1 files changed, 340 insertions, 204 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 20e9defa1060..48a55cda979b 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -43,40 +43,56 @@
 #define XENVIF_QUEUE_LENGTH 32
 #define XENVIF_NAPI_WEIGHT  64
 
+static inline void xenvif_stop_queue(struct xenvif_queue *queue)
+{
+        struct net_device *dev = queue->vif->dev;
+
+        if (!queue->vif->can_queue)
+                return;
+
+        netif_tx_stop_queue(netdev_get_tx_queue(dev, queue->id));
+}
+
 int xenvif_schedulable(struct xenvif *vif)
 {
-        return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
+        return netif_running(vif->dev) &&
+                test_bit(VIF_STATUS_CONNECTED, &vif->status);
 }
 
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
 {
-        struct xenvif *vif = dev_id;
+        struct xenvif_queue *queue = dev_id;
 
-        if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx))
-                napi_schedule(&vif->napi);
+        if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
+                napi_schedule(&queue->napi);
 
         return IRQ_HANDLED;
 }
 
-static int xenvif_poll(struct napi_struct *napi, int budget)
+int xenvif_poll(struct napi_struct *napi, int budget)
 {
-        struct xenvif *vif = container_of(napi, struct xenvif, napi);
+        struct xenvif_queue *queue =
+                container_of(napi, struct xenvif_queue, napi);
         int work_done;
 
         /* This vif is rogue, we pretend we've there is nothing to do
          * for this vif to deschedule it from NAPI. But this interface
          * will be turned off in thread context later.
+         * Also, if a guest doesn't post enough slots to receive data on one of
+         * its queues, the carrier goes down and NAPI is descheduled here so
+         * the guest can't send more packets until it's ready to receive.
          */
-        if (unlikely(vif->disabled)) {
+        if (unlikely(queue->vif->disabled ||
+                     !netif_carrier_ok(queue->vif->dev))) {
                 napi_complete(napi);
                 return 0;
         }
 
-        work_done = xenvif_tx_action(vif, budget);
+        work_done = xenvif_tx_action(queue, budget);
 
         if (work_done < budget) {
                 napi_complete(napi);
-                xenvif_napi_schedule_or_enable_events(vif);
+                xenvif_napi_schedule_or_enable_events(queue);
         }
 
         return work_done;
@@ -84,14 +100,23 @@ static int xenvif_poll(struct napi_struct *napi, int budget)
 
 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 {
-        struct xenvif *vif = dev_id;
+        struct xenvif_queue *queue = dev_id;
+        struct netdev_queue *net_queue =
+                netdev_get_tx_queue(queue->vif->dev, queue->id);
 
-        xenvif_kick_thread(vif);
+        /* QUEUE_STATUS_RX_PURGE_EVENT is only set if either QDisc was off OR
+         * the carrier went down and this queue was previously blocked
+         */
+        if (unlikely(netif_tx_queue_stopped(net_queue) ||
+                     (!netif_carrier_ok(queue->vif->dev) &&
+                      test_bit(QUEUE_STATUS_RX_STALLED, &queue->status))))
+                set_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status);
+        xenvif_kick_thread(queue);
 
         return IRQ_HANDLED;
 }
 
-static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
+irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 {
         xenvif_tx_interrupt(irq, dev_id);
         xenvif_rx_interrupt(irq, dev_id);
@@ -99,28 +124,57 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
-static void xenvif_wake_queue(unsigned long data)
+int xenvif_queue_stopped(struct xenvif_queue *queue)
+{
+        struct net_device *dev = queue->vif->dev;
+        unsigned int id = queue->id;
+        return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
+}
+
+void xenvif_wake_queue(struct xenvif_queue *queue)
 {
-        struct xenvif *vif = (struct xenvif *)data;
+        struct net_device *dev = queue->vif->dev;
+        unsigned int id = queue->id;
+        netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
+}
+
+/* Callback to wake the queue's thread and turn the carrier off on timeout */
+static void xenvif_rx_stalled(unsigned long data)
+{
+        struct xenvif_queue *queue = (struct xenvif_queue *)data;
 
-        if (netif_queue_stopped(vif->dev)) {
-                netdev_err(vif->dev, "draining TX queue\n");
-                vif->rx_queue_purge = true;
-                xenvif_kick_thread(vif);
-                netif_wake_queue(vif->dev);
+        if (xenvif_queue_stopped(queue)) {
+                set_bit(QUEUE_STATUS_RX_PURGE_EVENT, &queue->status);
+                xenvif_kick_thread(queue);
         }
 }
 
 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        u16 index;
         int min_slots_needed;
 
         BUG_ON(skb->dev != dev);
 
-        /* Drop the packet if vif is not ready */
-        if (vif->task == NULL ||
-            vif->dealloc_task == NULL ||
+        /* Drop the packet if queues are not set up */
+        if (num_queues < 1)
+                goto drop;
+
+        /* Obtain the queue to be used to transmit this packet */
+        index = skb_get_queue_mapping(skb);
+        if (index >= num_queues) {
+                pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
+                                    index, vif->dev->name);
+                index %= num_queues;
+        }
+        queue = &vif->queues[index];
+
+        /* Drop the packet if queue is not ready */
+        if (queue->task == NULL ||
+            queue->dealloc_task == NULL ||
             !xenvif_schedulable(vif))
                 goto drop;
 
@@ -139,16 +193,16 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
          * then turn off the queue to give the ring a chance to
          * drain.
          */
-        if (!xenvif_rx_ring_slots_available(vif, min_slots_needed)) {
-                vif->wake_queue.function = xenvif_wake_queue;
-                vif->wake_queue.data = (unsigned long)vif;
-                xenvif_stop_queue(vif);
-                mod_timer(&vif->wake_queue,
-                        jiffies + rx_drain_timeout_jiffies);
+        if (!xenvif_rx_ring_slots_available(queue, min_slots_needed)) {
+                queue->rx_stalled.function = xenvif_rx_stalled;
+                queue->rx_stalled.data = (unsigned long)queue;
+                xenvif_stop_queue(queue);
+                mod_timer(&queue->rx_stalled,
+                          jiffies + rx_drain_timeout_jiffies);
         }
 
-        skb_queue_tail(&vif->rx_queue, skb);
-        xenvif_kick_thread(vif);
+        skb_queue_tail(&queue->rx_queue, skb);
+        xenvif_kick_thread(queue);
 
         return NETDEV_TX_OK;
 
@@ -161,42 +215,82 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        unsigned long rx_bytes = 0;
+        unsigned long rx_packets = 0;
+        unsigned long tx_bytes = 0;
+        unsigned long tx_packets = 0;
+        unsigned int index;
+
+        if (vif->queues == NULL)
+                goto out;
+
+        /* Aggregate tx and rx stats from each queue */
+        for (index = 0; index < num_queues; ++index) {
+                queue = &vif->queues[index];
+                rx_bytes += queue->stats.rx_bytes;
+                rx_packets += queue->stats.rx_packets;
+                tx_bytes += queue->stats.tx_bytes;
+                tx_packets += queue->stats.tx_packets;
+        }
+
+out:
+        vif->dev->stats.rx_bytes = rx_bytes;
+        vif->dev->stats.rx_packets = rx_packets;
+        vif->dev->stats.tx_bytes = tx_bytes;
+        vif->dev->stats.tx_packets = tx_packets;
+
         return &vif->dev->stats;
 }
 
 static void xenvif_up(struct xenvif *vif)
 {
-        napi_enable(&vif->napi);
-        enable_irq(vif->tx_irq);
-        if (vif->tx_irq != vif->rx_irq)
-                enable_irq(vif->rx_irq);
-        xenvif_napi_schedule_or_enable_events(vif);
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        unsigned int queue_index;
+
+        for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+                queue = &vif->queues[queue_index];
+                napi_enable(&queue->napi);
+                enable_irq(queue->tx_irq);
+                if (queue->tx_irq != queue->rx_irq)
+                        enable_irq(queue->rx_irq);
+                xenvif_napi_schedule_or_enable_events(queue);
+        }
 }
 
 static void xenvif_down(struct xenvif *vif)
 {
-        napi_disable(&vif->napi);
-        disable_irq(vif->tx_irq);
-        if (vif->tx_irq != vif->rx_irq)
-                disable_irq(vif->rx_irq);
-        del_timer_sync(&vif->credit_timeout);
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        unsigned int queue_index;
+
+        for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+                queue = &vif->queues[queue_index];
+                napi_disable(&queue->napi);
+                disable_irq(queue->tx_irq);
+                if (queue->tx_irq != queue->rx_irq)
+                        disable_irq(queue->rx_irq);
+                del_timer_sync(&queue->credit_timeout);
+        }
 }
 
 static int xenvif_open(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
-        if (netif_carrier_ok(dev))
+        if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                 xenvif_up(vif);
-        netif_start_queue(dev);
+        netif_tx_start_all_queues(dev);
         return 0;
 }
 
 static int xenvif_close(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
-        if (netif_carrier_ok(dev))
+        if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
                 xenvif_down(vif);
-        netif_stop_queue(dev);
+        netif_tx_stop_all_queues(dev);
         return 0;
 }
 
@@ -236,29 +330,29 @@ static const struct xenvif_stat {
 } xenvif_stats[] = {
         {
                 "rx_gso_checksum_fixup",
-                offsetof(struct xenvif, rx_gso_checksum_fixup)
+                offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
         },
         /* If (sent != success + fail), there are probably packets never
          * freed up properly!
          */
         {
                 "tx_zerocopy_sent",
-                offsetof(struct xenvif, tx_zerocopy_sent),
+                offsetof(struct xenvif_stats, tx_zerocopy_sent),
         },
         {
                 "tx_zerocopy_success",
-                offsetof(struct xenvif, tx_zerocopy_success),
+                offsetof(struct xenvif_stats, tx_zerocopy_success),
         },
         {
                 "tx_zerocopy_fail",
-                offsetof(struct xenvif, tx_zerocopy_fail)
+                offsetof(struct xenvif_stats, tx_zerocopy_fail)
         },
         /* Number of packets exceeding MAX_SKB_FRAG slots. You should use
          * a guest with the same MAX_SKB_FRAG
          */
         {
                 "tx_frag_overflow",
-                offsetof(struct xenvif, tx_frag_overflow)
+                offsetof(struct xenvif_stats, tx_frag_overflow)
         },
 };
 
@@ -275,11 +369,20 @@ static int xenvif_get_sset_count(struct net_device *dev, int string_set)
 static void xenvif_get_ethtool_stats(struct net_device *dev,
                                      struct ethtool_stats *stats, u64 * data)
 {
-        void *vif = netdev_priv(dev);
+        struct xenvif *vif = netdev_priv(dev);
+        unsigned int num_queues = vif->num_queues;
         int i;
-
-        for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
-                data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
+        unsigned int queue_index;
+        struct xenvif_stats *vif_stats;
+
+        for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
+                unsigned long accum = 0;
+                for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+                        vif_stats = &vif->queues[queue_index].stats;
+                        accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
+                }
+                data[i] = accum;
+        }
 }
 
 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
@@ -321,10 +424,14 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         struct net_device *dev;
         struct xenvif *vif;
         char name[IFNAMSIZ] = {};
-        int i;
 
         snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
-        dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
+        /* Allocate a netdev with the max. supported number of queues.
+         * When the guest selects the desired number, it will be updated
+         * via netif_set_real_num_*_queues().
+         */
+        dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
+                              ether_setup, xenvif_max_queues);
         if (dev == NULL) {
                 pr_warn("Could not allocate netdev for %s\n", name);
                 return ERR_PTR(-ENOMEM);
@@ -334,66 +441,26 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 
         vif = netdev_priv(dev);
 
-        vif->grant_copy_op = vmalloc(sizeof(struct gnttab_copy) *
-                                     MAX_GRANT_COPY_OPS);
-        if (vif->grant_copy_op == NULL) {
-                pr_warn("Could not allocate grant copy space for %s\n", name);
-                free_netdev(dev);
-                return ERR_PTR(-ENOMEM);
-        }
-
         vif->domid  = domid;
         vif->handle = handle;
         vif->can_sg = 1;
         vif->ip_csum = 1;
         vif->dev = dev;
-
         vif->disabled = false;
 
-        vif->credit_bytes = vif->remaining_credit = ~0UL;
-        vif->credit_usec  = 0UL;
-        init_timer(&vif->credit_timeout);
-        vif->credit_window_start = get_jiffies_64();
-
-        init_timer(&vif->wake_queue);
+        /* Start out with no queues. */
+        vif->queues = NULL;
+        vif->num_queues = 0;
 
         dev->netdev_ops = &xenvif_netdev_ops;
         dev->hw_features = NETIF_F_SG |
                 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
                 NETIF_F_TSO | NETIF_F_TSO6;
         dev->features = dev->hw_features | NETIF_F_RXCSUM;
-        SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
+        dev->ethtool_ops = &xenvif_ethtool_ops;
 
         dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
 
-        skb_queue_head_init(&vif->rx_queue);
-        skb_queue_head_init(&vif->tx_queue);
-
-        vif->pending_cons = 0;
-        vif->pending_prod = MAX_PENDING_REQS;
-        for (i = 0; i < MAX_PENDING_REQS; i++)
-                vif->pending_ring[i] = i;
-        spin_lock_init(&vif->callback_lock);
-        spin_lock_init(&vif->response_lock);
-        /* If ballooning is disabled, this will consume real memory, so you
-         * better enable it. The long term solution would be to use just a
-         * bunch of valid page descriptors, without dependency on ballooning
-         */
-        err = alloc_xenballooned_pages(MAX_PENDING_REQS,
-                                       vif->mmap_pages,
-                                       false);
-        if (err) {
-                netdev_err(dev, "Could not reserve mmap_pages\n");
-                return ERR_PTR(-ENOMEM);
-        }
-        for (i = 0; i < MAX_PENDING_REQS; i++) {
-                vif->pending_tx_info[i].callback_struct = (struct ubuf_info)
-                        { .callback = xenvif_zerocopy_callback,
-                          .ctx = NULL,
-                          .desc = i };
-                vif->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
-        }
-
         /*
          * Initialise a dummy MAC address. We choose the numerically
          * largest non-broadcast address to prevent the address getting
@@ -403,8 +470,6 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         memset(dev->dev_addr, 0xFF, ETH_ALEN);
         dev->dev_addr[0] &= ~0x01;
 
-        netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
-
         netif_carrier_off(dev);
 
         err = register_netdev(dev);
@@ -421,98 +486,148 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
         return vif;
 }
 
-int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
+int xenvif_init_queue(struct xenvif_queue *queue)
+{
+        int err, i;
+
+        queue->credit_bytes = queue->remaining_credit = ~0UL;
+        queue->credit_usec  = 0UL;
+        init_timer(&queue->credit_timeout);
+        queue->credit_window_start = get_jiffies_64();
+
+        skb_queue_head_init(&queue->rx_queue);
+        skb_queue_head_init(&queue->tx_queue);
+
+        queue->pending_cons = 0;
+        queue->pending_prod = MAX_PENDING_REQS;
+        for (i = 0; i < MAX_PENDING_REQS; ++i)
+                queue->pending_ring[i] = i;
+
+        spin_lock_init(&queue->callback_lock);
+        spin_lock_init(&queue->response_lock);
+
+        /* If ballooning is disabled, this will consume real memory, so you
+         * better enable it. The long term solution would be to use just a
+         * bunch of valid page descriptors, without dependency on ballooning
+         */
+        err = alloc_xenballooned_pages(MAX_PENDING_REQS,
+                                       queue->mmap_pages,
+                                       false);
+        if (err) {
+                netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
+                return -ENOMEM;
+        }
+
+        for (i = 0; i < MAX_PENDING_REQS; i++) {
+                queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
+                        { .callback = xenvif_zerocopy_callback,
+                          .ctx = NULL,
+                          .desc = i };
+                queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
+        }
+
+        init_timer(&queue->rx_stalled);
+
+        netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
+                        XENVIF_NAPI_WEIGHT);
+
+        return 0;
+}
+
+void xenvif_carrier_on(struct xenvif *vif)
+{
+        rtnl_lock();
+        if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
+                dev_set_mtu(vif->dev, ETH_DATA_LEN);
+        netdev_update_features(vif->dev);
+        set_bit(VIF_STATUS_CONNECTED, &vif->status);
+        netif_carrier_on(vif->dev);
+        if (netif_running(vif->dev))
+                xenvif_up(vif);
+        rtnl_unlock();
+}
+
+int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
                    unsigned long rx_ring_ref, unsigned int tx_evtchn,
                    unsigned int rx_evtchn)
 {
         struct task_struct *task;
         int err = -ENOMEM;
 
-        BUG_ON(vif->tx_irq);
-        BUG_ON(vif->task);
-        BUG_ON(vif->dealloc_task);
+        BUG_ON(queue->tx_irq);
+        BUG_ON(queue->task);
+        BUG_ON(queue->dealloc_task);
 
-        err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
+        err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
         if (err < 0)
                 goto err;
 
-        init_waitqueue_head(&vif->wq);
-        init_waitqueue_head(&vif->dealloc_wq);
+        init_waitqueue_head(&queue->wq);
+        init_waitqueue_head(&queue->dealloc_wq);
 
         if (tx_evtchn == rx_evtchn) {
                 /* feature-split-event-channels == 0 */
                 err = bind_interdomain_evtchn_to_irqhandler(
-                        vif->domid, tx_evtchn, xenvif_interrupt, 0,
-                        vif->dev->name, vif);
+                        queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
+                        queue->name, queue);
                 if (err < 0)
                         goto err_unmap;
-                vif->tx_irq = vif->rx_irq = err;
-                disable_irq(vif->tx_irq);
+                queue->tx_irq = queue->rx_irq = err;
+                disable_irq(queue->tx_irq);
         } else {
                 /* feature-split-event-channels == 1 */
-                snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
-                         "%s-tx", vif->dev->name);
+                snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
+                         "%s-tx", queue->name);
                 err = bind_interdomain_evtchn_to_irqhandler(
-                        vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
-                        vif->tx_irq_name, vif);
+                        queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
+                        queue->tx_irq_name, queue);
                 if (err < 0)
                         goto err_unmap;
-                vif->tx_irq = err;
-                disable_irq(vif->tx_irq);
+                queue->tx_irq = err;
+                disable_irq(queue->tx_irq);
 
-                snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
-                         "%s-rx", vif->dev->name);
+                snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
+                         "%s-rx", queue->name);
                 err = bind_interdomain_evtchn_to_irqhandler(
-                        vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
-                        vif->rx_irq_name, vif);
+                        queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
+                        queue->rx_irq_name, queue);
                 if (err < 0)
                         goto err_tx_unbind;
-                vif->rx_irq = err;
-                disable_irq(vif->rx_irq);
+                queue->rx_irq = err;
+                disable_irq(queue->rx_irq);
         }
 
         task = kthread_create(xenvif_kthread_guest_rx,
-                              (void *)vif, "%s-guest-rx", vif->dev->name);
+                              (void *)queue, "%s-guest-rx", queue->name);
         if (IS_ERR(task)) {
-                pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
+                pr_warn("Could not allocate kthread for %s\n", queue->name);
                 err = PTR_ERR(task);
                 goto err_rx_unbind;
         }
-
-        vif->task = task;
+        queue->task = task;
 
         task = kthread_create(xenvif_dealloc_kthread,
-                              (void *)vif, "%s-dealloc", vif->dev->name);
+                              (void *)queue, "%s-dealloc", queue->name);
         if (IS_ERR(task)) {
-                pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
+                pr_warn("Could not allocate kthread for %s\n", queue->name);
                 err = PTR_ERR(task);
                 goto err_rx_unbind;
         }
+        queue->dealloc_task = task;
 
-        vif->dealloc_task = task;
-
-        rtnl_lock();
-        if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
-                dev_set_mtu(vif->dev, ETH_DATA_LEN);
-        netdev_update_features(vif->dev);
-        netif_carrier_on(vif->dev);
-        if (netif_running(vif->dev))
-                xenvif_up(vif);
-        rtnl_unlock();
-
-        wake_up_process(vif->task);
-        wake_up_process(vif->dealloc_task);
+        wake_up_process(queue->task);
+        wake_up_process(queue->dealloc_task);
 
         return 0;
 
 err_rx_unbind:
-        unbind_from_irqhandler(vif->rx_irq, vif);
-        vif->rx_irq = 0;
+        unbind_from_irqhandler(queue->rx_irq, queue);
+        queue->rx_irq = 0;
 err_tx_unbind:
-        unbind_from_irqhandler(vif->tx_irq, vif);
-        vif->tx_irq = 0;
+        unbind_from_irqhandler(queue->tx_irq, queue);
+        queue->tx_irq = 0;
 err_unmap:
-        xenvif_unmap_frontend_rings(vif);
+        xenvif_unmap_frontend_rings(queue);
 err:
         module_put(THIS_MODULE);
         return err;
@@ -523,85 +638,106 @@ void xenvif_carrier_off(struct xenvif *vif)
         struct net_device *dev = vif->dev;
 
         rtnl_lock();
-        netif_carrier_off(dev); /* discard queued packets */
-        if (netif_running(dev))
-                xenvif_down(vif);
+        if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
+                netif_carrier_off(dev); /* discard queued packets */
+                if (netif_running(dev))
+                        xenvif_down(vif);
+        }
         rtnl_unlock();
 }
 
-void xenvif_disconnect(struct xenvif *vif)
+static void xenvif_wait_unmap_timeout(struct xenvif_queue *queue,
+                                      unsigned int worst_case_skb_lifetime)
 {
-        if (netif_carrier_ok(vif->dev))
-                xenvif_carrier_off(vif);
+        int i, unmap_timeout = 0;
 
-        if (vif->task) {
-                del_timer_sync(&vif->wake_queue);
-                kthread_stop(vif->task);
-                vif->task = NULL;
+        for (i = 0; i < MAX_PENDING_REQS; ++i) {
+                if (queue->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) {
+                        unmap_timeout++;
+                        schedule_timeout(msecs_to_jiffies(1000));
+                        if (unmap_timeout > worst_case_skb_lifetime &&
+                            net_ratelimit())
+                                netdev_err(queue->vif->dev,
+                                           "Page still granted! Index: %x\n",
+                                           i);
+                        i = -1;
+                }
         }
+}
 
-        if (vif->dealloc_task) {
-                kthread_stop(vif->dealloc_task);
-                vif->dealloc_task = NULL;
-        }
+void xenvif_disconnect(struct xenvif *vif)
+{
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        unsigned int queue_index;
+
+        xenvif_carrier_off(vif);
+
+        for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+                queue = &vif->queues[queue_index];
+
+                if (queue->task) {
+                        del_timer_sync(&queue->rx_stalled);
+                        kthread_stop(queue->task);
+                        queue->task = NULL;
+                }
 
-        if (vif->tx_irq) {
-                if (vif->tx_irq == vif->rx_irq)
-                        unbind_from_irqhandler(vif->tx_irq, vif);
-                else {
-                        unbind_from_irqhandler(vif->tx_irq, vif);
-                        unbind_from_irqhandler(vif->rx_irq, vif);
+                if (queue->dealloc_task) {
+                        kthread_stop(queue->dealloc_task);
+                        queue->dealloc_task = NULL;
                 }
-                vif->tx_irq = 0;
+
+                if (queue->tx_irq) {
+                        if (queue->tx_irq == queue->rx_irq)
+                                unbind_from_irqhandler(queue->tx_irq, queue);
+                        else {
+                                unbind_from_irqhandler(queue->tx_irq, queue);
+                                unbind_from_irqhandler(queue->rx_irq, queue);
+                        }
+                        queue->tx_irq = 0;
+                }
+
+                xenvif_unmap_frontend_rings(queue);
         }
+}
 
-        xenvif_unmap_frontend_rings(vif);
+/* Reverse the relevant parts of xenvif_init_queue().
+ * Used for queue teardown from xenvif_free(), and on the
+ * error handling paths in xenbus.c:connect().
+ */
+void xenvif_deinit_queue(struct xenvif_queue *queue)
+{
+        free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages);
+        netif_napi_del(&queue->napi);
 }
 
 void xenvif_free(struct xenvif *vif)
 {
-        int i, unmap_timeout = 0;
+        struct xenvif_queue *queue = NULL;
+        unsigned int num_queues = vif->num_queues;
+        unsigned int queue_index;
         /* Here we want to avoid timeout messages if an skb can be legitimately
          * stuck somewhere else. Realistically this could be an another vif's
          * internal or QDisc queue. That another vif also has this
-         * rx_drain_timeout_msecs timeout, but the timer only ditches the
-         * internal queue. After that, the QDisc queue can put in worst case
-         * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's
-         * internal queue, so we need several rounds of such timeouts until we
-         * can be sure that no another vif should have skb's from us. We are
-         * not sending more skb's, so newly stuck packets are not interesting
-         * for us here.
+         * rx_drain_timeout_msecs timeout, so give it time to drain out.
+         * Although if that other guest wakes up just before its timeout happens
+         * and takes only one skb from QDisc, it can hold onto other skbs for a
+         * longer period.
          */
-        unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) *
-                DIV_ROUND_UP(XENVIF_QUEUE_LENGTH, (XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS));
+        unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000);
 
-        for (i = 0; i < MAX_PENDING_REQS; ++i) {
-                if (vif->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) {
-                        unmap_timeout++;
-                        schedule_timeout(msecs_to_jiffies(1000));
-                        if (unmap_timeout > worst_case_skb_lifetime &&
-                            net_ratelimit())
-                                netdev_err(vif->dev,
-                                           "Page still granted! Index: %x\n",
-                                           i);
-                        /* If there are still unmapped pages, reset the loop to
-                         * start checking again. We shouldn't exit here until
-                         * dealloc thread and NAPI instance release all the
-                         * pages. If a kernel bug causes the skbs to stall
-                         * somewhere, the interface cannot be brought down
-                         * properly.
-                         */
-                        i = -1;
-                }
-        }
-
-        free_xenballooned_pages(MAX_PENDING_REQS, vif->mmap_pages);
+        unregister_netdev(vif->dev);
 
-        netif_napi_del(&vif->napi);
+        for (queue_index = 0; queue_index < num_queues; ++queue_index) {
+                queue = &vif->queues[queue_index];
+                xenvif_wait_unmap_timeout(queue, worst_case_skb_lifetime);
+                xenvif_deinit_queue(queue);
+        }
 
-        unregister_netdev(vif->dev);
+        vfree(vif->queues);
+        vif->queues = NULL;
+        vif->num_queues = 0;
 
-        vfree(vif->grant_copy_op);
         free_netdev(vif->dev);
 
         module_put(THIS_MODULE);