Re: xdp generic default option

Lorenzo Bianconi [off-list ref] writes:

Hi Andrii,

working on xdp multi-buff I figured out now xdp generic is the default choice
if not specified by userspace. In particular after commit 7f0a838254bd
("bpf, xdp: Maintain info on attached XDP BPF programs in net_device"), running
the command below, XDP will run in generic mode even if the underlay driver
support XDP in native mode:

$ip link set dev eth0 xdp obj prog.o
$ip link show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdpgeneric qdisc mq state UP mode DEFAULT
   group default qlen 1024
   link/ether f0:ad:4e:09:6b:57 brd ff:ff:ff:ff:ff:ff
   prog/xdp id 1 tag 3b185187f1855c4c jited

Yeah, defaulting to xdpgeneric is not a good idea (and a change in
behaviour; I get native mode on the same command on a 5.8 kernel)...

-Toke