From 7c06458c102ee66068c03780527fcfc9b954ad91 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Fri, 27 Jan 2023 21:44:59 +0100 Subject: [PATCH 1/2] virtio_net: disable VIRTIO_NET_F_STANDBY if VIRTIO_NET_F_MAC is not set failover relies on the MAC address to pair the primary and the standby devices: "[...] the hypervisor needs to enable VIRTIO_NET_F_STANDBY feature on the virtio-net interface and assign the same MAC address to both virtio-net and VF interfaces." Documentation/networking/net_failover.rst This patch disables the STANDBY feature if the MAC address is not provided by the hypervisor. Signed-off-by: Laurent Vivier Acked-by: Michael S. Tsirkin Signed-off-by: Jakub Kicinski --- drivers/net/virtio_net.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7e1a98430190..a2fad99b06ad 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3813,6 +3813,12 @@ static int virtnet_validate(struct virtio_device *vdev) __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU); } + if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY) && + !virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) { + dev_warn(&vdev->dev, "device advertises feature VIRTIO_NET_F_STANDBY but not VIRTIO_NET_F_MAC, disabling standby"); + __virtio_clear_bit(vdev, VIRTIO_NET_F_STANDBY); + } + return 0; } From 9f62d221a4b0aa6a8d2a18053a0ca349c025297c Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Fri, 27 Jan 2023 21:45:00 +0100 Subject: [PATCH 2/2] virtio_net: notify MAC address change on device initialization 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 Acked-by: Michael S. Tsirkin Signed-off-by: Jakub Kicinski --- 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 a2fad99b06ad..ab5c275965e2 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3931,6 +3931,8 @@ 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 */ @@ -4058,6 +4060,24 @@ 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);