[Qemu-devel] [PATCH] virtio-net: only output the vlan table when VIRTIO_NET_F_CTRL_VLAN is negotiated

[Amos Kong <akong@redhat.com>]

Stefan Fritsch just fixed a virtio-net driver bug [1], virtio-net won't
filter out VLAN-tagged packets if VIRTIO_NET_F_CTRL_VLAN isn't negotiated.

We should also not send the vlan table to management, this patch makes
the vlan-talbe optional.

[1] http://lists.nongnu.org/archive/html/qemu-devel/2014-02/msg02604.html

Signed-off-by: Amos Kong <akong@redhat.com>
---
 hw/net/virtio-net.c | 38 +++++++++++++++++++++++++-------------
 qapi-schema.json    |  4 ++--
 qmp-commands.hx     |  2 +-
 3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3626608..0b32e6a 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -222,13 +222,33 @@ static char *mac_strdup_printf(const uint8_t *mac)
                             mac[1], mac[2], mac[3], mac[4], mac[5]);
 }
 
+static intList *get_vlan_table(VirtIONet *n)
+{
+    intList *list, *entry;
+    int i, j;
+
+    list = NULL;
+    for (i = 0; i < MAX_VLAN >> 5; i++) {
+        for (j = 0; n->vlans[i] && j < 0x1f; j++) {
+            if (n->vlans[i] & (1U << j)) {
+                entry = g_malloc0(sizeof(*entry));
+                entry->value = (i << 5) + j;
+                entry->next = list;
+                list = entry;
+            }
+        }
+    }
+
+    return list;
+}
+
 static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
+    VirtIODevice *vdev = VIRTIO_DEVICE(n);
     RxFilterInfo *info;
     strList *str_list, *entry;
-    intList *int_list, *int_entry;
-    int i, j;
+    int i;
 
     info = g_malloc0(sizeof(*info));
     info->name = g_strdup(nc->name);
@@ -274,18 +294,10 @@ static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
     }
     info->multicast_table = str_list;
 
-    int_list = NULL;
-    for (i = 0; i < MAX_VLAN >> 5; i++) {
-        for (j = 0; n->vlans[i] && j < 0x1f; j++) {
-            if (n->vlans[i] & (1U << j)) {
-                int_entry = g_malloc0(sizeof(*int_entry));
-                int_entry->value = (i << 5) + j;
-                int_entry->next = int_list;
-                int_list = int_entry;
-            }
-        }
+    if ((1 << VIRTIO_NET_F_CTRL_VLAN) & vdev->guest_features) {
+        info->has_vlan_table = true;
+        info->vlan_table = get_vlan_table(n);
     }
-    info->vlan_table = int_list;
 
     /* enable event notification after query */
     nc->rxfilter_notify_enabled = 1;
diff --git a/qapi-schema.json b/qapi-schema.json
index 7cfb5e5..5d48fa9 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4034,7 +4034,7 @@
 #
 # @main-mac: the main macaddr string
 #
-# @vlan-table: a list of active vlan id
+# @vlan-table: #optional a list of active vlan id
 #
 # @unicast-table: a list of unicast macaddr string
 #
@@ -4053,7 +4053,7 @@
     'multicast-overflow': 'bool',
     'unicast-overflow':   'bool',
     'main-mac':           'str',
-    'vlan-table':         ['int'],
+    '*vlan-table':         ['int'],
     'unicast-table':      ['str'],
     'multicast-table':    ['str'] }}
 
diff --git a/qmp-commands.hx b/qmp-commands.hx
index cce6b81..a1c1dfa 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3308,7 +3308,7 @@ Each array entry contains the following:
 - "multicast-overflow": multicast table is overflowed (json-bool)
 - "unicast-overflow": unicast table is overflowed (json-bool)
 - "main-mac": main macaddr string (json-string)
-- "vlan-table": a json-array of active vlan id
+- "vlan-table": a json-array of active vlan id (optoinal)
 - "unicast-table": a json-array of unicast macaddr string
 - "multicast-table": a json-array of multicast macaddr string
 
-- 
1.8.5.3