bpf: cpumap: Implement XDP_REDIRECT for eBPF programs attached to map entries

Introduce XDP_REDIRECT support for eBPF programs attached to cpumap
entries.
This patch has been tested on Marvell ESPRESSObin using a modified
version of xdp_redirect_cpu sample in order to attach a XDP program
to CPUMAP entries to perform a redirect on the mvneta interface.
In particular the following scenario has been tested:

rq (cpu0) --> mvneta - XDP_REDIRECT (cpu0) --> CPUMAP - XDP_REDIRECT (cpu1) --> mvneta

$./xdp_redirect_cpu -p xdp_cpu_map0 -d eth0 -c 1 -e xdp_redirect \
	-f xdp_redirect_kern.o -m tx_port -r eth0

tx: 285.2 Kpps rx: 285.2 Kpps

Attaching a simple XDP program on eth0 to perform XDP_TX gives
comparable results:

tx: 288.4 Kpps rx: 288.4 Kpps

Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org
This commit is contained in:
Lorenzo Bianconi 2020-07-14 15:56:39 +02:00 committed by Daniel Borkmann
parent 9216477449
commit 28b1520ebf
3 changed files with 20 additions and 4 deletions

View File

@ -99,6 +99,7 @@ struct xdp_frame {
}; };
struct xdp_cpumap_stats { struct xdp_cpumap_stats {
unsigned int redirect;
unsigned int pass; unsigned int pass;
unsigned int drop; unsigned int drop;
}; };

View File

@ -190,6 +190,7 @@ TRACE_EVENT(xdp_cpumap_kthread,
__field(int, sched) __field(int, sched)
__field(unsigned int, xdp_pass) __field(unsigned int, xdp_pass)
__field(unsigned int, xdp_drop) __field(unsigned int, xdp_drop)
__field(unsigned int, xdp_redirect)
), ),
TP_fast_assign( TP_fast_assign(
@ -201,18 +202,19 @@ TRACE_EVENT(xdp_cpumap_kthread,
__entry->sched = sched; __entry->sched = sched;
__entry->xdp_pass = xdp_stats->pass; __entry->xdp_pass = xdp_stats->pass;
__entry->xdp_drop = xdp_stats->drop; __entry->xdp_drop = xdp_stats->drop;
__entry->xdp_redirect = xdp_stats->redirect;
), ),
TP_printk("kthread" TP_printk("kthread"
" cpu=%d map_id=%d action=%s" " cpu=%d map_id=%d action=%s"
" processed=%u drops=%u" " processed=%u drops=%u"
" sched=%d" " sched=%d"
" xdp_pass=%u xdp_drop=%u", " xdp_pass=%u xdp_drop=%u xdp_redirect=%u",
__entry->cpu, __entry->map_id, __entry->cpu, __entry->map_id,
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB), __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
__entry->processed, __entry->drops, __entry->processed, __entry->drops,
__entry->sched, __entry->sched,
__entry->xdp_pass, __entry->xdp_drop) __entry->xdp_pass, __entry->xdp_drop, __entry->xdp_redirect)
); );
TRACE_EVENT(xdp_cpumap_enqueue, TRACE_EVENT(xdp_cpumap_enqueue,

View File

@ -239,7 +239,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
if (!rcpu->prog) if (!rcpu->prog)
return n; return n;
rcu_read_lock(); rcu_read_lock_bh();
xdp_set_return_frame_no_direct(); xdp_set_return_frame_no_direct();
xdp.rxq = &rxq; xdp.rxq = &rxq;
@ -267,6 +267,16 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
stats->pass++; stats->pass++;
} }
break; break;
case XDP_REDIRECT:
err = xdp_do_redirect(xdpf->dev_rx, &xdp,
rcpu->prog);
if (unlikely(err)) {
xdp_return_frame(xdpf);
stats->drop++;
} else {
stats->redirect++;
}
break;
default: default:
bpf_warn_invalid_xdp_action(act); bpf_warn_invalid_xdp_action(act);
/* fallthrough */ /* fallthrough */
@ -277,9 +287,12 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
} }
} }
if (stats->redirect)
xdp_do_flush_map();
xdp_clear_return_frame_no_direct(); xdp_clear_return_frame_no_direct();
rcu_read_unlock(); rcu_read_unlock_bh(); /* resched point, may call do_softirq() */
return nframes; return nframes;
} }