[PATCH 2/3] vdpa: load vlan configuration at NIC startup

["Eugenio Pérez" <eperezma@redhat.com>]

To have enabled vlans at device startup may happen in the destination of
a live migration, so this configuration must be restored.

At this moment the code is not accessible, since SVQ refuses to start if
vlan feature is exposed by the device.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 net/vhost-vdpa.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 4bc3fd01a8..ecbfd08eb9 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -100,6 +100,8 @@ static const uint64_t vdpa_svq_device_features =
     BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
     BIT_ULL(VIRTIO_NET_F_STANDBY);
 
+#define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
+
 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
 {
     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
@@ -423,6 +425,47 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
     return *s->status != VIRTIO_NET_OK;
 }
 
+static int vhost_vdpa_net_load_single_vlan(VhostVDPAState *s,
+                                           const VirtIONet *n,
+                                           uint16_t vid)
+{
+    ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_VLAN,
+                                                  VIRTIO_NET_CTRL_VLAN_ADD,
+                                                  &vid, sizeof(vid));
+    if (unlikely(dev_written < 0)) {
+        return dev_written;
+    }
+
+    if (unlikely(*s->status != VIRTIO_NET_OK)) {
+        return -EINVAL;
+    }
+
+    return 0;
+}
+
+static int vhost_vdpa_net_load_vlan(VhostVDPAState *s,
+                                    const VirtIONet *n)
+{
+    uint64_t features = n->parent_obj.guest_features;
+
+    if (!(features & BIT_ULL(VIRTIO_NET_F_CTRL_VLAN))) {
+        return 0;
+    }
+
+    for (int i = 0; i < MAX_VLAN >> 5; i++) {
+        for (int j = 0; n->vlans[i] && j <= 0x1f; j++) {
+            if (n->vlans[i] & (1U << j)) {
+                int r = vhost_vdpa_net_load_single_vlan(s, n, (i << 5) + j);
+                if (unlikely(r != 0)) {
+                    return r;
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
 static int vhost_vdpa_net_load(NetClientState *nc)
 {
     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
@@ -445,8 +488,7 @@ static int vhost_vdpa_net_load(NetClientState *nc)
     if (unlikely(r)) {
         return r;
     }
-
-    return 0;
+    return vhost_vdpa_net_load_vlan(s, n);
 }
 
 static NetClientInfo net_vhost_vdpa_cvq_info = {
-- 
2.31.1