[RFC PATCH 2/2] virtio-net: introduce a new control to set macaddr

akong
2013-01-10T14:45:47Z

From: Amos Kong <akong@redhat.com>

Currently we write MAC address to pci config space byte by byte,
this means that we have an intermediate step where mac is wrong.
This patch introduced a new control command to set MAC address
in one time.

VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility.

Signed-off-by: Amos Kong <akong@redhat.com>
---
drivers/net/virtio_net.c | 16 +++++++++++++++-
include/uapi/linux/virtio_net.h | 8 +++++++-
2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 395ab4f..ff22bcd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p)
struct virtio_device *vdev = vi->vdev;
int ret;

+ struct scatterlist sg;
+
ret = eth_mac_addr(dev, p);
if (ret)
return ret;

- if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC))
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) {
+ /* Set MAC address by sending vq command */
+ sg_init_one(&sg, dev->dev_addr, dev->addr_len);
+ virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC,
+ VIRTIO_NET_CTRL_MAC_ADDR_SET,
+ &sg, 1, 0);
+ return 0;
+ }
+
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) {
+ /* Set MAC address by writing config space */
vdev->config->set(vdev, offsetof(struct virtio_net_config, mac),
dev->dev_addr, dev->addr_len);
+ }

return 0;
}
@@ -1627,6 +1640,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS, VIRTIO_NET_F_CTRL_VQ,
VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
+ VIRTIO_NET_F_CTRL_MAC_ADDR,
};

static struct virtio_driver virtio_net_driver = {
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 848e358..a5a8c88 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -53,6 +53,7 @@
* network */
#define VIRTIO_NET_F_MQ 22 /* Device supports Receive Flow
* Steering */
+#define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */

#define VIRTIO_NET_S_LINK_UP 1 /* Link is up */
#define VIRTIO_NET_S_ANNOUNCE 2 /* Announcement is needed */
@@ -127,7 +128,7 @@ typedef __u8 virtio_net_ctrl_ack;
#define VIRTIO_NET_CTRL_RX_NOBCAST 5

/*
- * Control the MAC filter table.
+ * Control the MAC
*
* The MAC filter table is managed by the hypervisor, the guest should
* assume the size is infinite. Filtering should be considered
@@ -140,6 +141,10 @@ typedef __u8 virtio_net_ctrl_ack;
* first sg list contains unicast addresses, the second is for multicast.
* This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
* is available.
+ *
+ * The ADDR_SET command requests one out scatterlist, it contains a
+ * 6 bytes MAC address. This functionality is present if the
+ * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
*/
struct virtio_net_ctrl_mac {
__u32 entries;
@@ -148,6 +153,7 @@ struct virtio_net_ctrl_mac {

#define VIRTIO_NET_CTRL_MAC 1
#define VIRTIO_NET_CTRL_MAC_TABLE_SET 0
+ #define VIRTIO_NET_CTRL_MAC_ADDR_SET 1

/*
* Control VLAN filtering
--
1.7.11.7