[Qemu-devel] [PATCH 3/4] qemu:virtio-net: Add support for qemu_vlan_rxfilter

[Alex Williamson <alex.williamson@hp.com>]

Make use of qemu_vlan_rxfilter so that we can filter at a lower
level.  We implement callbacks for devices being added and removed
so that we can fall back to our own filtering or make another attempt
to push filtering off to someone else.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
---

 hw/virtio-net.c |   56 +++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 62153e9..3e4f526 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -35,6 +35,7 @@ typedef struct VirtIONet
     int mergeable_rx_bufs;
     int promisc;
     int allmulti;
+    int vlan_rxfilter;
     struct {
         int in_use;
         uint8_t *macs;
@@ -51,6 +52,43 @@ static VirtIONet *to_virtio_net(VirtIODevice *vdev)
     return (VirtIONet *)vdev;
 }
 
+static void virtio_net_set_vlan_rxfilter(VirtIONet *n)
+{
+    static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
+    uint8_t *buf;
+    int flags = 0;
+
+    if (n->promisc)
+        flags |= QEMU_NET_PROMISC;
+    if (n->allmulti)
+        flags |= QEMU_NET_ALLMULTI;
+
+    buf = qemu_mallocz((n->mac_table.in_use + 2) * ETH_ALEN);
+
+    memcpy(&buf[ETH_ALEN*0], n->mac, ETH_ALEN);
+    memcpy(&buf[ETH_ALEN*1], n->mac_table.macs, n->mac_table.in_use * ETH_ALEN);
+    /* broadcast is a multicast addr, so add it at the end */
+    memcpy(&buf[ETH_ALEN*(n->mac_table.in_use + 1)], bcast, ETH_ALEN);
+
+    n->vlan_rxfilter = qemu_vlan_rxfilter(n->vc, flags,
+                                          n->mac_table.in_use + 2, buf);
+    qemu_free(buf);
+}
+
+static void virtio_net_vlan_client_added(void *opaque)
+{
+    VirtIONet *n = opaque;
+
+    n->vlan_rxfilter = 0;
+}
+
+static void virtio_net_vlan_client_removed(void *opaque)
+{
+    VirtIONet *n = opaque;
+
+    virtio_net_set_vlan_rxfilter(n);
+}
+
 static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
 {
     VirtIONet *n = to_virtio_net(vdev);
@@ -70,6 +108,7 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
 
     if (memcmp(netcfg.mac, n->mac, ETH_ALEN)) {
         memcpy(n->mac, netcfg.mac, ETH_ALEN);
+        virtio_net_set_vlan_rxfilter(n);
         qemu_format_nic_info_str(n->vc, n->mac);
     }
 }
@@ -99,6 +138,7 @@ static void virtio_net_reset(VirtIODevice *vdev)
     /* Flush any MAC and VLAN filter table state */
     n->mac_table.in_use = 0;
     memset(n->mac_table.macs, 0, MAC_TABLE_ENTRIES * ETH_ALEN);
+    virtio_net_set_vlan_rxfilter(n);
     memset(n->vlans, 0, MAX_VLAN >> 3);
 }
 
@@ -247,6 +287,10 @@ static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
 
         virtqueue_push(vq, &elem, sizeof(status));
         virtio_notify(vdev, vq);
+
+        if (ctrl.class == VIRTIO_NET_CTRL_RX_MODE ||
+            ctrl.class == VIRTIO_NET_CTRL_MAC)
+            virtio_net_set_vlan_rxfilter(n);
     }
 }
 
@@ -334,15 +378,19 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
             return 0;
     }
 
-    if ((ptr[0] & 1) && n->allmulti)
+    /* If hw filtering is complete, no need to continue */
+    if (n->vlan_rxfilter)
         return 1;
 
-    if (!memcmp(ptr, bcast, sizeof(bcast)))
+    if ((ptr[0] & 1) && n->allmulti)
         return 1;
 
     if (!memcmp(ptr, n->mac, ETH_ALEN))
         return 1;
 
+    if (!memcmp(ptr, bcast, sizeof(bcast)))
+        return 1;
+
     for (i = 0; i < n->mac_table.in_use; i++) {
         if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN))
             return 1;
@@ -552,6 +600,8 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
     if (version_id >= 6)
         qemu_get_buffer(f, (uint8_t *)n->vlans, MAX_VLAN >> 3);
 
+    virtio_net_set_vlan_rxfilter(n);
+
     if (n->tx_timer_active) {
         qemu_mod_timer(n->tx_timer,
                        qemu_get_clock(vm_clock) + TX_TIMER_INTERVAL);
@@ -589,6 +639,8 @@ void virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
     n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,
                                  virtio_net_receive, virtio_net_can_receive, n);
     n->vc->link_status_changed = virtio_net_set_link_status;
+    n->vc->vlan_client_added = virtio_net_vlan_client_added;
+    n->vc->vlan_client_removed = virtio_net_vlan_client_removed;
 
     qemu_format_nic_info_str(n->vc, n->mac);