A summary of the flags being set for various drivers is given below.
Note that XDP_F_REDIRECT_TARGET and XDP_F_FRAG_TARGET are features
that can be turned off and on at runtime. This means that these flags
may be set and unset under RTNL lock protection by the driver. Hence,
READ_ONCE must be used by code loading the flag value.

Also, these flags are not used for synchronization against the availability
of XDP resources on a device. It is merely a hint, and hence the read
may race with the actual teardown of XDP resources on the device. This
may change in the future, e.g. operations taking a reference on the XDP
resources of the driver, and in turn inhibiting turning off this flag.
However, for now, it can only be used as a hint to check whether device
supports becoming a redirection target.

Turn 'hw-offload' feature flag on for:
 - netronome (nfp)
 - netdevsim.

Turn 'native' and 'zerocopy' features flags on for:
 - intel (i40e, ice, ixgbe, igc)
 - mellanox (mlx5).
 - stmmac
 - netronome (nfp)

Turn 'native' features flags on for:
 - amazon (ena)
 - broadcom (bnxt)
 - freescale (dpaa, dpaa2, enetc)
 - funeth
 - intel (igb)
 - marvell (mvneta, mvpp2, octeontx2)
 - mellanox (mlx4)
 - mtk_eth_soc
 - qlogic (qede)
 - sfc
 - socionext (netsec)
 - ti (cpsw)
 - tap
 - tsnep
 - veth
 - xen
 - virtio_net.

Turn 'basic' (tx, pass, aborted and drop) features flags on for:
 - netronome (nfp)
 - cavium (thunder)
 - hyperv.

Turn 'redirect_target' feature flag on for:
 - amanzon (ena)
 - broadcom (bnxt)
 - freescale (dpaa, dpaa2)
 - intel (i40e, ice, igb, ixgbe)
 - ti (cpsw)
 - marvell (mvneta, mvpp2)
 - sfc
 - socionext (netsec)
 - qlogic (qede)
 - mellanox (mlx5)
 - tap
 - veth
 - virtio_net
 - xen
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Marek Majtyka <alardam@gmail.com>
Link: https://lore.kernel.org/r/3eca9fafb308462f7edb1f58e451d59209aa07eb.1675245258.git.lorenzo@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>