net: multiqueue support

This patch adds basic multiqueue support for qemu. The idea is simple, an array
of NetClientStates were introduced in NICState, parse_netdev() were extended to
find and match all NetClientStates belongs to the backend and place their
pointers in NICConf. Then qemu_new_nic can setup a N:N mapping between NICStates
that belongs to a nic and NICStates belongs to the netdev. And a queue_index
were introduced in NetClientState to track its index. After this, each peers of
a NICState were abstracted as a queue.

After this change, all NetClientState that belongs to the same backend/nic has
the same id. When use want to change the link status, all NetClientStates that
belongs to the same backend/nic will be also changed. When user want to delete
a device or netdev, all NetClientStates that belongs to the same backend/nic
will be deleted also. Changing or deleting an specific queue is not allowed.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

4 files changed, 44 insertions, 12 deletions

diff --git a/hw/dp8393x.c b/hw/dp8393x.c
index 0273fad..808157b 100644
--- a/hw/dp8393x.c
+++ b/hw/dp8393x.c
@@ -900,7 +900,7 @@ void dp83932_init(NICInfo *nd, hwaddr base, int it_shift,
     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux */
 
     s->conf.macaddr = nd->macaddr;
-    s->conf.peer = nd->netdev;
+    s->conf.peers.ncs[0] = nd->netdev;
 
     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf, nd->model, nd->name, s);
 
diff --git a/hw/mcf_fec.c b/hw/mcf_fec.c
index 909e32b..8e60f09 100644
--- a/hw/mcf_fec.c
+++ b/hw/mcf_fec.c
@@ -472,7 +472,7 @@ void mcf_fec_init(MemoryRegion *sysmem, NICInfo *nd,
     memory_region_add_subregion(sysmem, base, &s->iomem);
 
     s->conf.macaddr = nd->macaddr;
-    s->conf.peer = nd->netdev;
+    s->conf.peers.ncs[0] = nd->netdev;
 
     s->nic = qemu_new_nic(&net_mcf_fec_info, &s->conf, nd->model, nd->name, s);
 
diff --git a/hw/qdev-properties-system.c b/hw/qdev-properties-system.c
index ce0f793..ce3af22 100644
--- a/hw/qdev-properties-system.c
+++ b/hw/qdev-properties-system.c
@@ -173,16 +173,47 @@ PropertyInfo qdev_prop_chr = {
 
 static int parse_netdev(DeviceState *dev, const char *str, void **ptr)
 {
-    NetClientState *netdev = qemu_find_netdev(str);
+    NICPeers *peers_ptr = (NICPeers *)ptr;
+    NICConf *conf = container_of(peers_ptr, NICConf, peers);
+    NetClientState **ncs = peers_ptr->ncs;
+    NetClientState *peers[MAX_QUEUE_NUM];
+    int queues, i = 0;
+    int ret;
 
-    if (netdev == NULL) {
-        return -ENOENT;
+    queues = qemu_find_net_clients_except(str, peers,
+                                          NET_CLIENT_OPTIONS_KIND_NIC,
+                                          MAX_QUEUE_NUM);
+    if (queues == 0) {
+        ret = -ENOENT;
+        goto err;
     }
-    if (netdev->peer) {
-        return -EEXIST;
+
+    if (queues > MAX_QUEUE_NUM) {
+        ret = -E2BIG;
+        goto err;
+    }
+
+    for (i = 0; i < queues; i++) {
+        if (peers[i] == NULL) {
+            ret = -ENOENT;
+            goto err;
+        }
+
+        if (peers[i]->peer) {
+            ret = -EEXIST;
+            goto err;
+        }
+
+        ncs[i] = peers[i];
+        ncs[i]->queue_index = i;
     }
-    *ptr = netdev;
+
+    conf->queues = queues;
+
     return 0;
+
+err:
+    return ret;
 }
 
 static const char *print_netdev(void *ptr)
@@ -249,7 +280,8 @@ static void set_vlan(Object *obj, Visitor *v, void *opaque,
 {
     DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
-    NetClientState **ptr = qdev_get_prop_ptr(dev, prop);
+    NICPeers *peers_ptr = qdev_get_prop_ptr(dev, prop);
+    NetClientState **ptr = &peers_ptr->ncs[0];
     Error *local_err = NULL;
     int32_t id;
     NetClientState *hubport;
diff --git a/hw/qdev-properties.h b/hw/qdev-properties.h
index ddcf774..20c67f3 100644
--- a/hw/qdev-properties.h
+++ b/hw/qdev-properties.h
@@ -31,7 +31,7 @@ extern PropertyInfo qdev_prop_pci_host_devaddr;
         .name      = (_name),                                    \
         .info      = &(_prop),                                   \
         .offset    = offsetof(_state, _field)                    \
-            + type_check(_type,typeof_field(_state, _field)),    \
+            + type_check(_type, typeof_field(_state, _field)),   \
         }
 #define DEFINE_PROP_DEFAULT(_name, _state, _field, _defval, _prop, _type) { \
         .name      = (_name),                                           \
@@ -77,9 +77,9 @@ extern PropertyInfo qdev_prop_pci_host_devaddr;
 #define DEFINE_PROP_STRING(_n, _s, _f)             \
     DEFINE_PROP(_n, _s, _f, qdev_prop_string, char*)
 #define DEFINE_PROP_NETDEV(_n, _s, _f)             \
-    DEFINE_PROP(_n, _s, _f, qdev_prop_netdev, NetClientState*)
+    DEFINE_PROP(_n, _s, _f, qdev_prop_netdev, NICPeers)
 #define DEFINE_PROP_VLAN(_n, _s, _f)             \
-    DEFINE_PROP(_n, _s, _f, qdev_prop_vlan, NetClientState*)
+    DEFINE_PROP(_n, _s, _f, qdev_prop_vlan, NICPeers)
 #define DEFINE_PROP_DRIVE(_n, _s, _f) \
     DEFINE_PROP(_n, _s, _f, qdev_prop_drive, BlockDriverState *)
 #define DEFINE_PROP_MACADDR(_n, _s, _f)         \