[5/5] virtio_net: Add support for VLAN filtering in the hypervisor
diff mbox

Message ID 20090116211339.22836.51815.stgit@debian.lart
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Alex Williamson Jan. 16, 2009, 9:13 p.m. UTC
VLAN filtering allows the hypervisor to drop packets from VLANs
that we're not a part of, further reducing the number of extraneous
packets recieved.  This makes use of the VLAN virtqueue command class.
The ENABLE command is used both to activate the filter and verify the
existence of the functionality on the backend.

Also, this fixes a sizing issue for MAX_PACKET_LEN when using VLANs.
VLANS add 4 bytes of header, resulting in a maximum full packet size
of 1518 bytes (destination MAC + source MAC + VLAN + ethernet type +
MTU).  Withouth this, a VLAN over virtio_net is likely to get a
truncation error in the backend.

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

 drivers/net/virtio_net.c   |   52 ++++++++++++++++++++++++++++++++++++--------
 include/linux/virtio_net.h |   15 +++++++++++++
 2 files changed, 58 insertions(+), 9 deletions(-)


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Comments

Mark McLoughlin Jan. 19, 2009, 9:32 a.m. UTC | #1
Hi Alex,

On Fri, 2009-01-16 at 14:13 -0700, Alex Williamson wrote:
> VLAN filtering allows the hypervisor to drop packets from VLANs
> that we're not a part of, further reducing the number of extraneous
> packets recieved.  This makes use of the VLAN virtqueue command class.
> The ENABLE command is used both to activate the filter and verify the
> existence of the functionality on the backend.
> 
> Also, this fixes a sizing issue for MAX_PACKET_LEN when using VLANs.
> VLANS add 4 bytes of header, resulting in a maximum full packet size
> of 1518 bytes (destination MAC + source MAC + VLAN + ethernet type +
> MTU).  Withouth this, a VLAN over virtio_net is likely to get a
> truncation error in the backend.

Looks good, but could you split the MAX_PACKET_LEN change out to a
separate patch, send to davem for 2.6.29. We should also get this into
stable.

> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 9be0d6a..8d4bc83 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -24,6 +24,7 @@
>  #include <linux/virtio.h>
>  #include <linux/virtio_net.h>
>  #include <linux/scatterlist.h>
> +#include <linux/if_vlan.h>
>  
>  static int napi_weight = 128;
>  module_param(napi_weight, int, 0444);
> @@ -38,7 +39,7 @@ MODULE_PARM_DESC(mac_entries,
>  	"Number of entries in the MAC filter table.");
>  
>  /* FIXME: MTU in config. */
> -#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
> +#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
>  #define GOOD_COPY_LEN	128
>  
>  struct virtnet_info
> @@ -743,6 +744,28 @@ set_mode:
>  		       dev->name, allmulti ? "en" : "dis");
>  }
>  
> +static void virnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
> +{
> +	struct virtnet_info *vi = netdev_priv(dev);
> +        u16 id = vid;

Indentation mixup.

> +
> +	if (virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
> +				 VIRTIO_NET_CTRL_VLAN_ADD, &id, sizeof(id)))
> +		printk(KERN_WARNING "%s: Failed to add VLAN ID %d.\n",
> +		       dev->name, id);
> +}
> +
> +static void virnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
> +{
> +	struct virtnet_info *vi = netdev_priv(dev);
> +        u16 id = vid;

Ditto.

> +
> +	if (virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
> +				 VIRTIO_NET_CTRL_VLAN_KILL, &id, sizeof(id)))
> +		printk(KERN_WARNING "%s: Failed to kill VLAN ID %d.\n",
> +		       dev->name, id);
> +}
> +
>  static struct ethtool_ops virtnet_ethtool_ops = {
>  	.set_tx_csum = virtnet_set_tx_csum,
>  	.set_sg = ethtool_op_set_sg,
> @@ -761,15 +784,17 @@ static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
>  }
>  
>  static const struct net_device_ops virtnet_netdev = {
> -	.ndo_open            = virtnet_open,
> -	.ndo_stop   	     = virtnet_close,
> -	.ndo_start_xmit      = start_xmit,
> -	.ndo_validate_addr   = eth_validate_addr,
> -	.ndo_set_mac_address = virtnet_set_mac_address,
> -	.ndo_set_rx_mode     = virtnet_set_rx_mode,
> -	.ndo_change_mtu	     = virtnet_change_mtu,
> +	.ndo_open             = virtnet_open,
> +	.ndo_stop   	      = virtnet_close,
> +	.ndo_start_xmit       = start_xmit,
> +	.ndo_validate_addr    = eth_validate_addr,
> +	.ndo_set_mac_address  = virtnet_set_mac_address,
> +	.ndo_set_rx_mode      = virtnet_set_rx_mode,
> +	.ndo_change_mtu	      = virtnet_change_mtu,
> +	.ndo_vlan_rx_add_vid  = virnet_vlan_rx_add_vid,
> +	.ndo_vlan_rx_kill_vid = virnet_vlan_rx_kill_vid,
>  #ifdef CONFIG_NET_POLL_CONTROLLER
> -	.ndo_poll_controller = virtnet_netpoll,
> +	.ndo_poll_controller  = virtnet_netpoll,
>  #endif
>  };
>  
> @@ -863,6 +888,7 @@ static int virtnet_probe(struct virtio_device *vdev)
>  		vi->cvq = NULL;
>  	else {
>  		unsigned int entries;
> +		u8 vlan_filter = 1;
>  
>  		/*
>  		 * We use a separate stack variable here because the
> @@ -878,6 +904,14 @@ static int virtnet_probe(struct virtio_device *vdev)
>  			       "MAC filter table allocation failed.\n");
>  			mac_entries = 0;
>  		}
> +
> +		/* Enable VLAN filtering if supported by the backend */
> +		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
> +					  VIRTIO_NET_CTRL_VLAN_ENABLE,
> +					  &vlan_filter, sizeof(vlan_filter))) {
> +			printk(KERN_INFO "virtio_net: VLAN filter enabled\n");

Do we need this KERN_INFO? KERN_DEBUG, maybe?

> +			dev->features |= NETIF_F_HW_VLAN_FILTER;
> +		}
>  	}
>  
>  	/* Initialize our empty receive and send queues. */
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 84086a6..a95028d 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -99,4 +99,19 @@ typedef __u8 virtio_net_ctrl_ack;
>   #define VIRTIO_NET_CTRL_MAC_TABLE_ALLOC      0
>   #define VIRTIO_NET_CTRL_MAC_TABLE_SET        1
>  
> +/*
> + * Control VLAN filtering
> + *
> + * The VLAN filter table is controlled via a simple ADD/KILL interface.
> + * VLAN IDs not added will be dropped.  Kill is the opposite of add.
> + * Both commands expect an out entry containing a 2 byte VLAN ID.
> + * The ENABLE command expects an out entry containing a single byte,
> + * zero to disable, non-zero to enable.  The default state is disabled
> + * for compatibility.
> + */
> +#define VIRTIO_NET_CTRL_VLAN       2
> + #define VIRTIO_NET_CTRL_VLAN_ENABLE          0
> + #define VIRTIO_NET_CTRL_VLAN_ADD             1
> + #define VIRTIO_NET_CTRL_VLAN_KILL            2

Not too keen on "kill" - it matches the linux API, but "remove" or
"delete" is probably more sensible.

Cheers,
Mark.

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Patch
diff mbox

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 9be0d6a..8d4bc83 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -24,6 +24,7 @@ 
 #include <linux/virtio.h>
 #include <linux/virtio_net.h>
 #include <linux/scatterlist.h>
+#include <linux/if_vlan.h>
 
 static int napi_weight = 128;
 module_param(napi_weight, int, 0444);
@@ -38,7 +39,7 @@  MODULE_PARM_DESC(mac_entries,
 	"Number of entries in the MAC filter table.");
 
 /* FIXME: MTU in config. */
-#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
+#define MAX_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
 #define GOOD_COPY_LEN	128
 
 struct virtnet_info
@@ -743,6 +744,28 @@  set_mode:
 		       dev->name, allmulti ? "en" : "dis");
 }
 
+static void virnet_vlan_rx_add_vid(struct net_device *dev, u16 vid)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+        u16 id = vid;
+
+	if (virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
+				 VIRTIO_NET_CTRL_VLAN_ADD, &id, sizeof(id)))
+		printk(KERN_WARNING "%s: Failed to add VLAN ID %d.\n",
+		       dev->name, id);
+}
+
+static void virnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+        u16 id = vid;
+
+	if (virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
+				 VIRTIO_NET_CTRL_VLAN_KILL, &id, sizeof(id)))
+		printk(KERN_WARNING "%s: Failed to kill VLAN ID %d.\n",
+		       dev->name, id);
+}
+
 static struct ethtool_ops virtnet_ethtool_ops = {
 	.set_tx_csum = virtnet_set_tx_csum,
 	.set_sg = ethtool_op_set_sg,
@@ -761,15 +784,17 @@  static int virtnet_change_mtu(struct net_device *dev, int new_mtu)
 }
 
 static const struct net_device_ops virtnet_netdev = {
-	.ndo_open            = virtnet_open,
-	.ndo_stop   	     = virtnet_close,
-	.ndo_start_xmit      = start_xmit,
-	.ndo_validate_addr   = eth_validate_addr,
-	.ndo_set_mac_address = virtnet_set_mac_address,
-	.ndo_set_rx_mode     = virtnet_set_rx_mode,
-	.ndo_change_mtu	     = virtnet_change_mtu,
+	.ndo_open             = virtnet_open,
+	.ndo_stop   	      = virtnet_close,
+	.ndo_start_xmit       = start_xmit,
+	.ndo_validate_addr    = eth_validate_addr,
+	.ndo_set_mac_address  = virtnet_set_mac_address,
+	.ndo_set_rx_mode      = virtnet_set_rx_mode,
+	.ndo_change_mtu	      = virtnet_change_mtu,
+	.ndo_vlan_rx_add_vid  = virnet_vlan_rx_add_vid,
+	.ndo_vlan_rx_kill_vid = virnet_vlan_rx_kill_vid,
 #ifdef CONFIG_NET_POLL_CONTROLLER
-	.ndo_poll_controller = virtnet_netpoll,
+	.ndo_poll_controller  = virtnet_netpoll,
 #endif
 };
 
@@ -863,6 +888,7 @@  static int virtnet_probe(struct virtio_device *vdev)
 		vi->cvq = NULL;
 	else {
 		unsigned int entries;
+		u8 vlan_filter = 1;
 
 		/*
 		 * We use a separate stack variable here because the
@@ -878,6 +904,14 @@  static int virtnet_probe(struct virtio_device *vdev)
 			       "MAC filter table allocation failed.\n");
 			mac_entries = 0;
 		}
+
+		/* Enable VLAN filtering if supported by the backend */
+		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_VLAN,
+					  VIRTIO_NET_CTRL_VLAN_ENABLE,
+					  &vlan_filter, sizeof(vlan_filter))) {
+			printk(KERN_INFO "virtio_net: VLAN filter enabled\n");
+			dev->features |= NETIF_F_HW_VLAN_FILTER;
+		}
 	}
 
 	/* Initialize our empty receive and send queues. */
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 84086a6..a95028d 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -99,4 +99,19 @@  typedef __u8 virtio_net_ctrl_ack;
  #define VIRTIO_NET_CTRL_MAC_TABLE_ALLOC      0
  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        1
 
+/*
+ * Control VLAN filtering
+ *
+ * The VLAN filter table is controlled via a simple ADD/KILL interface.
+ * VLAN IDs not added will be dropped.  Kill is the opposite of add.
+ * Both commands expect an out entry containing a 2 byte VLAN ID.
+ * The ENABLE command expects an out entry containing a single byte,
+ * zero to disable, non-zero to enable.  The default state is disabled
+ * for compatibility.
+ */
+#define VIRTIO_NET_CTRL_VLAN       2
+ #define VIRTIO_NET_CTRL_VLAN_ENABLE          0
+ #define VIRTIO_NET_CTRL_VLAN_ADD             1
+ #define VIRTIO_NET_CTRL_VLAN_KILL            2
+
 #endif /* _LINUX_VIRTIO_NET_H */