Re: [Qemu-devel] [RFC V2 PATCH 4/4] virtio-net: add multiqueue support

Re: [Qemu-devel] [RFC V2 PATCH 4/4] virtio-net: add multiqueue support

[Michael S. Tsirkin]

On Mon, Jun 25, 2012 at 06:04:49PM +0800, Jason Wang wrote:
> This patch let the virtio-net can transmit and recevie packets through multiuple
> VLANClientStates and abstract them as multiple virtqueues to guest. A new
> parameter 'queues' were introduced to specify the number of queue pairs.
> 
> The main goal for vhost support is to let the multiqueue could be used without
> changes in vhost code. So each vhost_net structure were used to track a single
> VLANClientState and two virtqueues in the past. As multiple VLANClientState were
> stored in the NICState, we can infer the correspond VLANClientState from this
> and queue_index easily.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Can this patch be split up?
1. extend vhost API to allow multiqueue and minimally tweak virtio
2. add real multiqueue for virtio

Hmm?

> ---
>  hw/vhost.c      |   58 ++++---
>  hw/vhost.h      |    1 
>  hw/vhost_net.c  |    7 +
>  hw/vhost_net.h  |    2 
>  hw/virtio-net.c |  461 +++++++++++++++++++++++++++++++++++++------------------
>  hw/virtio-net.h |    3 
>  6 files changed, 355 insertions(+), 177 deletions(-)
> 
> diff --git a/hw/vhost.c b/hw/vhost.c
> index 43664e7..6318bb2 100644
> --- a/hw/vhost.c
> +++ b/hw/vhost.c
> @@ -620,11 +620,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
>  {
>      target_phys_addr_t s, l, a;
>      int r;
> +    int vhost_vq_index = (idx > 2 ? idx - 1 : idx) % dev->nvqs;
>      struct vhost_vring_file file = {
> -        .index = idx,
> +	.index = vhost_vq_index
>      };
>      struct vhost_vring_state state = {
> -        .index = idx,
> +        .index = vhost_vq_index
>      };
>      struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
>  
> @@ -670,11 +671,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
>          goto fail_alloc_ring;
>      }
>  
> -    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
> +    r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
>      if (r < 0) {
>          r = -errno;
>          goto fail_alloc;
>      }
> +
>      file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
>      r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
>      if (r) {
> @@ -715,7 +717,7 @@ static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
>                                      unsigned idx)
>  {
>      struct vhost_vring_state state = {
> -        .index = idx,
> +        .index = (idx > 2 ? idx - 1 : idx) % dev->nvqs,
>      };
>      int r;
>      r = ioctl(dev->control, VHOST_GET_VRING_BASE, &state);
> @@ -829,7 +831,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>      }
>  
>      for (i = 0; i < hdev->nvqs; ++i) {
> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> +					     hdev->start_idx + i,
> +					     true);
>          if (r < 0) {
>              fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
>              goto fail_vq;
> @@ -839,7 +843,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>      return 0;
>  fail_vq:
>      while (--i >= 0) {
> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> +					     hdev->start_idx + i,
> +					     false);
>          if (r < 0) {
>              fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
>              fflush(stderr);
> @@ -860,7 +866,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>      int i, r;
>  
>      for (i = 0; i < hdev->nvqs; ++i) {
> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> +					     hdev->start_idx + i,
> +					     false);
>          if (r < 0) {
>              fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
>              fflush(stderr);
> @@ -874,15 +882,17 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
>  {
>      int i, r;
>      if (!vdev->binding->set_guest_notifiers) {
> -        fprintf(stderr, "binding does not support guest notifiers\n");
> +        fprintf(stderr, "binding does not support guest notifier\n");
>          r = -ENOSYS;
>          goto fail;
>      }
>  
> -    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
> -    if (r < 0) {
> -        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
> -        goto fail_notifiers;
> +    if (hdev->start_idx == 0) {
> +        r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
> +        if (r < 0) {
> +            fprintf(stderr, "Error binding guest notifier: %d\n", -r);
> +            goto fail_notifiers;
> +        }
>      }
>  
>      r = vhost_dev_set_features(hdev, hdev->log_enabled);
> @@ -898,7 +908,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
>          r = vhost_virtqueue_init(hdev,
>                                   vdev,
>                                   hdev->vqs + i,
> -                                 i);
> +                                 hdev->start_idx + i);
>          if (r < 0) {
>              goto fail_vq;
>          }
> @@ -925,11 +935,13 @@ fail_vq:
>          vhost_virtqueue_cleanup(hdev,
>                                  vdev,
>                                  hdev->vqs + i,
> -                                i);
> +                                hdev->start_idx + i);
>      }
> +    i = hdev->nvqs;
>  fail_mem:
>  fail_features:
> -    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> +    if (hdev->start_idx == 0)
> +        vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
>  fail_notifiers:
>  fail:
>      return r;
> @@ -944,18 +956,22 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>          vhost_virtqueue_cleanup(hdev,
>                                  vdev,
>                                  hdev->vqs + i,
> -                                i);
> +                                hdev->start_idx + i);
>      }
> +
>      for (i = 0; i < hdev->n_mem_sections; ++i) {
>          vhost_sync_dirty_bitmap(hdev, &hdev->mem_sections[i],
>                                  0, (target_phys_addr_t)~0x0ull);
>      }
> -    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> -    if (r < 0) {
> -        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
> -        fflush(stderr);
> +
> +    if (hdev->start_idx == 0) {
> +	r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> +	if (r < 0) {
> +	    fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
> +	    fflush(stderr);
> +	}
> +	assert (r >= 0);
>      }
> -    assert (r >= 0);
>  
>      hdev->started = false;
>      g_free(hdev->log);
> diff --git a/hw/vhost.h b/hw/vhost.h
> index 80e64df..fa5357a 100644
> --- a/hw/vhost.h
> +++ b/hw/vhost.h
> @@ -34,6 +34,7 @@ struct vhost_dev {
>      MemoryRegionSection *mem_sections;
>      struct vhost_virtqueue *vqs;
>      int nvqs;
> +    int start_idx;
>      unsigned long long features;
>      unsigned long long acked_features;
>      unsigned long long backend_features;
> diff --git a/hw/vhost_net.c b/hw/vhost_net.c
> index f672e9d..73a72bb 100644
> --- a/hw/vhost_net.c
> +++ b/hw/vhost_net.c
> @@ -138,13 +138,15 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
>  }
>  
>  int vhost_net_start(struct vhost_net *net,
> -                    VirtIODevice *dev)
> +                    VirtIODevice *dev,
> +                    int start_idx)
>  {
>      struct vhost_vring_file file = { };
>      int r;
>  
>      net->dev.nvqs = 2;
>      net->dev.vqs = net->vqs;
> +    net->dev.start_idx = start_idx;
>  
>      r = vhost_dev_enable_notifiers(&net->dev, dev);
>      if (r < 0) {
> @@ -227,7 +229,8 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
>  }
>  
>  int vhost_net_start(struct vhost_net *net,
> -		    VirtIODevice *dev)
> +                    VirtIODevice *dev,
> +                    int start_idx)
>  {
>      return -ENOSYS;
>  }
> diff --git a/hw/vhost_net.h b/hw/vhost_net.h
> index 91e40b1..79a4f09 100644
> --- a/hw/vhost_net.h
> +++ b/hw/vhost_net.h
> @@ -9,7 +9,7 @@ typedef struct vhost_net VHostNetState;
>  VHostNetState *vhost_net_init(VLANClientState *backend, int devfd, bool force);
>  
>  bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
> -int vhost_net_start(VHostNetState *net, VirtIODevice *dev);
> +int vhost_net_start(VHostNetState *net, VirtIODevice *dev, int start_idx);
>  void vhost_net_stop(VHostNetState *net, VirtIODevice *dev);
>  
>  void vhost_net_cleanup(VHostNetState *net);
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index 3f190d4..d42c4cc 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -26,34 +26,43 @@
>  #define MAC_TABLE_ENTRIES    64
>  #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
>  
> -typedef struct VirtIONet
> +struct VirtIONet;
> +
> +typedef struct VirtIONetQueue
>  {
> -    VirtIODevice vdev;
> -    uint8_t mac[ETH_ALEN];
> -    uint16_t status;
>      VirtQueue *rx_vq;
>      VirtQueue *tx_vq;
> -    VirtQueue *ctrl_vq;
> -    NICState *nic;
>      QEMUTimer *tx_timer;
>      QEMUBH *tx_bh;
>      uint32_t tx_timeout;
> -    int32_t tx_burst;
>      int tx_waiting;
> -    uint32_t has_vnet_hdr;
> -    uint8_t has_ufo;
>      struct {
>          VirtQueueElement elem;
>          ssize_t len;
>      } async_tx;
> +    struct VirtIONet *n;
> +    uint8_t vhost_started;
> +} VirtIONetQueue;
> +
> +typedef struct VirtIONet
> +{
> +    VirtIODevice vdev;
> +    uint8_t mac[ETH_ALEN];
> +    uint16_t status;
> +    VirtIONetQueue vqs[MAX_QUEUE_NUM];
> +    VirtQueue *ctrl_vq;
> +    NICState *nic;
> +    int32_t tx_burst;
> +    uint32_t has_vnet_hdr;
> +    uint8_t has_ufo;
>      int mergeable_rx_bufs;
> +    int multiqueue;
>      uint8_t promisc;
>      uint8_t allmulti;
>      uint8_t alluni;
>      uint8_t nomulti;
>      uint8_t nouni;
>      uint8_t nobcast;
> -    uint8_t vhost_started;
>      struct {
>          int in_use;
>          int first_multi;
> @@ -63,6 +72,7 @@ typedef struct VirtIONet
>      } mac_table;
>      uint32_t *vlans;
>      DeviceState *qdev;
> +    uint32_t queues;
>  } VirtIONet;
>  
>  /* TODO
> @@ -74,12 +84,25 @@ static VirtIONet *to_virtio_net(VirtIODevice *vdev)
>      return (VirtIONet *)vdev;
>  }
>  
> +static int vq_get_pair_index(VirtIONet *n, VirtQueue *vq)
> +{
> +    int i;
> +    for (i = 0; i < n->queues; i++) {
> +        if (n->vqs[i].tx_vq == vq || n->vqs[i].rx_vq == vq) {
> +            return i;
> +        }
> +    }
> +    assert(1);
> +    return -1;
> +}
> +
>  static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
>      struct virtio_net_config netcfg;
>  
>      stw_p(&netcfg.status, n->status);
> +    netcfg.queues = n->queues * 2;
>      memcpy(netcfg.mac, n->mac, ETH_ALEN);
>      memcpy(config, &netcfg, sizeof(netcfg));
>  }
> @@ -103,78 +126,140 @@ static bool virtio_net_started(VirtIONet *n, uint8_t status)
>          (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
>  }
>  
> -static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> +static void nc_vhost_status(VLANClientState *nc, VirtIONet *n,
> +                            uint8_t status)
>  {
> -    if (!n->nic->nc.peer) {
> +    int queue_index = nc->queue_index;
> +    VLANClientState *peer = nc->peer;
> +    VirtIONetQueue *netq = &n->vqs[nc->queue_index];
> +
> +    if (!peer) {
>          return;
>      }
> -    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> +    if (peer->info->type != NET_CLIENT_TYPE_TAP) {
>          return;
>      }
>  
> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> +    if (!tap_get_vhost_net(peer)) {
>          return;
>      }
> -    if (!!n->vhost_started == virtio_net_started(n, status) &&
> -                              !n->nic->nc.peer->link_down) {
> +    if (!!netq->vhost_started == virtio_net_started(n, status) &&
> +                                 !peer->link_down) {
>          return;
>      }
> -    if (!n->vhost_started) {
> -        int r;
> -        if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer), &n->vdev)) {
> +    if (!netq->vhost_started) {
> +	/* skip ctrl vq */
> +	int r, start_idx = queue_index == 0 ? 0 : queue_index * 2 + 1;
> +        if (!vhost_net_query(tap_get_vhost_net(peer), &n->vdev)) {
>              return;
>          }
> -        r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
> +        r = vhost_net_start(tap_get_vhost_net(peer), &n->vdev, start_idx);
>          if (r < 0) {
>              error_report("unable to start vhost net: %d: "
>                           "falling back on userspace virtio", -r);
>          } else {
> -            n->vhost_started = 1;
> +            netq->vhost_started = 1;
>          }
>      } else {
> -        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer), &n->vdev);
> -        n->vhost_started = 0;
> +        vhost_net_stop(tap_get_vhost_net(peer), &n->vdev);
> +        netq->vhost_started = 0;
> +    }
> +}
> +
> +static int peer_attach(VirtIONet *n, int index)
> +{
> +    if (!n->nic->ncs[index]->peer) {
> +	return -1;
> +    }
> +
> +    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> +	return -1;
> +    }
> +
> +    return tap_attach(n->nic->ncs[index]->peer);
> +}
> +
> +static int peer_detach(VirtIONet *n, int index)
> +{
> +    if (!n->nic->ncs[index]->peer) {
> +	return -1;
> +    }
> +
> +    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> +	return -1;
> +    }
> +
> +    return tap_detach(n->nic->ncs[index]->peer);
> +}
> +
> +static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> +{
> +    int i;
> +    for (i = 0; i < n->queues; i++) {
> +	if (!n->multiqueue && i != 0)
> +	    status = 0;
> +        nc_vhost_status(n->nic->ncs[i], n, status);
>      }
>  }
>  
>  static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
> +    int i;
>  
>      virtio_net_vhost_status(n, status);
>  
> -    if (!n->tx_waiting) {
> -        return;
> -    }
> +    for (i = 0; i < n->queues; i++) {
> +        VirtIONetQueue *netq = &n->vqs[i];
> +        if (!netq->tx_waiting) {
> +            continue;
> +        }
> +
> +	if (!n->multiqueue && i != 0)
> +	    status = 0;
>  
> -    if (virtio_net_started(n, status) && !n->vhost_started) {
> -        if (n->tx_timer) {
> -            qemu_mod_timer(n->tx_timer,
> -                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);
> +        if (virtio_net_started(n, status) && !netq->vhost_started) {
> +            if (netq->tx_timer) {
> +                qemu_mod_timer(netq->tx_timer,
> +                               qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
> +            } else {
> +                qemu_bh_schedule(netq->tx_bh);
> +            }
>          } else {
> -            qemu_bh_schedule(n->tx_bh);
> +            if (netq->tx_timer) {
> +                qemu_del_timer(netq->tx_timer);
> +            } else {
> +                qemu_bh_cancel(netq->tx_bh);
> +            }
>          }
> -    } else {
> -        if (n->tx_timer) {
> -            qemu_del_timer(n->tx_timer);
> -        } else {
> -            qemu_bh_cancel(n->tx_bh);
> +    }
> +}
> +
> +static bool virtio_net_is_link_up(VirtIONet *n)
> +{
> +    int i;
> +    for (i = 0; i < n->queues; i++) {
> +        if (n->nic->ncs[i]->link_down) {
> +            return false;
>          }
>      }
> +    return true;
>  }
>  
>  static void virtio_net_set_link_status(VLANClientState *nc)
>  {
> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> +    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
>      uint16_t old_status = n->status;
>  
> -    if (nc->link_down)
> +    if (virtio_net_is_link_up(n)) {
>          n->status &= ~VIRTIO_NET_S_LINK_UP;
> -    else
> +    } else {
>          n->status |= VIRTIO_NET_S_LINK_UP;
> +    }
>  
> -    if (n->status != old_status)
> +    if (n->status != old_status) {
>          virtio_notify_config(&n->vdev);
> +    }
>  
>      virtio_net_set_status(&n->vdev, n->vdev.status);
>  }
> @@ -202,13 +287,15 @@ static void virtio_net_reset(VirtIODevice *vdev)
>  
>  static int peer_has_vnet_hdr(VirtIONet *n)
>  {
> -    if (!n->nic->nc.peer)
> +    if (!n->nic->ncs[0]->peer) {
>          return 0;
> +    }
>  
> -    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
> +    if (n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>          return 0;
> +    }
>  
> -    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
> +    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->ncs[0]->peer);
>  
>      return n->has_vnet_hdr;
>  }
> @@ -218,7 +305,7 @@ static int peer_has_ufo(VirtIONet *n)
>      if (!peer_has_vnet_hdr(n))
>          return 0;
>  
> -    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
> +    n->has_ufo = tap_has_ufo(n->nic->ncs[0]->peer);
>  
>      return n->has_ufo;
>  }
> @@ -228,9 +315,13 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
>      VirtIONet *n = to_virtio_net(vdev);
>  
>      features |= (1 << VIRTIO_NET_F_MAC);
> +    features |= (1 << VIRTIO_NET_F_MULTIQUEUE);
>  
>      if (peer_has_vnet_hdr(n)) {
> -        tap_using_vnet_hdr(n->nic->nc.peer, 1);
> +        int i;
> +        for (i = 0; i < n->queues; i++) {
> +            tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
> +        }
>      } else {
>          features &= ~(0x1 << VIRTIO_NET_F_CSUM);
>          features &= ~(0x1 << VIRTIO_NET_F_HOST_TSO4);
> @@ -248,14 +339,15 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
>          features &= ~(0x1 << VIRTIO_NET_F_HOST_UFO);
>      }
>  
> -    if (!n->nic->nc.peer ||
> -        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> +    if (!n->nic->ncs[0]->peer ||
> +        n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>          return features;
>      }
> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> +    if (!tap_get_vhost_net(n->nic->ncs[0]->peer)) {
>          return features;
>      }
> -    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
> +    return vhost_net_get_features(tap_get_vhost_net(n->nic->ncs[0]->peer),
> +                                  features);
>  }
>  
>  static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
> @@ -276,25 +368,38 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
>  static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
> +    int i, r;
>  
>      n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
> +    n->multiqueue = !!(features & (1 << VIRTIO_NET_F_MULTIQUEUE));
>  
> -    if (n->has_vnet_hdr) {
> -        tap_set_offload(n->nic->nc.peer,
> -                        (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
> -                        (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
> -                        (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
> -                        (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
> -                        (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
> -    }
> -    if (!n->nic->nc.peer ||
> -        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> -        return;
> -    }
> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> -        return;
> +    for (i = 0; i < n->queues; i++) {
> +        if (!n->multiqueue && i != 0) {
> +            r = peer_detach(n, i);
> +            assert(r == 0);
> +        } else {
> +            r = peer_attach(n, i);
> +            assert(r == 0);
> +
> +            if (n->has_vnet_hdr) {
> +                tap_set_offload(n->nic->ncs[i]->peer,
> +                                (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
> +                                (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
> +                                (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
> +                                (features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
> +                                (features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
> +            }
> +            if (!n->nic->ncs[i]->peer ||
> +                n->nic->ncs[i]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> +                continue;
> +            }
> +            if (!tap_get_vhost_net(n->nic->ncs[i]->peer)) {
> +                continue;
> +            }
> +            vhost_net_ack_features(tap_get_vhost_net(n->nic->ncs[i]->peer),
> +                                   features);
> +        }
>      }
> -    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
>  }
>  
>  static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
> @@ -446,7 +551,7 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
>  
> -    qemu_flush_queued_packets(&n->nic->nc);
> +    qemu_flush_queued_packets(n->nic->ncs[vq_get_pair_index(n, vq)]);
>  
>      /* We now have RX buffers, signal to the IO thread to break out of the
>       * select to re-poll the tap file descriptor */
> @@ -455,36 +560,37 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
>  
>  static int virtio_net_can_receive(VLANClientState *nc)
>  {
> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> +    int queue_index = nc->queue_index;
> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
> +
>      if (!n->vdev.vm_running) {
>          return 0;
>      }
>  
> -    if (!virtio_queue_ready(n->rx_vq) ||
> +    if (!virtio_queue_ready(n->vqs[queue_index].rx_vq) ||
>          !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
>          return 0;
>  
>      return 1;
>  }
>  
> -static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
> +static int virtio_net_has_buffers(VirtIONet *n, int bufsize, VirtQueue *vq)
>  {
> -    if (virtio_queue_empty(n->rx_vq) ||
> -        (n->mergeable_rx_bufs &&
> -         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
> -        virtio_queue_set_notification(n->rx_vq, 1);
> +    if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs &&
> +        !virtqueue_avail_bytes(vq, bufsize, 0))) {
> +        virtio_queue_set_notification(vq, 1);
>  
>          /* To avoid a race condition where the guest has made some buffers
>           * available after the above check but before notification was
>           * enabled, check for available buffers again.
>           */
> -        if (virtio_queue_empty(n->rx_vq) ||
> -            (n->mergeable_rx_bufs &&
> -             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
> +        if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs &&
> +            !virtqueue_avail_bytes(vq, bufsize, 0))) {
>              return 0;
> +        }
>      }
>  
> -    virtio_queue_set_notification(n->rx_vq, 0);
> +    virtio_queue_set_notification(vq, 0);
>      return 1;
>  }
>  
> @@ -595,12 +701,15 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
>  
>  static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
>  {
> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> +    int queue_index = nc->queue_index;
> +    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
> +    VirtQueue *vq = n->vqs[queue_index].rx_vq;
>      struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
>      size_t guest_hdr_len, offset, i, host_hdr_len;
>  
> -    if (!virtio_net_can_receive(&n->nic->nc))
> +    if (!virtio_net_can_receive(n->nic->ncs[queue_index])) {
>          return -1;
> +    }
>  
>      /* hdr_len refers to the header we supply to the guest */
>      guest_hdr_len = n->mergeable_rx_bufs ?
> @@ -608,7 +717,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>  
>  
>      host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
> -    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
> +    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len, vq))
>          return 0;
>  
>      if (!receive_filter(n, buf, size))
> @@ -623,7 +732,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>  
>          total = 0;
>  
> -        if (virtqueue_pop(n->rx_vq, &elem) == 0) {
> +        if (virtqueue_pop(vq, &elem) == 0) {
>              if (i == 0)
>                  return -1;
>              error_report("virtio-net unexpected empty queue: "
> @@ -675,47 +784,50 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>          }
>  
>          /* signal other side */
> -        virtqueue_fill(n->rx_vq, &elem, total, i++);
> +        virtqueue_fill(vq, &elem, total, i++);
>      }
>  
>      if (mhdr) {
>          stw_p(&mhdr->num_buffers, i);
>      }
>  
> -    virtqueue_flush(n->rx_vq, i);
> -    virtio_notify(&n->vdev, n->rx_vq);
> +    virtqueue_flush(vq, i);
> +    virtio_notify(&n->vdev, vq);
>  
>      return size;
>  }
>  
> -static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
> +static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *tvq);
>  
>  static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
>  {
> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
> +    VirtIONetQueue *netq = &n->vqs[nc->queue_index];
>  
> -    virtqueue_push(n->tx_vq, &n->async_tx.elem, n->async_tx.len);
> -    virtio_notify(&n->vdev, n->tx_vq);
> +    virtqueue_push(netq->tx_vq, &netq->async_tx.elem, netq->async_tx.len);
> +    virtio_notify(&n->vdev, netq->tx_vq);
>  
> -    n->async_tx.elem.out_num = n->async_tx.len = 0;
> +    netq->async_tx.elem.out_num = netq->async_tx.len;
>  
> -    virtio_queue_set_notification(n->tx_vq, 1);
> -    virtio_net_flush_tx(n, n->tx_vq);
> +    virtio_queue_set_notification(netq->tx_vq, 1);
> +    virtio_net_flush_tx(n, netq);
>  }
>  
>  /* TX */
> -static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
> +static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *netq)
>  {
>      VirtQueueElement elem;
>      int32_t num_packets = 0;
> +    VirtQueue *vq = netq->tx_vq;
> +
>      if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
>          return num_packets;
>      }
>  
>      assert(n->vdev.vm_running);
>  
> -    if (n->async_tx.elem.out_num) {
> -        virtio_queue_set_notification(n->tx_vq, 0);
> +    if (netq->async_tx.elem.out_num) {
> +        virtio_queue_set_notification(vq, 0);
>          return num_packets;
>      }
>  
> @@ -747,12 +859,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
>              len += hdr_len;
>          }
>  
> -        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
> -                                      virtio_net_tx_complete);
> +        ret = qemu_sendv_packet_async(n->nic->ncs[vq_get_pair_index(n, vq)],
> +                                      out_sg, out_num, virtio_net_tx_complete);
>          if (ret == 0) {
> -            virtio_queue_set_notification(n->tx_vq, 0);
> -            n->async_tx.elem = elem;
> -            n->async_tx.len  = len;
> +            virtio_queue_set_notification(vq, 0);
> +            netq->async_tx.elem = elem;
> +            netq->async_tx.len  = len;
>              return -EBUSY;
>          }
>  
> @@ -771,22 +883,23 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
>  static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
> +    VirtIONetQueue *netq = &n->vqs[vq_get_pair_index(n, vq)];
>  
>      /* This happens when device was stopped but VCPU wasn't. */
>      if (!n->vdev.vm_running) {
> -        n->tx_waiting = 1;
> +        netq->tx_waiting = 1;
>          return;
>      }
>  
> -    if (n->tx_waiting) {
> +    if (netq->tx_waiting) {
>          virtio_queue_set_notification(vq, 1);
> -        qemu_del_timer(n->tx_timer);
> -        n->tx_waiting = 0;
> -        virtio_net_flush_tx(n, vq);
> +        qemu_del_timer(netq->tx_timer);
> +        netq->tx_waiting = 0;
> +        virtio_net_flush_tx(n, netq);
>      } else {
> -        qemu_mod_timer(n->tx_timer,
> -                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);
> -        n->tx_waiting = 1;
> +        qemu_mod_timer(netq->tx_timer,
> +                       qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
> +        netq->tx_waiting = 1;
>          virtio_queue_set_notification(vq, 0);
>      }
>  }
> @@ -794,48 +907,53 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>  static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
>  {
>      VirtIONet *n = to_virtio_net(vdev);
> +    VirtIONetQueue *netq = &n->vqs[vq_get_pair_index(n, vq)];
>  
> -    if (unlikely(n->tx_waiting)) {
> +    if (unlikely(netq->tx_waiting)) {
>          return;
>      }
> -    n->tx_waiting = 1;
> +    netq->tx_waiting = 1;
>      /* This happens when device was stopped but VCPU wasn't. */
>      if (!n->vdev.vm_running) {
>          return;
>      }
>      virtio_queue_set_notification(vq, 0);
> -    qemu_bh_schedule(n->tx_bh);
> +    qemu_bh_schedule(netq->tx_bh);
>  }
>  
>  static void virtio_net_tx_timer(void *opaque)
>  {
> -    VirtIONet *n = opaque;
> +    VirtIONetQueue *netq = opaque;
> +    VirtIONet *n = netq->n;
> +
>      assert(n->vdev.vm_running);
>  
> -    n->tx_waiting = 0;
> +    netq->tx_waiting = 0;
>  
>      /* Just in case the driver is not ready on more */
>      if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
>          return;
>  
> -    virtio_queue_set_notification(n->tx_vq, 1);
> -    virtio_net_flush_tx(n, n->tx_vq);
> +    virtio_queue_set_notification(netq->tx_vq, 1);
> +    virtio_net_flush_tx(n, netq);
>  }
>  
>  static void virtio_net_tx_bh(void *opaque)
>  {
> -    VirtIONet *n = opaque;
> +    VirtIONetQueue *netq = opaque;
> +    VirtQueue *vq = netq->tx_vq;
> +    VirtIONet *n = netq->n;
>      int32_t ret;
>  
>      assert(n->vdev.vm_running);
>  
> -    n->tx_waiting = 0;
> +    netq->tx_waiting = 0;
>  
>      /* Just in case the driver is not ready on more */
>      if (unlikely(!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)))
>          return;
>  
> -    ret = virtio_net_flush_tx(n, n->tx_vq);
> +    ret = virtio_net_flush_tx(n, netq);
>      if (ret == -EBUSY) {
>          return; /* Notification re-enable handled by tx_complete */
>      }
> @@ -843,33 +961,39 @@ static void virtio_net_tx_bh(void *opaque)
>      /* If we flush a full burst of packets, assume there are
>       * more coming and immediately reschedule */
>      if (ret >= n->tx_burst) {
> -        qemu_bh_schedule(n->tx_bh);
> -        n->tx_waiting = 1;
> +        qemu_bh_schedule(netq->tx_bh);
> +        netq->tx_waiting = 1;
>          return;
>      }
>  
>      /* If less than a full burst, re-enable notification and flush
>       * anything that may have come in while we weren't looking.  If
>       * we find something, assume the guest is still active and reschedule */
> -    virtio_queue_set_notification(n->tx_vq, 1);
> -    if (virtio_net_flush_tx(n, n->tx_vq) > 0) {
> -        virtio_queue_set_notification(n->tx_vq, 0);
> -        qemu_bh_schedule(n->tx_bh);
> -        n->tx_waiting = 1;
> +    virtio_queue_set_notification(vq, 1);
> +    if (virtio_net_flush_tx(n, netq) > 0) {
> +        virtio_queue_set_notification(vq, 0);
> +        qemu_bh_schedule(netq->tx_bh);
> +        netq->tx_waiting = 1;
>      }
>  }
>  
>  static void virtio_net_save(QEMUFile *f, void *opaque)
>  {
>      VirtIONet *n = opaque;
> +    int i;
>  
>      /* At this point, backend must be stopped, otherwise
>       * it might keep writing to memory. */
> -    assert(!n->vhost_started);
> +    for (i = 0; i < n->queues; i++) {
> +        assert(!n->vqs[i].vhost_started);
> +    }
>      virtio_save(&n->vdev, f);
>  
>      qemu_put_buffer(f, n->mac, ETH_ALEN);
> -    qemu_put_be32(f, n->tx_waiting);
> +    qemu_put_be32(f, n->queues);
> +    for (i = 0; i < n->queues; i++) {
> +        qemu_put_be32(f, n->vqs[i].tx_waiting);
> +    }
>      qemu_put_be32(f, n->mergeable_rx_bufs);
>      qemu_put_be16(f, n->status);
>      qemu_put_byte(f, n->promisc);
> @@ -902,7 +1026,10 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>      }
>  
>      qemu_get_buffer(f, n->mac, ETH_ALEN);
> -    n->tx_waiting = qemu_get_be32(f);
> +    n->queues = qemu_get_be32(f);
> +    for (i = 0; i < n->queues; i++) {
> +        n->vqs[i].tx_waiting = qemu_get_be32(f);
> +    }
>      n->mergeable_rx_bufs = qemu_get_be32(f);
>  
>      if (version_id >= 3)
> @@ -930,7 +1057,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>              n->mac_table.in_use = 0;
>          }
>      }
> - 
> +
>      if (version_id >= 6)
>          qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
>  
> @@ -941,13 +1068,16 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>          }
>  
>          if (n->has_vnet_hdr) {
> -            tap_using_vnet_hdr(n->nic->nc.peer, 1);
> -            tap_set_offload(n->nic->nc.peer,
> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
> -                    (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  & 1);
> +            for(i = 0; i < n->queues; i++) {
> +                tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
> +                tap_set_offload(n->nic->ncs[i]->peer,
> +                        (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
> +                        (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
> +                        (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
> +                        (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_ECN)  & 1,
> +                        (n->vdev.guest_features >> VIRTIO_NET_F_GUEST_UFO)  &
> +                        1);
> +           }
>          }
>      }
>  
> @@ -982,7 +1112,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>  
>  static void virtio_net_cleanup(VLANClientState *nc)
>  {
> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
>  
>      n->nic = NULL;
>  }
> @@ -1000,6 +1130,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>                                virtio_net_conf *net)
>  {
>      VirtIONet *n;
> +    int i;
>  
>      n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
>                                          sizeof(struct virtio_net_config),
> @@ -1012,7 +1143,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>      n->vdev.bad_features = virtio_net_bad_features;
>      n->vdev.reset = virtio_net_reset;
>      n->vdev.set_status = virtio_net_set_status;
> -    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
>  
>      if (net->tx && strcmp(net->tx, "timer") && strcmp(net->tx, "bh")) {
>          error_report("virtio-net: "
> @@ -1021,15 +1151,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>          error_report("Defaulting to \"bh\"");
>      }
>  
> -    if (net->tx && !strcmp(net->tx, "timer")) {
> -        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
> -        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
> -        n->tx_timeout = net->txtimer;
> -    } else {
> -        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
> -        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
> -    }
> -    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
>      qemu_macaddr_default_if_unset(&conf->macaddr);
>      memcpy(&n->mac[0], &conf->macaddr, sizeof(n->mac));
>      n->status = VIRTIO_NET_S_LINK_UP;
> @@ -1038,7 +1159,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>  
>      qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
>  
> -    n->tx_waiting = 0;
>      n->tx_burst = net->txburst;
>      n->mergeable_rx_bufs = 0;
>      n->promisc = 1; /* for compatibility */
> @@ -1046,6 +1166,32 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>      n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
>  
>      n->vlans = g_malloc0(MAX_VLAN >> 3);
> +    n->queues = conf->queues;
> +
> +    /* Allocate per rx/tx vq's */
> +    for (i = 0; i < n->queues; i++) {
> +        n->vqs[i].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
> +        if (net->tx && !strcmp(net->tx, "timer")) {
> +            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
> +                                               virtio_net_handle_tx_timer);
> +            n->vqs[i].tx_timer = qemu_new_timer_ns(vm_clock,
> +                                                   virtio_net_tx_timer,
> +                                                   &n->vqs[i]);
> +            n->vqs[i].tx_timeout = net->txtimer;
> +        } else {
> +            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
> +                                               virtio_net_handle_tx_bh);
> +            n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[i]);
> +        }
> +
> +        n->vqs[i].tx_waiting = 0;
> +        n->vqs[i].n = n;
> +
> +        if (i == 0) {
> +            /* keep compatiable with spec and old guest */
> +            n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
> +        }
> +    }
>  
>      n->qdev = dev;
>      register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
> @@ -1059,24 +1205,33 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>  void virtio_net_exit(VirtIODevice *vdev)
>  {
>      VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
> +    int i;
>  
>      /* This will stop vhost backend if appropriate. */
>      virtio_net_set_status(vdev, 0);
>  
> -    qemu_purge_queued_packets(&n->nic->nc);
> +    for (i = 0; i < n->queues; i++) {
> +        qemu_purge_queued_packets(n->nic->ncs[i]);
> +    }
>  
>      unregister_savevm(n->qdev, "virtio-net", n);
>  
>      g_free(n->mac_table.macs);
>      g_free(n->vlans);
>  
> -    if (n->tx_timer) {
> -        qemu_del_timer(n->tx_timer);
> -        qemu_free_timer(n->tx_timer);
> -    } else {
> -        qemu_bh_delete(n->tx_bh);
> +    for (i = 0; i < n->queues; i++) {
> +        VirtIONetQueue *netq = &n->vqs[i];
> +        if (netq->tx_timer) {
> +            qemu_del_timer(netq->tx_timer);
> +            qemu_free_timer(netq->tx_timer);
> +        } else {
> +            qemu_bh_delete(netq->tx_bh);
> +        }
>      }
>  
> -    qemu_del_vlan_client(&n->nic->nc);
>      virtio_cleanup(&n->vdev);
> +
> +    for (i = 0; i < n->queues; i++) {
> +        qemu_del_vlan_client(n->nic->ncs[i]);
> +    }
>  }
> diff --git a/hw/virtio-net.h b/hw/virtio-net.h
> index 36aa463..b35ba5d 100644
> --- a/hw/virtio-net.h
> +++ b/hw/virtio-net.h
> @@ -44,6 +44,7 @@
>  #define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support */
>  #define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering */
>  #define VIRTIO_NET_F_CTRL_RX_EXTRA 20   /* Extra RX mode control support */
> +#define VIRTIO_NET_F_MULTIQUEUE   22
>  
>  #define VIRTIO_NET_S_LINK_UP    1       /* Link is up */
>  
> @@ -72,6 +73,8 @@ struct virtio_net_config
>      uint8_t mac[ETH_ALEN];
>      /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
>      uint16_t status;
> +
> +    uint16_t queues;
>  } QEMU_PACKED;
>  
>  /* This is the first element of the scatter-gather list.  If you don't

Re: [Qemu-devel] [RFC V2 PATCH 4/4] virtio-net: add multiqueue support

[Jason Wang]

On 07/01/2012 05:43 PM, Michael S. Tsirkin wrote:
> On Mon, Jun 25, 2012 at 06:04:49PM +0800, Jason Wang wrote:
>> This patch let the virtio-net can transmit and recevie packets through multiuple
>> VLANClientStates and abstract them as multiple virtqueues to guest. A new
>> parameter 'queues' were introduced to specify the number of queue pairs.
>>
>> The main goal for vhost support is to let the multiqueue could be used without
>> changes in vhost code. So each vhost_net structure were used to track a single
>> VLANClientState and two virtqueues in the past. As multiple VLANClientState were
>> stored in the NICState, we can infer the correspond VLANClientState from this
>> and queue_index easily.
>>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
> Can this patch be split up?
> 1. extend vhost API to allow multiqueue and minimally tweak virtio
> 2. add real multiqueue for virtio
>
> Hmm?

Sure, do you think it's necessary to separate the vhost parts of 
multiqueue from virtio?
>> ---
>>   hw/vhost.c      |   58 ++++---
>>   hw/vhost.h      |    1
>>   hw/vhost_net.c  |    7 +
>>   hw/vhost_net.h  |    2
>>   hw/virtio-net.c |  461 +++++++++++++++++++++++++++++++++++++------------------
>>   hw/virtio-net.h |    3
>>   6 files changed, 355 insertions(+), 177 deletions(-)
>>
>> diff --git a/hw/vhost.c b/hw/vhost.c
>> index 43664e7..6318bb2 100644
>> --- a/hw/vhost.c
>> +++ b/hw/vhost.c
>> @@ -620,11 +620,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
>>   {
>>       target_phys_addr_t s, l, a;
>>       int r;
>> +    int vhost_vq_index = (idx>  2 ? idx - 1 : idx) % dev->nvqs;
>>       struct vhost_vring_file file = {
>> -        .index = idx,
>> +	.index = vhost_vq_index
>>       };
>>       struct vhost_vring_state state = {
>> -        .index = idx,
>> +        .index = vhost_vq_index
>>       };
>>       struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
>>
>> @@ -670,11 +671,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
>>           goto fail_alloc_ring;
>>       }
>>
>> -    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
>> +    r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
>>       if (r<  0) {
>>           r = -errno;
>>           goto fail_alloc;
>>       }
>> +
>>       file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
>>       r = ioctl(dev->control, VHOST_SET_VRING_KICK,&file);
>>       if (r) {
>> @@ -715,7 +717,7 @@ static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
>>                                       unsigned idx)
>>   {
>>       struct vhost_vring_state state = {
>> -        .index = idx,
>> +        .index = (idx>  2 ? idx - 1 : idx) % dev->nvqs,
>>       };
>>       int r;
>>       r = ioctl(dev->control, VHOST_GET_VRING_BASE,&state);
>> @@ -829,7 +831,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>>       }
>>
>>       for (i = 0; i<  hdev->nvqs; ++i) {
>> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
>> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
>> +					     hdev->start_idx + i,
>> +					     true);
>>           if (r<  0) {
>>               fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
>>               goto fail_vq;
>> @@ -839,7 +843,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>>       return 0;
>>   fail_vq:
>>       while (--i>= 0) {
>> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
>> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
>> +					     hdev->start_idx + i,
>> +					     false);
>>           if (r<  0) {
>>               fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
>>               fflush(stderr);
>> @@ -860,7 +866,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
>>       int i, r;
>>
>>       for (i = 0; i<  hdev->nvqs; ++i) {
>> -        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
>> +        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
>> +					     hdev->start_idx + i,
>> +					     false);
>>           if (r<  0) {
>>               fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
>>               fflush(stderr);
>> @@ -874,15 +882,17 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
>>   {
>>       int i, r;
>>       if (!vdev->binding->set_guest_notifiers) {
>> -        fprintf(stderr, "binding does not support guest notifiers\n");
>> +        fprintf(stderr, "binding does not support guest notifier\n");
>>           r = -ENOSYS;
>>           goto fail;
>>       }
>>
>> -    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
>> -    if (r<  0) {
>> -        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
>> -        goto fail_notifiers;
>> +    if (hdev->start_idx == 0) {
>> +        r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
>> +        if (r<  0) {
>> +            fprintf(stderr, "Error binding guest notifier: %d\n", -r);
>> +            goto fail_notifiers;
>> +        }
>>       }
>>
>>       r = vhost_dev_set_features(hdev, hdev->log_enabled);
>> @@ -898,7 +908,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
>>           r = vhost_virtqueue_init(hdev,
>>                                    vdev,
>>                                    hdev->vqs + i,
>> -                                 i);
>> +                                 hdev->start_idx + i);
>>           if (r<  0) {
>>               goto fail_vq;
>>           }
>> @@ -925,11 +935,13 @@ fail_vq:
>>           vhost_virtqueue_cleanup(hdev,
>>                                   vdev,
>>                                   hdev->vqs + i,
>> -                                i);
>> +                                hdev->start_idx + i);
>>       }
>> +    i = hdev->nvqs;
>>   fail_mem:
>>   fail_features:
>> -    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
>> +    if (hdev->start_idx == 0)
>> +        vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
>>   fail_notifiers:
>>   fail:
>>       return r;
>> @@ -944,18 +956,22 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>           vhost_virtqueue_cleanup(hdev,
>>                                   vdev,
>>                                   hdev->vqs + i,
>> -                                i);
>> +                                hdev->start_idx + i);
>>       }
>> +
>>       for (i = 0; i<  hdev->n_mem_sections; ++i) {
>>           vhost_sync_dirty_bitmap(hdev,&hdev->mem_sections[i],
>>                                   0, (target_phys_addr_t)~0x0ull);
>>       }
>> -    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
>> -    if (r<  0) {
>> -        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
>> -        fflush(stderr);
>> +
>> +    if (hdev->start_idx == 0) {
>> +	r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
>> +	if (r<  0) {
>> +	    fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
>> +	    fflush(stderr);
>> +	}
>> +	assert (r>= 0);
>>       }
>> -    assert (r>= 0);
>>
>>       hdev->started = false;
>>       g_free(hdev->log);
>> diff --git a/hw/vhost.h b/hw/vhost.h
>> index 80e64df..fa5357a 100644
>> --- a/hw/vhost.h
>> +++ b/hw/vhost.h
>> @@ -34,6 +34,7 @@ struct vhost_dev {
>>       MemoryRegionSection *mem_sections;
>>       struct vhost_virtqueue *vqs;
>>       int nvqs;
>> +    int start_idx;
>>       unsigned long long features;
>>       unsigned long long acked_features;
>>       unsigned long long backend_features;
>> diff --git a/hw/vhost_net.c b/hw/vhost_net.c
>> index f672e9d..73a72bb 100644
>> --- a/hw/vhost_net.c
>> +++ b/hw/vhost_net.c
>> @@ -138,13 +138,15 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
>>   }
>>
>>   int vhost_net_start(struct vhost_net *net,
>> -                    VirtIODevice *dev)
>> +                    VirtIODevice *dev,
>> +                    int start_idx)
>>   {
>>       struct vhost_vring_file file = { };
>>       int r;
>>
>>       net->dev.nvqs = 2;
>>       net->dev.vqs = net->vqs;
>> +    net->dev.start_idx = start_idx;
>>
>>       r = vhost_dev_enable_notifiers(&net->dev, dev);
>>       if (r<  0) {
>> @@ -227,7 +229,8 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
>>   }
>>
>>   int vhost_net_start(struct vhost_net *net,
>> -		    VirtIODevice *dev)
>> +                    VirtIODevice *dev,
>> +                    int start_idx)
>>   {
>>       return -ENOSYS;
>>   }
>> diff --git a/hw/vhost_net.h b/hw/vhost_net.h
>> index 91e40b1..79a4f09 100644
>> --- a/hw/vhost_net.h
>> +++ b/hw/vhost_net.h
>> @@ -9,7 +9,7 @@ typedef struct vhost_net VHostNetState;
>>   VHostNetState *vhost_net_init(VLANClientState *backend, int devfd, bool force);
>>
>>   bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
>> -int vhost_net_start(VHostNetState *net, VirtIODevice *dev);
>> +int vhost_net_start(VHostNetState *net, VirtIODevice *dev, int start_idx);
>>   void vhost_net_stop(VHostNetState *net, VirtIODevice *dev);
>>
>>   void vhost_net_cleanup(VHostNetState *net);
>> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
>> index 3f190d4..d42c4cc 100644
>> --- a/hw/virtio-net.c
>> +++ b/hw/virtio-net.c
>> @@ -26,34 +26,43 @@
>>   #define MAC_TABLE_ENTRIES    64
>>   #define MAX_VLAN    (1<<  12)   /* Per 802.1Q definition */
>>
>> -typedef struct VirtIONet
>> +struct VirtIONet;
>> +
>> +typedef struct VirtIONetQueue
>>   {
>> -    VirtIODevice vdev;
>> -    uint8_t mac[ETH_ALEN];
>> -    uint16_t status;
>>       VirtQueue *rx_vq;
>>       VirtQueue *tx_vq;
>> -    VirtQueue *ctrl_vq;
>> -    NICState *nic;
>>       QEMUTimer *tx_timer;
>>       QEMUBH *tx_bh;
>>       uint32_t tx_timeout;
>> -    int32_t tx_burst;
>>       int tx_waiting;
>> -    uint32_t has_vnet_hdr;
>> -    uint8_t has_ufo;
>>       struct {
>>           VirtQueueElement elem;
>>           ssize_t len;
>>       } async_tx;
>> +    struct VirtIONet *n;
>> +    uint8_t vhost_started;
>> +} VirtIONetQueue;
>> +
>> +typedef struct VirtIONet
>> +{
>> +    VirtIODevice vdev;
>> +    uint8_t mac[ETH_ALEN];
>> +    uint16_t status;
>> +    VirtIONetQueue vqs[MAX_QUEUE_NUM];
>> +    VirtQueue *ctrl_vq;
>> +    NICState *nic;
>> +    int32_t tx_burst;
>> +    uint32_t has_vnet_hdr;
>> +    uint8_t has_ufo;
>>       int mergeable_rx_bufs;
>> +    int multiqueue;
>>       uint8_t promisc;
>>       uint8_t allmulti;
>>       uint8_t alluni;
>>       uint8_t nomulti;
>>       uint8_t nouni;
>>       uint8_t nobcast;
>> -    uint8_t vhost_started;
>>       struct {
>>           int in_use;
>>           int first_multi;
>> @@ -63,6 +72,7 @@ typedef struct VirtIONet
>>       } mac_table;
>>       uint32_t *vlans;
>>       DeviceState *qdev;
>> +    uint32_t queues;
>>   } VirtIONet;
>>
>>   /* TODO
>> @@ -74,12 +84,25 @@ static VirtIONet *to_virtio_net(VirtIODevice *vdev)
>>       return (VirtIONet *)vdev;
>>   }
>>
>> +static int vq_get_pair_index(VirtIONet *n, VirtQueue *vq)
>> +{
>> +    int i;
>> +    for (i = 0; i<  n->queues; i++) {
>> +        if (n->vqs[i].tx_vq == vq || n->vqs[i].rx_vq == vq) {
>> +            return i;
>> +        }
>> +    }
>> +    assert(1);
>> +    return -1;
>> +}
>> +
>>   static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>>       struct virtio_net_config netcfg;
>>
>>       stw_p(&netcfg.status, n->status);
>> +    netcfg.queues = n->queues * 2;
>>       memcpy(netcfg.mac, n->mac, ETH_ALEN);
>>       memcpy(config,&netcfg, sizeof(netcfg));
>>   }
>> @@ -103,78 +126,140 @@ static bool virtio_net_started(VirtIONet *n, uint8_t status)
>>           (n->status&  VIRTIO_NET_S_LINK_UP)&&  n->vdev.vm_running;
>>   }
>>
>> -static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>> +static void nc_vhost_status(VLANClientState *nc, VirtIONet *n,
>> +                            uint8_t status)
>>   {
>> -    if (!n->nic->nc.peer) {
>> +    int queue_index = nc->queue_index;
>> +    VLANClientState *peer = nc->peer;
>> +    VirtIONetQueue *netq =&n->vqs[nc->queue_index];
>> +
>> +    if (!peer) {
>>           return;
>>       }
>> -    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
>> +    if (peer->info->type != NET_CLIENT_TYPE_TAP) {
>>           return;
>>       }
>>
>> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
>> +    if (!tap_get_vhost_net(peer)) {
>>           return;
>>       }
>> -    if (!!n->vhost_started == virtio_net_started(n, status)&&
>> -                              !n->nic->nc.peer->link_down) {
>> +    if (!!netq->vhost_started == virtio_net_started(n, status)&&
>> +                                 !peer->link_down) {
>>           return;
>>       }
>> -    if (!n->vhost_started) {
>> -        int r;
>> -        if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer),&n->vdev)) {
>> +    if (!netq->vhost_started) {
>> +	/* skip ctrl vq */
>> +	int r, start_idx = queue_index == 0 ? 0 : queue_index * 2 + 1;
>> +        if (!vhost_net_query(tap_get_vhost_net(peer),&n->vdev)) {
>>               return;
>>           }
>> -        r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer),&n->vdev);
>> +        r = vhost_net_start(tap_get_vhost_net(peer),&n->vdev, start_idx);
>>           if (r<  0) {
>>               error_report("unable to start vhost net: %d: "
>>                            "falling back on userspace virtio", -r);
>>           } else {
>> -            n->vhost_started = 1;
>> +            netq->vhost_started = 1;
>>           }
>>       } else {
>> -        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer),&n->vdev);
>> -        n->vhost_started = 0;
>> +        vhost_net_stop(tap_get_vhost_net(peer),&n->vdev);
>> +        netq->vhost_started = 0;
>> +    }
>> +}
>> +
>> +static int peer_attach(VirtIONet *n, int index)
>> +{
>> +    if (!n->nic->ncs[index]->peer) {
>> +	return -1;
>> +    }
>> +
>> +    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>> +	return -1;
>> +    }
>> +
>> +    return tap_attach(n->nic->ncs[index]->peer);
>> +}
>> +
>> +static int peer_detach(VirtIONet *n, int index)
>> +{
>> +    if (!n->nic->ncs[index]->peer) {
>> +	return -1;
>> +    }
>> +
>> +    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>> +	return -1;
>> +    }
>> +
>> +    return tap_detach(n->nic->ncs[index]->peer);
>> +}
>> +
>> +static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>> +{
>> +    int i;
>> +    for (i = 0; i<  n->queues; i++) {
>> +	if (!n->multiqueue&&  i != 0)
>> +	    status = 0;
>> +        nc_vhost_status(n->nic->ncs[i], n, status);
>>       }
>>   }
>>
>>   static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>> +    int i;
>>
>>       virtio_net_vhost_status(n, status);
>>
>> -    if (!n->tx_waiting) {
>> -        return;
>> -    }
>> +    for (i = 0; i<  n->queues; i++) {
>> +        VirtIONetQueue *netq =&n->vqs[i];
>> +        if (!netq->tx_waiting) {
>> +            continue;
>> +        }
>> +
>> +	if (!n->multiqueue&&  i != 0)
>> +	    status = 0;
>>
>> -    if (virtio_net_started(n, status)&&  !n->vhost_started) {
>> -        if (n->tx_timer) {
>> -            qemu_mod_timer(n->tx_timer,
>> -                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);
>> +        if (virtio_net_started(n, status)&&  !netq->vhost_started) {
>> +            if (netq->tx_timer) {
>> +                qemu_mod_timer(netq->tx_timer,
>> +                               qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
>> +            } else {
>> +                qemu_bh_schedule(netq->tx_bh);
>> +            }
>>           } else {
>> -            qemu_bh_schedule(n->tx_bh);
>> +            if (netq->tx_timer) {
>> +                qemu_del_timer(netq->tx_timer);
>> +            } else {
>> +                qemu_bh_cancel(netq->tx_bh);
>> +            }
>>           }
>> -    } else {
>> -        if (n->tx_timer) {
>> -            qemu_del_timer(n->tx_timer);
>> -        } else {
>> -            qemu_bh_cancel(n->tx_bh);
>> +    }
>> +}
>> +
>> +static bool virtio_net_is_link_up(VirtIONet *n)
>> +{
>> +    int i;
>> +    for (i = 0; i<  n->queues; i++) {
>> +        if (n->nic->ncs[i]->link_down) {
>> +            return false;
>>           }
>>       }
>> +    return true;
>>   }
>>
>>   static void virtio_net_set_link_status(VLANClientState *nc)
>>   {
>> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
>> +    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
>>       uint16_t old_status = n->status;
>>
>> -    if (nc->link_down)
>> +    if (virtio_net_is_link_up(n)) {
>>           n->status&= ~VIRTIO_NET_S_LINK_UP;
>> -    else
>> +    } else {
>>           n->status |= VIRTIO_NET_S_LINK_UP;
>> +    }
>>
>> -    if (n->status != old_status)
>> +    if (n->status != old_status) {
>>           virtio_notify_config(&n->vdev);
>> +    }
>>
>>       virtio_net_set_status(&n->vdev, n->vdev.status);
>>   }
>> @@ -202,13 +287,15 @@ static void virtio_net_reset(VirtIODevice *vdev)
>>
>>   static int peer_has_vnet_hdr(VirtIONet *n)
>>   {
>> -    if (!n->nic->nc.peer)
>> +    if (!n->nic->ncs[0]->peer) {
>>           return 0;
>> +    }
>>
>> -    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
>> +    if (n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>>           return 0;
>> +    }
>>
>> -    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
>> +    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->ncs[0]->peer);
>>
>>       return n->has_vnet_hdr;
>>   }
>> @@ -218,7 +305,7 @@ static int peer_has_ufo(VirtIONet *n)
>>       if (!peer_has_vnet_hdr(n))
>>           return 0;
>>
>> -    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
>> +    n->has_ufo = tap_has_ufo(n->nic->ncs[0]->peer);
>>
>>       return n->has_ufo;
>>   }
>> @@ -228,9 +315,13 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
>>       VirtIONet *n = to_virtio_net(vdev);
>>
>>       features |= (1<<  VIRTIO_NET_F_MAC);
>> +    features |= (1<<  VIRTIO_NET_F_MULTIQUEUE);
>>
>>       if (peer_has_vnet_hdr(n)) {
>> -        tap_using_vnet_hdr(n->nic->nc.peer, 1);
>> +        int i;
>> +        for (i = 0; i<  n->queues; i++) {
>> +            tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
>> +        }
>>       } else {
>>           features&= ~(0x1<<  VIRTIO_NET_F_CSUM);
>>           features&= ~(0x1<<  VIRTIO_NET_F_HOST_TSO4);
>> @@ -248,14 +339,15 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
>>           features&= ~(0x1<<  VIRTIO_NET_F_HOST_UFO);
>>       }
>>
>> -    if (!n->nic->nc.peer ||
>> -        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
>> +    if (!n->nic->ncs[0]->peer ||
>> +        n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>>           return features;
>>       }
>> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
>> +    if (!tap_get_vhost_net(n->nic->ncs[0]->peer)) {
>>           return features;
>>       }
>> -    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
>> +    return vhost_net_get_features(tap_get_vhost_net(n->nic->ncs[0]->peer),
>> +                                  features);
>>   }
>>
>>   static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
>> @@ -276,25 +368,38 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
>>   static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>> +    int i, r;
>>
>>       n->mergeable_rx_bufs = !!(features&  (1<<  VIRTIO_NET_F_MRG_RXBUF));
>> +    n->multiqueue = !!(features&  (1<<  VIRTIO_NET_F_MULTIQUEUE));
>>
>> -    if (n->has_vnet_hdr) {
>> -        tap_set_offload(n->nic->nc.peer,
>> -                        (features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
>> -                        (features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
>> -                        (features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
>> -                        (features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
>> -                        (features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
>> -    }
>> -    if (!n->nic->nc.peer ||
>> -        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
>> -        return;
>> -    }
>> -    if (!tap_get_vhost_net(n->nic->nc.peer)) {
>> -        return;
>> +    for (i = 0; i<  n->queues; i++) {
>> +        if (!n->multiqueue&&  i != 0) {
>> +            r = peer_detach(n, i);
>> +            assert(r == 0);
>> +        } else {
>> +            r = peer_attach(n, i);
>> +            assert(r == 0);
>> +
>> +            if (n->has_vnet_hdr) {
>> +                tap_set_offload(n->nic->ncs[i]->peer,
>> +                                (features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
>> +                                (features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
>> +                                (features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
>> +                                (features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
>> +                                (features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
>> +            }
>> +            if (!n->nic->ncs[i]->peer ||
>> +                n->nic->ncs[i]->peer->info->type != NET_CLIENT_TYPE_TAP) {
>> +                continue;
>> +            }
>> +            if (!tap_get_vhost_net(n->nic->ncs[i]->peer)) {
>> +                continue;
>> +            }
>> +            vhost_net_ack_features(tap_get_vhost_net(n->nic->ncs[i]->peer),
>> +                                   features);
>> +        }
>>       }
>> -    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
>>   }
>>
>>   static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
>> @@ -446,7 +551,7 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>>
>> -    qemu_flush_queued_packets(&n->nic->nc);
>> +    qemu_flush_queued_packets(n->nic->ncs[vq_get_pair_index(n, vq)]);
>>
>>       /* We now have RX buffers, signal to the IO thread to break out of the
>>        * select to re-poll the tap file descriptor */
>> @@ -455,36 +560,37 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
>>
>>   static int virtio_net_can_receive(VLANClientState *nc)
>>   {
>> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
>> +    int queue_index = nc->queue_index;
>> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
>> +
>>       if (!n->vdev.vm_running) {
>>           return 0;
>>       }
>>
>> -    if (!virtio_queue_ready(n->rx_vq) ||
>> +    if (!virtio_queue_ready(n->vqs[queue_index].rx_vq) ||
>>           !(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK))
>>           return 0;
>>
>>       return 1;
>>   }
>>
>> -static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
>> +static int virtio_net_has_buffers(VirtIONet *n, int bufsize, VirtQueue *vq)
>>   {
>> -    if (virtio_queue_empty(n->rx_vq) ||
>> -        (n->mergeable_rx_bufs&&
>> -         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
>> -        virtio_queue_set_notification(n->rx_vq, 1);
>> +    if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs&&
>> +        !virtqueue_avail_bytes(vq, bufsize, 0))) {
>> +        virtio_queue_set_notification(vq, 1);
>>
>>           /* To avoid a race condition where the guest has made some buffers
>>            * available after the above check but before notification was
>>            * enabled, check for available buffers again.
>>            */
>> -        if (virtio_queue_empty(n->rx_vq) ||
>> -            (n->mergeable_rx_bufs&&
>> -             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
>> +        if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs&&
>> +            !virtqueue_avail_bytes(vq, bufsize, 0))) {
>>               return 0;
>> +        }
>>       }
>>
>> -    virtio_queue_set_notification(n->rx_vq, 0);
>> +    virtio_queue_set_notification(vq, 0);
>>       return 1;
>>   }
>>
>> @@ -595,12 +701,15 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
>>
>>   static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
>>   {
>> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
>> +    int queue_index = nc->queue_index;
>> +    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
>> +    VirtQueue *vq = n->vqs[queue_index].rx_vq;
>>       struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
>>       size_t guest_hdr_len, offset, i, host_hdr_len;
>>
>> -    if (!virtio_net_can_receive(&n->nic->nc))
>> +    if (!virtio_net_can_receive(n->nic->ncs[queue_index])) {
>>           return -1;
>> +    }
>>
>>       /* hdr_len refers to the header we supply to the guest */
>>       guest_hdr_len = n->mergeable_rx_bufs ?
>> @@ -608,7 +717,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>>
>>
>>       host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
>> -    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
>> +    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len, vq))
>>           return 0;
>>
>>       if (!receive_filter(n, buf, size))
>> @@ -623,7 +732,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>>
>>           total = 0;
>>
>> -        if (virtqueue_pop(n->rx_vq,&elem) == 0) {
>> +        if (virtqueue_pop(vq,&elem) == 0) {
>>               if (i == 0)
>>                   return -1;
>>               error_report("virtio-net unexpected empty queue: "
>> @@ -675,47 +784,50 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
>>           }
>>
>>           /* signal other side */
>> -        virtqueue_fill(n->rx_vq,&elem, total, i++);
>> +        virtqueue_fill(vq,&elem, total, i++);
>>       }
>>
>>       if (mhdr) {
>>           stw_p(&mhdr->num_buffers, i);
>>       }
>>
>> -    virtqueue_flush(n->rx_vq, i);
>> -    virtio_notify(&n->vdev, n->rx_vq);
>> +    virtqueue_flush(vq, i);
>> +    virtio_notify(&n->vdev, vq);
>>
>>       return size;
>>   }
>>
>> -static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
>> +static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *tvq);
>>
>>   static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
>>   {
>> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
>> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
>> +    VirtIONetQueue *netq =&n->vqs[nc->queue_index];
>>
>> -    virtqueue_push(n->tx_vq,&n->async_tx.elem, n->async_tx.len);
>> -    virtio_notify(&n->vdev, n->tx_vq);
>> +    virtqueue_push(netq->tx_vq,&netq->async_tx.elem, netq->async_tx.len);
>> +    virtio_notify(&n->vdev, netq->tx_vq);
>>
>> -    n->async_tx.elem.out_num = n->async_tx.len = 0;
>> +    netq->async_tx.elem.out_num = netq->async_tx.len;
>>
>> -    virtio_queue_set_notification(n->tx_vq, 1);
>> -    virtio_net_flush_tx(n, n->tx_vq);
>> +    virtio_queue_set_notification(netq->tx_vq, 1);
>> +    virtio_net_flush_tx(n, netq);
>>   }
>>
>>   /* TX */
>> -static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
>> +static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *netq)
>>   {
>>       VirtQueueElement elem;
>>       int32_t num_packets = 0;
>> +    VirtQueue *vq = netq->tx_vq;
>> +
>>       if (!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK)) {
>>           return num_packets;
>>       }
>>
>>       assert(n->vdev.vm_running);
>>
>> -    if (n->async_tx.elem.out_num) {
>> -        virtio_queue_set_notification(n->tx_vq, 0);
>> +    if (netq->async_tx.elem.out_num) {
>> +        virtio_queue_set_notification(vq, 0);
>>           return num_packets;
>>       }
>>
>> @@ -747,12 +859,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
>>               len += hdr_len;
>>           }
>>
>> -        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
>> -                                      virtio_net_tx_complete);
>> +        ret = qemu_sendv_packet_async(n->nic->ncs[vq_get_pair_index(n, vq)],
>> +                                      out_sg, out_num, virtio_net_tx_complete);
>>           if (ret == 0) {
>> -            virtio_queue_set_notification(n->tx_vq, 0);
>> -            n->async_tx.elem = elem;
>> -            n->async_tx.len  = len;
>> +            virtio_queue_set_notification(vq, 0);
>> +            netq->async_tx.elem = elem;
>> +            netq->async_tx.len  = len;
>>               return -EBUSY;
>>           }
>>
>> @@ -771,22 +883,23 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
>>   static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>> +    VirtIONetQueue *netq =&n->vqs[vq_get_pair_index(n, vq)];
>>
>>       /* This happens when device was stopped but VCPU wasn't. */
>>       if (!n->vdev.vm_running) {
>> -        n->tx_waiting = 1;
>> +        netq->tx_waiting = 1;
>>           return;
>>       }
>>
>> -    if (n->tx_waiting) {
>> +    if (netq->tx_waiting) {
>>           virtio_queue_set_notification(vq, 1);
>> -        qemu_del_timer(n->tx_timer);
>> -        n->tx_waiting = 0;
>> -        virtio_net_flush_tx(n, vq);
>> +        qemu_del_timer(netq->tx_timer);
>> +        netq->tx_waiting = 0;
>> +        virtio_net_flush_tx(n, netq);
>>       } else {
>> -        qemu_mod_timer(n->tx_timer,
>> -                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);
>> -        n->tx_waiting = 1;
>> +        qemu_mod_timer(netq->tx_timer,
>> +                       qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
>> +        netq->tx_waiting = 1;
>>           virtio_queue_set_notification(vq, 0);
>>       }
>>   }
>> @@ -794,48 +907,53 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
>>   static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
>>   {
>>       VirtIONet *n = to_virtio_net(vdev);
>> +    VirtIONetQueue *netq =&n->vqs[vq_get_pair_index(n, vq)];
>>
>> -    if (unlikely(n->tx_waiting)) {
>> +    if (unlikely(netq->tx_waiting)) {
>>           return;
>>       }
>> -    n->tx_waiting = 1;
>> +    netq->tx_waiting = 1;
>>       /* This happens when device was stopped but VCPU wasn't. */
>>       if (!n->vdev.vm_running) {
>>           return;
>>       }
>>       virtio_queue_set_notification(vq, 0);
>> -    qemu_bh_schedule(n->tx_bh);
>> +    qemu_bh_schedule(netq->tx_bh);
>>   }
>>
>>   static void virtio_net_tx_timer(void *opaque)
>>   {
>> -    VirtIONet *n = opaque;
>> +    VirtIONetQueue *netq = opaque;
>> +    VirtIONet *n = netq->n;
>> +
>>       assert(n->vdev.vm_running);
>>
>> -    n->tx_waiting = 0;
>> +    netq->tx_waiting = 0;
>>
>>       /* Just in case the driver is not ready on more */
>>       if (!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK))
>>           return;
>>
>> -    virtio_queue_set_notification(n->tx_vq, 1);
>> -    virtio_net_flush_tx(n, n->tx_vq);
>> +    virtio_queue_set_notification(netq->tx_vq, 1);
>> +    virtio_net_flush_tx(n, netq);
>>   }
>>
>>   static void virtio_net_tx_bh(void *opaque)
>>   {
>> -    VirtIONet *n = opaque;
>> +    VirtIONetQueue *netq = opaque;
>> +    VirtQueue *vq = netq->tx_vq;
>> +    VirtIONet *n = netq->n;
>>       int32_t ret;
>>
>>       assert(n->vdev.vm_running);
>>
>> -    n->tx_waiting = 0;
>> +    netq->tx_waiting = 0;
>>
>>       /* Just in case the driver is not ready on more */
>>       if (unlikely(!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK)))
>>           return;
>>
>> -    ret = virtio_net_flush_tx(n, n->tx_vq);
>> +    ret = virtio_net_flush_tx(n, netq);
>>       if (ret == -EBUSY) {
>>           return; /* Notification re-enable handled by tx_complete */
>>       }
>> @@ -843,33 +961,39 @@ static void virtio_net_tx_bh(void *opaque)
>>       /* If we flush a full burst of packets, assume there are
>>        * more coming and immediately reschedule */
>>       if (ret>= n->tx_burst) {
>> -        qemu_bh_schedule(n->tx_bh);
>> -        n->tx_waiting = 1;
>> +        qemu_bh_schedule(netq->tx_bh);
>> +        netq->tx_waiting = 1;
>>           return;
>>       }
>>
>>       /* If less than a full burst, re-enable notification and flush
>>        * anything that may have come in while we weren't looking.  If
>>        * we find something, assume the guest is still active and reschedule */
>> -    virtio_queue_set_notification(n->tx_vq, 1);
>> -    if (virtio_net_flush_tx(n, n->tx_vq)>  0) {
>> -        virtio_queue_set_notification(n->tx_vq, 0);
>> -        qemu_bh_schedule(n->tx_bh);
>> -        n->tx_waiting = 1;
>> +    virtio_queue_set_notification(vq, 1);
>> +    if (virtio_net_flush_tx(n, netq)>  0) {
>> +        virtio_queue_set_notification(vq, 0);
>> +        qemu_bh_schedule(netq->tx_bh);
>> +        netq->tx_waiting = 1;
>>       }
>>   }
>>
>>   static void virtio_net_save(QEMUFile *f, void *opaque)
>>   {
>>       VirtIONet *n = opaque;
>> +    int i;
>>
>>       /* At this point, backend must be stopped, otherwise
>>        * it might keep writing to memory. */
>> -    assert(!n->vhost_started);
>> +    for (i = 0; i<  n->queues; i++) {
>> +        assert(!n->vqs[i].vhost_started);
>> +    }
>>       virtio_save(&n->vdev, f);
>>
>>       qemu_put_buffer(f, n->mac, ETH_ALEN);
>> -    qemu_put_be32(f, n->tx_waiting);
>> +    qemu_put_be32(f, n->queues);
>> +    for (i = 0; i<  n->queues; i++) {
>> +        qemu_put_be32(f, n->vqs[i].tx_waiting);
>> +    }
>>       qemu_put_be32(f, n->mergeable_rx_bufs);
>>       qemu_put_be16(f, n->status);
>>       qemu_put_byte(f, n->promisc);
>> @@ -902,7 +1026,10 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>       }
>>
>>       qemu_get_buffer(f, n->mac, ETH_ALEN);
>> -    n->tx_waiting = qemu_get_be32(f);
>> +    n->queues = qemu_get_be32(f);
>> +    for (i = 0; i<  n->queues; i++) {
>> +        n->vqs[i].tx_waiting = qemu_get_be32(f);
>> +    }
>>       n->mergeable_rx_bufs = qemu_get_be32(f);
>>
>>       if (version_id>= 3)
>> @@ -930,7 +1057,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>               n->mac_table.in_use = 0;
>>           }
>>       }
>> -
>> +
>>       if (version_id>= 6)
>>           qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN>>  3);
>>
>> @@ -941,13 +1068,16 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>           }
>>
>>           if (n->has_vnet_hdr) {
>> -            tap_using_vnet_hdr(n->nic->nc.peer, 1);
>> -            tap_set_offload(n->nic->nc.peer,
>> -                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
>> -                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
>> -                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
>> -                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
>> -                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
>> +            for(i = 0; i<  n->queues; i++) {
>> +                tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
>> +                tap_set_offload(n->nic->ncs[i]->peer,
>> +                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
>> +                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
>> +                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
>> +                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
>> +                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_UFO)&
>> +                        1);
>> +           }
>>           }
>>       }
>>
>> @@ -982,7 +1112,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>>
>>   static void virtio_net_cleanup(VLANClientState *nc)
>>   {
>> -    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
>> +    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
>>
>>       n->nic = NULL;
>>   }
>> @@ -1000,6 +1130,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>                                 virtio_net_conf *net)
>>   {
>>       VirtIONet *n;
>> +    int i;
>>
>>       n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
>>                                           sizeof(struct virtio_net_config),
>> @@ -1012,7 +1143,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>       n->vdev.bad_features = virtio_net_bad_features;
>>       n->vdev.reset = virtio_net_reset;
>>       n->vdev.set_status = virtio_net_set_status;
>> -    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
>>
>>       if (net->tx&&  strcmp(net->tx, "timer")&&  strcmp(net->tx, "bh")) {
>>           error_report("virtio-net: "
>> @@ -1021,15 +1151,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>           error_report("Defaulting to \"bh\"");
>>       }
>>
>> -    if (net->tx&&  !strcmp(net->tx, "timer")) {
>> -        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
>> -        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
>> -        n->tx_timeout = net->txtimer;
>> -    } else {
>> -        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
>> -        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
>> -    }
>> -    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
>>       qemu_macaddr_default_if_unset(&conf->macaddr);
>>       memcpy(&n->mac[0],&conf->macaddr, sizeof(n->mac));
>>       n->status = VIRTIO_NET_S_LINK_UP;
>> @@ -1038,7 +1159,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>
>>       qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
>>
>> -    n->tx_waiting = 0;
>>       n->tx_burst = net->txburst;
>>       n->mergeable_rx_bufs = 0;
>>       n->promisc = 1; /* for compatibility */
>> @@ -1046,6 +1166,32 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>       n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
>>
>>       n->vlans = g_malloc0(MAX_VLAN>>  3);
>> +    n->queues = conf->queues;
>> +
>> +    /* Allocate per rx/tx vq's */
>> +    for (i = 0; i<  n->queues; i++) {
>> +        n->vqs[i].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
>> +        if (net->tx&&  !strcmp(net->tx, "timer")) {
>> +            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
>> +                                               virtio_net_handle_tx_timer);
>> +            n->vqs[i].tx_timer = qemu_new_timer_ns(vm_clock,
>> +                                                   virtio_net_tx_timer,
>> +&n->vqs[i]);
>> +            n->vqs[i].tx_timeout = net->txtimer;
>> +        } else {
>> +            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
>> +                                               virtio_net_handle_tx_bh);
>> +            n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh,&n->vqs[i]);
>> +        }
>> +
>> +        n->vqs[i].tx_waiting = 0;
>> +        n->vqs[i].n = n;
>> +
>> +        if (i == 0) {
>> +            /* keep compatiable with spec and old guest */
>> +            n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
>> +        }
>> +    }
>>
>>       n->qdev = dev;
>>       register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
>> @@ -1059,24 +1205,33 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
>>   void virtio_net_exit(VirtIODevice *vdev)
>>   {
>>       VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
>> +    int i;
>>
>>       /* This will stop vhost backend if appropriate. */
>>       virtio_net_set_status(vdev, 0);
>>
>> -    qemu_purge_queued_packets(&n->nic->nc);
>> +    for (i = 0; i<  n->queues; i++) {
>> +        qemu_purge_queued_packets(n->nic->ncs[i]);
>> +    }
>>
>>       unregister_savevm(n->qdev, "virtio-net", n);
>>
>>       g_free(n->mac_table.macs);
>>       g_free(n->vlans);
>>
>> -    if (n->tx_timer) {
>> -        qemu_del_timer(n->tx_timer);
>> -        qemu_free_timer(n->tx_timer);
>> -    } else {
>> -        qemu_bh_delete(n->tx_bh);
>> +    for (i = 0; i<  n->queues; i++) {
>> +        VirtIONetQueue *netq =&n->vqs[i];
>> +        if (netq->tx_timer) {
>> +            qemu_del_timer(netq->tx_timer);
>> +            qemu_free_timer(netq->tx_timer);
>> +        } else {
>> +            qemu_bh_delete(netq->tx_bh);
>> +        }
>>       }
>>
>> -    qemu_del_vlan_client(&n->nic->nc);
>>       virtio_cleanup(&n->vdev);
>> +
>> +    for (i = 0; i<  n->queues; i++) {
>> +        qemu_del_vlan_client(n->nic->ncs[i]);
>> +    }
>>   }
>> diff --git a/hw/virtio-net.h b/hw/virtio-net.h
>> index 36aa463..b35ba5d 100644
>> --- a/hw/virtio-net.h
>> +++ b/hw/virtio-net.h
>> @@ -44,6 +44,7 @@
>>   #define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support */
>>   #define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering */
>>   #define VIRTIO_NET_F_CTRL_RX_EXTRA 20   /* Extra RX mode control support */
>> +#define VIRTIO_NET_F_MULTIQUEUE   22
>>
>>   #define VIRTIO_NET_S_LINK_UP    1       /* Link is up */
>>
>> @@ -72,6 +73,8 @@ struct virtio_net_config
>>       uint8_t mac[ETH_ALEN];
>>       /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
>>       uint16_t status;
>> +
>> +    uint16_t queues;
>>   } QEMU_PACKED;
>>
>>   /* This is the first element of the scatter-gather list.  If you don't
> --
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> the body of a message to majordomo@vger.kernel.org
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Re: [Qemu-devel] [RFC V2 PATCH 4/4] virtio-net: add multiqueue support

[Michael S. Tsirkin]

On Mon, Jul 02, 2012 at 03:04:00PM +0800, Jason Wang wrote:
> On 07/01/2012 05:43 PM, Michael S. Tsirkin wrote:
> >On Mon, Jun 25, 2012 at 06:04:49PM +0800, Jason Wang wrote:
> >>This patch let the virtio-net can transmit and recevie packets through multiuple
> >>VLANClientStates and abstract them as multiple virtqueues to guest. A new
> >>parameter 'queues' were introduced to specify the number of queue pairs.
> >>
> >>The main goal for vhost support is to let the multiqueue could be used without
> >>changes in vhost code. So each vhost_net structure were used to track a single
> >>VLANClientState and two virtqueues in the past. As multiple VLANClientState were
> >>stored in the NICState, we can infer the correspond VLANClientState from this
> >>and queue_index easily.
> >>
> >>Signed-off-by: Jason Wang<jasowang@redhat.com>
> >Can this patch be split up?
> >1. extend vhost API to allow multiqueue and minimally tweak virtio
> >2. add real multiqueue for virtio
> >
> >Hmm?
> 
> Sure, do you think it's necessary to separate the vhost parts of
> multiqueue from virtio?

Separating is always nice if it is not too hard.

> >>---
> >>  hw/vhost.c      |   58 ++++---
> >>  hw/vhost.h      |    1
> >>  hw/vhost_net.c  |    7 +
> >>  hw/vhost_net.h  |    2
> >>  hw/virtio-net.c |  461 +++++++++++++++++++++++++++++++++++++------------------
> >>  hw/virtio-net.h |    3
> >>  6 files changed, 355 insertions(+), 177 deletions(-)
> >>
> >>diff --git a/hw/vhost.c b/hw/vhost.c
> >>index 43664e7..6318bb2 100644
> >>--- a/hw/vhost.c
> >>+++ b/hw/vhost.c
> >>@@ -620,11 +620,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
> >>  {
> >>      target_phys_addr_t s, l, a;
> >>      int r;
> >>+    int vhost_vq_index = (idx>  2 ? idx - 1 : idx) % dev->nvqs;
> >>      struct vhost_vring_file file = {
> >>-        .index = idx,
> >>+	.index = vhost_vq_index
> >>      };
> >>      struct vhost_vring_state state = {
> >>-        .index = idx,
> >>+        .index = vhost_vq_index
> >>      };
> >>      struct VirtQueue *vvq = virtio_get_queue(vdev, idx);
> >>
> >>@@ -670,11 +671,12 @@ static int vhost_virtqueue_init(struct vhost_dev *dev,
> >>          goto fail_alloc_ring;
> >>      }
> >>
> >>-    r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
> >>+    r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
> >>      if (r<  0) {
> >>          r = -errno;
> >>          goto fail_alloc;
> >>      }
> >>+
> >>      file.fd = event_notifier_get_fd(virtio_queue_get_host_notifier(vvq));
> >>      r = ioctl(dev->control, VHOST_SET_VRING_KICK,&file);
> >>      if (r) {
> >>@@ -715,7 +717,7 @@ static void vhost_virtqueue_cleanup(struct vhost_dev *dev,
> >>                                      unsigned idx)
> >>  {
> >>      struct vhost_vring_state state = {
> >>-        .index = idx,
> >>+        .index = (idx>  2 ? idx - 1 : idx) % dev->nvqs,
> >>      };
> >>      int r;
> >>      r = ioctl(dev->control, VHOST_GET_VRING_BASE,&state);
> >>@@ -829,7 +831,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>      }
> >>
> >>      for (i = 0; i<  hdev->nvqs; ++i) {
> >>-        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
> >>+        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> >>+					     hdev->start_idx + i,
> >>+					     true);
> >>          if (r<  0) {
> >>              fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
> >>              goto fail_vq;
> >>@@ -839,7 +843,9 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>      return 0;
> >>  fail_vq:
> >>      while (--i>= 0) {
> >>-        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
> >>+        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> >>+					     hdev->start_idx + i,
> >>+					     false);
> >>          if (r<  0) {
> >>              fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
> >>              fflush(stderr);
> >>@@ -860,7 +866,9 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>      int i, r;
> >>
> >>      for (i = 0; i<  hdev->nvqs; ++i) {
> >>-        r = vdev->binding->set_host_notifier(vdev->binding_opaque, i, false);
> >>+        r = vdev->binding->set_host_notifier(vdev->binding_opaque,
> >>+					     hdev->start_idx + i,
> >>+					     false);
> >>          if (r<  0) {
> >>              fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
> >>              fflush(stderr);
> >>@@ -874,15 +882,17 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>  {
> >>      int i, r;
> >>      if (!vdev->binding->set_guest_notifiers) {
> >>-        fprintf(stderr, "binding does not support guest notifiers\n");
> >>+        fprintf(stderr, "binding does not support guest notifier\n");
> >>          r = -ENOSYS;
> >>          goto fail;
> >>      }
> >>
> >>-    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
> >>-    if (r<  0) {
> >>-        fprintf(stderr, "Error binding guest notifier: %d\n", -r);
> >>-        goto fail_notifiers;
> >>+    if (hdev->start_idx == 0) {
> >>+        r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, true);
> >>+        if (r<  0) {
> >>+            fprintf(stderr, "Error binding guest notifier: %d\n", -r);
> >>+            goto fail_notifiers;
> >>+        }
> >>      }
> >>
> >>      r = vhost_dev_set_features(hdev, hdev->log_enabled);
> >>@@ -898,7 +908,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>          r = vhost_virtqueue_init(hdev,
> >>                                   vdev,
> >>                                   hdev->vqs + i,
> >>-                                 i);
> >>+                                 hdev->start_idx + i);
> >>          if (r<  0) {
> >>              goto fail_vq;
> >>          }
> >>@@ -925,11 +935,13 @@ fail_vq:
> >>          vhost_virtqueue_cleanup(hdev,
> >>                                  vdev,
> >>                                  hdev->vqs + i,
> >>-                                i);
> >>+                                hdev->start_idx + i);
> >>      }
> >>+    i = hdev->nvqs;
> >>  fail_mem:
> >>  fail_features:
> >>-    vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> >>+    if (hdev->start_idx == 0)
> >>+        vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> >>  fail_notifiers:
> >>  fail:
> >>      return r;
> >>@@ -944,18 +956,22 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> >>          vhost_virtqueue_cleanup(hdev,
> >>                                  vdev,
> >>                                  hdev->vqs + i,
> >>-                                i);
> >>+                                hdev->start_idx + i);
> >>      }
> >>+
> >>      for (i = 0; i<  hdev->n_mem_sections; ++i) {
> >>          vhost_sync_dirty_bitmap(hdev,&hdev->mem_sections[i],
> >>                                  0, (target_phys_addr_t)~0x0ull);
> >>      }
> >>-    r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> >>-    if (r<  0) {
> >>-        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
> >>-        fflush(stderr);
> >>+
> >>+    if (hdev->start_idx == 0) {
> >>+	r = vdev->binding->set_guest_notifiers(vdev->binding_opaque, false);
> >>+	if (r<  0) {
> >>+	    fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
> >>+	    fflush(stderr);
> >>+	}
> >>+	assert (r>= 0);
> >>      }
> >>-    assert (r>= 0);
> >>
> >>      hdev->started = false;
> >>      g_free(hdev->log);
> >>diff --git a/hw/vhost.h b/hw/vhost.h
> >>index 80e64df..fa5357a 100644
> >>--- a/hw/vhost.h
> >>+++ b/hw/vhost.h
> >>@@ -34,6 +34,7 @@ struct vhost_dev {
> >>      MemoryRegionSection *mem_sections;
> >>      struct vhost_virtqueue *vqs;
> >>      int nvqs;
> >>+    int start_idx;
> >>      unsigned long long features;
> >>      unsigned long long acked_features;
> >>      unsigned long long backend_features;
> >>diff --git a/hw/vhost_net.c b/hw/vhost_net.c
> >>index f672e9d..73a72bb 100644
> >>--- a/hw/vhost_net.c
> >>+++ b/hw/vhost_net.c
> >>@@ -138,13 +138,15 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
> >>  }
> >>
> >>  int vhost_net_start(struct vhost_net *net,
> >>-                    VirtIODevice *dev)
> >>+                    VirtIODevice *dev,
> >>+                    int start_idx)
> >>  {
> >>      struct vhost_vring_file file = { };
> >>      int r;
> >>
> >>      net->dev.nvqs = 2;
> >>      net->dev.vqs = net->vqs;
> >>+    net->dev.start_idx = start_idx;
> >>
> >>      r = vhost_dev_enable_notifiers(&net->dev, dev);
> >>      if (r<  0) {
> >>@@ -227,7 +229,8 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
> >>  }
> >>
> >>  int vhost_net_start(struct vhost_net *net,
> >>-		    VirtIODevice *dev)
> >>+                    VirtIODevice *dev,
> >>+                    int start_idx)
> >>  {
> >>      return -ENOSYS;
> >>  }
> >>diff --git a/hw/vhost_net.h b/hw/vhost_net.h
> >>index 91e40b1..79a4f09 100644
> >>--- a/hw/vhost_net.h
> >>+++ b/hw/vhost_net.h
> >>@@ -9,7 +9,7 @@ typedef struct vhost_net VHostNetState;
> >>  VHostNetState *vhost_net_init(VLANClientState *backend, int devfd, bool force);
> >>
> >>  bool vhost_net_query(VHostNetState *net, VirtIODevice *dev);
> >>-int vhost_net_start(VHostNetState *net, VirtIODevice *dev);
> >>+int vhost_net_start(VHostNetState *net, VirtIODevice *dev, int start_idx);
> >>  void vhost_net_stop(VHostNetState *net, VirtIODevice *dev);
> >>
> >>  void vhost_net_cleanup(VHostNetState *net);
> >>diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> >>index 3f190d4..d42c4cc 100644
> >>--- a/hw/virtio-net.c
> >>+++ b/hw/virtio-net.c
> >>@@ -26,34 +26,43 @@
> >>  #define MAC_TABLE_ENTRIES    64
> >>  #define MAX_VLAN    (1<<  12)   /* Per 802.1Q definition */
> >>
> >>-typedef struct VirtIONet
> >>+struct VirtIONet;
> >>+
> >>+typedef struct VirtIONetQueue
> >>  {
> >>-    VirtIODevice vdev;
> >>-    uint8_t mac[ETH_ALEN];
> >>-    uint16_t status;
> >>      VirtQueue *rx_vq;
> >>      VirtQueue *tx_vq;
> >>-    VirtQueue *ctrl_vq;
> >>-    NICState *nic;
> >>      QEMUTimer *tx_timer;
> >>      QEMUBH *tx_bh;
> >>      uint32_t tx_timeout;
> >>-    int32_t tx_burst;
> >>      int tx_waiting;
> >>-    uint32_t has_vnet_hdr;
> >>-    uint8_t has_ufo;
> >>      struct {
> >>          VirtQueueElement elem;
> >>          ssize_t len;
> >>      } async_tx;
> >>+    struct VirtIONet *n;
> >>+    uint8_t vhost_started;
> >>+} VirtIONetQueue;
> >>+
> >>+typedef struct VirtIONet
> >>+{
> >>+    VirtIODevice vdev;
> >>+    uint8_t mac[ETH_ALEN];
> >>+    uint16_t status;
> >>+    VirtIONetQueue vqs[MAX_QUEUE_NUM];
> >>+    VirtQueue *ctrl_vq;
> >>+    NICState *nic;
> >>+    int32_t tx_burst;
> >>+    uint32_t has_vnet_hdr;
> >>+    uint8_t has_ufo;
> >>      int mergeable_rx_bufs;
> >>+    int multiqueue;
> >>      uint8_t promisc;
> >>      uint8_t allmulti;
> >>      uint8_t alluni;
> >>      uint8_t nomulti;
> >>      uint8_t nouni;
> >>      uint8_t nobcast;
> >>-    uint8_t vhost_started;
> >>      struct {
> >>          int in_use;
> >>          int first_multi;
> >>@@ -63,6 +72,7 @@ typedef struct VirtIONet
> >>      } mac_table;
> >>      uint32_t *vlans;
> >>      DeviceState *qdev;
> >>+    uint32_t queues;
> >>  } VirtIONet;
> >>
> >>  /* TODO
> >>@@ -74,12 +84,25 @@ static VirtIONet *to_virtio_net(VirtIODevice *vdev)
> >>      return (VirtIONet *)vdev;
> >>  }
> >>
> >>+static int vq_get_pair_index(VirtIONet *n, VirtQueue *vq)
> >>+{
> >>+    int i;
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        if (n->vqs[i].tx_vq == vq || n->vqs[i].rx_vq == vq) {
> >>+            return i;
> >>+        }
> >>+    }
> >>+    assert(1);
> >>+    return -1;
> >>+}
> >>+
> >>  static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>      struct virtio_net_config netcfg;
> >>
> >>      stw_p(&netcfg.status, n->status);
> >>+    netcfg.queues = n->queues * 2;
> >>      memcpy(netcfg.mac, n->mac, ETH_ALEN);
> >>      memcpy(config,&netcfg, sizeof(netcfg));
> >>  }
> >>@@ -103,78 +126,140 @@ static bool virtio_net_started(VirtIONet *n, uint8_t status)
> >>          (n->status&  VIRTIO_NET_S_LINK_UP)&&  n->vdev.vm_running;
> >>  }
> >>
> >>-static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> >>+static void nc_vhost_status(VLANClientState *nc, VirtIONet *n,
> >>+                            uint8_t status)
> >>  {
> >>-    if (!n->nic->nc.peer) {
> >>+    int queue_index = nc->queue_index;
> >>+    VLANClientState *peer = nc->peer;
> >>+    VirtIONetQueue *netq =&n->vqs[nc->queue_index];
> >>+
> >>+    if (!peer) {
> >>          return;
> >>      }
> >>-    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>+    if (peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>          return;
> >>      }
> >>
> >>-    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> >>+    if (!tap_get_vhost_net(peer)) {
> >>          return;
> >>      }
> >>-    if (!!n->vhost_started == virtio_net_started(n, status)&&
> >>-                              !n->nic->nc.peer->link_down) {
> >>+    if (!!netq->vhost_started == virtio_net_started(n, status)&&
> >>+                                 !peer->link_down) {
> >>          return;
> >>      }
> >>-    if (!n->vhost_started) {
> >>-        int r;
> >>-        if (!vhost_net_query(tap_get_vhost_net(n->nic->nc.peer),&n->vdev)) {
> >>+    if (!netq->vhost_started) {
> >>+	/* skip ctrl vq */
> >>+	int r, start_idx = queue_index == 0 ? 0 : queue_index * 2 + 1;
> >>+        if (!vhost_net_query(tap_get_vhost_net(peer),&n->vdev)) {
> >>              return;
> >>          }
> >>-        r = vhost_net_start(tap_get_vhost_net(n->nic->nc.peer),&n->vdev);
> >>+        r = vhost_net_start(tap_get_vhost_net(peer),&n->vdev, start_idx);
> >>          if (r<  0) {
> >>              error_report("unable to start vhost net: %d: "
> >>                           "falling back on userspace virtio", -r);
> >>          } else {
> >>-            n->vhost_started = 1;
> >>+            netq->vhost_started = 1;
> >>          }
> >>      } else {
> >>-        vhost_net_stop(tap_get_vhost_net(n->nic->nc.peer),&n->vdev);
> >>-        n->vhost_started = 0;
> >>+        vhost_net_stop(tap_get_vhost_net(peer),&n->vdev);
> >>+        netq->vhost_started = 0;
> >>+    }
> >>+}
> >>+
> >>+static int peer_attach(VirtIONet *n, int index)
> >>+{
> >>+    if (!n->nic->ncs[index]->peer) {
> >>+	return -1;
> >>+    }
> >>+
> >>+    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>+	return -1;
> >>+    }
> >>+
> >>+    return tap_attach(n->nic->ncs[index]->peer);
> >>+}
> >>+
> >>+static int peer_detach(VirtIONet *n, int index)
> >>+{
> >>+    if (!n->nic->ncs[index]->peer) {
> >>+	return -1;
> >>+    }
> >>+
> >>+    if (n->nic->ncs[index]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>+	return -1;
> >>+    }
> >>+
> >>+    return tap_detach(n->nic->ncs[index]->peer);
> >>+}
> >>+
> >>+static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
> >>+{
> >>+    int i;
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+	if (!n->multiqueue&&  i != 0)
> >>+	    status = 0;
> >>+        nc_vhost_status(n->nic->ncs[i], n, status);
> >>      }
> >>  }
> >>
> >>  static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>+    int i;
> >>
> >>      virtio_net_vhost_status(n, status);
> >>
> >>-    if (!n->tx_waiting) {
> >>-        return;
> >>-    }
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        VirtIONetQueue *netq =&n->vqs[i];
> >>+        if (!netq->tx_waiting) {
> >>+            continue;
> >>+        }
> >>+
> >>+	if (!n->multiqueue&&  i != 0)
> >>+	    status = 0;
> >>
> >>-    if (virtio_net_started(n, status)&&  !n->vhost_started) {
> >>-        if (n->tx_timer) {
> >>-            qemu_mod_timer(n->tx_timer,
> >>-                           qemu_get_clock_ns(vm_clock) + n->tx_timeout);
> >>+        if (virtio_net_started(n, status)&&  !netq->vhost_started) {
> >>+            if (netq->tx_timer) {
> >>+                qemu_mod_timer(netq->tx_timer,
> >>+                               qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
> >>+            } else {
> >>+                qemu_bh_schedule(netq->tx_bh);
> >>+            }
> >>          } else {
> >>-            qemu_bh_schedule(n->tx_bh);
> >>+            if (netq->tx_timer) {
> >>+                qemu_del_timer(netq->tx_timer);
> >>+            } else {
> >>+                qemu_bh_cancel(netq->tx_bh);
> >>+            }
> >>          }
> >>-    } else {
> >>-        if (n->tx_timer) {
> >>-            qemu_del_timer(n->tx_timer);
> >>-        } else {
> >>-            qemu_bh_cancel(n->tx_bh);
> >>+    }
> >>+}
> >>+
> >>+static bool virtio_net_is_link_up(VirtIONet *n)
> >>+{
> >>+    int i;
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        if (n->nic->ncs[i]->link_down) {
> >>+            return false;
> >>          }
> >>      }
> >>+    return true;
> >>  }
> >>
> >>  static void virtio_net_set_link_status(VLANClientState *nc)
> >>  {
> >>-    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> >>+    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
> >>      uint16_t old_status = n->status;
> >>
> >>-    if (nc->link_down)
> >>+    if (virtio_net_is_link_up(n)) {
> >>          n->status&= ~VIRTIO_NET_S_LINK_UP;
> >>-    else
> >>+    } else {
> >>          n->status |= VIRTIO_NET_S_LINK_UP;
> >>+    }
> >>
> >>-    if (n->status != old_status)
> >>+    if (n->status != old_status) {
> >>          virtio_notify_config(&n->vdev);
> >>+    }
> >>
> >>      virtio_net_set_status(&n->vdev, n->vdev.status);
> >>  }
> >>@@ -202,13 +287,15 @@ static void virtio_net_reset(VirtIODevice *vdev)
> >>
> >>  static int peer_has_vnet_hdr(VirtIONet *n)
> >>  {
> >>-    if (!n->nic->nc.peer)
> >>+    if (!n->nic->ncs[0]->peer) {
> >>          return 0;
> >>+    }
> >>
> >>-    if (n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP)
> >>+    if (n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>          return 0;
> >>+    }
> >>
> >>-    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->nc.peer);
> >>+    n->has_vnet_hdr = tap_has_vnet_hdr(n->nic->ncs[0]->peer);
> >>
> >>      return n->has_vnet_hdr;
> >>  }
> >>@@ -218,7 +305,7 @@ static int peer_has_ufo(VirtIONet *n)
> >>      if (!peer_has_vnet_hdr(n))
> >>          return 0;
> >>
> >>-    n->has_ufo = tap_has_ufo(n->nic->nc.peer);
> >>+    n->has_ufo = tap_has_ufo(n->nic->ncs[0]->peer);
> >>
> >>      return n->has_ufo;
> >>  }
> >>@@ -228,9 +315,13 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>
> >>      features |= (1<<  VIRTIO_NET_F_MAC);
> >>+    features |= (1<<  VIRTIO_NET_F_MULTIQUEUE);
> >>
> >>      if (peer_has_vnet_hdr(n)) {
> >>-        tap_using_vnet_hdr(n->nic->nc.peer, 1);
> >>+        int i;
> >>+        for (i = 0; i<  n->queues; i++) {
> >>+            tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
> >>+        }
> >>      } else {
> >>          features&= ~(0x1<<  VIRTIO_NET_F_CSUM);
> >>          features&= ~(0x1<<  VIRTIO_NET_F_HOST_TSO4);
> >>@@ -248,14 +339,15 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev, uint32_t features)
> >>          features&= ~(0x1<<  VIRTIO_NET_F_HOST_UFO);
> >>      }
> >>
> >>-    if (!n->nic->nc.peer ||
> >>-        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>+    if (!n->nic->ncs[0]->peer ||
> >>+        n->nic->ncs[0]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>          return features;
> >>      }
> >>-    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> >>+    if (!tap_get_vhost_net(n->nic->ncs[0]->peer)) {
> >>          return features;
> >>      }
> >>-    return vhost_net_get_features(tap_get_vhost_net(n->nic->nc.peer), features);
> >>+    return vhost_net_get_features(tap_get_vhost_net(n->nic->ncs[0]->peer),
> >>+                                  features);
> >>  }
> >>
> >>  static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
> >>@@ -276,25 +368,38 @@ static uint32_t virtio_net_bad_features(VirtIODevice *vdev)
> >>  static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>+    int i, r;
> >>
> >>      n->mergeable_rx_bufs = !!(features&  (1<<  VIRTIO_NET_F_MRG_RXBUF));
> >>+    n->multiqueue = !!(features&  (1<<  VIRTIO_NET_F_MULTIQUEUE));
> >>
> >>-    if (n->has_vnet_hdr) {
> >>-        tap_set_offload(n->nic->nc.peer,
> >>-                        (features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
> >>-                        (features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
> >>-                        (features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
> >>-                        (features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
> >>-                        (features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
> >>-    }
> >>-    if (!n->nic->nc.peer ||
> >>-        n->nic->nc.peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>-        return;
> >>-    }
> >>-    if (!tap_get_vhost_net(n->nic->nc.peer)) {
> >>-        return;
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        if (!n->multiqueue&&  i != 0) {
> >>+            r = peer_detach(n, i);
> >>+            assert(r == 0);
> >>+        } else {
> >>+            r = peer_attach(n, i);
> >>+            assert(r == 0);
> >>+
> >>+            if (n->has_vnet_hdr) {
> >>+                tap_set_offload(n->nic->ncs[i]->peer,
> >>+                                (features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
> >>+                                (features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
> >>+                                (features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
> >>+                                (features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
> >>+                                (features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
> >>+            }
> >>+            if (!n->nic->ncs[i]->peer ||
> >>+                n->nic->ncs[i]->peer->info->type != NET_CLIENT_TYPE_TAP) {
> >>+                continue;
> >>+            }
> >>+            if (!tap_get_vhost_net(n->nic->ncs[i]->peer)) {
> >>+                continue;
> >>+            }
> >>+            vhost_net_ack_features(tap_get_vhost_net(n->nic->ncs[i]->peer),
> >>+                                   features);
> >>+        }
> >>      }
> >>-    vhost_net_ack_features(tap_get_vhost_net(n->nic->nc.peer), features);
> >>  }
> >>
> >>  static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
> >>@@ -446,7 +551,7 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>
> >>-    qemu_flush_queued_packets(&n->nic->nc);
> >>+    qemu_flush_queued_packets(n->nic->ncs[vq_get_pair_index(n, vq)]);
> >>
> >>      /* We now have RX buffers, signal to the IO thread to break out of the
> >>       * select to re-poll the tap file descriptor */
> >>@@ -455,36 +560,37 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
> >>
> >>  static int virtio_net_can_receive(VLANClientState *nc)
> >>  {
> >>-    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> >>+    int queue_index = nc->queue_index;
> >>+    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
> >>+
> >>      if (!n->vdev.vm_running) {
> >>          return 0;
> >>      }
> >>
> >>-    if (!virtio_queue_ready(n->rx_vq) ||
> >>+    if (!virtio_queue_ready(n->vqs[queue_index].rx_vq) ||
> >>          !(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK))
> >>          return 0;
> >>
> >>      return 1;
> >>  }
> >>
> >>-static int virtio_net_has_buffers(VirtIONet *n, int bufsize)
> >>+static int virtio_net_has_buffers(VirtIONet *n, int bufsize, VirtQueue *vq)
> >>  {
> >>-    if (virtio_queue_empty(n->rx_vq) ||
> >>-        (n->mergeable_rx_bufs&&
> >>-         !virtqueue_avail_bytes(n->rx_vq, bufsize, 0))) {
> >>-        virtio_queue_set_notification(n->rx_vq, 1);
> >>+    if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs&&
> >>+        !virtqueue_avail_bytes(vq, bufsize, 0))) {
> >>+        virtio_queue_set_notification(vq, 1);
> >>
> >>          /* To avoid a race condition where the guest has made some buffers
> >>           * available after the above check but before notification was
> >>           * enabled, check for available buffers again.
> >>           */
> >>-        if (virtio_queue_empty(n->rx_vq) ||
> >>-            (n->mergeable_rx_bufs&&
> >>-             !virtqueue_avail_bytes(n->rx_vq, bufsize, 0)))
> >>+        if (virtio_queue_empty(vq) || (n->mergeable_rx_bufs&&
> >>+            !virtqueue_avail_bytes(vq, bufsize, 0))) {
> >>              return 0;
> >>+        }
> >>      }
> >>
> >>-    virtio_queue_set_notification(n->rx_vq, 0);
> >>+    virtio_queue_set_notification(vq, 0);
> >>      return 1;
> >>  }
> >>
> >>@@ -595,12 +701,15 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
> >>
> >>  static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
> >>  {
> >>-    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> >>+    int queue_index = nc->queue_index;
> >>+    VirtIONet *n = ((NICState *)(nc->opaque))->opaque;
> >>+    VirtQueue *vq = n->vqs[queue_index].rx_vq;
> >>      struct virtio_net_hdr_mrg_rxbuf *mhdr = NULL;
> >>      size_t guest_hdr_len, offset, i, host_hdr_len;
> >>
> >>-    if (!virtio_net_can_receive(&n->nic->nc))
> >>+    if (!virtio_net_can_receive(n->nic->ncs[queue_index])) {
> >>          return -1;
> >>+    }
> >>
> >>      /* hdr_len refers to the header we supply to the guest */
> >>      guest_hdr_len = n->mergeable_rx_bufs ?
> >>@@ -608,7 +717,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
> >>
> >>
> >>      host_hdr_len = n->has_vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
> >>-    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len))
> >>+    if (!virtio_net_has_buffers(n, size + guest_hdr_len - host_hdr_len, vq))
> >>          return 0;
> >>
> >>      if (!receive_filter(n, buf, size))
> >>@@ -623,7 +732,7 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
> >>
> >>          total = 0;
> >>
> >>-        if (virtqueue_pop(n->rx_vq,&elem) == 0) {
> >>+        if (virtqueue_pop(vq,&elem) == 0) {
> >>              if (i == 0)
> >>                  return -1;
> >>              error_report("virtio-net unexpected empty queue: "
> >>@@ -675,47 +784,50 @@ static ssize_t virtio_net_receive(VLANClientState *nc, const uint8_t *buf, size_
> >>          }
> >>
> >>          /* signal other side */
> >>-        virtqueue_fill(n->rx_vq,&elem, total, i++);
> >>+        virtqueue_fill(vq,&elem, total, i++);
> >>      }
> >>
> >>      if (mhdr) {
> >>          stw_p(&mhdr->num_buffers, i);
> >>      }
> >>
> >>-    virtqueue_flush(n->rx_vq, i);
> >>-    virtio_notify(&n->vdev, n->rx_vq);
> >>+    virtqueue_flush(vq, i);
> >>+    virtio_notify(&n->vdev, vq);
> >>
> >>      return size;
> >>  }
> >>
> >>-static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq);
> >>+static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *tvq);
> >>
> >>  static void virtio_net_tx_complete(VLANClientState *nc, ssize_t len)
> >>  {
> >>-    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> >>+    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
> >>+    VirtIONetQueue *netq =&n->vqs[nc->queue_index];
> >>
> >>-    virtqueue_push(n->tx_vq,&n->async_tx.elem, n->async_tx.len);
> >>-    virtio_notify(&n->vdev, n->tx_vq);
> >>+    virtqueue_push(netq->tx_vq,&netq->async_tx.elem, netq->async_tx.len);
> >>+    virtio_notify(&n->vdev, netq->tx_vq);
> >>
> >>-    n->async_tx.elem.out_num = n->async_tx.len = 0;
> >>+    netq->async_tx.elem.out_num = netq->async_tx.len;
> >>
> >>-    virtio_queue_set_notification(n->tx_vq, 1);
> >>-    virtio_net_flush_tx(n, n->tx_vq);
> >>+    virtio_queue_set_notification(netq->tx_vq, 1);
> >>+    virtio_net_flush_tx(n, netq);
> >>  }
> >>
> >>  /* TX */
> >>-static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
> >>+static int32_t virtio_net_flush_tx(VirtIONet *n, VirtIONetQueue *netq)
> >>  {
> >>      VirtQueueElement elem;
> >>      int32_t num_packets = 0;
> >>+    VirtQueue *vq = netq->tx_vq;
> >>+
> >>      if (!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK)) {
> >>          return num_packets;
> >>      }
> >>
> >>      assert(n->vdev.vm_running);
> >>
> >>-    if (n->async_tx.elem.out_num) {
> >>-        virtio_queue_set_notification(n->tx_vq, 0);
> >>+    if (netq->async_tx.elem.out_num) {
> >>+        virtio_queue_set_notification(vq, 0);
> >>          return num_packets;
> >>      }
> >>
> >>@@ -747,12 +859,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
> >>              len += hdr_len;
> >>          }
> >>
> >>-        ret = qemu_sendv_packet_async(&n->nic->nc, out_sg, out_num,
> >>-                                      virtio_net_tx_complete);
> >>+        ret = qemu_sendv_packet_async(n->nic->ncs[vq_get_pair_index(n, vq)],
> >>+                                      out_sg, out_num, virtio_net_tx_complete);
> >>          if (ret == 0) {
> >>-            virtio_queue_set_notification(n->tx_vq, 0);
> >>-            n->async_tx.elem = elem;
> >>-            n->async_tx.len  = len;
> >>+            virtio_queue_set_notification(vq, 0);
> >>+            netq->async_tx.elem = elem;
> >>+            netq->async_tx.len  = len;
> >>              return -EBUSY;
> >>          }
> >>
> >>@@ -771,22 +883,23 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
> >>  static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>+    VirtIONetQueue *netq =&n->vqs[vq_get_pair_index(n, vq)];
> >>
> >>      /* This happens when device was stopped but VCPU wasn't. */
> >>      if (!n->vdev.vm_running) {
> >>-        n->tx_waiting = 1;
> >>+        netq->tx_waiting = 1;
> >>          return;
> >>      }
> >>
> >>-    if (n->tx_waiting) {
> >>+    if (netq->tx_waiting) {
> >>          virtio_queue_set_notification(vq, 1);
> >>-        qemu_del_timer(n->tx_timer);
> >>-        n->tx_waiting = 0;
> >>-        virtio_net_flush_tx(n, vq);
> >>+        qemu_del_timer(netq->tx_timer);
> >>+        netq->tx_waiting = 0;
> >>+        virtio_net_flush_tx(n, netq);
> >>      } else {
> >>-        qemu_mod_timer(n->tx_timer,
> >>-                       qemu_get_clock_ns(vm_clock) + n->tx_timeout);
> >>-        n->tx_waiting = 1;
> >>+        qemu_mod_timer(netq->tx_timer,
> >>+                       qemu_get_clock_ns(vm_clock) + netq->tx_timeout);
> >>+        netq->tx_waiting = 1;
> >>          virtio_queue_set_notification(vq, 0);
> >>      }
> >>  }
> >>@@ -794,48 +907,53 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
> >>  static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
> >>  {
> >>      VirtIONet *n = to_virtio_net(vdev);
> >>+    VirtIONetQueue *netq =&n->vqs[vq_get_pair_index(n, vq)];
> >>
> >>-    if (unlikely(n->tx_waiting)) {
> >>+    if (unlikely(netq->tx_waiting)) {
> >>          return;
> >>      }
> >>-    n->tx_waiting = 1;
> >>+    netq->tx_waiting = 1;
> >>      /* This happens when device was stopped but VCPU wasn't. */
> >>      if (!n->vdev.vm_running) {
> >>          return;
> >>      }
> >>      virtio_queue_set_notification(vq, 0);
> >>-    qemu_bh_schedule(n->tx_bh);
> >>+    qemu_bh_schedule(netq->tx_bh);
> >>  }
> >>
> >>  static void virtio_net_tx_timer(void *opaque)
> >>  {
> >>-    VirtIONet *n = opaque;
> >>+    VirtIONetQueue *netq = opaque;
> >>+    VirtIONet *n = netq->n;
> >>+
> >>      assert(n->vdev.vm_running);
> >>
> >>-    n->tx_waiting = 0;
> >>+    netq->tx_waiting = 0;
> >>
> >>      /* Just in case the driver is not ready on more */
> >>      if (!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK))
> >>          return;
> >>
> >>-    virtio_queue_set_notification(n->tx_vq, 1);
> >>-    virtio_net_flush_tx(n, n->tx_vq);
> >>+    virtio_queue_set_notification(netq->tx_vq, 1);
> >>+    virtio_net_flush_tx(n, netq);
> >>  }
> >>
> >>  static void virtio_net_tx_bh(void *opaque)
> >>  {
> >>-    VirtIONet *n = opaque;
> >>+    VirtIONetQueue *netq = opaque;
> >>+    VirtQueue *vq = netq->tx_vq;
> >>+    VirtIONet *n = netq->n;
> >>      int32_t ret;
> >>
> >>      assert(n->vdev.vm_running);
> >>
> >>-    n->tx_waiting = 0;
> >>+    netq->tx_waiting = 0;
> >>
> >>      /* Just in case the driver is not ready on more */
> >>      if (unlikely(!(n->vdev.status&  VIRTIO_CONFIG_S_DRIVER_OK)))
> >>          return;
> >>
> >>-    ret = virtio_net_flush_tx(n, n->tx_vq);
> >>+    ret = virtio_net_flush_tx(n, netq);
> >>      if (ret == -EBUSY) {
> >>          return; /* Notification re-enable handled by tx_complete */
> >>      }
> >>@@ -843,33 +961,39 @@ static void virtio_net_tx_bh(void *opaque)
> >>      /* If we flush a full burst of packets, assume there are
> >>       * more coming and immediately reschedule */
> >>      if (ret>= n->tx_burst) {
> >>-        qemu_bh_schedule(n->tx_bh);
> >>-        n->tx_waiting = 1;
> >>+        qemu_bh_schedule(netq->tx_bh);
> >>+        netq->tx_waiting = 1;
> >>          return;
> >>      }
> >>
> >>      /* If less than a full burst, re-enable notification and flush
> >>       * anything that may have come in while we weren't looking.  If
> >>       * we find something, assume the guest is still active and reschedule */
> >>-    virtio_queue_set_notification(n->tx_vq, 1);
> >>-    if (virtio_net_flush_tx(n, n->tx_vq)>  0) {
> >>-        virtio_queue_set_notification(n->tx_vq, 0);
> >>-        qemu_bh_schedule(n->tx_bh);
> >>-        n->tx_waiting = 1;
> >>+    virtio_queue_set_notification(vq, 1);
> >>+    if (virtio_net_flush_tx(n, netq)>  0) {
> >>+        virtio_queue_set_notification(vq, 0);
> >>+        qemu_bh_schedule(netq->tx_bh);
> >>+        netq->tx_waiting = 1;
> >>      }
> >>  }
> >>
> >>  static void virtio_net_save(QEMUFile *f, void *opaque)
> >>  {
> >>      VirtIONet *n = opaque;
> >>+    int i;
> >>
> >>      /* At this point, backend must be stopped, otherwise
> >>       * it might keep writing to memory. */
> >>-    assert(!n->vhost_started);
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        assert(!n->vqs[i].vhost_started);
> >>+    }
> >>      virtio_save(&n->vdev, f);
> >>
> >>      qemu_put_buffer(f, n->mac, ETH_ALEN);
> >>-    qemu_put_be32(f, n->tx_waiting);
> >>+    qemu_put_be32(f, n->queues);
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        qemu_put_be32(f, n->vqs[i].tx_waiting);
> >>+    }
> >>      qemu_put_be32(f, n->mergeable_rx_bufs);
> >>      qemu_put_be16(f, n->status);
> >>      qemu_put_byte(f, n->promisc);
> >>@@ -902,7 +1026,10 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> >>      }
> >>
> >>      qemu_get_buffer(f, n->mac, ETH_ALEN);
> >>-    n->tx_waiting = qemu_get_be32(f);
> >>+    n->queues = qemu_get_be32(f);
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        n->vqs[i].tx_waiting = qemu_get_be32(f);
> >>+    }
> >>      n->mergeable_rx_bufs = qemu_get_be32(f);
> >>
> >>      if (version_id>= 3)
> >>@@ -930,7 +1057,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> >>              n->mac_table.in_use = 0;
> >>          }
> >>      }
> >>-
> >>+
> >>      if (version_id>= 6)
> >>          qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN>>  3);
> >>
> >>@@ -941,13 +1068,16 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> >>          }
> >>
> >>          if (n->has_vnet_hdr) {
> >>-            tap_using_vnet_hdr(n->nic->nc.peer, 1);
> >>-            tap_set_offload(n->nic->nc.peer,
> >>-                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
> >>-                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
> >>-                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
> >>-                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
> >>-                    (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_UFO)&  1);
> >>+            for(i = 0; i<  n->queues; i++) {
> >>+                tap_using_vnet_hdr(n->nic->ncs[i]->peer, 1);
> >>+                tap_set_offload(n->nic->ncs[i]->peer,
> >>+                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_CSUM)&  1,
> >>+                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO4)&  1,
> >>+                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_TSO6)&  1,
> >>+                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_ECN)&  1,
> >>+                        (n->vdev.guest_features>>  VIRTIO_NET_F_GUEST_UFO)&
> >>+                        1);
> >>+           }
> >>          }
> >>      }
> >>
> >>@@ -982,7 +1112,7 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> >>
> >>  static void virtio_net_cleanup(VLANClientState *nc)
> >>  {
> >>-    VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
> >>+    VirtIONet *n = ((NICState *)nc->opaque)->opaque;
> >>
> >>      n->nic = NULL;
> >>  }
> >>@@ -1000,6 +1130,7 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>                                virtio_net_conf *net)
> >>  {
> >>      VirtIONet *n;
> >>+    int i;
> >>
> >>      n = (VirtIONet *)virtio_common_init("virtio-net", VIRTIO_ID_NET,
> >>                                          sizeof(struct virtio_net_config),
> >>@@ -1012,7 +1143,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>      n->vdev.bad_features = virtio_net_bad_features;
> >>      n->vdev.reset = virtio_net_reset;
> >>      n->vdev.set_status = virtio_net_set_status;
> >>-    n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
> >>
> >>      if (net->tx&&  strcmp(net->tx, "timer")&&  strcmp(net->tx, "bh")) {
> >>          error_report("virtio-net: "
> >>@@ -1021,15 +1151,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>          error_report("Defaulting to \"bh\"");
> >>      }
> >>
> >>-    if (net->tx&&  !strcmp(net->tx, "timer")) {
> >>-        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_timer);
> >>-        n->tx_timer = qemu_new_timer_ns(vm_clock, virtio_net_tx_timer, n);
> >>-        n->tx_timeout = net->txtimer;
> >>-    } else {
> >>-        n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx_bh);
> >>-        n->tx_bh = qemu_bh_new(virtio_net_tx_bh, n);
> >>-    }
> >>-    n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
> >>      qemu_macaddr_default_if_unset(&conf->macaddr);
> >>      memcpy(&n->mac[0],&conf->macaddr, sizeof(n->mac));
> >>      n->status = VIRTIO_NET_S_LINK_UP;
> >>@@ -1038,7 +1159,6 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>
> >>      qemu_format_nic_info_str(&n->nic->nc, conf->macaddr.a);
> >>
> >>-    n->tx_waiting = 0;
> >>      n->tx_burst = net->txburst;
> >>      n->mergeable_rx_bufs = 0;
> >>      n->promisc = 1; /* for compatibility */
> >>@@ -1046,6 +1166,32 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>      n->mac_table.macs = g_malloc0(MAC_TABLE_ENTRIES * ETH_ALEN);
> >>
> >>      n->vlans = g_malloc0(MAX_VLAN>>  3);
> >>+    n->queues = conf->queues;
> >>+
> >>+    /* Allocate per rx/tx vq's */
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        n->vqs[i].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
> >>+        if (net->tx&&  !strcmp(net->tx, "timer")) {
> >>+            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
> >>+                                               virtio_net_handle_tx_timer);
> >>+            n->vqs[i].tx_timer = qemu_new_timer_ns(vm_clock,
> >>+                                                   virtio_net_tx_timer,
> >>+&n->vqs[i]);
> >>+            n->vqs[i].tx_timeout = net->txtimer;
> >>+        } else {
> >>+            n->vqs[i].tx_vq = virtio_add_queue(&n->vdev, 256,
> >>+                                               virtio_net_handle_tx_bh);
> >>+            n->vqs[i].tx_bh = qemu_bh_new(virtio_net_tx_bh,&n->vqs[i]);
> >>+        }
> >>+
> >>+        n->vqs[i].tx_waiting = 0;
> >>+        n->vqs[i].n = n;
> >>+
> >>+        if (i == 0) {
> >>+            /* keep compatiable with spec and old guest */
> >>+            n->ctrl_vq = virtio_add_queue(&n->vdev, 64, virtio_net_handle_ctrl);
> >>+        }
> >>+    }
> >>
> >>      n->qdev = dev;
> >>      register_savevm(dev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
> >>@@ -1059,24 +1205,33 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
> >>  void virtio_net_exit(VirtIODevice *vdev)
> >>  {
> >>      VirtIONet *n = DO_UPCAST(VirtIONet, vdev, vdev);
> >>+    int i;
> >>
> >>      /* This will stop vhost backend if appropriate. */
> >>      virtio_net_set_status(vdev, 0);
> >>
> >>-    qemu_purge_queued_packets(&n->nic->nc);
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        qemu_purge_queued_packets(n->nic->ncs[i]);
> >>+    }
> >>
> >>      unregister_savevm(n->qdev, "virtio-net", n);
> >>
> >>      g_free(n->mac_table.macs);
> >>      g_free(n->vlans);
> >>
> >>-    if (n->tx_timer) {
> >>-        qemu_del_timer(n->tx_timer);
> >>-        qemu_free_timer(n->tx_timer);
> >>-    } else {
> >>-        qemu_bh_delete(n->tx_bh);
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        VirtIONetQueue *netq =&n->vqs[i];
> >>+        if (netq->tx_timer) {
> >>+            qemu_del_timer(netq->tx_timer);
> >>+            qemu_free_timer(netq->tx_timer);
> >>+        } else {
> >>+            qemu_bh_delete(netq->tx_bh);
> >>+        }
> >>      }
> >>
> >>-    qemu_del_vlan_client(&n->nic->nc);
> >>      virtio_cleanup(&n->vdev);
> >>+
> >>+    for (i = 0; i<  n->queues; i++) {
> >>+        qemu_del_vlan_client(n->nic->ncs[i]);
> >>+    }
> >>  }
> >>diff --git a/hw/virtio-net.h b/hw/virtio-net.h
> >>index 36aa463..b35ba5d 100644
> >>--- a/hw/virtio-net.h
> >>+++ b/hw/virtio-net.h
> >>@@ -44,6 +44,7 @@
> >>  #define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support */
> >>  #define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering */
> >>  #define VIRTIO_NET_F_CTRL_RX_EXTRA 20   /* Extra RX mode control support */
> >>+#define VIRTIO_NET_F_MULTIQUEUE   22
> >>
> >>  #define VIRTIO_NET_S_LINK_UP    1       /* Link is up */
> >>
> >>@@ -72,6 +73,8 @@ struct virtio_net_config
> >>      uint8_t mac[ETH_ALEN];
> >>      /* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */
> >>      uint16_t status;
> >>+
> >>+    uint16_t queues;
> >>  } QEMU_PACKED;
> >>
> >>  /* This is the first element of the scatter-gather list.  If you don't
> >--
> >To unsubscribe from this list: send the line "unsubscribe kvm" in
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