On 8/27/2024 9:02 AM, Dragos Tatulea wrote:
When the vdpa device is configured without a specific MAC
address, the vport MAC address is used. However, this
address can be 0 which prevents the driver from properly
configuring the MPFS and breaks steering.
The solution is to simply generate a random MAC address
when no MAC is set on the nic vport.
Now it's possible to create a vdpa device without a
MAC address and run qemu with this device without needing
to configure an explicit MAC address.
Signed-off-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index fa78e8288ebb..1c26139d02fe 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3824,6 +3824,9 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac);
if (err)
goto err_alloc;
+
+ if (is_zero_ether_addr(config->mac))
+ eth_random_addr(config->mac);
I wonder with this change we no longer honor the historical behaviour to
retain the zero mac address and clear the _F_MAC bit, should we head to
remove the below logic? It looks to me below would become dead code
effectively.
} else if ((add_config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES))
== 0) {
/*
* We used to clear _F_MAC feature bit if seeing
* zero mac address when device features are not
* specifically provisioned. Keep the behaviour
* so old scripts do not break.
*/
device_features &= ~BIT_ULL(VIRTIO_NET_F_MAC);
If we are not going to honor old behaviour any more, looks to me we
should also block users from creating vdpa device with zero mac address,
if the mac attribute is specified. There's more sorrow than help the
zero mac address could buy for users.
if (add_config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR)) {
memcpy(ndev->config.mac, add_config->net.mac, ETH_ALEN);
Regards,
-Siwei
}
if (!is_zero_ether_addr(config->mac)) {
