From: Laurent Vivier lvivier@redhat.com
[ Upstream commit 9f62d221a4b0aa6a8d2a18053a0ca349c025297c ]
In virtnet_probe(), if the device doesn't provide a MAC address the driver assigns a random one. As we modify the MAC address we need to notify the device to allow it to update all the related information.
The problem can be seen with vDPA and mlx5_vdpa driver as it doesn't assign a MAC address by default. The virtio_net device uses a random MAC address (we can see it with "ip link"), but we can't ping a net namespace from another one using the virtio-vdpa device because the new MAC address has not been provided to the hardware: RX packets are dropped since they don't go through the receive filters, TX packets go through unaffected.
Signed-off-by: Laurent Vivier lvivier@redhat.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 51b813176f09 ("virtio-net: set queues after driver_ok") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/virtio_net.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 075d5d42f5eb6..b7a4df4bab817 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3825,6 +3825,8 @@ static int virtnet_probe(struct virtio_device *vdev) eth_hw_addr_set(dev, addr); } else { eth_hw_addr_random(dev); + dev_info(&vdev->dev, "Assigned random MAC address %pM\n", + dev->dev_addr); }
/* Set up our device-specific information */ @@ -3954,6 +3956,24 @@ static int virtnet_probe(struct virtio_device *vdev)
virtio_device_ready(vdev);
+ /* a random MAC address has been assigned, notify the device. + * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there + * because many devices work fine without getting MAC explicitly + */ + if (!virtio_has_feature(vdev, VIRTIO_NET_F_MAC) && + virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { + struct scatterlist sg; + + sg_init_one(&sg, dev->dev_addr, dev->addr_len); + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, + VIRTIO_NET_CTRL_MAC_ADDR_SET, &sg)) { + pr_debug("virtio_net: setting MAC address failed\n"); + rtnl_unlock(); + err = -EINVAL; + goto free_unregister_netdev; + } + } + rtnl_unlock();
err = virtnet_cpu_notif_add(vi);