[PATCH] vdpa/mlx5: Use random MAC address when no nic vport MAC set

From: Dragos Tatulea
Date: Tue Aug 27 2024 - 12:03:41 EST


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);
}

if (!is_zero_ether_addr(config->mac)) {
--
2.45.1