[5/7] net: reduce the unnecessary memory allocation of multiqueue

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 573c669..bb2c26c 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -44,7 +44,7 @@  typedef struct VirtIONet
     VirtIODevice vdev;
     uint8_t mac[ETH_ALEN];
     uint16_t status;
-    VirtIONetQueue vqs[MAX_QUEUE_NUM];
+    VirtIONetQueue *vqs;
     VirtQueue *ctrl_vq;
     NICState *nic;
     uint32_t tx_timeout;
@@ -1326,8 +1326,9 @@  VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf,
     n->vdev.set_status = virtio_net_set_status;
     n->vdev.guest_notifier_mask = virtio_net_guest_notifier_mask;
     n->vdev.guest_notifier_pending = virtio_net_guest_notifier_pending;
+    n->max_queues = MAX(conf->queues, 1);
+    n->vqs = g_malloc0(sizeof(VirtIONetQueue) * n->max_queues);
     n->vqs[0].rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
-    n->max_queues = conf->queues;
     n->curr_queues = 1;
     n->vqs[0].n = n;
     n->tx_timeout = net->txtimer;
@@ -1412,6 +1413,7 @@  void virtio_net_exit(VirtIODevice *vdev)
         }
     }
 
+    g_free(n->vqs);
     qemu_del_nic(n->nic);
     virtio_cleanup(&n->vdev);
 }
diff --git a/include/net/net.h b/include/net/net.h
index 43a045e..cb049a1 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -72,7 +72,7 @@  struct NetClientState {
 };
 
 typedef struct NICState {
-    NetClientState ncs[MAX_QUEUE_NUM];
+    NetClientState *ncs;
     NICConf *conf;
     void *opaque;
     bool peer_deleted;
diff --git a/net/net.c b/net/net.c
index a66aa02..f3d67f8 100644
--- a/net/net.c
+++ b/net/net.c
@@ -235,23 +235,20 @@  NICState *qemu_new_nic(NetClientInfo *info,
                        const char *name,
                        void *opaque)
 {
-    NetClientState *nc;
     NetClientState **peers = conf->peers.ncs;
     NICState *nic;
-    int i;
+    int i, queues = MAX(1, conf->queues);
 
     assert(info->type == NET_CLIENT_OPTIONS_KIND_NIC);
     assert(info->size >= sizeof(NICState));
 
-    nc = qemu_new_net_client(info, peers[0], model, name);
-    nc->queue_index = 0;
-
-    nic = qemu_get_nic(nc);
+    nic = g_malloc0(info->size + sizeof(NetClientState) * queues);
+    nic->ncs = (void *)nic + info->size;
     nic->conf = conf;
     nic->opaque = opaque;
 
-    for (i = 1; i < conf->queues; i++) {
-        qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, nc->name,
+    for (i = 0; i < queues; i++) {
+        qemu_net_client_setup(&nic->ncs[i], info, peers[i], model, name,
                               NULL);
         nic->ncs[i].queue_index = i;
     }
@@ -261,7 +258,7 @@  NICState *qemu_new_nic(NetClientInfo *info,
 
 NetClientState *qemu_get_subqueue(NICState *nic, int queue_index)
 {
-    return &nic->ncs[queue_index];
+    return nic->ncs + queue_index;
 }
 
 NetClientState *qemu_get_queue(NICState *nic)
@@ -273,7 +270,7 @@  NICState *qemu_get_nic(NetClientState *nc)
 {
     NetClientState *nc0 = nc - nc->queue_index;
 
-    return DO_UPCAST(NICState, ncs[0], nc0);
+    return (NICState *)((void *)nc0 - nc->info->size);
 }
 
 void *qemu_get_nic_opaque(NetClientState *nc)
@@ -368,6 +365,8 @@  void qemu_del_nic(NICState *nic)
         qemu_cleanup_net_client(nc);
         qemu_free_net_client(nc);
     }
+
+    g_free(nic);
 }
 
 void qemu_foreach_nic(qemu_nic_foreach func, void *opaque)