tx and rx rings to match the
+ * expectations of the VALE switch code (see nm_bdg_flush).
+ *
+ * The bwrap works by interposing a netmap_bwrap_adapter between the
+ * rest of the system and the hwna. The netmap_bwrap_adapter looks like
+ * a netmap_vp_adapter to the rest the system, but, internally, it
+ * translates all callbacks to what the hwna expects.
+ *
+ * Note that we have to intercept callbacks coming from two sides:
+ *
+ *  - callbacks coming from the netmap module are intercepted by
+ *    passing around the netmap_bwrap_adapter instead of the hwna
+ *
+ *  - callbacks coming from outside of the netmap module only know
+ *    about the hwna. This, however, only happens in interrupt
+ *    handlers, where only the hwna->nm_notify callback is called.
+ *    What the bwrap does is to overwrite the hwna->nm_notify callback
+ *    with its own netmap_bwrap_intr_notify.
+ *    XXX This assumes that the hwna->nm_notify callback was the
+ *    standard netmap_notify(), as it is the case for nic adapters.
+ *    Any additional action performed by hwna->nm_notify will not be
+ *    performed by netmap_bwrap_intr_notify.
+ *
+ * Additionally, the bwrap can optionally attach the host rings pair
+ * of the wrapped adapter to a different port of the switch.
+ */
+
 
 static void
 netmap_bwrap_dtor(struct netmap_adapter *na)
 {
 	struct netmap_bwrap_adapter *bna = (struct netmap_bwrap_adapter*)na;
 	struct netmap_adapter *hwna = bna->hwna;
-	struct nm_bridge *b = bna->up.na_bdg,
-		*bh = bna->host.na_bdg;
-	struct ifnet *ifp = na->ifp;
 
 	ND("na %p", na);
+	/* drop reference to hwna->ifp.
+	 * If we don't do this, netmap_detach_common(na)
+	 * will think it has set NA(na->ifp) to NULL
+	 */
+	na->ifp = NULL;
+	/* for safety, also drop the possible reference
+	 * in the hostna
+	 */
+	bna->host.up.ifp = NULL;
 
-	if (b) {
-		netmap_bdg_detach_common(b, bna->up.bdg_port,
-			(bh ? bna->host.bdg_port : -1));
-	}
-
+	hwna->nm_mem = bna->save_nmd;
 	hwna->na_private = NULL;
+	hwna->na_vp = hwna->na_hostvp = NULL;
+	hwna->na_flags &= ~NAF_BUSY;
 	netmap_adapter_put(hwna);
 
-	bzero(ifp, sizeof(*ifp));
-	free(ifp, M_DEVBUF);
-	na->ifp = NULL;
-
 }
 
 
@@ -1737,7 +1915,6 @@ netmap_bwrap_dtor(struct netmap_adapter *na)
 static int
 netmap_bwrap_intr_notify(struct netmap_adapter *na, u_int ring_nr, enum txrx tx, int flags)
 {
-	struct ifnet *ifp = na->ifp;
 	struct netmap_bwrap_adapter *bna = na->na_private;
 	struct netmap_vp_adapter *hostna = &bna->host;
 	struct netmap_kring *kring, *bkring;
@@ -1747,20 +1924,24 @@ netmap_bwrap_intr_notify(struct netmap_adapter *na, u_int ring_nr, enum txrx tx,
 	int error = 0;
 
 	if (netmap_verbose)
-	    D("%s %s%d 0x%x", NM_IFPNAME(ifp),
+	    D("%s %s%d 0x%x", na->name,
 		(tx == NR_TX ? "TX" : "RX"), ring_nr, flags);
 
 	if (flags & NAF_DISABLE_NOTIFY) {
-		kring = tx == NR_TX ? na->tx_rings : na->rx_rings;
-		bkring = tx == NR_TX ? vpna->up.rx_rings : vpna->up.tx_rings;
-		if (kring[ring_nr].nkr_stopped)
-			netmap_disable_ring(&bkring[ring_nr]);
-		else
-			bkring[ring_nr].nkr_stopped = 0;
+		/* the enabled/disabled state of the ring has changed,
+		 * propagate the info to the wrapper (with tx/rx swapped)
+		 */
+		if (tx == NR_TX) {
+			netmap_set_rxring(&vpna->up, ring_nr,
+					na->tx_rings[ring_nr].nkr_stopped);
+		} else {
+			netmap_set_txring(&vpna->up, ring_nr,
+					na->rx_rings[ring_nr].nkr_stopped);
+		}
 		return 0;
 	}
 
-	if (ifp == NULL || !(ifp->if_capenable & IFCAP_NETMAP))
+	if (!nm_netmap_on(na))
 		return 0;
 
 	/* we only care about receive interrupts */
@@ -1786,7 +1967,7 @@ netmap_bwrap_intr_notify(struct netmap_adapter *na, u_int ring_nr, enum txrx tx,
 	 * the info from the rx kring.
 	 */
 	if (netmap_verbose)
-	    D("%s head %d cur %d tail %d (kring %d %d %d)",  NM_IFPNAME(ifp),
+	    D("%s head %d cur %d tail %d (kring %d %d %d)",  na->name,
 		ring->head, ring->cur, ring->tail,
 		kring->rhead, kring->rcur, kring->rtail);
 
@@ -1807,7 +1988,7 @@ netmap_bwrap_intr_notify(struct netmap_adapter *na, u_int ring_nr, enum txrx tx,
 		goto put_out;
 	if (kring->nr_hwcur == kring->nr_hwtail && netmap_verbose) {
 		D("how strange, interrupt with no packets on %s",
-			NM_IFPNAME(ifp));
+			na->name);
 		goto put_out;
 	}
 
@@ -1823,7 +2004,7 @@ netmap_bwrap_intr_notify(struct netmap_adapter *na, u_int ring_nr, enum txrx tx,
 
 	/* pass packets to the switch */
 	nm_txsync_prologue(bkring); // XXX error checking ?
-	netmap_vp_txsync(vpna, ring_nr, flags);
+	netmap_vp_txsync(bkring, flags);
 
 	/* mark all buffers as released on this ring */
 	ring->head = ring->cur = kring->nr_hwtail;
@@ -1845,6 +2026,7 @@ put_out:
 }
 
 
+/* nm_register callback for bwrap */
 static int
 netmap_bwrap_register(struct netmap_adapter *na, int onoff)
 {
@@ -1854,22 +2036,35 @@ netmap_bwrap_register(struct netmap_adapter *na, int onoff)
 	struct netmap_vp_adapter *hostna = &bna->host;
 	int error;
 
-	ND("%s %s", NM_IFPNAME(na->ifp), onoff ? "on" : "off");
+	ND("%s %s", na->name, onoff ? "on" : "off");
 
 	if (onoff) {
 		int i;
 
+		/* netmap_do_regif has been called on the bwrap na.
+		 * We need to pass the information about the
+		 * memory allocator down to the hwna before
+		 * putting it in netmap mode
+		 */
 		hwna->na_lut = na->na_lut;
 		hwna->na_lut_objtotal = na->na_lut_objtotal;
+		hwna->na_lut_objsize = na->na_lut_objsize;
 
 		if (hostna->na_bdg) {
+			/* if the host rings have been attached to switch,
+			 * we need to copy the memory allocator information
+			 * in the hostna also
+			 */
 			hostna->up.na_lut = na->na_lut;
 			hostna->up.na_lut_objtotal = na->na_lut_objtotal;
+			hostna->up.na_lut_objsize = na->na_lut_objsize;
 		}
 
 		/* cross-link the netmap rings
 		 * The original number of rings comes from hwna,
 		 * rx rings on one side equals tx rings on the other.
+		 * We need to do this now, after the initialization
+		 * of the kring->ring pointers
 		 */
 		for (i = 0; i < na->num_rx_rings + 1; i++) {
 			hwna->tx_rings[i].nkr_num_slots = na->rx_rings[i].nkr_num_slots;
@@ -1881,27 +2076,31 @@ netmap_bwrap_register(struct netmap_adapter *na, int onoff)
 		}
 	}
 
-	if (hwna->ifp) {
-		error = hwna->nm_register(hwna, onoff);
-		if (error)
-			return error;
-	}
+	/* forward the request to the hwna */
+	error = hwna->nm_register(hwna, onoff);
+	if (error)
+		return error;
 
-	bdg_netmap_reg(na, onoff);
+	/* impersonate a netmap_vp_adapter */
+	netmap_vp_reg(na, onoff);
+	if (hostna->na_bdg)
+		netmap_vp_reg(&hostna->up, onoff);
 
 	if (onoff) {
+		/* intercept the hwna nm_nofify callback */
 		bna->save_notify = hwna->nm_notify;
 		hwna->nm_notify = netmap_bwrap_intr_notify;
 	} else {
 		hwna->nm_notify = bna->save_notify;
 		hwna->na_lut = NULL;
 		hwna->na_lut_objtotal = 0;
+		hwna->na_lut_objsize = 0;
 	}
 
 	return 0;
 }
 
-
+/* nm_config callback for bwrap */
 static int
 netmap_bwrap_config(struct netmap_adapter *na, u_int *txr, u_int *txd,
 				    u_int *rxr, u_int *rxd)
@@ -1922,6 +2121,7 @@ netmap_bwrap_config(struct netmap_adapter *na, u_int *txr, u_int *txd,
 }
 
 
+/* nm_krings_create callback for bwrap */
 static int
 netmap_bwrap_krings_create(struct netmap_adapter *na)
 {
@@ -1931,21 +2131,33 @@ netmap_bwrap_krings_create(struct netmap_adapter *na)
 	struct netmap_adapter *hostna = &bna->host.up;
 	int error;
 
-	ND("%s", NM_IFPNAME(na->ifp));
+	ND("%s", na->name);
 
+	/* impersonate a netmap_vp_adapter */
 	error = netmap_vp_krings_create(na);
 	if (error)
 		return error;
 
+	/* also create the hwna krings */
 	error = hwna->nm_krings_create(hwna);
 	if (error) {
 		netmap_vp_krings_delete(na);
 		return error;
 	}
+	/* the connection between the bwrap krings and the hwna krings
+	 * will be perfomed later, in the nm_register callback, since
+	 * now the kring->ring pointers have not been initialized yet
+	 */
 
 	if (na->na_flags & NAF_HOST_RINGS) {
+		/* the hostna rings are the host rings of the bwrap.
+		 * The corresponding krings must point back to the
+		 * hostna
+		 */
 		hostna->tx_rings = na->tx_rings + na->num_tx_rings;
+		hostna->tx_rings[0].na = hostna;
 		hostna->rx_rings = na->rx_rings + na->num_rx_rings;
+		hostna->rx_rings[0].na = hostna;
 	}
 
 	return 0;
@@ -1959,7 +2171,7 @@ netmap_bwrap_krings_delete(struct netmap_adapter *na)
 		(struct netmap_bwrap_adapter *)na;
 	struct netmap_adapter *hwna = bna->hwna;
 
-	ND("%s", NM_IFPNAME(na->ifp));
+	ND("%s", na->name);
 
 	hwna->nm_krings_delete(hwna);
 	netmap_vp_krings_delete(na);
@@ -1986,13 +2198,13 @@ netmap_bwrap_notify(struct netmap_adapter *na, u_int ring_n, enum txrx tx, int f
 	ring = kring->ring;
 	lim = kring->nkr_num_slots - 1;
 
-	if (hwna->ifp == NULL || !(hwna->ifp->if_capenable & IFCAP_NETMAP))
+	if (!nm_netmap_on(hwna))
 		return 0;
 	mtx_lock(&kring->q_lock);
 	/* first step: simulate a user wakeup on the rx ring */
-	netmap_vp_rxsync(na, ring_n, flags);
+	netmap_vp_rxsync_locked(kring, flags);
 	ND("%s[%d] PRE rx(c%3d t%3d l%3d) ring(h%3d c%3d t%3d) tx(c%3d ht%3d t%3d)",
-		NM_IFPNAME(na->ifp), ring_n,
+		na->name, ring_n,
 		kring->nr_hwcur, kring->nr_hwtail, kring->nkr_hwlease,
 		ring->head, ring->cur, ring->tail,
 		hw_kring->nr_hwcur, hw_kring->nr_hwtail, hw_ring->rtail);
@@ -2013,9 +2225,9 @@ netmap_bwrap_notify(struct netmap_adapter *na, u_int ring_n, enum txrx tx, int f
 	ring->tail = kring->rtail; /* restore saved value of tail, for safety */
 
 	/* fifth step: the user goes to sleep again, causing another rxsync */
-	netmap_vp_rxsync(na, ring_n, flags);
+	netmap_vp_rxsync_locked(kring, flags);
 	ND("%s[%d] PST rx(c%3d t%3d l%3d) ring(h%3d c%3d t%3d) tx(c%3d ht%3d t%3d)",
-		NM_IFPNAME(na->ifp), ring_n,
+		na->name, ring_n,
 		kring->nr_hwcur, kring->nr_hwtail, kring->nkr_hwlease,
 		ring->head, ring->cur, ring->tail,
 		hw_kring->nr_hwcur, hw_kring->nr_hwtail, hw_kring->rtail);
@@ -2024,6 +2236,7 @@ netmap_bwrap_notify(struct netmap_adapter *na, u_int ring_n, enum txrx tx, int f
 }
 
 
+/* notify method for the bridge-->host-rings path */
 static int
 netmap_bwrap_host_notify(struct netmap_adapter *na, u_int ring_n, enum txrx tx, int flags)
 {
@@ -2035,23 +2248,95 @@ netmap_bwrap_host_notify(struct netmap_adapter *na, u_int ring_n, enum txrx tx,
 }
 
 
-/* attach a bridge wrapper to the 'real' device */
+/* nm_bdg_ctl callback for the bwrap.
+ * Called on bridge-attach and detach, as an effect of vale-ctl -[ahd].
+ * On attach, it needs to provide a fake netmap_priv_d structure and
+ * perform a netmap_do_regif() on the bwrap. This will put both the
+ * bwrap and the hwna in netmap mode, with the netmap rings shared
+ * and cross linked. Moroever, it will start intercepting interrupts
+ * directed to hwna.
+ */
 static int
-netmap_bwrap_attach(struct ifnet *fake, struct ifnet *real)
+netmap_bwrap_bdg_ctl(struct netmap_adapter *na, struct nmreq *nmr, int attach)
+{
+	struct netmap_priv_d *npriv;
+	struct netmap_bwrap_adapter *bna = (struct netmap_bwrap_adapter*)na;
+	struct netmap_if *nifp;
+	int error = 0;
+
+	if (attach) {
+		if (NETMAP_OWNED_BY_ANY(na)) {
+			return EBUSY;
+		}
+		if (bna->na_kpriv) {
+			/* nothing to do */
+			return 0;
+		}
+		npriv = malloc(sizeof(*npriv), M_DEVBUF, M_NOWAIT|M_ZERO);
+		if (npriv == NULL)
+			return ENOMEM;
+		nifp = netmap_do_regif(npriv, na, nmr->nr_ringid, nmr->nr_flags, &error);
+		if (!nifp) {
+			bzero(npriv, sizeof(*npriv));
+			free(npriv, M_DEVBUF);
+			return error;
+		}
+		bna->na_kpriv = npriv;
+		na->na_flags |= NAF_BUSY;
+	} else {
+		int last_instance;
+
+		if (na->active_fds == 0) /* not registered */
+			return EINVAL;
+		last_instance = netmap_dtor_locked(bna->na_kpriv);
+		if (!last_instance) {
+			D("--- error, trying to detach an entry with active mmaps");
+			error = EINVAL;
+		} else {
+			struct nm_bridge *b = bna->up.na_bdg,
+				*bh = bna->host.na_bdg;
+			npriv = bna->na_kpriv;
+			bna->na_kpriv = NULL;
+			D("deleting priv");
+
+			bzero(npriv, sizeof(*npriv));
+			free(npriv, M_DEVBUF);
+			if (b) {
+				/* XXX the bwrap dtor should take care
+				 * of this (2014-06-16)
+				 */
+				netmap_bdg_detach_common(b, bna->up.bdg_port,
+				    (bh ? bna->host.bdg_port : -1));
+			}
+			na->na_flags &= ~NAF_BUSY;
+		}
+	}
+	return error;
+
+}
+
+/* attach a bridge wrapper to the 'real' device */
+int
+netmap_bwrap_attach(const char *nr_name, struct netmap_adapter *hwna)
 {
 	struct netmap_bwrap_adapter *bna;
-	struct netmap_adapter *na;
-	struct netmap_adapter *hwna = NA(real);
-	struct netmap_adapter *hostna;
-	int error;
+	struct netmap_adapter *na = NULL;
+	struct netmap_adapter *hostna = NULL;
+	int error = 0;
 
+	/* make sure the NIC is not already in use */
+	if (NETMAP_OWNED_BY_ANY(hwna)) {
+		D("NIC %s busy, cannot attach to bridge", hwna->name);
+		return EBUSY;
+	}
 
 	bna = malloc(sizeof(*bna), M_DEVBUF, M_NOWAIT | M_ZERO);
-	if (bna == NULL)
+	if (bna == NULL) {
 		return ENOMEM;
+	}
 
 	na = &bna->up.up;
-	na->ifp = fake;
+	strncpy(na->name, nr_name, sizeof(na->name));
 	/* fill the ring data for the bwrap adapter with rx/tx meanings
 	 * swapped. The real cross-linking will be done during register,
 	 * when all the krings will have been created.
@@ -2068,17 +2353,28 @@ netmap_bwrap_attach(struct ifnet *fake, struct ifnet *real)
 	na->nm_krings_create = netmap_bwrap_krings_create;
 	na->nm_krings_delete = netmap_bwrap_krings_delete;
 	na->nm_notify = netmap_bwrap_notify;
-	na->nm_mem = hwna->nm_mem;
-	na->na_private = na; /* prevent NIOCREGIF */
+	na->nm_bdg_ctl = netmap_bwrap_bdg_ctl;
+	na->pdev = hwna->pdev;
+	na->nm_mem = netmap_mem_private_new(na->name,
+			na->num_tx_rings, na->num_tx_desc,
+			na->num_rx_rings, na->num_rx_desc,
+			0, 0, &error);
+	na->na_flags |= NAF_MEM_OWNER;
+	if (na->nm_mem == NULL)
+		goto err_put;
 	bna->up.retry = 1; /* XXX maybe this should depend on the hwna */
 
 	bna->hwna = hwna;
 	netmap_adapter_get(hwna);
 	hwna->na_private = bna; /* weak reference */
-	
+	hwna->na_vp = &bna->up;
+
 	if (hwna->na_flags & NAF_HOST_RINGS) {
+		if (hwna->na_flags & NAF_SW_ONLY)
+			na->na_flags |= NAF_SW_ONLY;
 		na->na_flags |= NAF_HOST_RINGS;
 		hostna = &bna->host.up;
+		snprintf(hostna->name, sizeof(hostna->name), "%s^", nr_name);
 		hostna->ifp = hwna->ifp;
 		hostna->num_tx_rings = 1;
 		hostna->num_tx_desc = hwna->num_rx_desc;
@@ -2089,20 +2385,44 @@ netmap_bwrap_attach(struct ifnet *fake, struct ifnet *real)
 		hostna->nm_notify = netmap_bwrap_host_notify;
 		hostna->nm_mem = na->nm_mem;
 		hostna->na_private = bna;
+		hostna->na_vp = &bna->up;
+		na->na_hostvp = hwna->na_hostvp =
+			hostna->na_hostvp = &bna->host;
+		hostna->na_flags = NAF_BUSY; /* prevent NIOCREGIF */
 	}
 
 	ND("%s<->%s txr %d txd %d rxr %d rxd %d",
-		fake->if_xname, real->if_xname,
+		na->name, ifp->if_xname,
 		na->num_tx_rings, na->num_tx_desc,
 		na->num_rx_rings, na->num_rx_desc);
 
 	error = netmap_attach_common(na);
 	if (error) {
-		netmap_adapter_put(hwna);
-		free(bna, M_DEVBUF);
-		return error;
+		goto err_free;
 	}
+	/* make bwrap ifp point to the real ifp
+	 * NOTE: netmap_attach_common() interprets a non-NULL na->ifp
+	 * as a request to make the ifp point to the na. Since we
+	 * do not want to change the na already pointed to by hwna->ifp,
+	 * the following assignment has to be delayed until now
+	 */
+	na->ifp = hwna->ifp;
+	hwna->na_flags |= NAF_BUSY;
+	/* make hwna point to the allocator we are actually using,
+	 * so that monitors will be able to find it
+	 */
+	bna->save_nmd = hwna->nm_mem;
+	hwna->nm_mem = na->nm_mem;
 	return 0;
+
+err_free:
+	netmap_mem_private_delete(na->nm_mem);
+err_put:
+	hwna->na_vp = hwna->na_hostvp = NULL;
+	netmap_adapter_put(hwna);
+	free(bna, M_DEVBUF);
+	return error;
+
 }