Re: [PATCH net-next v3 3/3] selftests: ethtool: Introduce ethernet PHY selftests on netdevsim

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 10 Jul 2025 08:22:47 +0200 Maxime Chevallier wrote:
> +set -o pipefail
> +
> +# Check simple PHY addition and listing
> +
> +# Parent == 0 means that the PHY's parent is the netdev
> +PHY_DFS=$(make_phydev_on_netdev "$NSIM_ID" 0)
> +
> +# First PHY gets index 1
> +index=$(ethtool --show-phys "$NSIM_NETDEV" | grep "PHY index" | cut -d ' ' -f 3)
> +check $? "$index" "1"
> +
> +# Insert a second PHY, same parent. It gets index 2.
> +PHY2_DFS=$(make_phydev_on_netdev "$NSIM_ID" 0)
> +
> +# Create another netdev
> +NSIM_ID2=$((RANDOM % 1024))
> +NSIM_NETDEV_2=$(make_netdev_from_id "$NSIM_ID2")
> +
> +PHY3_DFS=$(make_phydev_on_netdev "$NSIM_ID2" 0);
> +
> +# Check unfiltered PHY Dump
> +n_phy=$(ethtool --show-phys '*' | grep -c "PHY index")
> +check $? "$n_phy" "3"
> +
> +# Check filtered Dump
> +n_phy=$(ethtool --show-phys "$NSIM_NETDEV" | grep -c "PHY index")
> +check $? "$n_phy" "2"

Not a very strong preference, but I wonder if we should wire up the
paths to the Python lib for drivers/net/netdevsim and switch to Python?
It does the setup and cleanup and it gives us direct YNL access.
More convenient for testing new stuff than jugging ethtool builds..
But I guess you could argue that testing the CLI is good in itself.