X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fdevices%2Flnx_virtio_nic.c;h=bb13a6959e54f553105c625f693c012c9d8a70ee;hb=16047acf61f82cb4ae33bcb84b221c2098215172;hp=6da189319c7de848ed412a127eee5b4081f06300;hpb=e2964f7234daa3429275c039769a313f0870c212;p=palacios.git

diff --git a/palacios/src/devices/lnx_virtio_nic.c b/palacios/src/devices/lnx_virtio_nic.c
index 6da1893..bb13a69 100644
--- a/palacios/src/devices/lnx_virtio_nic.c
+++ b/palacios/src/devices/lnx_virtio_nic.c
@@ -29,6 +29,8 @@
 #include <palacios/vmm_lock.h>
 #include <palacios/vmm_util.h>
 #include <devices/pci.h>
+#include <palacios/vmm_ethernet.h>
+#include <palacios/vmm_time.h>
 
 
 #ifndef CONFIG_DEBUG_VIRTIO_NET
@@ -36,13 +38,12 @@
 #define PrintDebug(fmt, args...)
 #endif
 
-#define VIRTIO_NET_S_LINK_UP	1	/* Link is up */
 #define VIRTIO_NET_MAX_BUFSIZE (sizeof(struct virtio_net_hdr) + (64 << 10))
 
+
 struct virtio_net_hdr {
 	uint8_t flags;
-
-#define VIRTIO_NET_HDR_GSO_NONE		0	/* Not a GSO frame */
+	
 	uint8_t gso_type;
 	uint16_t hdr_len;		/* Ethernet + IP + tcp/udp hdrs */
 	uint16_t gso_size;		/* Bytes to append to hdr_len per frame */
@@ -51,23 +52,24 @@ struct virtio_net_hdr {
 }__attribute__((packed));
 
 
-/* This is the version of the header to use when the MRG_RXBUF
- * feature has been negotiated. */
 struct virtio_net_hdr_mrg_rxbuf {
 	struct virtio_net_hdr hdr;
 	uint16_t num_buffers;	/* Number of merged rx buffers */
 };
 
 	
-#define TX_QUEUE_SIZE 64
-#define RX_QUEUE_SIZE 1024
+#define TX_QUEUE_SIZE 256
+#define RX_QUEUE_SIZE 4096
 #define CTRL_QUEUE_SIZE 64
-#define ETH_ALEN 6
 
 #define VIRTIO_NET_F_MRG_RXBUF	15	/* Host can merge receive buffers. */
 #define VIRTIO_NET_F_MAC	5	/* Host has given MAC address. */
 #define VIRTIO_NET_F_GSO	6	/* Host handles pkts w/ any GSO type */
 #define VIRTIO_NET_F_HOST_TSO4	11	/* Host can handle TSOv4 in. */
+#define VIRTIO_NET_F_HOST_UFO	14	/* Host can handle UFO in. */
+
+/* Port to get virtio config */
+#define VIRTIO_NET_CONFIG 20  
 
 struct virtio_net_config
 {
@@ -79,6 +81,8 @@ struct virtio_dev_state {
     struct vm_device * pci_bus;
     struct list_head dev_list;
     struct v3_vm_info *vm;
+
+    uint8_t mac[ETH_ALEN];
 };
 
 struct virtio_net_state {
@@ -89,38 +93,26 @@ struct virtio_net_state {
     struct pci_device * pci_dev; 
     int io_range_size;
     
-    struct virtio_queue rx_vq;   	/* idx 0, pkts to guest */
-    struct virtio_queue tx_vq;   	/* idx 1, pkts from guest */
-    struct virtio_queue ctrl_vq;  	/* idx 2 */
+    struct virtio_queue rx_vq;   	/* idx 0*/
+    struct virtio_queue tx_vq;   	/* idx 1*/
+    struct virtio_queue ctrl_vq;  	/* idx 2*/
 
-    int buffed_rx;
-    int tx_disabled; 			/* stop TX pkts from guest */
+    struct v3_timer * timer;
 
-    uint64_t pkt_sent, pkt_recv, pkt_drop;
+    struct nic_statistics statistics;
 
     struct v3_dev_net_ops * net_ops;
     v3_lock_t rx_lock, tx_lock;
 
+    uint8_t tx_notify, rx_notify;
+    uint32_t tx_pkts, rx_pkts;
+    uint64_t past_ms;
+
     void * backend_data;
     struct virtio_dev_state * virtio_dev;
     struct list_head dev_link;
 };
 
-/* virtio nic error type */
-#define ERR_VIRTIO_OTHER  1
-#define ERR_VIRTIO_RXQ_FULL  2
-#define ERR_VIRTIO_RXQ_NOSET  3
-#define ERR_VIRTIO_TXQ_NOSET 4
-#define ERR_VIRTIO_TXQ_FULL 5
-#define ERR_VIRTIO_TXQ_DISABLED 6
-
-
-static int virtio_free(struct vm_device * dev) 
-{
-	
-    return 0;
-}
-
 static int virtio_init_state(struct virtio_net_state * virtio) 
 {
     virtio->rx_vq.queue_size = RX_QUEUE_SIZE;
@@ -147,21 +139,19 @@ static int virtio_init_state(struct virtio_net_state * virtio)
 
     virtio->virtio_cfg.pci_isr = 0;
 	
-    virtio->virtio_cfg.host_features = 0; // (1 << VIRTIO_NET_F_MAC);
+    virtio->virtio_cfg.host_features = 0 | (1 << VIRTIO_NET_F_MAC) | 
+								(1 << VIRTIO_NET_F_HOST_UFO) | 
+								(1 << VIRTIO_NET_F_HOST_TSO4);
 
     if ((v3_lock_init(&(virtio->rx_lock)) == -1) ||
 	(v3_lock_init(&(virtio->tx_lock)) == -1)){
         PrintError("Virtio NIC: Failure to init locks for net_state\n");
     }
 
-    virtio->pkt_sent = virtio->pkt_recv = virtio->pkt_drop = 0;
-    virtio->buffed_rx = 0;
-
     return 0;
 }
 
-static int 
-pkt_tx(struct guest_info * core, 
+static int tx_one_pkt(struct guest_info * core, 
        struct virtio_net_state * virtio, 
        struct vring_desc * buf_desc) 
 {
@@ -169,11 +159,20 @@ pkt_tx(struct guest_info * core,
     uint32_t len = buf_desc->length;
 
     if (v3_gpa_to_hva(core, buf_desc->addr_gpa, (addr_t *)&(buf)) == -1) {
-	PrintError("Could not translate buffer address\n");
-	return -ERR_VIRTIO_OTHER;
+	PrintDebug("Could not translate buffer address\n");
+	return -1;
     }
 
-    return virtio->net_ops->send(buf, len, virtio->backend_data);
+    if(virtio->net_ops->send(buf, len, virtio->backend_data) >= 0){
+	virtio->statistics.tx_pkts ++;
+	virtio->statistics.tx_bytes += len;
+
+	return 0;
+    }
+
+    virtio->statistics.tx_dropped ++;
+
+    return -1;
 }
 
 
@@ -220,50 +219,37 @@ static inline void disable_cb(struct virtio_queue *queue) {
 }
 
 
-/* interrupt the guest, so the guest core get EXIT to Palacios
- * this happens when there are either incoming pkts for the guest
- * or the guest can start TX pkts again */
+/* interrupt the guest, so the guest core get EXIT to Palacios */
 static inline void notify_guest(struct virtio_net_state * virtio){
     v3_interrupt_cpu(virtio->virtio_dev->vm, virtio->virtio_dev->vm->cores[0].cpu_id, 0);
 }
 
 
-/* guest free some pkts from rx queue */
-static int handle_rx_kick(struct guest_info *core, 
+/* guest free some pkts for rx queue */
+static int handle_rx_queue_kick(struct guest_info * core, 
 			  struct virtio_net_state * virtio) 
 {
-    unsigned long flags;
-
-    flags = v3_lock_irqsave(virtio->rx_lock);
-
-    virtio->net_ops->start_rx(virtio->backend_data);
-    disable_cb(&virtio->rx_vq);
-
-    v3_unlock_irqrestore(virtio->rx_lock, flags);
-	
     return 0;
 }
 
 
-static int handle_ctrl(struct guest_info *core, 
+static int handle_ctrl(struct guest_info * core, 
 		       struct virtio_net_state * virtio) {
 	
     return 0;
 }
 
-static int handle_pkt_tx(struct guest_info *core, 
+static int handle_pkt_tx(struct guest_info * core, 
 			 struct virtio_net_state * virtio_state) 
 {
-    struct virtio_queue * q = &(virtio_state->tx_vq);
-    struct virtio_net_hdr * hdr = NULL;
-    int recved = 0;
+    struct virtio_queue *q = &(virtio_state->tx_vq);
+    struct virtio_net_hdr *hdr = NULL;
+    int txed = 0;
     unsigned long flags;
 
-    if (!q->ring_avail_addr) 
-	return -ERR_VIRTIO_TXQ_NOSET;
-
-    if(virtio_state->tx_disabled)
-	return -ERR_VIRTIO_TXQ_DISABLED;
+    if (!q->ring_avail_addr) {
+	return -1;
+    }
 
     flags = v3_lock_irqsave(virtio_state->tx_lock);
     while (q->cur_avail_idx != q->avail->index) {
@@ -280,18 +266,18 @@ static int handle_pkt_tx(struct guest_info *core,
 	    goto exit_error;
 	}
 
-	hdr = (struct virtio_net_hdr*)hdr_addr;
+	hdr = (struct virtio_net_hdr *)hdr_addr;
 	desc_idx = hdr_desc->next;
 
 	if(desc_cnt > 2){
-	    PrintError("VNIC: merged rx buffer not supported\n");
+	    PrintError("VNIC: merged rx buffer not supported, desc_cnt %d\n", desc_cnt);
 	    goto exit_error;
 	}
 
 	/* here we assumed that one ethernet pkt is not splitted into multiple virtio buffer */
 	for (i = 0; i < desc_cnt - 1; i++) {	
 	    struct vring_desc * buf_desc = &(q->desc[desc_idx]);
-	    if (pkt_tx(core, virtio_state, buf_desc) == -1) {
+	    if (tx_one_pkt(core, virtio_state, buf_desc) == -1) {
 		PrintError("Error handling nic operation\n");
 		goto exit_error;
 	    }
@@ -299,24 +285,23 @@ static int handle_pkt_tx(struct guest_info *core,
 	    req_len += buf_desc->length;
 	    desc_idx = buf_desc->next;
 	}
-	virtio_state->pkt_sent ++;
-	recved ++;
 
 	q->used->ring[q->used->index % q->queue_size].id = q->avail->ring[q->cur_avail_idx % q->queue_size];
-	q->used->ring[q->used->index % q->queue_size].length = req_len; // What do we set this to????
+	q->used->ring[q->used->index % q->queue_size].length = req_len; /* What do we set this to???? */
 	q->used->index ++;
 	
 	q->cur_avail_idx ++;
+
+	txed ++;
     }
 
     v3_unlock_irqrestore(virtio_state->tx_lock, flags);
-
-    if(!recved)
-	return 0;
 	
-    if (!(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
+    if (txed && !(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
 	v3_pci_raise_irq(virtio_state->virtio_dev->pci_bus, 0, virtio_state->pci_dev);
 	virtio_state->virtio_cfg.pci_isr = 0x1;
+
+	virtio_state->statistics.interrupts ++;
     }
 
     return 0;
@@ -324,7 +309,7 @@ static int handle_pkt_tx(struct guest_info *core,
 exit_error:
 	
     v3_unlock_irqrestore(virtio_state->tx_lock, flags);
-    return -ERR_VIRTIO_OTHER;
+    return -1;
 }
 
 
@@ -375,7 +360,6 @@ static int virtio_io_write(struct guest_info *core,
     struct virtio_net_state * virtio = (struct virtio_net_state *)private_data;
     int port_idx = port % virtio->io_range_size;
 
-
     PrintDebug("VIRTIO NIC %p Write for port %d (index=%d) len=%d, value=%x\n", private_data,
 	       port, port_idx,  length, *(uint32_t *)src);
 
@@ -399,11 +383,9 @@ static int virtio_io_write(struct guest_info *core,
 	    switch (queue_idx) {
 		case 0:
 		    virtio_setup_queue(core, virtio, &virtio->rx_vq, pfn, page_addr);
-		    disable_cb(&virtio->rx_vq);
 		    break;
 		case 1:
 		    virtio_setup_queue(core, virtio, &virtio->tx_vq, pfn, page_addr);
-		    disable_cb(&virtio->tx_vq);
 		    break;
 		case 2:
 		    virtio_setup_queue(core, virtio, &virtio->ctrl_vq, pfn, page_addr);
@@ -426,17 +408,18 @@ static int virtio_io_write(struct guest_info *core,
 	    {
 		uint16_t queue_idx = *(uint16_t *)src;	   		
 		if (queue_idx == 0){
-		    handle_rx_kick(core, virtio);
-		    PrintError("rx kick\n");
+		    if(handle_rx_queue_kick(core, virtio) == -1){
+			PrintError("Could not handle Virtio NIC rx kick\n");
+			return -1;
+		    }
 		} else if (queue_idx == 1){
-		    PrintError("tx kick\n");
 		    if (handle_pkt_tx(core, virtio) == -1) {
-			PrintError("Could not handle NIC Notification\n");
+			PrintError("Could not handle Virtio NIC tx kick\n");
 			return -1;
 		    }
 		} else if (queue_idx == 2){
 		    if (handle_ctrl(core, virtio) == -1) {
-			PrintError("Could not handle NIC Notification\n");
+			PrintError("Could not handle Virtio NIC ctrl kick\n");
 			return -1;
 		    }
 		} else {
@@ -448,7 +431,6 @@ static int virtio_io_write(struct guest_info *core,
 	case VIRTIO_STATUS_PORT:
 	    virtio->virtio_cfg.status = *(uint8_t *)src;
 	    if (virtio->virtio_cfg.status == 0) {
-		PrintDebug("Resetting device\n");
 		virtio_init_state(virtio);
 	    }
 	    break;
@@ -473,7 +455,7 @@ static int virtio_io_read(struct guest_info *core,
     int port_idx = port % virtio->io_range_size;
     uint16_t queue_idx = virtio->virtio_cfg.vring_queue_selector;
 
-    PrintDebug("Virtio NIC %p: Read  for port %d (index =%d), length=%d\n", private_data,
+    PrintDebug("Virtio NIC %p: Read  for port 0x%x (index =%d), length=%d\n", private_data,
 	       port, port_idx, length);
 	
     switch (port_idx) {
@@ -539,6 +521,10 @@ static int virtio_io_read(struct guest_info *core,
 	    v3_pci_lower_irq(virtio->virtio_dev->pci_bus, 0, virtio->pci_dev);
 	    break;
 
+	case VIRTIO_NET_CONFIG ... VIRTIO_NET_CONFIG + ETH_ALEN:
+	    *(uint8_t *)dst = virtio->net_cfg.mac[port_idx-VIRTIO_NET_CONFIG];
+	    break;
+
 	default:
 	    PrintError("Virtio NIC: Read of Unhandled Virtio Read:%d\n", port_idx);
 	    return -1;
@@ -548,32 +534,29 @@ static int virtio_io_read(struct guest_info *core,
 }
 
 
+/* receiving raw ethernet pkt from backend */
 static int virtio_rx(uint8_t * buf, uint32_t size, void * private_data) {
     struct virtio_net_state * virtio = (struct virtio_net_state *)private_data;
     struct virtio_queue * q = &(virtio->rx_vq);
     struct virtio_net_hdr_mrg_rxbuf hdr;
     uint32_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
-    uint32_t data_len = size;
+    uint32_t data_len;
     uint32_t offset = 0;
     unsigned long flags;
-    int ret_val = -ERR_VIRTIO_OTHER;
-    int raw = 1;
 
-    flags = v3_lock_irqsave(virtio->rx_lock);
+#ifdef CONFIG_DEBUG_VIRTIO_NET
+    PrintDebug("Virtio-NIC: virtio_rx: size: %d\n", size);	
+    v3_hexdump(buf, size, NULL, 0);
+#endif
 
-    virtio->pkt_recv ++;
-    if (!raw)
-    	data_len -= hdr_len;
+    flags = v3_lock_irqsave(virtio->rx_lock);
 
-    if (!raw)
-        memcpy(&hdr, buf, sizeof(struct virtio_net_hdr_mrg_rxbuf));
-    else
-        memset(&hdr, 0, sizeof(struct virtio_net_hdr_mrg_rxbuf));
+    data_len = size;
+    memset(&hdr, 0, sizeof(struct virtio_net_hdr_mrg_rxbuf));
 
     if (q->ring_avail_addr == 0) {
-	PrintError("Queue is not set\n");
-	ret_val = -ERR_VIRTIO_RXQ_NOSET;
-	goto exit;
+	PrintDebug("Queue is not set\n");
+	goto err_exit;
     }
 
     if (q->cur_avail_idx != q->avail->index){
@@ -584,8 +567,8 @@ static int virtio_rx(uint8_t * buf, uint32_t size, void * private_data) {
 
 	hdr_desc = &(q->desc[hdr_idx]);
 	if (v3_gpa_to_hva(&(virtio->virtio_dev->vm->cores[0]), hdr_desc->addr_gpa, &(hdr_addr)) == -1) {
-	    PrintError("Could not translate receive buffer address\n");
-	    goto exit;
+	    PrintDebug("Could not translate receive buffer address\n");
+	    goto err_exit;
 	}
 	hdr.num_buffers = 1;
 	memcpy((void *)hdr_addr, &hdr, sizeof(struct virtio_net_hdr_mrg_rxbuf));
@@ -612,86 +595,69 @@ static int virtio_rx(uint8_t * buf, uint32_t size, void * private_data) {
 	q->used->index++;
 	q->cur_avail_idx++;
 
-	/* if there are certain num of pkts in the RX queue, notify guest 
-	  * so guest will exit to palacios
-         * when it returns, guest gets the virtio rx interrupt */
-	if((++virtio->buffed_rx > q->queue_size/5) &&
-	    (q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
-	    if(virtio->virtio_dev->vm->cores[0].cpu_id != V3_Get_CPU()){
-		  notify_guest(virtio);
-	    }
-	    virtio->buffed_rx = 0;
-	}
+ 	virtio->statistics.rx_pkts ++;
+	virtio->statistics.rx_bytes += size;
     } else {
-	virtio->pkt_drop++;
-	/* RX queue is full,  tell backend to stop RX on this device */
-	virtio->net_ops->stop_rx(virtio->backend_data);
-	enable_cb(&virtio->rx_vq);
+	virtio->statistics.rx_dropped ++;
 	
-	ret_val = -ERR_VIRTIO_RXQ_FULL;
-	goto exit;
+	goto err_exit;
     }
 
     if (!(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
 	PrintDebug("Raising IRQ %d\n",  virtio->pci_dev->config_header.intr_line);
+	
 	v3_pci_raise_irq(virtio->virtio_dev->pci_bus, 0, virtio->pci_dev);
 	virtio->virtio_cfg.pci_isr = 0x1;
+	virtio->statistics.interrupts ++;
     }
 
-    ret_val = offset;
+    v3_unlock_irqrestore(virtio->rx_lock, flags);
+
+    /* notify guest if guest is running */
+    if(virtio->rx_notify == 1){
+	v3_interrupt_cpu(virtio->virtio_dev->vm, virtio->virtio_dev->vm->cores[0].cpu_id, 0);
+    }
 
-exit:
+    return 0;
+
+err_exit:
 
     v3_unlock_irqrestore(virtio->rx_lock, flags);
  
-    return ret_val;
+    return -1;
 }
 
+static int virtio_free(struct virtio_dev_state * virtio) {
+    struct virtio_net_state * backend = NULL;
+    struct virtio_net_state * tmp = NULL;
 
-static struct v3_device_ops dev_ops = {
-    .free = virtio_free,
-};
 
+    list_for_each_entry_safe(backend, tmp, &(virtio->dev_list), dev_link) {
 
-/* TODO: Issue here: which vm info it needs? calling VM or the device's own VM? */
-static void virtio_nic_poll(struct v3_vm_info * vm, void * data){
-    struct virtio_net_state * virtio = (struct virtio_net_state *)data;
-	
-    handle_pkt_tx(&(vm->cores[0]), virtio);
+	// unregister from PCI
+
+	list_del(&(backend->dev_link));
+	V3_Free(backend);
+    }
+
+    V3_Free(virtio);
+    return 0;
 }
 
-static void virtio_start_tx(void * data){
-    struct virtio_net_state * virtio = (struct virtio_net_state *)data;
-    unsigned long flags;
 
-    flags = v3_lock_irqsave(virtio->tx_lock);
-    virtio->tx_disabled = 0;
+static struct v3_device_ops dev_ops = {
+    .free = (int (*)(void *))virtio_free,
+};
 
-    /* notify the device's guest to start sending pkt */
-    if(virtio->virtio_dev->vm->cores[0].cpu_id != V3_Get_CPU()){
-	notify_guest(virtio);
-    }
-    v3_unlock_irqrestore(virtio->tx_lock, flags);	
-}
 
-static void virtio_stop_tx(void * data){
+static void virtio_nic_poll(struct v3_vm_info * vm, int budget, void * data){
     struct virtio_net_state * virtio = (struct virtio_net_state *)data;
-    unsigned long flags;
-
-    flags = v3_lock_irqsave(virtio->tx_lock);
-    virtio->tx_disabled = 1;
 
-    /* stop the guest to exit to palacios for sending pkt? */
-    if(virtio->virtio_dev->vm->cores[0].cpu_id != V3_Get_CPU()){
-       disable_cb(&virtio->tx_vq);
+    if(virtio->tx_notify == 0){
+    	handle_pkt_tx(&(vm->cores[0]), virtio);
     }
-
-    v3_unlock_irqrestore(virtio->tx_lock, flags);
 }
 
-	
-
-
 static int register_dev(struct virtio_dev_state * virtio, 
 			struct virtio_net_state * net_state) 
 {
@@ -708,8 +674,9 @@ static int register_dev(struct virtio_dev_state * virtio,
 	net_state->io_range_size <<= 1;
     }
 	
-    // this is to account for any low order bits being set in num_ports
-    // if there are none, then num_ports was already a power of 2 so we shift right to reset it
+    /* this is to account for any low order bits being set in num_ports
+      * if there are none, then num_ports was already a power of 2 so we shift right to reset it
+      */
     if ((num_ports & ((net_state->io_range_size >> 1) - 1)) == 0) {
 	net_state->io_range_size >>= 1;
     }
@@ -753,16 +720,71 @@ static int register_dev(struct virtio_dev_state * virtio,
     net_state->pci_dev = pci_dev;
     net_state->virtio_dev = virtio;
 
-    uchar_t mac[6] = {0x11,0x11,0x11,0x11,0x11,0x11};
-    memcpy(net_state->net_cfg.mac, mac, 6);
-	                                                                                                   
-    memcpy(pci_dev->config_data, net_state->net_cfg.mac, ETH_ALEN);
-    
+    memcpy(net_state->net_cfg.mac, virtio->mac, 6);                           
+	
     virtio_init_state(net_state);
 
+    /* Add backend to list of devices */
+    list_add(&(net_state->dev_link), &(virtio->dev_list));
+
     return 0;
 }
 
+#define RATE_UPPER_THRESHOLD 10  /* 10000 pkts per second, around 100Mbits */
+#define RATE_LOWER_THRESHOLD 1
+#define PROFILE_PERIOD 50 /*50ms*/
+
+/* Timer Functions */
+static void virtio_nic_timer(struct guest_info * core, 
+			     uint64_t cpu_cycles, uint64_t cpu_freq, 
+			     void * priv_data) {
+    struct virtio_net_state * net_state = (struct virtio_net_state *)priv_data;
+    uint64_t period_ms;
+
+    period_ms = cpu_cycles/cpu_freq;
+    net_state->past_ms += period_ms;
+
+    if(net_state->past_ms >  PROFILE_PERIOD){ 
+	uint32_t tx_rate, rx_rate;
+	
+	tx_rate = (net_state->statistics.tx_pkts - net_state->tx_pkts)/net_state->past_ms; /* pkts/per ms */
+	rx_rate = (net_state->statistics.rx_pkts - net_state->rx_pkts)/net_state->past_ms;
+
+	net_state->tx_pkts = net_state->statistics.tx_pkts;
+	net_state->rx_pkts = net_state->statistics.rx_pkts;
+
+	if(tx_rate > RATE_UPPER_THRESHOLD && net_state->tx_notify == 1){
+	    V3_Print("Virtio NIC: Switch TX to VMM driven mode\n");
+	    disable_cb(&(net_state->tx_vq));
+	    net_state->tx_notify = 0;
+	}
+
+	if(tx_rate < RATE_LOWER_THRESHOLD && net_state->tx_notify == 0){
+	    V3_Print("Virtio NIC: Switch TX to Guest  driven mode\n");
+	    enable_cb(&(net_state->tx_vq));
+	    net_state->tx_notify = 1;
+	}
+
+	if(rx_rate > RATE_UPPER_THRESHOLD && net_state->rx_notify == 1){
+	    PrintDebug("Virtio NIC: Switch RX to VMM None notify mode\n");
+	    net_state->rx_notify = 0;
+	}
+
+	if(rx_rate < RATE_LOWER_THRESHOLD && net_state->rx_notify == 0){
+	    PrintDebug("Virtio NIC: Switch RX to VMM notify mode\n");
+	    net_state->rx_notify = 1;
+	}
+
+	net_state->past_ms = 0;
+    }
+}
+
+
+static struct v3_timer_ops timer_ops = {
+    .update_timer = virtio_nic_timer,
+};
+
+
 static int connect_fn(struct v3_vm_info * info, 
 		      void * frontend_data, 
 		      struct v3_dev_net_ops * ops, 
@@ -776,12 +798,16 @@ static int connect_fn(struct v3_vm_info * info,
 
     net_state->net_ops = ops;
     net_state->backend_data = private_data;
+    net_state->virtio_dev = virtio;
+    net_state->tx_notify = 1;
+    net_state->rx_notify = 1;
+
+    net_state->timer = v3_add_timer(&(info->cores[0]),&timer_ops,net_state);
 
     ops->recv = virtio_rx;
     ops->poll = virtio_nic_poll;
-    ops->start_tx = virtio_start_tx;
-    ops->stop_tx = virtio_stop_tx;
     ops->frontend_data = net_state;
+    memcpy(ops->fnt_mac, virtio->mac, ETH_ALEN);
 
     return 0;
 }
@@ -790,8 +816,9 @@ static int virtio_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
     struct vm_device * pci_bus = v3_find_dev(vm, v3_cfg_val(cfg, "bus"));
     struct virtio_dev_state * virtio_state = NULL;
     char * dev_id = v3_cfg_val(cfg, "ID");
-
-    PrintDebug("Virtio NIC: Initializing VIRTIO Network device: %s\n", dev_id);
+    char macstr[128];
+    char * str = v3_cfg_val(cfg, "mac");
+    memcpy(macstr, str, strlen(str));
 
     if (pci_bus == NULL) {
 	PrintError("Virtio NIC: VirtIO devices require a PCI Bus");
@@ -805,14 +832,30 @@ static int virtio_init(struct v3_vm_info * vm, v3_cfg_tree_t * cfg) {
     virtio_state->pci_bus = pci_bus;
     virtio_state->vm = vm;
 
-    struct vm_device * dev = v3_allocate_device(dev_id, &dev_ops, virtio_state);
-    if (v3_attach_device(vm, dev) == -1) {
+    if (macstr != NULL && !str2mac(macstr, virtio_state->mac)) {
+	PrintDebug("Virtio NIC: Mac specified %s\n", macstr);
+	PrintDebug("MAC: %x:%x:%x:%x:%x:%x\n", virtio_state->mac[0],
+				virtio_state->mac[1],
+				virtio_state->mac[2],
+				virtio_state->mac[3],
+				virtio_state->mac[4],
+				virtio_state->mac[5]);
+    }else {
+    	PrintDebug("Virtio NIC: MAC not specified\n");
+	random_ethaddr(virtio_state->mac);
+    }
+
+    struct vm_device * dev = v3_add_device(vm, dev_id, &dev_ops, virtio_state);
+
+    if (dev == NULL) {
 	PrintError("Virtio NIC: Could not attach device %s\n", dev_id);
+	V3_Free(virtio_state);
 	return -1;
     }
 
     if (v3_dev_add_net_frontend(vm, dev_id, connect_fn, (void *)virtio_state) == -1) {
 	PrintError("Virtio NIC: Could not register %s as net frontend\n", dev_id);
+	v3_remove_device(dev);
 	return -1;
     }