From 28b1520ebf81ced970141640d90279ac7b9f1f9a Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Tue, 14 Jul 2020 15:56:39 +0200 Subject: [PATCH] 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 Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org --- include/net/xdp.h | 1 + include/trace/events/xdp.h | 6 ++++-- kernel/bpf/cpumap.c | 17 +++++++++++++++-- 3 files changed, 20 insertions(+), 4 deletions(-) diff --git a/include/net/xdp.h b/include/net/xdp.h index 83b9e01..5be0d4d 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -99,6 +99,7 @@ struct xdp_frame { }; struct xdp_cpumap_stats { + unsigned int redirect; unsigned int pass; unsigned int drop; }; diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h index e2c99f5..cd24e8a 100644 --- a/include/trace/events/xdp.h +++ b/include/trace/events/xdp.h @@ -190,6 +190,7 @@ TRACE_EVENT(xdp_cpumap_kthread, __field(int, sched) __field(unsigned int, xdp_pass) __field(unsigned int, xdp_drop) + __field(unsigned int, xdp_redirect) ), TP_fast_assign( @@ -201,18 +202,19 @@ TRACE_EVENT(xdp_cpumap_kthread, __entry->sched = sched; __entry->xdp_pass = xdp_stats->pass; __entry->xdp_drop = xdp_stats->drop; + __entry->xdp_redirect = xdp_stats->redirect; ), TP_printk("kthread" " cpu=%d map_id=%d action=%s" " processed=%u drops=%u" " sched=%d" - " xdp_pass=%u xdp_drop=%u", + " xdp_pass=%u xdp_drop=%u xdp_redirect=%u", __entry->cpu, __entry->map_id, __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB), __entry->processed, __entry->drops, __entry->sched, - __entry->xdp_pass, __entry->xdp_drop) + __entry->xdp_pass, __entry->xdp_drop, __entry->xdp_redirect) ); TRACE_EVENT(xdp_cpumap_enqueue, diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index b3a8aea..4c95d06 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -239,7 +239,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, if (!rcpu->prog) return n; - rcu_read_lock(); + rcu_read_lock_bh(); xdp_set_return_frame_no_direct(); xdp.rxq = &rxq; @@ -267,6 +267,16 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, stats->pass++; } 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: bpf_warn_invalid_xdp_action(act); /* 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(); - rcu_read_unlock(); + rcu_read_unlock_bh(); /* resched point, may call do_softirq() */ return nframes; } -- 2.7.4