[PATCH v2 3/4] virtio_net: Add a MAC filter table

Alex Williamson
2009-01-29T23:05:18Z

Make use of the MAC control virtqueue class to support a MAC
filter table. The filter table is managed by the hypervisor.
We consider the table to be available if the CTRL_MAC feature
bit is set. We leave it to the hypervisor to manage the table
and enable promiscuous or all-multi mode as necessary depending
on the resources available to it.

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

drivers/net/virtio_net.c | 89 +++++++++++++++++++++++++++++++++++++++++++-
include/linux/virtio_net.h | 17 ++++++++
2 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index b247558..23610ce 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -664,12 +664,22 @@ static void virtnet_set_rx_mode(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
u8 promisc, allmulti;
+ struct scatterlist sg[4];
+ struct virtio_net_ctrl_hdr ctrl;
+ virtio_net_ctrl_ack status;
+ u8 *uc_buf = NULL, *mc_buf = NULL;
+ unsigned int tmp;

if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_RX))
return;

- promisc = ((dev->flags & IFF_PROMISC) != 0 || dev->uc_count > 0);
- allmulti = ((dev->flags & IFF_ALLMULTI) != 0 || dev->mc_count > 0);
+ promisc = ((dev->flags & IFF_PROMISC) != 0);
+ allmulti = ((dev->flags & IFF_ALLMULTI) != 0);
+
+ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_MAC)) {
+ promisc |= (dev->uc_count > 0);
+ allmulti |= (dev->mc_count > 0);
+ }

if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_RX,
VIRTIO_NET_CTRL_RX_PROMISC,
@@ -682,6 +692,79 @@ static void virtnet_set_rx_mode(struct net_device *dev)
&allmulti, sizeof(allmulti)))
printk(KERN_WARNING "%s: Failed to %sable allmulti mode.\n",
dev->name, allmulti ? "en" : "dis");
+
+ if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_MAC))
+ return;
+
+ sg_init_table(sg, 4);
+
+ sg_set_buf(&sg[0], &ctrl, sizeof(ctrl));
+ sg_set_buf(&sg[3], &status, sizeof(status));
+
+ ctrl.class = VIRTIO_NET_CTRL_MAC;
+ ctrl.cmd = VIRTIO_NET_CTRL_MAC_TABLE_SET;
+
+ status = ~0;
+
+ if (dev->uc_count) {
+ u8 *cur;
+ struct dev_addr_list *uc;
+ int i;
+
+ cur = uc_buf = kzalloc(dev->uc_count * ETH_ALEN, GFP_ATOMIC);
+ if (!uc_buf) {
+ printk(KERN_WARNING "%s: No memory for UC list\n",
+ dev->name);
+ return;
+ }
+
+ uc = dev->uc_list;
+ for (i = 0; i < dev->uc_count; i++) {
+ memcpy(cur, uc->da_addr, ETH_ALEN);
+ cur += ETH_ALEN;
+ uc = uc->next;
+ }
+
+ sg_set_buf(&sg[1], uc_buf, dev->uc_count * ETH_ALEN);
+ }
+
+ if (dev->mc_count) {
+ u8 *cur;
+ struct dev_addr_list *mc;
+ int i;
+
+ cur = mc_buf = kzalloc(dev->mc_count * ETH_ALEN, GFP_ATOMIC);
+ if (!mc_buf) {
+ printk(KERN_WARNING "%s: No memory for MC list\n",
+ dev->name);
+ goto free_uc;
+ }
+
+ mc = dev->mc_list;
+ for (i = 0; i < dev->mc_count; i++) {
+ memcpy(cur, mc->da_addr, ETH_ALEN);
+ cur += ETH_ALEN;
+ mc = mc->next;
+ }
+
+ sg_set_buf(&sg[2], mc_buf, dev->mc_count * ETH_ALEN);
+ }
+
+ if (vi->cvq->vq_ops->add_buf(vi->cvq, sg, 3, 1, vi) != 0)
+ BUG();
+
+ vi->cvq->vq_ops->kick(vi->cvq);
+
+ while (!vi->cvq->vq_ops->get_buf(vi->cvq, &tmp))
+ cpu_relax();
+
+ if (status != VIRTIO_NET_OK)
+ printk(KERN_WARNING "%s: Failed to set MAC filter table (%d)\n",
+ dev->name, status);
+
+ kfree(mc_buf);
+free_uc:
+ kfree(uc_buf);
}

static struct ethtool_ops virtnet_ethtool_ops = {
@@ -927,7 +1010,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,
VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */
VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
- VIRTIO_NET_F_CTRL_RX,
+ VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_MAC,
VIRTIO_F_NOTIFY_ON_EMPTY,
};

diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index aac09ec..c8e945a 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -24,6 +24,7 @@
#define VIRTIO_NET_F_STATUS 16 /* virtio_net_config.status available */
#define VIRTIO_NET_F_CTRL_VQ 17 /* Control channel available */
#define VIRTIO_NET_F_CTRL_RX 18 /* Control channel RX mode support */
+#define VIRTIO_NET_F_CTRL_MAC 19 /* Control channel MAC filtering */

#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */

@@ -86,4 +87,20 @@ typedef __u8 virtio_net_ctrl_ack;
#define VIRTIO_NET_CTRL_RX_PROMISC 0
#define VIRTIO_NET_CTRL_RX_ALLMULTI 1

+/*
+ * Control the MAC filter table.
+ *
+ * The MAC filter table is managed by the hypervisor, the guest should
+ * assume the size is infinite. Filtering should be considered
+ * non-perfect, ie. based on hypervisor resources, the guest may
+ * received packets from sources not specified in the filter list.
+ *
+ * In addition to the class/cmd header, the TABLE_SET command requires
+ * two out scatterlists. The first is a concatenated byte stream of the
+ * ETH_ALEN unicast MAC addresses for the table, the second is the same
+ * for multicast addresses.
+ */
+#define VIRTIO_NET_CTRL_MAC 1
+ #define VIRTIO_NET_CTRL_MAC_TABLE_SET 0
+
#endif /* _LINUX_VIRTIO_NET_H */